I am looking into what rear tire to get next, and wonder if 120/90 is actually a better choice than 120/80, as it raises gearing between 3 and 4 percent, or slightly more than 1 tooth less on the rear sprocket. Is there any disadvantage to a 120/90 vs 120/80 that I am unaware of? I already have longer shocks, so fender clearance is not an issue. Both Bridgestone BT45 and Avon AM26 tyres are available in 120/90, so that is no problem.
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120/90 vs 120/80 rear tire
- Thread starter arcticXS
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- gearing tire choose help
I guess it’s a lot down to how it will look when fitted. Originally probably had a 400/18 fitted which is quite a tall tyre
Aspect ratio would not be far away. Can’t see a problem.
Aspect ratio would not be far away. Can’t see a problem.
Some chatter about tire size inconsistencies in here.
http://www.xs650.com/threads/center-stand-technique.44774/
http://www.xs650.com/threads/center-stand-technique.44774/
I prefer lower ratio tires ie 80 or even 70 and adjust gearing with sprockets. What works for good handling has changed more than little since 1980 "balloon" tires. I'll assume an 18" rim here and unless you have gone much wider on the rim a 120 is too wide. But not everyone rides like a lunatic (me) on the street.
This guide might help with reasonable choices.
This guide might help with reasonable choices.
I am going to fit the new tire to my new rear wheel, with a 2.50x18 unflanged Morad (Akront) alloy rim, so rim width is no issue. I went for unflanged because they are much easier to keep clean....
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Well, I just ordered an Avon AM26 Roadrider in 120/90-18. I somewhat disagree with gggGary regarding changing sprockets for gearing. I currently have a 33T rear, and get pretty severe chain rub on the swing arm already, since my shocks are 343 mm/ 13,5" long. Altering gearing by tyre selection is almost free, as you need to replace them pretty often anyway. Ivan Hoey's high primary would be the ultimate solution, but I have no budget for that now....
