140/90 tyres on 130/90 rims?

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ultimax · #1 Unread post by **ultimax** » Mon Jul 18, 2005 9:30 pm

Hi,

I'd like to hear from those who've fitted oversized tyres on their rims. I'm planning on installing a 140/90 tyre on my rear rim (recommended tyre: 130/90), but people tell me I risk having a blow-out. I suppose that's true, but I'd like to know if it's THAT much dangerous. I mean we modify our bikes all the time outside the manufacturer's recommendations anyway.

I ride a Virago 125 BTW.

thanks!

Shu

BuzZz · #2 Unread post by **BuzZz** » Mon Jul 18, 2005 10:45 pm

As long as the tire is not rubbing on the chain or swingarm, it should be no problem. You don't want to go up more than about 2 sizes from stock without getting a wider rim, but one size is reasonable on a stock width rim. It may affect your handleing a bit, slowing response time a little. It's not ussually an issue with such a small change, but your results may vary.

ultimax · #3 Unread post by **ultimax** » Mon Jul 18, 2005 11:32 pm

BuzZz wrote:As long as the tire is not rubbing on the chain or swingarm, it should be no problem. You don't want to go up more than about 2 sizes from stock without getting a wider rim, but one size is reasonable on a stock width rim. It may affect your handleing a bit, slowing response time a little. It's not ussually an issue with such a small change, but your results may vary.

Hi Buzz,

thanks for your reply. Good to know that going up a size will be OK.

Is a 140 tyre that much heavier than a 130? Someone told me my top speed will suffer because the tyre's heavier.

thanks!

Joe Mc · #4 Unread post by **Joe Mc** » Tue Jul 19, 2005 6:39 am

I put a 120/90/18 on the rear of my bike. Stock was 110/90/18.

The difference I noticed is the acceleration is slower because the tire is taller. And RPM's are lower for any given speed.

I plan to go with a larger rear sprocket to compensate.

You might want to try a lower aspect ratio with the wider tire. 140/80/

ultimax · #5 Unread post by **ultimax** » Tue Jul 19, 2005 6:55 am

Hi Joe,

thanks for the advice!

Are there any other advantages to having a bigger tyre? I am, of course, assuming lower RPM at any given speed is a good thing?

I got a sweet deal for a used Bridgestone Exedra 524 from someone at a local forum. He's just bought a bike from a shop and is replacing most of the "wear and tear" parts (chain, sprockets, tyres, brake pads). He wants the equiv of US$15 for it. What do you think? Are the treads OK?

Joe Mc wrote:I put a 120/90/18 on the rear of my bike. Stock was 110/90/18.

The difference I noticed is the acceleration is slower because the tire is taller. And RPM's are lower for any given speed.

I plan to go with a larger rear sprocket to compensate.

You might want to try a lower aspect ratio with the wider tire. 140/80/

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Joe Mc · #6 Unread post by **Joe Mc** » Tue Jul 19, 2005 8:40 am

Yeah, lower RPM's is definately a good thing. That is one reason why I'm hesitant to change my sprocket size. It is more comfortable at 120KMH+ with the lower RPM's. Acceleration is more important for me though, so I'll be changing sprockets.

If I were to do it over, I would get the stock size tire. The only reason I got the bigger one is that no local stores had my size and I needed a tire pronto.

As for the $15 used tire. If it's in better shape than whats on your bike, you can't go wrong for $15. Just make sure you give it a good visual inspection first.

ronboskz650sr · Tue Jul 19, 2005 9:07 am

I had a 140/90 on mine when I bought the bike. When it was tire time, I went back to stock 130/90. I noticed a pronounced improvement in turning, but the tire On the bike was pretty squared off when I got it. I got rid of the chicken strips, but could never catch up with all the wear in the middle. Because the tire was still kindof squared off, I'm not sure how much of the improvement was because of the narrower tire, but I think some of it was. I like the slight acceleration improvement, but didn't care for the higher rpms at highway speed. A better pair of earplugs fixed that.

ultimax · #8 Unread post by **ultimax** » Tue Jul 19, 2005 4:26 pm

thanks to both of you for your advice!

I want 140s over 130s because I think cruisers should have a bigger rear end, and the 130 just doesn't cut it haha. I ride a Virago 125, which is the same as a 250 which is more common in the US. If you've seen a 250, it's pretty skinny behind.

Does having a bigger tyre affect one's cruising and top speed? I'm not really concerned about acceleration because I'm not aiming for a holeshot at every traffic light, but I am worried abt my cruising speed. As it is, it's decent, but not fantastic. I wouldn't be happy if it went down.

Thanks!

Joe Mc wrote:Yeah, lower RPM's is definately a good thing. That is one reason why I'm hesitant to change my sprocket size. It is more comfortable at 120KMH+ with the lower RPM's. Acceleration is more important for me though, so I'll be changing sprockets.

If I were to do it over, I would get the stock size tire. The only reason I got the bigger one is that no local stores had my size and I needed a tire pronto.

As for the $15 used tire. If it's in better shape than whats on your bike, you can't go wrong for $15. Just make sure you give it a good visual inspection first.

Joe Mc · #9 Unread post by **Joe Mc** » Wed Jul 20, 2005 4:43 am

You will get a slightly higher top speed with a taller tire. How much I'm not sure. The speedo will be off a bit too I think.

ultimax · #10 Unread post by **ultimax** » Wed Jul 20, 2005 4:50 am

Hi Joe,

that's good to know!

I think the speedo won't be affected as I'm changing the rear tyre, not the front tyre. But thanks for pointing that out anyway

Joe Mc wrote:You will get a slightly higher top speed with a taller tire. How much I'm not sure. The speedo will be off a bit too I think.