tires and handling

[alehman]

hey guys,

I wanted to run another tire-related question by you. I got a rear tire that's 2.25 inches smaller in diameter than my front tire because I wanted that sort of look for the bike. I know I shouldn't monkey around with tire sizes relative to stock, but I wanted to know if any of you think that that would very significantly affect handling and if so, how. I haven't mounted them yet so I'm asking just because I want to anticipate how they'll be from guys who know their stuff

[rrgunslinger]

I'm running a 100x90/19 on the front and a 120/80x17 on the rear (1973 K3).  What should be on the back is 120/80x18, so the wheel is a inch smaller.  What this did was of course lower the gearing and made the bike handle very quick.  U turn's are not a problem neither.  I put a 19" front sprocket (from CycleX) on to make the gearing higher to make up for what was lost in the smaller wheel. It is still low but makes for faster acceleration. For now I am ok with this setup because I ride mostly in town.
So in answer to your question, smaller tire on the back = quicker handling at least for my bike.  

[Lucky 1]

IF the outside diameter of the rear wheel is smaller it would make the bike possibly have slightly more rake
(very small amount) and have slower handling not quicker handling.

[alehman]

The tire on the rear is the same OD as the stock rear, so no issues with gearing. However, it's .5 inches narrower. It's the front that's gotten a larger OD. That will increase the rake, but I'm hoping a narrower rear will help the bike lean easier.

[shinyribs]

The affect on the rake would soooo minimal you'd never notice it. And if you did,more rake is more stable at speed,which is something these bikes could use anyway.IMO.I wouldn't worry about it.