rear tire 180 to 190 question!

[whiterabbit]

IM planing to change my rear tire to 190, but some one told me if i do so i might lose some horse power. Is this true?
If anyone knows about it please let me know.

[zx10Duran]

I really dont see how you would lose power by switching tires?

[photodigm1]

There are countless arguments about this......What some people "theorize" is the 180/55 tire is a taller tire in circumference. Ergo you will be losing ride height in the rear if you switch to a 190/50....and beacause the circumference is smaller.....some think that it is the same as going 1 tooth down in the rear....some may look at it as increasing your top end.....or decreasing your get up and go power.....

Personally I think that the difference is very very non noticable...

I have a friend of mine who is a brainiac and a drag racer. He has a certain profile size of tire for each rear end he has.....telling me how this 1.85% increase in radius is giving him more lowend.......I'd like to see it.


So if your friend rides motorcycles please hit him/her with a stupid stick and tell them "from now on when I want your opinion....I'll give it to ya"

Who ever told you that you will lose HP is full of CaCa.

[whiterabbit]

Originally Posted by photodigm1

There are countless arguments about this......What some people "theorize" is the 180/55 tire is a taller tire in circumference. Ergo you will be losing ride height in the rear if you switch to a 190/50....and beacause the circumference is smaller.....some think that it is the same as going 1 tooth down in the rear....some may look at it as increasing your top end.....or decreasing your get up and go power.....

Personally I think that the difference is very very non noticable...

I have a friend of mine who is a brainiac and a drag racer. He has a certain profile size of tire for each rear end he has.....telling me how this 1.85% increase in radius is giving him more lowend.......I'd like to see it.


So if your friend rides motorcycles please hit him/her with a stupid stick and tell them "from now on when I want your opinion....I'll give it to ya"

Who ever told you that you will lose HP is full of CaCa.

LMAO Ok will do

thank you:eyecrazy:

[SkyDork]

Originally Posted by photodigm1

There are countless arguments about this......What some people "theorize" is the 180/55 tire is a taller tire in circumference. Ergo you will be losing ride height in the rear if you switch to a 190/50....and beacause the circumference is smaller.....some think that it is the same as going 1 tooth down in the rear....some may look at it as increasing your top end.....or decreasing your get up and go power.....

Personally I think that the difference is very very non noticable...

I have a friend of mine who is a brainiac and a drag racer. He has a certain profile size of tire for each rear end he has.....telling me how this 1.85% increase in radius is giving him more lowend.......I'd like to see it.


So if your friend rides motorcycles please hit him/her with a stupid stick and tell them "from now on when I want your opinion....I'll give it to ya"

Who ever told you that you will lose HP is full of CaCa.

This is all very true. Keep in mind that horsepower is made at the engine crank, not at the rear wheel. Different tire sizes and profiles affect a lot of things about the bike, but horsepower isn't one of them. Torque can be affected as photodigm1 has suggested by essentially "regearing" the bike with the tire size. The bigger tire does weigh more, so some of the horsepower of the engine will be used to sling the heavier tire around and this will affect acceleration much more than anything else. Most people won't notice this and unless you're racing and looking for better handling/ultimate acceleration, you'll be fine.

[photodigm1]

Originally Posted by SkyDork

This is all very true. Keep in mind that horsepower is made at the engine crank, not at the rear wheel. Different tire sizes and profiles affect a lot of things about the bike, but horsepower isn't one of them. Torque can be affected as photodigm1 has suggested by essentially "regearing" the bike with the tire size. The bigger tire does weigh more, so some of the horsepower of the engine will be used to sling the heavier tire around and this will affect acceleration much more than anything else. Most people won't notice this and unless you're racing and looking for better handling/ultimate acceleration, you'll be fine.

Sky Dork you are a good man. There is another thread about this same topic....the guy was wanting to go from a 190/50 to a 180/55 go "gain more accell"....instead of a larger rear sprocket......he wasn't taking into concideration that he was putting a 190/50 tire on a rim made for a 180/55....oh well

[speedgsx98]

Don't do it. Stick with a 180. Going 190 will pinch the tire ever so slightly on the 5.5" wheel, causing you to wear a flat spot down the center of the rear tread sooner, and tucking the edges of the tire so far in, you could never use all of the tire at full lean. Most guys who have 190's, often like to switch to a 180 to get a more street useable profile. A 190/50 will give you better acceleration than a 180/55 just to let you know.

[The Joker 008]

To make that theory inaccurate just look at the MotoGp bikes. They are 800cc's that have well over 200+ hp and run 200 rear tires. Not 190, not 180, and those riders handle that very well. Just my .02.

[speedgsx98]

What's motoGP?

[Andy]

Technicaly you do lose hp although very little.

A 190 rear weighs more than a 180, therefore more power is robbed reaching the pavement.

The GP bikes need more tire width on the back to deal with the 200+hp, same reason the litrebikes run 190s instead of the 180s standard on the 600 and 750s.