rear wheel size

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Oct 30, 2003
Hi there! I just purchased a 72 roadster that needs to be de-chopperized. the rear frame loop was cut off about 7" from the battery box area (but that's for another time). the original drum brake set-up is laced to a 16" steel wheel and I want to return this puppy to a fairly normal look. Most of the text that I've read says 19" rims are original and the way to go. However, I've noticed a lot of bikes have 18" rims. the 18" rim appeals to me just in the fact that there seems to be a lot more tire choices out there in that size. I'm not a purist who needs to restore this bike to its original specs. I just want a relatively reliable and good handling ride. Any advice would be appreciated! P.S. I'm not an outlaw and I wasn't born in 1875 (close though). That is just a type of handgun I have in my old west collection. Hey! I live in Arizona, what do you expect.
wheel size

You'd probably do best to install an 18" rim in WM3 size. Just resist the temptation to go nuts on the tire size. IMHO a 110/90 is as big as you need if not bigger, unless you plan to carry a lot of weight.
Outlaw: I've got an extra rear hub (sans rim) and a whole rear wheel with stock 19" hoop in my garage. Lemme know if you want either one...

A WM3 x 18 is a bit narrow for today's tires according to the recommended rim size by the tire manufactures. I went with a WM4 x 18 on my 72 Commando and I'm well satisfied.
I run a 110/90 18 on an MT 2.5 (often referred to as WM4) and I'm quite happy with it. No clearance problems on a Mk111 and the tyre is nicely spread on the rim.

It is the preferred rim for the 110 tyre.
A 120/90-18 will have about 1/4 clearance on my 72 Combat and that's with a 520 chain. I talked to one of our popular Brit bike suppliers about rear tire size. He said he was having a wider swing arm developed to accomodate a tire wider than 120/90. When I asked how he was going to move the chain outboard he didn't have an answer. I don't care how wide the swing arm is, you still need to clear the chain. I guess you could start offsetting the rim more. Seems like a lot of hassle when a 110/90 is already an oversize tire. I do know that I now have a great handling bike with the Dunlop GT 501's, 100/90-19 WM-2 front and a 120/90-18 WM-4 rear.
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