XR 75/80/100's belong on top!

[The_GDFP]

Twin-shock XR's are still the coolest mini's ever. Always been, always will be:action-smiley-035:
Now, there are even MORE reasons why. Tak's new roller head can let the Upright Citizens crowd 20HP and 14,000+ RPM's. Wooo-Hooo!


+R head, Stage 1-2, stocker:

 

[storminnorman07]

you really think the +r will pull almost 20 and rev to 14grand at a 115cc? my guess on the dyno i use 13-14hp with knobby tire if i'm not lazy and change the tires to street tires 15-16hp 11-11500 max hp.

 

[The_GDFP]

I'd put 115cc closer to 15-16HP range, and close to 15K. Bigger 125/130/136 needed for bigger power. I know Tak's horses are smaller than all but old Italian ones, but...

Buy a $20 tire, ya cheapskate:bocul:

 

[storminnorman07]

Well so far my experience with the take stuff in a Dyno is always less than what they claim I would ave about 3 hp difference. With that said I do not high hopes this will hit those numbers. Lmao its not the price of the tire that bothers me its installing it. Its like a monkey rocking a football I end up tearing the s'not out the rim and on a good day ill tear up 3 tubes til I get one in with out punching a hole in it.

 

[The_GDFP]

Maybe you guys could go in on a spare wheel, and share it for dyno/neighborhood use?


Tak's numbers are likely inflated, or at least made on a generous dyno, but the rev range and curve shapes are pretty accurate.
I do know of a 124+R "50" that went from mid 15's as-assembled to 19.2-ish with a bit of work. Tumbled gears, ceramics throughout, coatings, and a decent port/valve job. Makes a 20HP 125 upright not seem out of reach, with the better B/S ratio. Guess you'll know soon enough We'll dyno this 58x54 Stage II as soon as my buddy's shop building is finished.