That seems to be what miniGP at NJMP does - the "L" versions (with the bigger wheels) are allowed in Stock 100 but the non-L versions aren't. And the line about the XR80 below is where I got the idea but if it's really a push between extra speed vs worse brakes than I'll just save the money and time and keep the stock wheel on there. So it sounds like I just need some BT45s on the bike and it's ready to race
That's interesting that their rule reads as if ANY bike in that class can use the Honda front wheel. actually using the wheel would require a ton of modification to stay legal with their OEM fork rule though. OMRL's stock moto rule explicitly says that Honda XR/CRF 100's can use an XR80 front wheel, or (new for 2017) lace a stock rear hoop to a front hub. it's a tad wider. Not sure there is any performance advantage. We're also allowed to use Buchanan spokes. They add weight, so the only 'performance advantage' is that they don't break as often.
a couple of guys have put the MB5 disc setup on their bikes at Herrins. None of them were fast enough to make an impact with that setup. I believe the fastest Formula 3 spec 100 Ive seen went 42.3 for a qualifying time this year. Herrin's personal fastest recorded lap on a stock class spec 100 is a 43.0. (usually what everyone uses as a benchmark) Both bikes have stock drum brakes. The faster bike is owned & ridden by James Stroud. The 19" front on the TTR isnt terrible. The 16" feels much better to me. The BTs do come in a usable 19" size... so thats a plus. I really want to put 19"s on both ends of a 100 for giggles. The swingarm needs about 1.5" more length. I got a quote for $300 to extend & brace it. Kinda lost interest at that point.
What would the advantage of that be? Why not just go to 17" wheels with better tire options? I know you can scrap a peg with the 16's, but are there 19" tire options be good enough to exploit the extra clearance? seems like it would also create a gearing problem.
While I find that really interesting (the disk setup didn't really go any faster) I feel like a disk setup would be a decent improvement in consistency and feel more like the brakes on the bigger bikes. I don't use much rear brake on the XR and the front drum doesn't really seem to let me know what is going to happen in terms of slowing down until I'm through the corner anyways lol. And after about 10 laps around the kart track I worry its going to stop me at all.
The bt45 is good enough in the 19" variety. Not in search of extra traction just maybe some ride height. (and some how I ended up with 2 19" BT tires...lol)
There are a few tricks to getting the front drums to work. Stock pads, a clean/scuffed drum, and a well lubed unstretched cable. I havent found a longer "lever" that would bolt onto the stock hub. The rear is easy enough to put a longer lever on & it dramatically increases its power...even at the end of a race. Sometimes Ill accidently stab it and the back end is squealing and fishtailing.
^^ I try and make sure I do all of the "known" stuff to keep the drums as good as they can be: new oem shoes, new oem cable, lightly sand the hub and really clean it when installing, center the drum and hold while tighten the axle. It does make a difference but ...... still not exactly great.
at Herrins I dont think there are any formal rules other than it has to be a Grom. But some guys have big bores, etc. In the Middleweight classes you can get into some good battles with other makes & models but its run what you brung.
just saw Suddens class picture post. Doesnt say anything about "intakes or airbox" mods so that should be ok.
I'm not impressed with the TT-R's front disc. Even with an oversize floating rotor, YZ pads (sintered) and a line and master upgrade they were still pretty meh. I got most of my woah out of dropping a gear or three at the right time.
only Honda 100 brake "trick" i haven't seen suggested yet is the thumb-screw adjuster. You can use a clutch-cable adjuster from a full-sized bike on the XR brake lever. It not only makes it quicker and easier to tighten up the cable throughout the race day, but the aftermarket adjuster has a longer threaded area, so you actually get MORE adjustment out of it before you have to move the (shoe) lever up a tooth. I couldnt' find the exact one I have, but this is what I'm talking about: Just by looking at the picture, you can see how much longer the threaded area is than the stock part.
Your time post made me curious. I found this when I started digging for quicker times http://speedhive.mylaps.com/Sessions/3857470 That also happens to be a race I was in. I did NOT get near a 43. Would have been happy with a 45!
Nice call on the adjuster, now to find one that is inexpensive and wouldn't look so garish on my beat XR lol