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Tire size question

Started by BovineFreedom, August 28, 2010, 11:17:09 PM

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BovineFreedom

Hey guys, I am in need of a new front tire. My buddy has one with 80%+ tread left but its a 120x60x17 and my bike has a 120x70x17. Will that 10mm difference in height cause any problems with handling? Low on funds and can't really afford a new tire at the moment. Thanks
Keep the rubber side down.

jlavallee

Quote from: BovineFreedom on August 28, 2010, 11:17:09 PM
Hey guys, I am in need of a new front tire. My buddy has one with 80%+ tread left but its a 120x60x17 and my bike has a 120x70x17. Will that 10mm difference in height cause any problems with handling? Low on funds and can't really afford a new tire at the moment. Thanks

The 70 is an aspect ratio not a direct measurement so it'll be a little more than 10mm. the bike will steer a little quicker and generally have a little less contact patch at lean since (assuming they're the same brand/model) the profile will be a little flatter. Essentially, it is nothing that you will really notice for normal street riding. Go for it.

TWF

Quote from: jlavallee on August 29, 2010, 07:41:34 AM

The 70 is an aspect ratio not a direct measurement so it'll be a little more than 10mm.
Maybe, maybe not. stamps on tire mean nothing. To know exact difference you need to measure it. I have 60 series tire that is bigger than 70.

jlavallee

Quote from: TWF on August 29, 2010, 03:46:15 PM
Maybe, maybe not. stamps on tire mean nothing. To know exact difference you need to measure it. I have 60 series tire that is bigger than 70.

True, hence my note that it is assuming they're the same brand/model.

BovineFreedom

Thanks for the info guys.  Now to get it installed.
Keep the rubber side down.

Scott

here's a good explanation and breakdown of motorcycle tire sizing.
http://www.retrocycle.com/tiresizes.php
GSX-R600

A DRAGON

Quote from: BovineFreedom on August 28, 2010, 11:17:09 PM
Hey guys, I am in need of a new front tire. My buddy has one with 80%+ tread left but its a 120x60x17 and my bike has a 120x70x17. Will that 10mm difference in height cause any problems with handling? Low on funds and can't really afford a new tire at the moment. Thanks

Bovine.  I understand your concerns.  I would just mount it.  If your on  a race track turning mad skills time. It's something you should worry about.   I used to.  Now for the street I just mount it. 

Races are flipping tires on the race track now.  It's unbelievable what people are doing now.  A rear is a directional tyre.  It's now turning the opposite way and it still works.   Fronts I'll even mix and match the brands.  I haven't had a problem..  Sometimes the new height rubs my front fender.  Haven't broken it yet.   

Do what ever you feel comfortable...  What I do works for me.  Good luck :2cents
In Garage:
ZX9R
Aprillia RSV 1000
SV-650
GSXR-750