Topic: 76' cb750k build part 2, GSXR conversion

[Retro Rocket]

Thanks for the link with the measurements! Curious, what happened to the upper triple? Are they like early 750 "unicorns", that often cracked?

Ya I don't know why the 03-04 gsxr1000 triple are so scarce. I actually just picked up one tho. Hopwfully gonna get the triple on the cb this week.

Gday Elan, i have 2 GSXR front ends i am using on builds, {43mm right side up 1989 1100K model forks}one thing to watch with the stock Gixxer clamps is that they have a 35mm offset, compared to 60mm for stock K model Honda, this adds trail and slows down the way the front end reacts, it can make the bike feel like its falling into corners. I am having 2 sets of 50mm offset clamps made for my bikes to counter this and keep trail around 4 inches....

[Elan]

Great JOB ELan...Just spent 30 minutes catching up...You inspire me to do a build thread once that frame gets in.   Nice forks BTW!!!! Im soo jelly.   Im prob. gonna go with the 600RR upside down ones...Might run alittle cheaper.  But if all else fails on budget then prob stick to all my f3 parts hehe...

THanks. Ya you should definitely do a thread, its a great way to get input through all stages of the build. Greanjeans is selling a gsxr600 front end for only a hundred bucks, great deal.  I got mine on ebay for around $150, not bad.

[Elan]

Thanks for the link with the measurements! Curious, what happened to the upper triple? Are they like early 750 "unicorns", that often cracked?

Ya I don't know why the 03-04 gsxr1000 triple are so scarce. I actually just picked up one tho. Hopwfully gonna get the triple on the cb this week.

Gday Elan, i have 2 GSXR front ends i am using on builds, {43mm right side up 1989 1100K model forks}one thing to watch with the stock Gixxer clamps is that they have a 35mm offset, compared to 60mm for stock K model Honda, this adds trail and slows down the way the front end reacts, it can make the bike feel like its falling into corners. I am having 2 sets of 50mm offset clamps made for my bikes to counter this and keep trail around 4 inches....

Thanks. Yeah I've been wondering what to expect from the differences. Having larger offset clamps is a good idea. I think I'm gonna try it out and if its scary, i'll have some clamps made

[oasis]

Nice build!!! love the attention to detail on the motor and can't wait to see that front end on.

Mike

[Retro Rocket]

Thanks for the link with the measurements! Curious, what happened to the upper triple? Are they like early 750 "unicorns", that often cracked?

Ya I don't know why the 03-04 gsxr1000 triple are so scarce. I actually just picked up one tho. Hopwfully gonna get the triple on the cb this week.

Gday Elan, i have 2 GSXR front ends i am using on builds, {43mm right side up 1989 1100K model forks}one thing to watch with the stock Gixxer clamps is that they have a 35mm offset, compared to 60mm for stock K model Honda, this adds trail and slows down the way the front end reacts, it can make the bike feel like its falling into corners. I am having 2 sets of 50mm offset clamps made for my bikes to counter this and keep trail around 4 inches....

Thanks. Yeah I've been wondering what to expect from the differences. Having larger offset clamps is a good idea. I think I'm gonna try it out and if its scary, i'll have some clamps made

Maybe scary is too harsh a word, maybe a bit lazy will nail it....

[MRieck]

You are very ambitious Elan.

[Elan]

haha probably too ambitious for my own good

Ran into my first hiccup, with the stem. I purchased the bearings listed on all balls for the conversion...
Suzuki   GSX-R1000   2004   

upper bearing    30ID     48.5 OD      15 HEIGHT        99-3541-5   
lower bearing     30ID      50OD       14.25 HEIGHT       99-3512-5

these bearings have the OD of the CB head, and ID of the 04 gsxr1000 stem.

hiccup#1, lower bearing: I thought I was going to get the washer spacers for the bottom bearing, but didn't.  the bearing is recessed so the triple can't reach it. I need a 2.5mm spacer so the triple clears the frame, and that will leave a gap of about 1mm between the triple and the frame.

Hiccup #2:, upper bearing: The bearing sits too high, there is no thread to tighten it down. See pic below. I need about 8mm of thread to be exposed, and I have none.


SO my options are, (and feel free to suggest something else!)

1. machine a new stem and press it in.
2. cut the stem in half, machine a spacer that has inserts on both sides to slide into the stem halves, and weld. someone on here did this, and I like the idea of keeping the gixxer stem.
3. press in the cb stem to the gixxer triple.

[srbakker]

I got my calliper bolts in titanium for $4 each on eBay, if you still want that look.

[Elan]

I got my calliper bolts in titanium for $4 each on eBay, if you still want that look.

yeah I bought some high grade steel bolts already, thanks though!

[knowsnothing]

Hey Elan, nice to meet you the other day. 

Sorry to see you ran into some issues, but I am sure you will get everything sorted by the time the weather warms up.  The bike already looks awesome even without a front end.   I can't wait to see the the finished product.

-Treeve

[Elan]

You to Treeve. I definately knew it would be too good to be true for it to just bolt up hehe.


Heres a crappy drawing of what I mean by option number 2.

[knowsnothing]

I am by no means an expert, but i vote for #3 if everything fits and nothing requires machining.  Option 1 also works, but i think it would be a little pricier.  Option 2 i don't like at all and wouldn't trust.  Too many things may go wrong for such a crucial part, i wouldn't chance it. 

Maybe wait until a few more knowledgeable people chime in before deciding. 

[Elan]

 mmm baked triple..



been thinking a little more, and pressed the stem out. I wish i took a picture of my jerry rigged setup, but it involved a bottlejack pushing the stem, a pipe behind the lower triple to support it, all sandwiched by 2 large pieces of square stock that was held by 4 pipe clamps. worked like a charm. I first tried threaded rod and it snapped. Heres some pics of the stem...





Too bad I baked on the powed coat before sizing it up, that was dumb. damaged the powdercoat a little, but its underneath, so youll never see it i suppose.


So heres what im now thinking. The ID of the stem is 17.5mm, which is the exact size for a 20x2.5mm tap.

[iron_worker]

A pretty clever idea. I would cut the threaded insert to match the stem diameter first if possible... I guess the problem would be work holding.

Use a bit of red loctite to make sure it's never coming apart (though I really doubt it would).

IW

[Elan]

A pretty clever idea. I would cut the threaded insert to match the stem diameter first if possible... I guess the problem would be work holding.

Use a bit of red loctite to make sure it's never coming apart (though I really doubt it would).

IW

Thanks. I was thinking of spinning it down after because 754 brought up a good point that the id of the stem might not be perfectly center. Making a .0000 transition unlikely. This way corrects any discrepancy.

I'm pretty sure they have open ended lathes so you could tighten the stem down just before the base. Not sure how common they are thought. My work has one but I can't touch it...

[Letze]

I'm currently getting a small run together for stems for my conversion I have the same issue. I'm waiting on my tooling to come in so I can thread the sections (M28 and M30 dies are expensive.) But I should be working on a prototype by this weekend without threads of course. you're using an 04 1k stem which uses different size thread than my 07 750.

 

[Elan]

ok its been a little while, but things are still moving...

754 is making a new stem for me out of 7075 AL. Once I get that things will move much quicker. When its all fit up, i can upload some dims of it if anyone else is doing this conversion.

Since I sold my controls as a package with my old clubmans, I rebuild/powdercoated  another set of controls...


I was going to run the wiring through the clipons, but im a little weary of affecting the integrity of the bar. And you would actually see MORE wiring by running it through. So ill have to file a slot in these controls for the wiring.

Ive been thinking and thinking about how the headlight will be mounted, and was looking for inspiration, when I came across how the headlight is mounted on earlier ducati monsters. It looks like it has standard headlight brrackets, but it is actuall bolted to the lower triple. So I bought one...



And it comes with a headlight, looks shallower, and probably gives better light. Anyone know what kind of bulb it is?



Also ordered new tires! I bought the Shinko 712's. I know theyre not spitfires, but they are getting awesome reviews, and the price is great. I think they will be perfect for my type of riding.  110/90-19 on the front, and 120-90-18 on the back. Im running a 2.5x19 harley rim on the front.

lastly, 754 made me these awesome hubcentric rings for fitting the hayabusa rotors on the harley rim....

[Elan]

oh, and lasercutting this bracket, and buying this sick speedo from speedhut....

[Garystratos201]

Very interesting.............Gary

[brandEn]

whoa, that speedo bracket is cool!

[Retro Rocket]

Looking good mate....

[banana44]

Great build, lots of good info.

I'm in MA too!

Just wondering what method you used to polish the valve covers?

[Elan]

Great build, lots of good info.

I'm in MA too!

Just wondering what method you used to polish the valve covers?

HEy dude,

I just went up the line of wet sanding. I Think i started at 220, 400, 600, 800, 1200, 1600, 2000, then buffed with a cloth wheel and some compound.  I have to go back with some mothers every few months. Take your time. I set up infront of the tv. maybe 5 hours total, but i dont remember.  I TOTALLY recommend painting the center part.  It would double your hours trying to polish it and you cant see it anyway. I painted it with the black vht engine paint, and didnt bother baking. Its funny how little of the valve cover is actually visible.

[Elan]

Hmm so the headlight is an h4 55/60 watt. Not sure if its worth the trouble with resistors and added draw. Might just stick with the stock light. But the bracket looks like its going to work well.

[Vinhead1957]

MA,   Is that where all the Hondas are?

Groveland Ma here!