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tire sizes

kyle whalen

Tuned and Synch'ed
Joined
Mar 23, 2015
Messages
26
Location
United States
Has anyone tried fitting a 140 on the rear of a racer? I know the fronts a 100 and rears a 130 but I feel as if you could go a size up on both front and rear and possibly even a 120 on the front

Has anyone dabbled with this or am I the first to have it cross my mind?
 
Our friend Rick put some over-sized off-road tires on his, so I'm sure large sizes would fit, with some installation/removal headaches. I believe you'll have to put some spacers under the front fender mounts if so as well.

GTRx-SS22-1-1.jpg
 
110 will fit on the front with some washer spacers under the front fender mounts.

The rear could probably take a 140 wide tire but it would be a close call to the swing arm or could even depend on the manufacturer of the tire. Some of those off road style tires tend to stick out more on the sides because of the knobby thing.
 
It will barely clear the swing arm drive shaft side. If something sticks to the side of the tire it could skin the shaft housing.
 
I have a 13 Stone with a 140 Pirelli Sport Demon on the rear. it fits with about a 5 mm gap between the sidewall and the swing arm. I like the look but the handling characteristics have altered a little. I also have a 110 Pirelli on the front but that was a mistake either in my ordering or the bike shops error, not sure which. I do not like the heavy look it gives the bike and will return to the stock 100 as soon as practicable. It fits without any alteration to the fender.
 
I have a 13 Stone with a 140 Pirelli Sport Demon on the rear. it fits with about a 5 mm gap between the sidewall and the swing arm. I like the look but the handling characteristics have altered a little. I also have a 110 Pirelli on the front but that was a mistake either in my ordering or the bike shops error, not sure which. I do not like the heavy look it gives the bike and will return to the stock 100 as soon as practicable. It fits without any alteration to the fender.
Would you mind posting a photo of the front end and rear end and a over all photo of the setup?
 
Ok Kyle. Will do once I figure out how to post a photo! It's 11.15 pm here and pissing down with rain so it will be a task for tomorrow.
 
So the Photo above is one i have on file which shows the 140 on the rear on the stock 100 on the front. I will endeavour to get other images which show the 110 on the front and fitment tolerances tomorrow.
 
Kyle, am in the middle of a major rain even here (Eastern Australia). Not conducive to getting outside and organising photos and what not. Will do at soonest opportunity however.

Das
 
For what it is worth here are some pics which show rear tyre 140/80 and the front 110/90. My preference is for either completely stock or retain the 140 rear and take the front back to stock. IMG 0384 IMG 0401 IMG 0360 IMG 0390
 
I've got a 110 up front and used some washers to raise the front fender. Under hard braking the tire was rubbing the inside rear of the front fender, washers spaced it out enough to stop that from happening. That 140 on the back looks very close to the swing arm but at least it clears. I have found with the 110 up front the bike is less likely to trap that front tire. The stock front tire trapped on me twice and I thought it was going to go full blown tank slapper. It did it once on the freeway which scared the crap out of me and another time on a back road, since I put the 110 up front it's never hinted at doing that. I've read that 110 front tires are less likely to trap and so far it looks that way to me. So far so good.
 
Side of the front tire hits something onto one side of the tire and then that sets up a steering oscillation. A 110 front tire is less likely or more forgiving in that situation. It tends to re-trac faster or resist the urge to go ballistic. It's been proven to do just that although a 100 wide tire will cut in faster. So you give up a little faster handling for a margin of safety with a 110 wide tire. I can actually feel the stability margin with a 110 over a 100 series tire.
 
As to not to confuse folks, in my 40+ years of motorcycling, I've never heard the word "trapping" used with tires. The physics might hold true, but I've posted on this before that I won three regional road-race class championships on a 100, and preferred it over a 110. If you want a wider looking tire, go for it.
 
The reason you only won 3 regional titles is because you only had a wimpy 100 series front tire. A 110 series front tire would have taken you all the way to National title status.

But at least you can walk into any establishment and not have people ask for autographs.
 
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The reason you only won 3 regional titles is because you only had a wimpy 100 series front tire. A 110 series front tire would have taken you all the way to National title status.

But at least you can walk into any establishment and not have people ask for autographs.
But, on the other hand, you still have to buy your own beer.
 
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