So… I came into a Birel CR832 (1999) with working 4wb, for the princely sum of $300… I also have acquired a freshly replated Rotax 257 (250cc) that just needs a piston / wristpin / bearing installed to be a runner, also for $300. Net result – with a little cleaning and restoring, I’ll have a $750 road racing setup. WKA has already issued me a provisional Unlimited license.
My question: has anyone here run one of these chassis, know what it likes, etc? I plan to remove as much caster and camber as possible due to the RR intent… And I’ll be fabbing up some custom bodywork too. (Think Shadow UoP CanAm…)
Input appreciated. I’ll be posting here as I progress. Time to strip it down and check for cracks and straightness (though I expect it’s fine on both counts.)
It will be used mostly for long course road racing, Unlimited class, but I will probably play around with it at GoPro Motorplex. I want to get a modern frame and jump back into KA100 if I can find a cheap package deal…
We ran a 2002 Birel for several years with a 250 on it. The kart handled well but got a little “floppy” after a few years. We went to a slightly newer one (2005 and 50 mm axle) and still have it. You will need to change the brakes. The old style you have use shims behind the pads and they will wear faster than the end of the race comes - you will chase the setup all the time. We went to Brembos and MCP masters on our and they never give a bit of trouble. We even put the old spindles on the newer kart when we got it. If you do that, get new masters and use DOT 3/4 fluid in them. The calipers work best with it and new masters can use either one. I wouldn’t worry about bodywork much. The biggest CIK nose and a Hegar type fairing is all you need. Here is a link to some pictures of our set-up. Brakes
I’m considering mounting some suitable motorcycle calipers for ease of pad sourcing and compound choice. I figure doing that on fronts and leaving the rear as-is… thoughts? As long as the m/c volume actuates the motorcycle calipers enough – that seems the only issue to me. Mounting is simply an issue of adapter plates…and the disc width will require some choice of caliper. If I can find that brembo setup cheap, perhaps. But brakes aren’t something to skimp on or experiment with lightly… Esp. with a 250…
I recommend dumping the rear system as they are problematic as they get older in age no matter what you do to it.
MRP most likely still has the old style banana system that is bolt on. Paired up with the correct rotor and you’ll be safe.
Getting the front system to operate normally and not leak any fluid is key. Making sure the bore of the caliper is smooth and clean is key-might require a quick hone.
So… after some discussion with knowledgable friends… The somewhat rarer 250 Rotax has been sold to a guy who’s using it at Daytona with WKA this year. And the Birel is being rehabbed with new nerfs and rear hardware to run in a local LO206 series. Sure, it’s not quite as glorious as the project seemed, but it’s also far less likely to become a fireball in a concrete wall… And it’s affordable. The 250 idea is still brewing, though, so stay tuned. Cheers, ~Ted
UPDATE: Frame has been stripped down from the OEM brakes, and gasp MCP’s fitted. Temporary until I find a cheap caliper to work. Rear 35mm axle was rusted badly, so whole unit lifted out and replaced with 40mm axle and hardware. Smaller cadet tank being fitted to column, but OEM will be retained and cleaned. Going to source some 32mm clamps for fitting the seat, otherwise, cleaning up OK. The spindles were rusted solid between the bearings, so had to remove the disc and top hats seperately, clean spindle, then slide bearings off. There’s some pitting , but it will work for now. Getting some DSM fronts to use. Becoming a LO206 chassis. Also sourced some white breadbox pods, and have 4 old style nerfs, so it’s going to be a RetroRocket…
UPDATE:: I’ve scored a KA-100 for $900, so that’s going on this Birel…i am also getting a DAP T85 w/c ICA to throw on there again too. And the freeline brakes should show up today to replace the MCPs I almost (tragically) installed… Signs of life for an old girl…
Still kicking… Got the MCP brakes about retrofitted, and got a new suede wheel for it last weekend. Should be getting some 32mm seat clamps mid-April, and sold off the KA for another racer to grow in their journey…this chassis just isn’t new enough for modern times…But will be fun to play with for ICA.
Pics soon. 40mm rear conversion was painless.
The 250 idea is still brewing, though, so stay tuned. Cheers, ~Ted
