Supermoto Problem - Help !!

16 replies to this topic
  • Nige_Uk

Posted March 24, 2002 - 09:43 PM


Problem is when the back wheel is in & equally aligned, the chain is rubbing on the tyre. I've tried to space the rear sproket out slightly by putting a washer behind each bolt but its still won't allow the chain to run freely. I've measured how much is needed to enable the chain to miss the tyre & its about 10mm.

Can the hub in the wheel be offset by 10mm by tweeking the spokes ?? (I'd take it to a shop for that !) or is there any other surgestions ??

  • jamracing

Posted March 25, 2002 - 04:27 AM


If you're running a 160 section rear tire, the chain will rub. If you can find a 150 rear (pretty rare) go with that. Otherwise, shave the tire's left side till the chain doesn't drag.

  • fastkevin

Posted March 25, 2002 - 05:21 AM


150s aren't rare at all. Pirelli has made their Corsa in a 150 for years. They now have their SuperCorsa (DOT race tire) in a 150 too. Michelin's Pilot Sport is available in a 150 as well.

  • moto614

Posted March 25, 2002 - 05:35 AM


i had the same problem with my cr500 motard with the 160 rear tire,i laced the rear wheel up slightly offset,that and washers behind the front and rear sprockets gave me some room although it still hits at times,i still shaved a little off the tire as jam said and now it rarly hits.if you do space the sprockets out watch the frame clearance to the inside as the chain may hit there also.

good luck

  • SFO

Posted March 25, 2002 - 05:57 AM


You could make up a set of offset sprockets and bring the chain out to 5/16" closer to the frame.
Cutting tires is a pain, but you might be able to find a shop that has a tire profiler. I used to work at one that had one. Changing the offset of the wheel is also a solution.

  • Nige_Uk

Posted March 25, 2002 - 06:11 AM


Thanks for all the replies & advice, I'm going to get the wheel slightly off-set, if this doesn't bring it out far enough, I'll shave the tyre if it's its close. Other than that I'll have to put a 150 tyre on it & scrap this new 160 (well sell it !!!)



  • The_Missile

Posted March 25, 2002 - 06:34 AM


Having the tire offset will screw up your wheel alignment and make you 'crab'. I would NOT recommend it given the speeds you will be hitting.

[ March 25, 2002: Message edited by: The Missile ]

  • Guy

Posted March 25, 2002 - 08:30 AM


:) Nige, which flavour of 160 do you have??? The new Metzler RenSport 160 is the same size as a Bridgestone BT96 150, which is what I'm running with no problem, Have a word with WRSM, he has some good info on tyre sizes, gearing etc, :D

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  • wrsm

Posted March 25, 2002 - 12:50 PM



My 98 wr400 needed loads of offset. I just kept turning the spokes 1/4 turn at a time until it cleared. Must have moved it a good 6mm. Then I cut the edge off the tyre by about 5mm anf ground it nice and flat. It still kisses it, but not too bad.

My friemds 99 had no problem as the swingarm and wheel are different on post 98's. Both our bikes have 150 section BT96.

As it comes from the builders the centre is about 15mm to the right than the MX wheel (I took off my rear shock and played with the wheel/subframe relationship), but this does not affect handling. I can grind both pegs on the floor with ease on fast corners, swaps line fine, corners same both ways. I check alignment of front to rear wheels with string line & ignore the adjuster marks, the chain ends up ever so slightly out, but the wheels are equal.
If you space out the sprockets your chain guides will be out of line and this will cause problems. Plus how do you space out the front sprocket??

Try a 150 tyre - £30 for a remould from 01653 697226.


  • TeamScream

Posted March 25, 2002 - 04:02 PM


I have a 2001 WR426 in Supermot trim, I started with the 160 tire and had to shave sucked, because when you "hack' into corners with it laid over pretty good it hits the flat spot on the tire and gets really un predictable, I went with the Pirelli Corsa 150 rear (after running the Dunlop 150 for a while) and it clears perfectly, a 160 rear is overkill anyway and doesnt allow the bike to slide as nicely as the 150, just to give you an example I can enter a corner at full hack (bars to the lock) and knee on the ground feet on the pegs, and get back on the power-FULL power before the apex. If you really are set on a 160 go to white brothers and get a tire groover (like a giant soldering iron with a razor knife blade) for $70.00 and whack the tire at will. Offsetting the rear is NOT the answer, and neither is offsetting the sprocket, you will wear your chain and sprockets out earlier and it really isnt as safe as it should be. I will throw up a temp website after this comming weekend to show you some closeup pics of my bike. let me know if you need some help.

  • Nige_Uk

Posted March 26, 2002 - 03:32 AM


Right - you've all convinced me to go with a 150 tyre insted of the 160.... what wall depth of tyre are you lot running. The tyre I was trying to put on was a 160-60 maxif.

On the 150 tyre is any shaving required or should it just pop straight on.

  • NJG426

Posted March 26, 2002 - 03:52 AM


Just put a new Michelin Hi-Sport 150 section on this weekend. Chain doesn't touch at all.

Although when I first had the wheels, I moved the hub over slightly doing the tightening and untightening thing.


  • TeamScream

Posted March 26, 2002 - 04:27 AM


Should clear perfectly~no issues

  • jamracing

Posted March 26, 2002 - 05:46 AM


Hey Scream,
What kind of speeds do you get out of the 15/46 combo? I have 15 and 16 fronts, and a 48 and 42 rear to play with. Problem is, I need to shorten the chain to run the 42 rear...Decisions decisions. :)

  • SFO

Posted March 26, 2002 - 05:49 AM


If both sprockets are offset the same, how would that wear the chain?

  • TeamScream

Posted March 26, 2002 - 07:05 AM


*** SFO *** I was under the impression that he was just going to offset the mistake.

*** Jam *** I get about 93 MPH out of the that combo WFO, the best part about it realy is that the ratio is just right for typical tight canyon riding and 1 or 2 downshifts will get the back end comming around with little rear brake modulation, still need to feather it (rear brake) a little to get it hacked at lower speeds but from 5th to 3rd for example it steps out really nicely to square the corner

  • TeamScream

Posted March 26, 2002 - 07:07 AM


SFO : here is what made me think he was only doing the rear: "I've tried to space the rear sproket out slightly by putting a washer behind each bolt"

then i read your post about offset sprocket(s)


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