Author Topic: CB750 F1 Streettracker/Bratstyle conversion  (Read 31092 times)

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Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #50 on: November 29, 2014, 05:37:23 PM »
I meant more the way you explain things makes you qualified, besides your obvious knowledge and experience in this field. Thats the reason I love Hondman's book; the way he explains everything and the pace at which the book works helps so much, along with in depth knowledge.
I am a P.E. teacher and it is my day job to explain and teach kids exercises they have never even heard of and don't have any reference to, which can be hard This is kind of the same, as it all needs to happen in your mind to make sense, and the way you explain makes it very easy to understand. Thanks for that!
Single best thing I've done to make this build easier is joining this forum!


These are beautiful! I can't find them on their website www.motogpwerks.com, would be amazing to have on these on there! Wonder what they would go for.

They make some insane bikes over there! I thought there was nothing like it in the Netherlands. Turns out I live in the same town as the guy that does all the Laverda bikes nowadays. The factory used to send him new parts to make better and than put on the bikes. There is also a few companies near where I live that build parts for MotoGP! It is a shame that those people aren't recognised for what they do, we aren't used to customisation as much.
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline Retro Rocket

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #51 on: November 29, 2014, 05:47:12 PM »
Yes, they aren't on Chris's website, only on FB, you'll have to scroll back a bit on his FB page to follow from the start. They are around $625 USD i think, thats not exact ,  but its close, he also makes them for Z series Kawasaki's, GS series Suzuki's, Triumphs and a few others including CB500/550, he has some nice pipes as well....
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #52 on: December 05, 2014, 02:12:33 PM »
Yes, they aren't on Chris's website, only on FB, you'll have to scroll back a bit on his FB page to follow from the start. They are around $625 USD i think, thats not exact ,  but its close, he also makes them for Z series Kawasaki's, GS series Suzuki's, Triumphs and a few others including CB500/550, he has some nice pipes as well....

Thats not that bad! With shipping and customs, it'll be around $1200 by the time its on my bike, which is way over my budget. I'm having the one I have modified right now, will cost me around 100,- euro's ($80,-).
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #53 on: December 05, 2014, 02:58:15 PM »
Today I got a whole bunch of stuff done for a change! This have been a bit slow for the last two months.

Yesterday I picked up a bag that I'm going to use as a cover for my seat. It's a Swiss army bag stamped "1977" (same as my bike, nice coincidence). Its a waterproof main compartment with a leather bottom. The seat will be made by someone, but took all the bits and pieces off to see of it would work. I hope it does!



I got started on the engine internals today. Got my micrometer and other measurement stuff in. It looks like the top-end has been rebuilt because everything is well within limits. The bottom-end to a certain extend as well I think, but will replace bearings on the big end and stuff anyways. It's open now and might as well! This bike ran well before I took it apart, it had an ignition problem but that was a leak in the HT lead on cylinder 3 and pods 1 and 2 getting rained on when it was parked (its a rainy country).

The rocker shoes all look great, except for two of them:

The one on the left has a small pit, but there is no damage to the corresponding lobe, at least nothing on the face itself.
Another pic:


The one on the right has a massive groove in it, but it looks like a problem with the casting. Couldn't get a better photo with the light I had, can try again tomorrow.
This is the corresponding lobe face:


It has a raised edge, but it seems like the shoe is not lined up with the lobe.

The rocker shafts are all in good condition, as are the towers. The wear is right on the 0,04mm mark that Hondaman states is the limit to have them sit without the two 5mm bolts. Its a 1978 F2 engine. Can I do this or better to rotate 180 degrees and bolt down?

The wrist pins look new, but I'm not sure if they are. They are smooth from end to end, but have copper coloured marks on them that correspond with marks in the small end:

The dimensions are well within spec and the rods are straight as an arrow. Hardly any play on the wrist pins as well, both in the piston and small end.

These are the sprockets on the clutch side of the primary drive. The teeth look way to worn down to put them back. Can I take this apart or do I need to replace the entire unit? The gears have the milling marks from the factory still on them, the bearings seem to be in really good condition.


The one problem with the bike was the gearbox. It wouldn't really go in neutral and would fall into gear when idling. Happened when I had it on the stand, idling and closing a gate: it dropped into gear, picked it up from the side stand, stalled and fell back onto the stand, almost tipping over.
When I would pull away at the light and belt it through the gears, it would jump out of third gear. It was a pain to get it back in, besides possible engine damage and getting rear ended.
I haven't gone over the gears and forks yet, I'm still working on the clutch right now.
I found a slanted groove plate in there, possibly the reason I had a slipping clutch. The plates are all good still, but since I bought a new set I might replace them. Maybe if I can get my hands on a regular plate, I'll just replace one.
The metal plates I have, have this pattern on them (see below on double plate pic). The replacements are blank, smooth metal. Which ones are the best to use?


There is this weird double plate in there, which is riveted together and measures 4,7mm/0,185". Is this a model F thing or some aftermarket replacement?



My pressure plate has a spot on it, but instead of deeper wear it seems to be the original milled surface. It has perfect, tiny grooves in there, like it just came out of the machine. Replace or keep?


Tomorrow I'll dive into the gears and stuff!
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #54 on: February 21, 2015, 11:49:55 AM »
It has been a long time since my last post because I had to wait forever on my shortened swing arm. I got pretty discouraged, so had to put my mind on other things to not go insane and kill the fabricator.
I ordered it in December, but the fabricator got ill for about two weeks and has been behind the ball ever since. I finally got it back early this month and started work at Tin Can Customs again.

Things have gone pretty quick from there, but before that I needed to go over the gearbox because of the problem with 3rd gear jumping out on high revs at low speed.
I haven't taken a pic for some reason, but it turned out that the third gear and it's locking gear were worn down, making the teeth angled and allowing it to slip.
I have ordered replacement second hand gears to go on, just have to pull the bearing, swap it and have it put back on. Fortunately there is a really good engine rebuilding shop near the garage I work at. They're going to mill and port the head and work on the valves.
They will probably pull the bearings as well.

My clutch pack has this weird double plate in there, but my new plates don't come with one. Does anyone what this one is for?


The swingarm has finally been shortened by 8 cm/3.14" and along with a slightly shorter offset it comes as close to the original rake and trail as possible with this set up.

Two problems came out of this:
The rear brake hits the rear shock when I set up the wheel closest to the frame, so the bracket needs to be flipped. Will get this done this week.
The swingarm is so much bigger at the pivot axle it doesn't clear the back of the engine. Not sure how to fix this problem yet, might be able to take off a few mm off at that end, taken into the engine expands when running.

A problem I knew I'd have and will tackle ASAP is the sprockets not lining up. The rear sprocket can come in a bit still, I need to figure out how far I can move the front sprocket. Also the rear is a 520 sprocket and the F2 engine comes with a 630 sprocket. Not sure how to fix this yet. Any ideas?


I finally mounted the handlebars, but ran into a problem there as well. The tops of the forks are too high, since it originally had clip ons. I handmade a set of blocks that raise the bar. I'm using the ZX6R controls for now, because I will be using this as a daily driver and want all the functions that come with it. Looking to replace them with nicer looking ones later on.



The blocks I made out of 23 mm aluminium, which took waaaaaay too long. Still need to lose 2 mm from the top, but don't have a machine to do so.


I decided to cut the rear footrest mounts and replace them with removable pegs. This changed the lines a lot and now the side covers look very out of place. This means changing the idea for my under-seat tray/oil tank. The mounts on the right side will hold the rear brake master, the reservoir will be mounted on the frame. I found a brake-line bolt that has a built-in brake light switch, so that eliminates the need for a the old switch.

This is with side cover and no footrest mounts, and with the exhaust it came with.


The exhaust looked out of place now, so I ended up getting a Supertrapp for a steal: 150 euro's. Looks much better and I don't need a long exhaust brace.




I cut the hoop because it was on crooked and the frame seems to be crooked as well at the back. On side looks like its sitting lower somehow. I will check this when it is put into the frame jig for welding.

Tuesday I can pick up my fenders, will have a quarter fender up front and a 1/3 in the rear. It rains a lot here and this will be my daily driver, so need them.
Wednesday will be fabricating mounts and drilling holes. The upholsterer comes by that evening to go over the plans. I bought a waterproof army bag to use as a seat
Thursday I will drop by the painter with the whole shabang.
Originally I was going with a white frame, but that will be dirty all day every day, so black it is. Not sure if I should go gloss or matte finish on it.
The tank won't be getting the portrait yet, because of time restraints: I'll be leaving for Spain on april 12th until the end of September and this needs to be done before that. I'm bringing it on a trailer to ride it there.
Not sure what to do with the swingarm, triple and alu fenders. Fenders will be same as the tank most likely, a very flat grey. Maybe keeping the swingarm and triple bare alu or have it powdercoated the same as the frame.

Again, any tips, advice or comments are more than welcome!
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline koendd

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #55 on: February 21, 2015, 12:42:07 PM »
hoi Yvo,

double metal plate is indeed an F thing, reduces clutch noise if I'm correct.

520 vs 630: just swap the front sprocket for an 520, many have done this ;) 630 is considered "overkill" so no problem for using an 520
1972 cb750K2 brat
1976 cb360
1984 GPZ900R

Offline Retro Rocket

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #56 on: February 21, 2015, 01:49:26 PM »
Quote
A problem I knew I'd have and will tackle ASAP is the sprockets not lining up. The rear sprocket can come in a bit still, I need to figure out how far I can move the front sprocket. Also the rear is a 520 sprocket and the F2 engine comes with a 630 sprocket. Not sure how to fix this yet. Any ideas?

Looks like you may have enough room if you have the rear sprocket carrier machined down, {measure carefully}  also CycleX have 530 offset front sprockets, 3/8ths of an inch wider, if you need it. I would change from the 630 to a 530/520 also, 630 are big and heavy and no stronger than a good 530/520 chain, the added bonus is gaining more room between the tire and the smaller 530/520 chain...
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #57 on: February 22, 2015, 07:29:14 AM »


hoi Yvo,

double metal plate is indeed an F thing, reduces clutch noise if I'm correct.

520 vs 630: just swap the front sprocket for an 520, many have done this ;) 630 is considered "overkill" so no problem for using an 520
Thanks for the info, I will put it back in then.

Quote
A problem I knew I'd have and will tackle ASAP is the sprockets not lining up. The rear sprocket can come in a bit still, I need to figure out how far I can move the front sprocket. Also the rear is a 520 sprocket and the F2 engine comes with a 630 sprocket. Not sure how to fix this yet. Any ideas?

Looks like you may have enough room if you have the rear sprocket carrier machined down, {measure carefully}  also CycleX have 530 offset front sprockets, 3/8ths of an inch wider, if you need it. I would change from the 630 to a 530/520 also, 630 are big and heavy and no stronger than a good 530/520 chain, the added bonus is gaining more room between the tire and the smaller 530/520 chain...
I can take another couple of mms of the carrier before it hits the tire (taking minimum clearance into account). It already got machined down to clear the shortened and narrower swing arm.

I was thinking about having an offset 520 sprocket made, but I'll get one from CycleX then. Is it a problem using a 530 front and 520 rear? The rear sprocket is brand new and don't feel like digging up a 530 that fits the pattern, and paying for one...

I need a new set of studs, are the CycleX studs any good? Anyone any experience? Will order both if they're good!


Verzonden vanaf mijn iPhone met behulp van Tapatalk
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline ginick99

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #58 on: February 22, 2015, 09:54:20 AM »
Interesting how the lining will come, good task.

Offline Restoration Fan

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #59 on: February 22, 2015, 10:06:44 AM »
hoi Yvo,

double metal plate is indeed an F thing, reduces clutch noise if I'm correct.


I think they started putting it in both the K and F models in 77 and 78.  I know my 78K has the double metal plate in the middle of the clutch pack.

InAquaVeritas = "In Water is Truth"...correct?

Really enjoying this build thread.  I thought your bike was gorgeous the way it was but it's looking good now.
« Last Edit: February 22, 2015, 10:08:19 AM by Restoration Fan »
Ron

Stella - Logan's Senior Project    78 750K http://forums.sohc4.net/index.php?topic=141761.0

Logan's Reward - CB500 and CB550 Cafes    http://forums.sohc4.net/index.php/topic,147787.0.html

Offline Retro Rocket

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #60 on: February 22, 2015, 01:49:50 PM »


hoi Yvo,

double metal plate is indeed an F thing, reduces clutch noise if I'm correct.

520 vs 630: just swap the front sprocket for an 520, many have done this ;) 630 is considered "overkill" so no problem for using an 520
Thanks for the info, I will put it back in then.

Quote
A problem I knew I'd have and will tackle ASAP is the sprockets not lining up. The rear sprocket can come in a bit still, I need to figure out how far I can move the front sprocket. Also the rear is a 520 sprocket and the F2 engine comes with a 630 sprocket. Not sure how to fix this yet. Any ideas?

Looks like you may have enough room if you have the rear sprocket carrier machined down, {measure carefully}  also CycleX have 530 offset front sprockets, 3/8ths of an inch wider, if you need it. I would change from the 630 to a 530/520 also, 630 are big and heavy and no stronger than a good 530/520 chain, the added bonus is gaining more room between the tire and the smaller 530/520 chain...
I can take another couple of mms of the carrier before it hits the tire (taking minimum clearance into account). It already got machined down to clear the shortened and narrower swing arm.

I was thinking about having an offset 520 sprocket made, but I'll get one from CycleX then. Is it a problem using a 530 front and 520 rear? The rear sprocket is brand new and don't feel like digging up a 530 that fits the pattern, and paying for one...

I need a new set of studs, are the CycleX studs any good? Anyone any experience? Will order both if they're good!


Verzonden vanaf mijn iPhone met behulp van Tapatalk


Is this pic before or after you removed material from the sprocket carrier..?  There's plenty there that can be removed in that picture, you need to centre the wheel, fit the front sprocket, run a string down the side of the rear sprocket towards the front sprocket, touching the rear sprocket surface evenly and them measure how far the two sprockets are out, I have a 4.5 inch GSXR wheel i've had material removed of the carrier and its closer to the tire than yours and still clears... You can not use a 520 with a 530, both sprockets MUST be the same pitch..... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline 754

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #61 on: February 22, 2015, 02:30:03 PM »
520 and 530 are the same pitch..
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It's All part of the ADVENTURE...

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Lost quite a few CB 750's along the way

Offline Retro Rocket

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #62 on: February 22, 2015, 03:09:58 PM »
520 and 530 are the same pitch..

Your post should be more informative  Frank,  520, 525, and 530 chains will all fit on a 520 sprocket although the bigger chain will have more side play,  a 530 sprocket will only fit 530 chain, I have yet to see anyone condoning the use of different size sprockets and chains together, plus if you get it the wrong way around it definitely Doesn't work.... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #63 on: February 23, 2015, 05:16:00 PM »


hoi Yvo,

double metal plate is indeed an F thing, reduces clutch noise if I'm correct.

520 vs 630: just swap the front sprocket for an 520, many have done this ;) 630 is considered "overkill" so no problem for using an 520
Thanks for the info, I will put it back in then.

Quote
A problem I knew I'd have and will tackle ASAP is the sprockets not lining up. The rear sprocket can come in a bit still, I need to figure out how far I can move the front sprocket. Also the rear is a 520 sprocket and the F2 engine comes with a 630 sprocket. Not sure how to fix this yet. Any ideas?

Looks like you may have enough room if you have the rear sprocket carrier machined down, {measure carefully}  also CycleX have 530 offset front sprockets, 3/8ths of an inch wider, if you need it. I would change from the 630 to a 530/520 also, 630 are big and heavy and no stronger than a good 530/520 chain, the added bonus is gaining more room between the tire and the smaller 530/520 chain...
I can take another couple of mms of the carrier before it hits the tire (taking minimum clearance into account). It already got machined down to clear the shortened and narrower swing arm.

I was thinking about having an offset 520 sprocket made, but I'll get one from CycleX then. Is it a problem using a 530 front and 520 rear? The rear sprocket is brand new and don't feel like digging up a 530 that fits the pattern, and paying for one...

I need a new set of studs, are the CycleX studs any good? Anyone any experience? Will order both if they're good!


Verzonden vanaf mijn iPhone met behulp van Tapatalk


Is this pic before or after you removed material from the sprocket carrier..?  There's plenty there that can be removed in that picture, you need to centre the wheel, fit the front sprocket, run a string down the side of the rear sprocket towards the front sprocket, touching the rear sprocket surface evenly and them measure how far the two sprockets are out, I have a 4.5 inch GSXR wheel i've had material removed of the carrier and its closer to the tire than yours and still clears... You can not use a 520 with a 530, both sprockets MUST be the same pitch..... ;)

There has already been some material removed for the sprocket to clear the swingarm. With shortening it, it obviously became narrower. I can take off some more, but as you said, I need to centre the wheel first. This is a 5.5 if I remembered correctly so I will still need an offset front sprocket I think.

The current, brand new, rear sprocket is a 520 43. I will be around 2600 RPM higher at 130 kph/80 MPH if I stick with 14/43. I run a 17" instead of the 18" and the tire is 15 cm smaller in circumference. With Gearing Commander I figured out that with my set up I will need 17/48. The smallest steel offset sprocket I've seen is a 530 17, and a 48 rear comes closest to what it was and I liked that.

48 on the ZX6R is stunt bike territory, so I found one that is 520, which is too narrow as has been pointed out. The 48 530 is available for the ZX12R, the biggest brother of my parts donor, but I don't know if the pattern is the same. If it is, I'm lucky, because the other option is a twice as expensive brand that does the 530 48 for the ZX6R....

Im not out of the woods yet, as I need to figure out what the circumference of the 48 sprocket is and if it will clear the swingarm if once more material has been taken off.

As a bonus, I just found an off-the-shelve F2 swingarm for a wide tire, for less than the donor arm and labour cost me, along with a 2 month wait... (sorry, still can't get over that..). Lesson learned, don't look for parts you already have bought, you will always find a cheaper option...

Tomorrow I'm picking up and fabbing up the fenders.
Seat maker comes in on Wednesday and it all goes to the painter on Thursday. I will make a plan with both, so I can take it all back for some last minute fabrication if needed, after which I drop the stuff at their shops.

Getting there!
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline scottly

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #64 on: February 23, 2015, 05:27:16 PM »

The one problem with the bike was the gearbox. It wouldn't really go in neutral and would fall into gear when idling. Happened when I had it on the stand, idling and closing a gate: it dropped into gear, picked it up from the side stand, stalled and fell back onto the stand, almost tipping over.

Read this, if you haven't already ;)
http://forums.sohc4.net/index.php?topic=86429.msg972262#msg972262
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #65 on: February 23, 2015, 06:48:28 PM »

The one problem with the bike was the gearbox. It wouldn't really go in neutral and would fall into gear when idling. Happened when I had it on the stand, idling and closing a gate: it dropped into gear, picked it up from the side stand, stalled and fell back onto the stand, almost tipping over.

Read this, if you haven't already ;)
http://forums.sohc4.net/index.php?topic=86429.msg972262#msg972262
Yes! You are my hero, because I would've probably got it wrong. I will have a look at my disassembly photos, it might be visible. The dogs and gears are worn in a way that would make sense if that was the problem.

I will do this properly when I put it back together!
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #66 on: February 24, 2015, 06:10:39 AM »

hoi Yvo,

double metal plate is indeed an F thing, reduces clutch noise if I'm correct.


I think they started putting it in both the K and F models in 77 and 78.  I know my 78K has the double metal plate in the middle of the clutch pack.

InAquaVeritas = "In Water is Truth"...correct?

Really enjoying this build thread.  I thought your bike was gorgeous the way it was but it's looking good now.

As far as my Latin goes it means "in water we trust".

Thanks, I did really like it as it was, but had my mind set on the USD forks and cast wheels.


Verzonden vanaf mijn iPhone met behulp van Tapatalk
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline InAquaVeritas

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CB750 F1 Streettracker/Bratstyle conversion
« Reply #67 on: February 24, 2015, 06:17:13 AM »

The one problem with the bike was the gearbox. It wouldn't really go in neutral and would fall into gear when idling. Happened when I had it on the stand, idling and closing a gate: it dropped into gear, picked it up from the side stand, stalled and fell back onto the stand, almost tipping over.

Read this, if you haven't already ;)
http://forums.sohc4.net/index.php?topic=86429.msg972262#msg972262

You sir, are a life saver! I checked most of the clips today and those were all on backwards. One of the clip seats was damaged, the gears behind had trouble sliding off. Will smooth it down with some fine grit wet sand paper.
The gears that wouldn't come off had what looks like impact damage as well, both on the dogs and the receivers. The other side, where it didn't move (still, clip was on wrong) the wear is very even.

Damaged dog and receiver:






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Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline ginick99

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #68 on: March 17, 2015, 02:24:56 PM »
LET US KNOW HOW THE LINING BETWEEN THE SPROCKETS ARE GOING. THANKS

Offline Wredas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #69 on: March 18, 2015, 07:31:11 AM »
Looks awesome. Can't wait to see it done!

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #70 on: March 24, 2015, 01:38:58 PM »
Alright! Finally a chance to post an update! Have been insanely busy building over the last weeks. My deadline has come forward about 2 months all of the sudden. I leave for Spain the 14th of April and won't be back until september 30th, so I want to finish this and bring it as well. I bought a small closed trailer for only €150,-! It should fit exactly, keyword here is should...the wheels were going to paint the day I picked it up, so haven't been able to test fit.

I was reading my posts from the start and I had to laugh at myself for thinking I was going be done this time last year. I'm now where I thought I would be last year in March. Planning is not my forté...

I'm working on the last 20% right now, which takes up 80% of the time...the status is as following:

- Frame is almost welded up all the way, needs a bracket for the brake pedal, the battery box and under seat tray. I might have the time to powder coat it, but not sure. If not, I will spray it for now and powder it when I get back. Also good to see if anything needs changing, rather strip a spray coat than a powder coat.

- Fenders were made (took 3 months..) but pretty bad shape. Long story, ended up working until 5 in the morning getting them straight and ready for the painter. Made mounts and brackets, still need to finished (time crunch sucks..). Primed and ready for paint.

- Tank was stripped of the emblem bracket, but ended up going through. Painter tinned it back up. Is primed and ready for paint.

- Under seat tray/batterybox/oiltank idea was ditched and is now a battery box under the swing arm, small tray under the removable seat and basic oil tank. Only tube available was a .6 mm wall heavy beast. Closed it up with a bit of a lip, so it shows the thickness. The whole bike is thick and chunky, so this fits really well.

- Swing arm now has the brake mount stop welded back, brake mount needed to be mirrored to fit upside down as it didn't fit right way up. Needs new bearings.

- I finally came up with a good system to take the seat off. Want to put a chain lock in the tray, so I can lock it up when parked. It will be a daily driver (with an €1150,- paint job, I know I'm insane..). Seat has gone out to be upholstered.

- Speedo mount bracket made.

- Headlight mount made, looks like it floats now. Including indicators (again, daily in mad traffic).

- Engine is at a rebuilder to have the head milled, ported, valves lapped, blasted and painted matte black. Pistons are within spec, just need new rings. Cylinder sleeves sunk .004 mm, but milling will fix that. All the new/replacement parts are in for the rebuild.

- Wheels have been painted and will be picked up to sort out brake lines and spacers.

- Need to figure out what to do with the sprocket alignment. I either have to go 17 teeth front offset with a ZX6R 48 rear, which is only used in the stunt world. I hope it lines up, so I can use the new 43 rear the wheel came with.

- Airbox needs to be ordered, will be a Dragon Performance.

- Mirrors will be mounted under the handlebars. Regular mounts and place (on the brake and clutch lever perch) but hanging off instead of sitting on.

- M-Unit V2.0 needs installing but the shop just hired a certified sparky, he's Irish so he's probably useless... (he's actually a really good guy and a really good sparky).

- Rear shocks need a rebuild, took the springs off one and the piston sank into the chamber...thought it felt bouncy and spongy when I was riding it before. Will also be repainted, since the chrome was shot. All in all this will be a chromeless bike, the Supertrapp exhaust I got might be painted as well. If I can find the time to spray the lettering white and the rest black.

- Exhausts will be wrapped black or titanium.

- Throttle cable will be a customised ZX6R system.

Photo's will follow, I need to sleep before I do die of a heart attack, at 28...dangerous age: too young to stop yourself from doing stupid stuff, old enough to have money to do stupid stuff....
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline calj737

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #71 on: March 24, 2015, 01:48:57 PM »
Fly me over, I'm Irish and I know the m-unit and its accessories really well!  ;)

Your offset sprocket is only on the front, so a 17 front offset should not require a change to your rear sprocket.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #72 on: March 24, 2015, 04:54:23 PM »

Fly me over, I'm Irish and I know the m-unit and its accessories really well!  ;)

Your offset sprocket is only on the front, so a 17 front offset should not require a change to your rear sprocket.

Haha! If I had the cash I would, unfortunately this has gotten out of hand a bit.

To get a better gearing I would have to change the rear to 48, otherwise it wouldn't run nice.
Did the math on gearingcommander.com, it would rev way to high with 43 rear.
Original is 14/43 630, the new and improved way according to the forum is 17/48 520/530. I hope it all lines up, my rear can come in a bit more, maybe I'll put a thick washer behind it if that doesn't put too much extra stress on the shaft/bearings. Get a 14 520 front and chain, save some money!


Verzonden vanaf mijn iPhone met behulp van Tapatalk
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3

Offline Retro Rocket

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #73 on: March 24, 2015, 05:32:35 PM »

Fly me over, I'm Irish and I know the m-unit and its accessories really well!  ;)

Your offset sprocket is only on the front, so a 17 front offset should not require a change to your rear sprocket.

Haha! If I had the cash I would, unfortunately this has gotten out of hand a bit.

To get a better gearing I would have to change the rear to 48, otherwise it wouldn't run nice.
Did the math on gearingcommander.com, it would rev way to high with 43 rear.
Original is 14/43 630, the new and improved way according to the forum is 17/48 520/530. I hope it all lines up, my rear can come in a bit more, maybe I'll put a thick washer behind it if that doesn't put too much extra stress on the shaft/bearings. Get a 14 520 front and chain, save some money!


Verzonden vanaf mijn iPhone met behulp van Tapatalk

You have it all back the front mate, a 48 tooth rear sprocket will make the bike rev higher for any given speed than a 43 tooth rear...
17/43 or 18/48 for highway use, using 17/48 will have your bike revving a lot higher for highway use but will be more spirited round town, it will also use more fuel with the 17/48.. A smaller front sprocket means more revs, a smaller rear sprocket means less revs for any given speed, so, a bigger front sprocket means less revs and a bigger rear sprocket means more revs...., Just look at a mountain bike and all its gears, its not too hard to work out... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline InAquaVeritas

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Re: CB750 F1 Streettracker/Bratstyle conversion
« Reply #74 on: March 26, 2015, 02:13:34 PM »
You have it all back the front mate, a 48 tooth rear sprocket will make the bike rev higher for any given speed than a 43 tooth rear...
17/43 or 18/48 for highway use, using 17/48 will have your bike revving a lot higher for highway use but will be more spirited round town, it will also use more fuel with the 17/48.. A smaller front sprocket means more revs, a smaller rear sprocket means less revs for any given speed, so, a bigger front sprocket means less revs and a bigger rear sprocket means more revs...., Just look at a mountain bike and all its gears, its not too hard to work out... ;)

Yes, you are correct, I remembered it the wrong way around, late night posting isn't always a good idea... ;) Thanks for the heads up.
The website I used gives all the parameters for the change, since I also changed rim size from 18 to 17, and different tires of course. According to the site gearingcommander.com the 17/48 on 17" 150/60 works out the same as a 14/43 stock with stock wheels.
The revs should be nearly identical to the original gearing etc.

Hope it works out, still trying to figure out what to do, especially since the 17 offset (if needed) is unavailable at the moment and I have a very tight deadline all of the sudden.
Surf bum trying his hand at wrenching!

Past "bikes" ;)
1981 Honda MT 50cc - Torn apart, put back together and got run down on..
1994 Derby Senda R 50cc - Fell apart
2001 Derby Senda R 50cc - 13/45 changed to 15/70, hit 90 kph in under 150 meters! Undriveable fun!
1987 Suzuki GN250 - Sold
Current bikes
1977 Honda CB750 F1 - F2 engine, '05 ZX6R front end and wheels, '04 ZX6R shortened swing arm converted to twin shock. http://forums.sohc4.net/index.php?topic=133411.0
1987 Honda XR600 Supermoto conversion. CR250 forks and triple. SM wheels, discs front and back. Rebuilt engine. Loudest exhaust in the world: Leovinci X3