Building a vintage track bike

[one_civic]

Hey guys,

I'm slowly acquiring parts to build an 8 valve 750 track bike for the VRRA, I will be using a Katana 37mm front end with fork brace, shortened rear swinger off an 1100E that was professionally done for a GS550, GSXR 750 18" front and rear rims with rotors,77 GS750 frame and engine to keep me in P3 middleweight.

I'm not planning on racing until next year and I have my first child due in a few days so money is tight right now.

My question is regarding the 1100E swinger, it is about 0.5" shorter than the stock 750 tube one. I know this will affect straight line stability but will be quicker in the corners, what do you guys think? Should I sell it and get the stock length 1100E one or can I use this shortened one?

looking forward for everyones input,

cheers

 

[one_civic]

here are a couple pics

 

[one_civic]

 

[Guest]

Subscribed.......... If you need a regular length 1100 swingarm I'm got a few of them, including one that has all the tabs taken off in prep for the track.

 

[one_civic]

thanks Azr, right now this is just a quick mock up, I'm going to have bushings machined to use the stock pivot bolt, I'm more curious about the handling characteristics of using a shorter swingarm, and I have to have the tabs intact for using a chain guard as per the VRRA rule book

 

[Guest]

My question is regarding the 1100E swinger, it is about 0.5" shorter than the stock 750 tube one. I know this will affect straight line stability but will be quicker in the corners, what do you guys think? Should I sell it and get the stock length 1100E one or can I use this shortened one?

What do I think? Unless you are AMA Pro fast (and maybe not even then) I think you won't notice the difference on a heavy, flexy, moderately powered vintage bike like this. Add an extra link or two to the chain and run the axle near the rear limit of adjustment and it will be so close as to be indistinguishable. Unless you are looking for an excuse to get a stock length 1100E swingarm, then ignore what I just said.


Mark

 

[one_civic]

Thanks mmatockx, that's exactly what I wanted to hear, lol. I would rather use the parts I have since they cost me nothing and I'd rather use that money for brakes, dyna coils, etc

 

[Buffalo Bill]

Sure, you're only talking theory now.
About the long term refinement of your race bike, that's what it is.
Get on the track as soon as you can, and begin the development your track skills. Along the way you will continuously refine your skills and the bike's mechanical tuning.
That's what the whole experience is.
Keeping yourself from being swallowed up by the hobby, is a biggie.

 

[limeex2]

What do I think? Unless you are AMA Pro fast (and maybe not even then) I think you won't notice the difference on a heavy, flexy, moderately powered vintage bike like this. Add an extra link or two to the chain and run the axle near the rear limit of adjustment and it will be so close as to be indistinguishable. Unless you are looking for an excuse to get a stock length 1100E swingarm, then ignore what I just said.


Mark

In regards to vintage racing rules, If a person is not following the rules, is NOT winning, the bike is safe and tight, can it still be run? If your not winning would it matter? Example, 4v 1100 have many rules and restrictions. 2v 1000 is like carte blanche.

 

[one_civic]

Not too worried about winning since there is not really any money in it, more for a hobby and getting on the track,if anyone wants a quick read on the rules, bike eligibility and restrictions here's the VRRA website,

http://www.vrra.ca/

I'm doing this more for fun but will keep your advice in the back of my mind Buffalo Bill

 

[steve murdoch]

I will also be following along.
Heck, maybe in '17 they will add Calabogie to the schedule and you will have home field advantage. haha.
When you say the modified swinger is .5" shorter than a stock 750 , do you know how much it was shortened altogether?

 

[one_civic]

No, it was given to me on a parts swap, I roughly measured it compared to the stock one. All I know is that it came off a GS550. I actually marshal at Calabogie so yeah, I know every corner by the back of my hand, lol And yes,the VRRA will be at calabogie this year in setpember for the final round.
Do you race as well steve?

 

[steve murdoch]

No racing for me, just a fan.
Hopefully get to Mosport in August but it always seems to conflict with family vacation.

 

[Guest]

In regards to vintage racing rules, If a person is not following the rules, is NOT winning, the bike is safe and tight, can it still be run? If your not winning would it matter? Example, 4v 1100 have many rules and restrictions. 2v 1000 is like carte blanche.

Since no one else has answered, I will give it a shot. My experience with racing organizations (not extensive, just local) is that they aren't willing to let you ignore rules if it is obvious, regardless of where you are finishing. None of your competitors may care about it if you are in the back half of the pack but the scrutineers won't let things slide that they notice. What rules are you thinking of not wanting to follow?

What you are describing sounds a lot like a track day to me. It sounds like you just want to get out, ride the track and have fun, which is what track days are for. I don't know if you have raced or not, but it is a very different experience than open track time.


Mark

 

[Buffalo Bill]

The amount of time on the track racing is greatly reduced from track days. Like down to 8-10 laps per race day, or for the whole race weekend.

 

[one_civic]

There are actually quite a few track days open to vintage classes at Shannonville and I do plan on racing in the VRRA possibly next year. You have to first complete and pass a racing school training class with both on track time and in classroom time. They do not simply let any yahoo on the track. The bike would be built according to period 3 middleweight rules regarding the bike build and what is allowed.

What other rules are you guys referring to? i.e. minimum points, bike restrictions... etc.?

 

[Bones]

One-civic, i don't see anything in the VRRA rules that say you need to have a change guard. Is this the language that you are referencing? "The top portion of the chain/belt on the primary drive, and the portion of the chain/belt on the rearhalf of the clutch, must have an adequate protection guard."

 

[tas850g]

I'm no suspension guru so I would speak with one to get their feedback on your expected setup. I know on my track SV the front and rear ride height is very important along with fork and shock valving. Maybe speak with Richdesmond here on the forum as he knows his ****.

 

[one_civic]

yeah, I've got a couple of people who I can talk to locally. I just found out the previous owner shortened the katana front end as well by milling some material off the rebound cylinder of the front forks.

Think maybe I should try and source some different front forks, thing is I just fabricated some front brake caliper brackets so I can use kawasaki twin pot brake calipers on the gsxr 310mm rotors so I need to use non leading front axle forks off either a gs850g or a gs1000e that use the same caliper bracket holes as the katana one, plus I can get rid of the anti dive at the same time.

 

[one_civic]

Well, after much consideration I'm going to build this as a vintage track bike and maybe race it after some track time,

first things first, here are the pivot bolt sleeves and spacer my friend made for me, the needle roller bearing bushing sleeve is the same inside diameter as the stock 750 pivot bolt and is made out of 4140, while the middle spacer is made out of 1020,

just waiting on some alls balls steering stem conversion bearings for the katana front end and new swing arm bearings from suzuki