Topic: Building Vintage Racebikes for Dummies

[rbmgf7]

So, one of my biggest ambitions is to build and eventually race a bike. Preferably an older bike.

Right now I'm juggling a few projects one of which is turning my bare '72 CB750 into a trackable bike. I'm not looking to build a CR750 replica but something definately I'd enjoy tracking and eventually competing. The problem is: where do I begin? I didn't grow up around racing. I've practically had to teach myself up to this point. The bike is currently a bare frame with the engine in the cradle on top of a stand. I need to establish a plan before I start digging in. I don't have the cash to hot rod the engine but I figure the next most important thing I can begin is the suspension and controls.

As far as the bureaucracy to track, race, and compete, I'm hashing that out. I've downloaded the AHRMA and MRA rulebooks and started to read through them. This will also have a factor in how I design the bike but I'm just looking to start. Gotta work the bike and myself steadily to a higher championship.

What are your thoughts and words of wisdom?

[Sam Green Racing]

Consentrate on loosing weight and go for 18 inch aluminum wheel rims, it will be easier to find good rubber.

Sam.

[voxonda]

+1, and do not aim too high at first. Get yourself familiair with the bike and improve step by step. Too much at onces and you will loose track of what works and what not. A standard bike can easily be improved by making sure everything works as intended. Good adjusted, and greased, pivotpoints. Use good tyres. See what gives you a problem and solve that, you'll see that there is always a next 'problem' to solve. Make sure you feel comfortable on the bike, ergonomics are more important then looks. Good luck and keep us informed.

Cheers, Rob

[754]

Gearing changes on front sprocket are very reasonable cost wise.
 Removing alternator rotor could give huge changes in response and downbraking, cost nearly nothing but you may want to sleeve the crank to cover starter ring oilhole..

[turboguzzi]

think that best piece of advice i can give you is to attend more than one vintage race meeting at your local track and have a look at what people run, talk with owners /racers while taking plenty of shots

helped me lots when i was taking my first steps.

[seanbarney41]

rbmfg7...thanks for starting this thread, as I have similar aspirations, skills, and knowledge I think...although I have been thinking that I would be better off starting out on something smaller like a cb350 twin or even a 125

[gene03079]

I race vintage on the east coast.

Attending some races and talking with guys will give you tons of good information . Most vintage racers love to help get folks started.

A 750 will be a heavy bike to start out on.The Honda 350 it nice to learn racing on. Smaller bikes help you learn corner speed faster. Watch the fast guys, they are always passing in the corners. Buy the best gear you can find. You will crash, you will slide and tumble. The gear saves your body.

I was over 50 when I went back to racing vintage. I only run the light bikes now but the fun never stops. If you think you want to race jump in and don't look back.

[gene03079]

Consentrate on loosing weight and go for 18 inch aluminum wheel rims, it will be easier to find good rubber.

Sam.

Sam

I tried to get Mike on my 175 racer today. We could use him racing with us. He will not go for it

Maybe you can get him on the track.

[MRieck]

Consentrate on loosing weight and go for 18 inch aluminum wheel rims, it will be easier to find good rubber.

Sam.

Sam

I tried to get Mike on my 175 racer today. We could use him racing with us. He will not go for it

Maybe you can get him on the track.

I weigh more than the bike Gene.

[Triffecpa]

... I've downloaded the AHRMA and MRA rulebooks and started to read through them. This

The MRA isn't real big into vintage stuff.  They run some "Modern Vintage" bikes, but those are generally 10+ year old VIN bikes, so you would be running against '98 Yamaha R1's...  Nuff said.

The CB750 fits into two areas with AHRMA.  You can run in Formula 750.  Displacement limts are 750cc and there are restrictions on fork and wheels sizes as well as brakes.  They are slanting the rules towards having folks build CR750 replica type bikes in that class.   Full fairings are encouraged as well as "period type and design parts".  Read "not cheap"

The second AHRMA class that you can run in is Heavyweight Vintage SuperBike.  You can go to 1025cc in this class and there are more liberal rules on forks and wheels and brakes.  But you need to run stock bodywork and you need to run a tubular handlebar that sits above the top triple clamp.  Think AMA 1979 SuperBike rules.  The downside here is that you get to run against GS1000 Suzukis and 1015cc Kawasaki KZ900/1000 bikes that have better frames and more HP output for the same or less weight.

Not trying to discourage you from Vintage racing, but if your goal is to be competitive, then the SOHC CB750 isn't the best starting point.  I do have a CB750 vintage race bike though, but "running up front" is no longer my main goal.

That said, we run a pretty active club race vintage program in Albuquerue with SMRI (www.smri-racing.org).  We have rules that are a bit more flexible than the AHRMA stuff.  We have a few folks who come down from Colorado to race with us, so even though it is a bit of a drive from Colorado Springs, you will find more "like minded" people than at MRA (not trying to dis- MRA, just that they aren't real big on the vintage bike scene.

Anyway, drop me a PM if you are interested in more details.

Tracy

[MRieck]

... I've downloaded the AHRMA and MRA rulebooks and started to read through them. This

The MRA isn't real big into vintage stuff.  They run some "Modern Vintage" bikes, but those are generally 10+ year old VIN bikes, so you would be running against '98 Yamaha R1's...  Nuff said.

The CB750 fits into two areas with AHRMA.  You can run in Formula 750.  Displacement limts are 750cc and there are restrictions on fork and wheels sizes as well as brakes.  They are slanting the rules towards having folks build CR750 replica type bikes in that class.   Full fairings are encouraged as well as "period type and design parts".  Read "not cheap"

The second AHRMA class that you can run in is Heavyweight Vintage SuperBike.  You can go to 1025cc in this class and there are more liberal rules on forks and wheels and brakes.  But you need to run stock bodywork and you need to run a tubular handlebar that sits above the top triple clamp.  Think AMA 1979 SuperBike rules.  The downside here is that you get to run against GS1000 Suzukis and 1015cc Kawasaki KZ900/1000 bikes that have better frames and more HP output for the same or less weight.

Not trying to discourage you from Vintage racing, but if your goal is to be competitive, then the SOHC CB750 isn't the best starting point.  I do have a CB750 vintage race bike though, but "running up front" is no longer my main goal.

That said, we run a pretty active club race vintage program in Albuquerue with SMRI (www.smri-racing.org).  We have rules that are a bit more flexible than the AHRMA stuff.  We have a few folks who come down from Colorado to race with us, so even though it is a bit of a drive from Colorado Springs, you will find more "like minded" people than at MRA (not trying to dis- MRA, just that they aren't real big on the vintage bike scene.

Anyway, drop me a PM if you are interested in more details.

Tracy

Real vintage is dead as dead as dead unless the displacements are real small....that's MO

[lordmoonpie]

Talking to people in the paddock is good advice as is losing weight and starting small. For my first ever race I didn't have a clue either so I set my goal to get through scrutineering (tech inspection in the US?), complete practice and line up on the grid, the race itself was almost immaterial and as a result I enjoyed it thoroughly.

Starting small is a great tip and unless you're a real hot rider to start with (most people who think they're fast on the street get their eyes opened very quickly on track!) go small to keep the limits of the bike closer to the limits of your abilities. You have a smaller headroom then to learn how to push braking, acceleration and handling on track. When you consistently hit the limits of the capabilities of the bike, move up to something bigger/faster/more powerful and start to learn to move towards its limits etc.

I made the mistake of going from a 30bhp classic ducati that I could ride on the limit to a 158bhp superbike that I couldn't get anywhere near the limits on and my racing style and times suffered. I went back for a year to a 70 something horsepower 250 and things started to improve again.

The suggestion of a Honda 350 twin is a great one. They are cheap to run, modify and maintain and you will have endless fun trying to find the limits. Maintenance of your own bike is a major learning point if you want to race cheap. I couldn't change the oil on my first race bike and had to learn everything from there. On the 350 K4 I got to be able to swap a crank in between races I could strip the engine so fast. Doing the mechanics side is what got me into restorations and tuning and that's where I spend my time now rather than the track and I love every minute of it.

Final thing is, enjoy yourself. As soon as you stop having fun, it's time to stop racing (unless you're getting paid megabucks in motogp:-)). In the UK the average career of a club racer is just three years - make every minute of your time in the paddock count!