Should I use a bigger rubber?

[OUTLAWD]

I've been having some circulation proble...


On a more serious note, I did a quick search and did not come up with anything, but I know it has got to be a beaten to death topic.

How will running a 190 on the rear effect how the bike handles?

Its a K3 GSXR 750, 5.5" rim, currently 180/55.

going to a 190/50 should keep the height roughly the same, but will probably slow the turn in because it will have a less steep 'profile', if you will...

Going to a 190/55 will make the rear taller, and keep a similar, if not steeper profile than the 180/55, correct? Will this help it turn it quicker? or just make it harder to stand up coming out of the turn, and harder to transition form side to side.

Take note, that this would be going on a 5.5" wheel, not a 6"

It needs new tires again, and I was thinking of playing with different sizes for the hell of it, or should I not even bother and leave well enough alone?

Thanks!

[~Barn~]

You probably won't like the way it handles if you go to a 190. More than likely it'll feel marginally slower responding to turn-input, and unless you think the bike is acting skitish now, I can't see this being a positive result.

Not to mention the tire is going to be more expensive to buy.

Just my .02 though. YMMV.

EDIT: P.S. I actually really enjoyed the swap when I did it in reverse, on my R1. The less expensive tire cost was nice, and that little bit of quicker flickibility, was also a plus. :up:

[Zach929rr]

Stick with the OEM tire size. Yes, the bigger width sounds nice, but the smaller rim will pinch and flatten the profile of the tire. Also, the 180's are body-touchingly cheaper.

You couldn't fit in a Magnum anyway.

[OUTLAWD]

Doesn't feel skitish, maybe a bit slower turning than I'd like, but that might just be the nature of the older 750 vs a newer 600...

I have a few things with the suspension I want to try, but before I get to a lapping day to screw with the suspension, I need new tires

[Zach929rr]

Did you snatch up a copy of Suspension for Mortals by Traxxion? Watched that yesterday and it was well worth my 2-3 hours.

[CaneZach]

Actually, I'm in the opposite camp than Brandon. The GSXR rear rim is 6.5" wide, iirc. Taking a 190/55 and forcing it onto that rear is going to crown the rubber and increase your contact patch. It'll be like running a smaller wheel where the tire is still the same size. The raised rear will turn in faster and more responsive.

[Captain Obvious]

You couldn't fit in a Magnum anyway.

I don't think that is the problem, he can fit inside it just fine, just isn't able to touch the sides or end to keep it on. When he takes his hands off, it falls off onto his balls.


Ref the rear, I have tried both on the TLR, the difference was minimal based on best recollection, that is why I run stock sizes. And any changes the tire may make are minimal to what you can do with suspension tweaking.

[~Barn~]

Doesn't feel skitish, maybe a bit slower turning than I'd like<Snip...>

If that's the case, then the switch up from a 180 to a 190, will likely only exacerbate that feeling.



Actually, I'm in the opposite camp than Brandon. The GSXR rear rim is 6.5" wide, iirc. Taking a 190/55 and forcing it onto that rear is going to crown the rubber and increase your contact patch. It'll be like running a smaller wheel where the tire is still the same size. The raised rear will turn in faster and more responsive.


See below:


Take note, that this would be going on a 5.5" wheel, not a 6"

[Zach929rr]

Actually, I'm in the opposite camp than Brandon. The GSXR rear rim is 6.5" wide, iirc. Taking a 190/55 and forcing it onto that rear is going to crown the rubber and increase your contact patch. It'll be like running a smaller wheel where the tire is still the same size. The raised rear will turn in faster and more responsive.

It would actually do the exact opposite of that putting a 190 on a 5.5". I guarantee it. It will pinch the base of the sidewall in and draw the crown of the tire downward, effectively shortening the height of the tire. Granted we are talking millimeters here, but this is on machines where +/- 5mm of trail and degrees of swingarm angle will drastically affect the handling.

Also, "fit" is a relative term. If you can't keep it on without your hands, you're not "fitting" in it.

[CaneZach]

Which is why I said a 6.5" rear. For some reason, I thought the gix rear was 6.5".

[Nick_Ninja]

I'll go with this:

http://image.sportrider.com/f/8888109+w750+st0/tire-size-profile-zoom.jpg

http://www.sportrider.com/tech/tires/146_0206_tire_size/index.html

[Black Phantom]

I've been through this, my Speed Triple came with 180/55 on 5.5" rim and I hated the look of the skinny rear tire so went to 190/50. I can tell you your bike will turn slower, and no matter how far you lean you'll never get ride of the chicken strip. The 190/50 on 5.5 has a very steep sides that there is no way you can use them, and the time I tried I low sided. I know the previous owner had a 190/50 and he did low side on the track as well. That being said, the bike feels more stable at higher speeds on the 190 vs. 180.

Things are the opposite on my TLR. I have a 6" with 180/55 and man that bike turn so quick, but feels interesting tho. It could be in my head tho.

I know I'm going back to 190 on the Speed Triple, I just hate the look of the 180/55.

[dragos13]

Stay with the 180, imo. 190 size rears are for built superbikes that have tons of power to spin that baby up. If you are doing it only for looks, then it doesn't really matter what you throw on. If you want to keep your sportbike nimble like a sportbike should be, keep what rubber that the hard working R&D guys designed the bike to use.

[rybo]

+1 for Casey

The 5.5 inch rim will not take well to the big tire. I would stick with the 180. If you want the bike to turn in differently, we can change that with set-up changes.

Also, you spent some money with me to help dial in your bike. We did that to a specific tire and size. Changing it changes the set up. Unless you really dislike what your bike is doing I would go so far as not only to stay with the same size, but also the same tire.



S

[OUTLAWD]

cool...thanks guys, I just wanted to see what difference it would make, or if it would be worth trying before i picked up a new rear.

180 it is :up: