Thinking about building a race bike. WERA vs AHRMA

doc_rot

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So I have gotten the itch to do some vintage road racing. I have done a couple track days over the years but that is all. I would be building a KZ750 twin overbored to 906cc. After talking with a guy racing one in Canada I think I can get the weight down to 350lbs with 80-85HP. The classes I would be looking at would be WERA Vintage 4, or ARHMA Superbike - heavyweight.


Right now I'm leaning more towards WERA because it seems like the class rules are a little more lax, and this bike might be competitive in that class. In the ARHMA heavyweight class I would be significantly outgunned on power because I would be racing with the KZ1000 and other big 4s. Also a big part of the ARHMA superbike class is to preserve the look of the era. which they are pretty strict on. I understand the desire for that, but that is less appealing to me.

Thoughts on the two organizations?
 
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irk miller

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Not an expert on either, but I want to hear what people that know stuff say. I've looked at AHRMA for vintage dirt over the years and still plan to run a vintage class ride.
 

teazer

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We ran in both but mainly AHRMA and I think it comes down to where you are located and how many races you can reasonably expect to get to. I guess that AHRMA has more focus on recreating the past and WERA on getting guys out to race, but that difference never got in our way. Just be nice to the officials and they let you bend some of those not really important rules.

I have written rules about appearance and recreating the past, but to me, sas long as you aren't cheating and the bike generally looks period, the rest is unimportant.

In terms of winning or losing, there will always be people who cheat and others with deep pockets, so I mentally discount them and see where we finished against other regular joes. That said, I like to be at the front end of the pack and have been lucky to stay there by building lighter faster bikes, but that's because I'm obsessive about details and I think you are too.

Some ( or most) riders are better than I am so have to have an advantage and that's in machine prep and development. If I raced again, I'd probably build a light stiff frame that looks close enough to stock to not get people guessing and I would lighten everything and improve handling and brakes.

I imagine that there's a lot of weight that could be trimmed off teh chassis before you have to resort of magnesium wheels and titanium everything. I used to cross drill axles and drill and grind down brake cams (drums in our class) and drill our the bearing spacers and so on. It all adds up. Go for it. It's always good to see different bikes out there. We don't need any more mega buck Z1 clones. Good luck.
 

doc_rot

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Im located in Southern California so I would be competing in the WERA west. The tracks are all a reasonable drive from me, with 6 events in the year. I have been reading that there are not many racers in the vintage classes. One guy was saying he was frequently the sole entrant in his class and raced with other classes. To that end I might be better just doing a bunch of track days? IDK. Part of me wants to build somethign super wild that would not be allowed in any class that it would be competitive in and just take it to the track rather than sanctioned events.
 

teazer

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That is equally valid and allows you to focus on what mods you want to make without other people telling you that it's illegal, or not in the period, or even worse - can't be done that way.....

Just keep an eye on the costs because building race bikes tends to be a bottomless pit of never ending upgrades which I enjoy but could never really afford. When I first raced a CB72, I tried every cam grind available and plotted acceleration and jerk rates to understand why one worked differently to another. Not much was available back then so it was a case of trying things and seeing what worked and what blew up. Great learning curve for sure.
 

doc_rot

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My current plan is to build the 906cc engine. and drop it into the KZ750 I have now. Ride that on the street for a bit and if i still have the urge at that point I will build a second stockish engine tow swap out, and sell the bike to fund a second KZ750 race bike build. The reason I'm considering all this now is, for example, I would really like some 39mm FCR pumper carbs but those are not legal in the ARHMA superbike class. So if i would want to race in ARHMA in the future it would be wise to base the decisions i'm making now so they will be legal later. that way I'm not doing everything twice.
 

irk miller

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it would be wise to base the decisions i'm making now so they will be legal later. that way I'm not doing everything twice.
Being a bit tongue-in-cheek, but isn't this a pretty anti-I want to race comment? LOL. It's been 30 years since I last ran a drag car, but we grew up doing it. It was a family affair that even my grandmother took part in. We were lucky if we only did stuff twice. My brother and I learned to pull a VW engine in under 40 seconds to make it through another run.
 

Rider52

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I raced WERA for 4 years in the 80s. I mostly ran at Blackhawk, Mid Ohio and Nelson Ledges. I raced on a team as none of us could afford to race individually. We won Lightweight Superbike at Daytona one year. It is fun and is very addictive. My suggestion is your run a stock or near stock bike for a bit to get a feel for the tracks and the class which fits you the best. When I went to race school the instructor said less than 1% of all riders could ride to the capabilities of a stock motorcycle.
 

doc_rot

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Being a bit tongue-in-cheek, but isn't this a pretty anti-I want to race comment? LOL. It's been 30 years since I last ran a drag car, but we grew up doing it. It was a family affair that even my grandmother took part in. We were lucky if we only did stuff twice. My brother and I learned to pull a VW engine in under 40 seconds to make it through another run.

There is a difference in between doing something twice because it didn't work the first time, and doing something twice because it didn't meet regulations. I'm certainly OK with doing something multiple times to get the results I want. (Hell, this is the third engine build)

I raced WERA for 4 years in the 80s. I mostly ran at Blackhawk, Mid Ohio and Nelson Ledges. I raced on a team as none of us could afford to race individually. We won Lightweight Superbike at Daytona one year. It is fun and is very addictive. My suggestion is your run a stock or near stock bike for a bit to get a feel for the tracks and the class which fits you the best. When I went to race school the instructor said less than 1% of all riders could ride to the capabilities of a stock motorcycle.

I apprciate the input and I agree with that logic, but racing a stock KZ750 might be a tad underwhelming with nearly 500lbs wet weight and 48HP to the wheel. Also a big part of the desire to race is to build something crazy around this black sheep of an engine. I'm sure i will enjoy the racing aspect of it but building the bike is a big part of the allure for me. Being able to measure the performance by comparing it to similar bikes and riders is a way of validating my design decisions. If it was just about going racing I would find a cheap track bike to thrash.
 
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teazer

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I raced WERA for 4 years in the 80s. I mostly ran at Blackhawk, Mid Ohio and Nelson Ledges. I raced on a team as none of us could afford to race individually. We won Lightweight Superbike at Daytona one year. It is fun and is very addictive. My suggestion is your run a stock or near stock bike for a bit to get a feel for the tracks and the class which fits you the best. When I went to race school the instructor said less than 1% of all riders could ride to the capabilities of a stock motorcycle.


fortunately 99% of us were never destined to be in the top 1%......
 

ex119x

Been Around the Block
I saw your post on the WERA board. I have raced with WERA for over 40 years and there is no doubt that the racers are generally the most helpful bunch. I have also raced with AHRMA and while I enjoyed the races and the racers, I find that the officials are more of a good ole boys network and they let some people get away with more than others. It never affected me personally, but didn't sit well since it is supposed to be a member owned organization. WERA is a business owned by Evelyne Clark and it is run like a business, which sits just fine with me. I have also raced with CCS, CRA and MRA over the years. That being said, build your bike the way you want and run it in V-4, V-5 and clubman. It may not be strictly legal, but they will let you run and I doubt anybody will protest as the vintage guys just aren't that way. Also, if you are up for a road trip, the GNF at Barber is really a fun weekend. If you have any particular questions about race prep or legality, ask away.
Ken
 

doc_rot

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I saw your post on the WERA board. I have raced with WERA for over 40 years and there is no doubt that the racers are generally the most helpful bunch. I have also raced with AHRMA and while I enjoyed the races and the racers, I find that the officials are more of a good ole boys network and they let some people get away with more than others. It never affected me personally, but didn't sit well since it is supposed to be a member owned organization. WERA is a business owned by Evelyne Clark and it is run like a business, which sits just fine with me. I have also raced with CCS, CRA and MRA over the years. That being said, build your bike the way you want and run it in V-4, V-5 and clubman. It may not be strictly legal, but they will let you run and I doubt anybody will protest as the vintage guys just aren't that way. Also, if you are up for a road trip, the GNF at Barber is really a fun weekend. If you have any particular questions about race prep or legality, ask away.
Ken


thanks Ken. I have decided to proceed with WERA.
 

ex119x

Been Around the Block
thanks Ken. I have decided to proceed with WERA.
Good choice, but if it becomes convenient to run an AHRMA event, don't shy away from it as those are fun races, too. I'll really race with anybody, but prefer WERA since I have been doing it for so long and Evelyne and I have been friends since before she owned WERA. I have a bit of bias.
As far as carbs go, I wouldn't overthink it and just run what you have on it.
For V4 and V5, you can run any wheels you want, so I would look at some modern 17" cast wheels. The kind of weight and HP you are looking at should have you running 600 sized wheels and tires. Maybe find a set off a ZX600 or something. Dual discs on the front wouldn't hurt, either. No such thing as too much brakes on the track.
 

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