110's or 120's on front

[Edwardp33]

I am considering a 120/70 Bridgestone RS10 front tire. The tire guy has indicated that he supplies many racers with 120's for 200's, 250's, 300's and RC 390's. He said that the RC 390 owners prefer this to the 110's and it should not change the bike geometry.

The same applies for the Dunlop Q3's as I couldn't find a Q3 in a 110.

Any thoughts?

 

[green_bread]

I run 110 SC1s and am more than happy with them.

 

[orange crusher]

your front rim is not wide enough for a 120, the 110 is perfect for our rim width, we use Pirellis but I believe bridgestone makes a 110 race tire

 

[Chris The Welder]

Maybe it won't change the bike geometry, but it will damn sure change the tire profile. Proceed with caution.

 

[ToraTora]

Maybe it won't change the bike geometry, but it will damn sure change the tire profile. Proceed with caution.

This is very true. Use the correct size tire. When I get back to a real computer I'll write up a better post explaining the why.

 

[Diploman]

I concur with all the posters. Just as the OEM 150 has its profile distorted by a rim designed for a 140, the same would happen on the front if you fit a 120. Correct sizes are 110 front, 140 rear.

 

[reenmachine]

I concur with all the posters. Just as the OEM 150 has its profile distorted by a rim designed for a 140, the same would happen on the front if you fit a 120. Correct sizes are 110 front, 140 rear.

I agree. I switched to a 140 rear and am very happy with it. I use all the tire now too.

 

[Jon W]

I am running Bridgstone slicks 120 front 165 rear ,it rails

 

[Edwardp33]

I cannot report anything negative about the RS10 120/70. I ran the 120 RS 10 today at COTA. The tire changed the geometry of the bike. It raised the front axle by several mm this is an estimate, I did not measure, but I could definitely feel the difference immediately when I sat on the bike. I raised the ride height at the rear shock a few mm to compensate but did not achieve the same aggressive riding position as I had previously. The bike did not tip in the same as the Pirelli. It seemed to tip in faster. The tire did not look like a V it looked like a U. At first I was very concerned, but spoke to another rider who races 250's and is very fast. He said just ride it. I am not a top level rider. I am respectably fast for my class and raced for a coupe of yeas in the 90. Not an expert and not a neophyte.I am after all on the track to have fun, learn, and experiment with my speed prosthetic.

I have an EVO - standard size on the back and an RS10 on the front. Both are new rubber.the EVO has about 600 miles on it primarily from the Three Sisters in West Texas.

BOTOM LINE - RS 10 is a great tire, the EVO is a great tire.They both stick like glue. I was not running at race pace but am very happy with the performance.

Thanks for all of the responses.

 

[ToraTora]

It's all about the shape

Here's why you want to get the right size tires. It has to do with shape. When you put on the right size you get more of a V shape. This is what you want (on a sport/cornering bike) so that when you lean the bike you get a nice roll onto a proper surface. When you put on a tire that's too large it creates a U shape which develops a corner. This corner will make the bike less stable when you lean--although up to that corner it will feel more stable (can you see why?).

Unlike a car where you can put different tire sizes on with relatively the same diameter this doesn't work with bikes because the tire shape changes.

Now there are folks that will tell you that "I put on this tire, and I can out ride you..." which doesn't really mean anything. So they are crazy enough to override a bad tire shape. Does that mean that they couldn't ride better on a proper tire shape?

Get a good tire of the right size for your wheel, and you will be better off.

As an aside--a better way to correct for a larger diameter front tire would have been to lower the triples a bit. Changing the rear changes other things, but lowering the triples (raising the tubes) would return the front to its previous geometry without upsetting anything else.

 

[Edwardp33]

Thanks for takings the time to respond in detail. Matt at Formula390 echoed the same sentiment. He hung out at the track with me yesterday. His picture was not as pretty, but he had the same good advice. When the time comes I intend to switch back to the specified size and stick with the the RS 10. I suspected the adjustment to the triples would have been a better approach. Thanks for confirming. I simply didn't have the time.

 

[ToraTora]

Yeah sorry it took me so long to get to a proper post. I was at Laguna Seca for WSBK and well I need an actual computer on which to type. lolz

That image is from Simon Crafter's MotoVudu video.

 

[nino209]

for track/racing I have been using a 115, it is a moto 3 rear Dunlop slick, and the alpha 13 150 rear, so far the best convo i have found, i have tried the RS10 and rear but it didn't work all that well, started sliding a lot at race pace, first race was ok, the second race of the day the tire dropped off by the 2nd lap

 

[SWdragon]

Where can I get a Bridgestone RS10 110 front and a 140 rear as I like to try them.

 

[Major]

stickboyracing.com

 

[Formula390]

I've been ordering my tires from SWMotoTires.com (now Discount Moto Tires) for years and been very happy with their prices and PROMPT shipping. I'm not seeing those specific sizes on their site, but you might try calling them and seeing if they can get them for you as I'm not seeing any of the other standard places I look at tire prices as having them in stock either. Might just be a special order thing and the various sellers just don't have 'em on hand but could very likely drop ship them from the Bridgestone US Distributor.

 

[SWdragon]

Well, I sent Discount moto tires a e-mail asking if they can get them and price. Sizes do show on the Bridgestone website. I would ask stickyboyracing but there website is a little mad!

 

[Major]

If you are a member of WERA, you can pm him on the wera board and he will get back to you immediately. My tires were dropped shipped and the cost for shipping was only $20. Great guy to do business with and he can and will answer any question you have.

 

[Major]

FYI, the RS10 tires in 110/140 sizes can only be purchased a race tire vendor.

 

[Fangfactor]

I have RS10 110/70 front and 140/70 rear. I notice these are the RS10 ''R'' compound. Does any one know how this differs from an R10 soft compound?
The R10 only comes in 120/70 and am willing to try it even though the size and profile isnt perfect for the 3.00 rim but would like a softer compound as Im chasing more front grip.

Ari from Motorcyclist mag is using the 120 R10 front and a 165 bridgstone slick rear and seems happy

Can anyone else comment on this setup or a 120 R10 front and 140 RS10R rear.

Ive read Pirelli sc are the prefered setup but for me Bridgestones are easily accessible and good value where Pirellis are very hard to source in the sizes I need.