Can I put a 120/17 70 on an R6?

[The Awesome]

Originally Posted by OreoGaborio

The change in handling would be minimal. You're not going to reduce the ability of the bike much, if at all. It may steer a little heavier, but that's about it.

If that's all you've got & you need something in a pinch, throw it on there and give it a try. If you don't like it, then swap it out when you can. It's not going to pose a safety hazard.

A smaller profile number just means it's a little "flatter" of a tire in the middle of the tread. It doesn't automatically mean the tire won't give as much lean angle or you'll run out of tire sooner. And contrary to popular belief, the profile ratio doesn't necessarily denote the size of the sidewall, but the overall profile or "pointiness" of the tire. A 70 series is a "peakier", more triangular tire than a 60 series, which typically means a larger rolling diameter and a SLIGHTLY bigger contact patch when leaned over.'

For street riders, the biggest effect of switching from one to another is just the handling FEEL of the bike, not handling performance.

End of discussion.