Author Topic: Period sohc Pro Stock project . (Read 59272 times)

Greg H · « **on:** August 25, 2012, 01:20:27 PM »

Hi Guys . As the title says I'm building a period sohc 750 based Pro Stock bike . I've managed to find a donor F1 to base it on, along with a spare motor and a complete period Pro Stock body kit, plus a 3ins over chrome moly swing arm etc off guys off here, so the parts are stacking up nicely . Engine wise I'm still researching which components to use bearing in mind that this is going to be a period bike , so although I intend utilising some modern engine components, purely for reasons of reliability, the bike will be built as a more extreme version of the sohc Honda I raced back in the day .

Greg H · « **Reply #1 on:** August 25, 2012, 01:35:28 PM »

I've tried to put up a couple of pictures without any success

. I'll keep trying .

Greg H · « **Reply #2 on:** August 26, 2012, 02:18:47 PM »

Some of the bits for my project .

Greggo · « **Reply #3 on:** August 26, 2012, 02:22:06 PM »

Nice bits & pieces! I'll watch.

Stev-o · « **Reply #4 on:** August 26, 2012, 03:09:47 PM »

Cool....subscribed. What's next?

Greg H · « **Reply #5 on:** August 27, 2012, 01:55:32 AM »

Glad you like the pics . I've managed to locate a donor F1 with spare motor , the guy I'm buying it off has been away on holiday , and now I am ,which delays proceedings a little .So when I get back home I'll go pick it up, take it down to my old shed at my mothers and strip it ,so I'm gonna do a lot of the work there and do the assembly in my small workshop at home . You know us Brits have a proud tradition of building things like boats, aeroplanes etc in the lofts of houses , and then having to take the roof of the house off to get them out . So whether I'll be able to get the completed bike out of my extremely small workshop at home in one piece when it's done remains to be seen

. I've got some fairly major mods lined up for the stock frame , I'll post pics when I start chopping .

johno · « **Reply #6 on:** September 05, 2012, 05:15:45 AM »

Hi Greg,
Your away now mate! the journey begins and I,m looking forward to sharing the buzz.
It will be a great excuse to visit your mom, I reckon she will get to like your bike Greg,

cheers Johno

Greg H · « **Reply #7 on:** September 08, 2012, 07:25:14 AM »

Cheers johno . Picked up the F1 donor today ( I think it's what you guys in the states call "a barn job "

) Anyway, first job is to spray all the nuts bolts etc with releasing fluid , then do it again mid week , before tearing it down next weekend . I've also managed to pick up a nice K7 rear hub and brake plate , so when I've finally worked out the best way to restore the hub to a decent standard and fitted new bearings/seals It'll be off to be laced up to a nice wide 18ins ally rim .

Greg H · « **Reply #8 on:** September 08, 2012, 12:42:52 PM »

Some pics of my donor F1 and spare motor etc.

Greg H · « **Reply #9 on:** September 15, 2012, 12:42:10 PM »

A few pics of the strip down today . Dousing everything in releasing fluid really paid off with me only having to use the angle grinder a couple of times

.

Greg H · « **Reply #10 on:** September 15, 2012, 12:54:43 PM »

The picture of the top rear shock mount isn't one of the things which had to be cut off , I chose to cut the threaded section off cos someone had welded the thread on in the past , so it had to go . I have some big plans for the stock frame , after de lugging I'm going to rake the steering head out a couple of degrees and either lower the stock seat rails a couple of inches or maybe re fabricate a new rear end .

Garystratos201 · « **Reply #11 on:** September 15, 2012, 01:32:20 PM »

This one sounds like its gonna be good..........I`m in. Gary

lucky · « **Reply #12 on:** September 16, 2012, 01:57:10 PM »

Quote from: Greg H on September 15, 2012, 12:54:43 PM

The picture of the top rear shock mount isn't one of the things which had to be cut off , I chose to cut the threaded section off cos someone had welded the thread on in the past , so it had to go . I have some big plans for the stock frame , after de lugging I'm going to rake the steering head out a couple of degrees and either lower the stock seat rails a couple of inches or maybe re fabricate a new rear end .

What rake have you decided on?

Greg H · « **Reply #13 on:** September 17, 2012, 01:14:52 PM »

I'm not sure what the wheelbase will be yet,so I will need to study a copy of the relevant construction regulations before I start cutting . But initially I'm thinking along the lines of altering the head angle from the stock 27 degs 10 minutes out to 35 degs .

Greg H · « **Reply #14 on:** September 19, 2012, 09:48:49 PM »

Just a quick update on my last post . I've been taking a close look at some images of early pro stockers , and by blowing them up and using a protractor on the images it seems like the very earliest bikes ran stock geometry . I'm currently having a re think about my proposed frame mods .

Greg H · « **Reply #15 on:** October 06, 2012, 02:06:47 PM »

Just a bit of an update guys , things are happening with the bike . Like most, I work full time but always try and do a job on the bike every day whether it takes ten minutes or a hundred an ten minutes . That way I can just keep chipping away doing those little jobs which in themselves seem fairly inconsequential , but which all add up.

This picture inspires me on the cold nights in the workshop .

Dimitri13 · « **Reply #16 on:** October 06, 2012, 02:32:04 PM »

Definitely a cool idea. I've always wanted to do something up pro stock, but we don't have a track here (and I don't have the funds

).

Can't wait to see how it turns out.

Greg H · « **Reply #17 on:** October 06, 2012, 03:10:27 PM »

Cheers Dimitri

. Yeh ,it aint gonna be cheap , although I think that the rolling chassis will be a fairly cheap piece to build , I already have most of the trick bits for that and luckily I'm able to do whatever fabricating/welding/machining which needs to be done on that myself . However, I think that the motor will be a different deal . I have a H2 triple Pro Stocker,as well as other bits an bobs which will have to go to help fund the motor build , so its just going to be a question of working longer hours at work, and selling some stuff to fund the project .

Dimitri13 · « **Reply #18 on:** October 06, 2012, 04:04:29 PM »

Yeah, the frame doesn't seem to be the expensive part, as long as you know what you're doing. Hopping up the motor is a different story.

Any pics of that H2? Hopefully even going down the track or some time slips?

Greg H · « **Reply #19 on:** October 07, 2012, 04:18:13 AM »

I've had to do a fair bit of digging to find things like suitably sized wheel rims/tyres etc , now I'm looking for the sort of brake/fork components I would have used if I'd have been building the bike back in the seventies .A few years ago I sold a couple of AP racing calipers and discs to a budy of mine who was building a classic racing sidecar outfit ,I just wish now that I'd have kept hold of them

as these were the very best parts you could have used back in the day, so now I'm looking to find something similar to use on this bike . Motor wise , there is a picture forming in my mind of how it will be , and I reckon that the cost of the bottom end alone will exceed the total cost of the rolling chassis .
Regarding pics of the H2 , well , they're in storage at the moment along with all of the pics of the sohc bikes I raced in the past . When I next go down to the storage depot I'll see if I can dig out some pics

754 · « **Reply #20 on:** October 07, 2012, 11:59:15 AM »

By slamming the rear of the bike you will increase rake slightly, increased rake will help high speed stability.
My 836 in stock frame with 6 over arm had a 77K front end. At 45 mph you could let go of the bars and slow down to about 10mph riding no hands...try that on a Stocker..

Dimitri13 · « **Reply #21 on:** October 07, 2012, 04:47:58 PM »

Quote from: 754 on October 07, 2012, 11:59:15 AM

By slamming the rear of the bike you will increase rake slightly, increased rake will help high speed stability.
My 836 in stock frame with 6 over arm had a 77K front end. At 45 mph you could let go of the bars and slow down to about 10mph riding no hands...try that on a Stocker..

I tried... Hit the tiniest bump in the road and it almost sent me into the car in the next lane

Greg H · « **Reply #22 on:** October 13, 2012, 07:14:10 AM »

Quote from: 754 on October 07, 2012, 11:59:15 AM

By slamming the rear of the bike you will increase rake slightly, increased rake will help high speed stability.
My 836 in stock frame with 6 over arm had a 77K front end. At 45 mph you could let go of the bars and slow down to about 10mph riding no hands...try that on a Stocker..

I did a bit of Production Racing back in the day(before I got into straightline racing) and we used to raise the forks in the yokes and fit longer rear shockers to try and gain some more ground clearance . Raising or lowering either end of the bike to either speed up or slow the steering( as well as playing with spring rates/lengths , different oils in forks/shocks etc ) was all part of what it took to get a near stock bike to circulate a track a few tenths quicker per lap. Some of the tracks were a bit bumpy and if you got it wrong things could get a bit "interesting" to say the least

. As I'll be running struts on this bike , the rear ride height will be something that I'll be able to play around with .

Greg H · « **Reply #23 on:** October 29, 2012, 02:45:52 PM »

Had a day off work today

. I spent most of the day stripping out some old shelves and cupboards from my workshop at home and then took them down to the local tip , before calling at my mothers to pick up a couple of my old workbenches from out the shed for my workshop in preparation for the coming winter.

We were down at SCRW on Sunday racing the old Busa , well we would have been if it had been dry

. It wasn't a complete waste of time though, as a couple of German Kawasaki nuts we were introduced to expressed an interest in buying my old H 2 Dragbike, so some good came of the day . The Busa will also be being sold soon ,hopefully before winter, so it was a great pity that I didn't get to use it in anger for the last time before it has to go

.

I've been keeping myself busy lately working on various chassis brackets etc on the Honda whilst trying to source local blasting/ plating/painting specialists , there are a couple of guys ( who have been recommended to me) who's shops are pretty close to me that I'll be using , so things are moving on .

Engine wise the more I think about it the more I fancy building a relatively small ( 970/1000 ) high revving motor . In my opinion I reckon that I have two options , either build a large capacity motor with the emphasis on torque, or build a free breathing , high revving high horsepower motor.
I know that some of you people on here have done this sort of thing in the past , and have real expertise in this subject , so if you wish to your comment on my plans your help and advice would be greatly appreciated .

I'll be starting on the frame this week , so there'll be some more pics soon

Z-MO · « **Reply #24 on:** October 29, 2012, 03:10:39 PM »

What did that swing arm come off of?

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Author Topic: Period sohc Pro Stock project . (Read 59272 times)