Do You Moto 100?

[Nathan S]

Will there be a sub-class for bikes with dual-range transmissions? I seem to be a magnet for them ATM.

[DG 26]

Giday
Why not make it up to 125cc 2stroke so at1 yamahas ect could run in the class?

[vandy010]

sorry DG, but 100cc 2 smokers is the max!
and the first lap everyone must stand up for the entire lap. unless you only have one leg, then you get to stand up for half a lap.

[Tim754]

Damn !! bet my Nitrous oxide kit is out too!!  Looks good Firko! Found a use for one of my stock SL125 engine.

[firko]

I'm more than happy with Nathans revisions of our original proposal. The extra words I had in were there because it was a part of a magazine article aimed at people who had never followed the original thread on this forum. I'm still not convinced about allowing methanol but seeing that most potential punters seem to not care about winners or losers and seem to agree with my personal take that it'd be more fun if we had trophies for the best presented bike, the best berm shot, the best bit of airtime or the most entertaining crash and burn...that sort of thing. For that reason I think it'd be a prick act to refuse Noel and his cool little methanol Honda. The last thing this "class" needs however is a win at all costs mentality with punters spending shitloads on mega porting and state of the art pipes and ignitions. Take away the winning and there'd be no need to spend stupid money. 
I dropped my ex bucket racing super ported TS90 barrel on the garage floor and broke off the bottom of the sleeve, ruining it. I was a bit pissed off but in retrospect it was the best thing that could have happened. I'll keep the little puppy fairly stock now and It'll be a much nicer bike to ride.

[oldfart]

Pump fuel it is ... so don't try and bend the rules, as it will open the flood gates all types of senarios .   

[Tim754]

And only caster based oils in the 2 strokes Mmmm that scent!!! , Hey oldfart can I put a cap full of R30 or R40 caster in with the stinky unleaded for upper cylinder lube on the SL125?   Ok is really just to make it smell nicer

[caps 999]

found a use for the ts 100 now 

[Nathan S]

Firko, what's the logic behind 32mm forks?
Best as I can guess, none of the eligible bikes came with anything that big, so 32 seems to be a bit of a random number.

I'd suggest that either the largest diameter originally fitted to an eligible bike, or 34mm would be the wy to go (34mm still excludes all of the 'good' forks from the era).

[firko]

 Nathan, we went with 32mm forks to keep the suspension within the 100-125 class standard of the day. While none of us are totally up to date with our knowledge of these tiddlers, we guessed that most of them would have had 28-30mm forks as standard so figured that a logical update would be to use 32mm forks that were available on the next generation trailies and 125 MXers. 32mm Betors, Yamaha and other Jap brands seemed to be fairly common and would be a cheap upgrade. My personal thoughts are that we should keep the 34-35mm 250 forks out of the equation purely for aesthetic and cost factors. Using 32mm forks uses up parts that are overlooked by serious 125 class racers who  often opt for the fatter and more stable 250 model forks.....
Still, as I said originally, our proposal is purely a platform to work from and is merely the result of a bunch of old boys throwing ideas around one Sunday arvo over a carton of Kozel. Maybe a 34mm limit is more feasible, what do others think?

[vandy010]

i reckon 30mm units are absolute crap! and therefore perfect for the moto~100class.
i've got the 34mm from the 250 on my MX125a and they work pretty good.
keep it simple i reckon and 30~32 is fine for me even though i don't own a descent set.

[Nathan S]

Just for the sake of having a reference, I've done some measuring of forks:
1. Yamaha AT1/CT1/early twinshock DT125/175, Early AG100 = 30mm.
2. Kawasaki G4TR = 30mm.
3. Suzuki TC90, TC100, and TS185 = 30mm. TS90, TS100, TS125.
4. Honda SL100 = 31mm. SL125, bubble tank XL100/125.
5. Yamaha DT175 late (post 75) twin shock/early mono = 31mm.

Bikes in red have NOT been measured, but are educated guesses.

[firko]

Out of curiosity, What bikes come with 34mm forks? I'm only aware of TM/TS Suzuki and assumed that most of the over pre '75 250cc Japanese bikes had 35mm forks.

[Nathan S]

DT2/3 (and probably DT1, but you'd have a better idea than me on that one).
RT1/2/3.
DT250 (all).
DT360/400 (all).
MX250/360 (all)
YZ250A/B.
YZ360A/B.
YZ125C.

The monoshock version have the same travel as the twinshock versions, but have about 30mm more total length (all in the upper tube). They could be shortened to be indistingushable from the twin-shock versions, if you were so inclined.
The YZs' upper tube have a reduced diameter between the triple clamps.
Internals are all essentially the same, despite the expected damping tweaks across models.
Lower legs are all essentially the same, but there are small differences WRT drain screw location and mudguard mounts.

They've got longer travel than the 30mm units fitted to the 125/175 Yammies.

[Nathan S]

Anyway, the reason I brought it up, is that I feel that 32mm is the worst of both worlds: Its neither "Stop taking this too seriously - Just use the stock stuff", nor does it really allow you to fit a decent pair of forks.