I've got a (rod brake, single speed) roadster bike with 28 inch wheels. I wanted to put a 3 speed coaster hub on it, so yesterday I bought a replacement rear wheel. Unfortunately it's not the size I thought I was getting, as 28 inches can apparently mean either 635mm or 622mm. So now I'm wondering: should I set up my bike with the 622 wheel? Is it a problem having a 635 in front and a 622 in back? Also, would the bike ride worse with the smaller 622?

Can be done, but I do not advise it, and it will look ridculous.

Have your existing wheel re-laced with the coasterbrake 3-speed hub (I hope it is one of the present models, as the old S3C and TCW hubs are not reliable enough to serve as your one solitary brake).

-Kurt

Tire size tutorial:

https://www.sheldonbrown.com/tire-sizing.html

17" wheels are larger than 18" wheels.

tcs

The problem with my old wheel is that it's a 40 spoke wheel. So I'd need to find a new 635mm rim with 36 holes, and finding anything 635mm is hard in the US.

Will it actually look ridiculous? I guess I'm just not sure how noticeable the 1.3cm difference in diameters (that's what 635 and 622 refer to, no?) is going to be (visually or in riding it).

@Tcs: I found that exact page when trying to figure out how my old tire didn't fit the new rim. It is quite helpful; I see how we came to misunderstand eachother.

The 635MM wheel is about 1/2" difference in diameter.
I wouldn't even notice that on another bike!
"FAT" 622 tires are called 29's!
Assuming your 28's are 635x 1-1/2", that would be a 37MM "thick" tire.
a 622x 41MM would theoretically be the same OD.

Does the bike have a rear brake that has to match rim diameter? If so, that would be a bigger issue to me.

If you adjust the fender line (the way the fender hugs the radius of the wheel), it'll look fine. That'll mean putting in a 1cm or so spacer where your fender connects to the chainstay bridge. And, of course, you won't be able to use your rear rod brakes (and might have to remove the pads, too), but the coaster brake should render them moot. If you already have the wheel, it's certainly worth a try.

Neal

The rear brake is a stirrup type rod brake. I think I can get it to match by making part of the rod a little longer, but if I can't it's easy to remove and there's a coaster on the hub (and the rear brake has never been great anyways: steel rims, long mechanical linkage with a good amount of flex, no mechanical advantage, ...).

The current tires are 2 by 1 1/2. Getting a wider tire for the rear wheel to bring it up to closer to the same size would make sense.

If I do keep this new rear wheel, one upside would be that is it a much more common size.

Alright; off to the bike shop to get a new rear tire. Then home to put it on.

Thanks for the advice.

Sell the bike, buy one with a coaster brake. That's the easy way. I've been watching for a good rod-brake bike for cheap, and haven't seen any- would hate to see one get converted to something else.

(As far as I know, the rod brake won't work with newer rim profiles, so not only do you get the coaster brake, you ruin your rod brakes.)

Did you try Yellow Jersey to see if they had the correct rim

I put the wheel on yesterday morning. A little work dealing with the chain guard, but aside from that everything was great. You can't really see the difference in wheel sizes and I was able to adjust the rear rod brake to fit the smaller rim. Nice thing about rod brakes -- they're so simple you can make them do what you want. (The new wheel has a westwood profile).

Three gears, 186% range, and a coaster brake.

Couldn't be Westwood - never heard of a 700C rim for rod-brakes only.

Westrick (rod/caliper), perhaps, but I haven't seen that either. What brand is it?

-Kurt

Doesn't exist? I think I've got one. The people at the dutch bicycle company <https://www.dutchbikes.us> where I got it told me it was a stainless steel "german made regita" rim, and it really looks like a westwood profile. I'll double check tomorrow morning.

I've looked at pictures of westrik rims, and it doesn't look like that to me.

I have to see that. I can believe it's existence for the overseas market, come to think of it - just never thought that one would pop up here.

They didn't happen to offer 28" rims not laced, by any chance?

-Kurt

One of these things is not like the other...



The front wheel is an English 28 (635) while the rear is a Canadian 28 (622)... the original wheel is in the front.

Kurt: looking at my bike now, turns out you're right -- westrik after all.

More details on the rim: it's a "regida", not a "regita". It's westrick pattern, stainless steel, 622mm, 36 hole.

Now to look for a 622/700c for the front so I can buy studded tires and not wipe out on ice.

Thanks for posting the info above regarding ISO 635 rims.

I've been emailing a friend in Delhi to arrange for some Westwood and Westrick rims to be mailed to me!

I think ordering from Europe (or the Dutch Bicycle Company) might be a better choice, if they've got what I need.

Thanks again!

As for the dutch bicycle company, when I asked if they could get me an ISO 635 wheel (instead of ISO 622) they said something like "we can, but it will have to come from europe, take weeks, and cost twice as much".

I've been pretty happy with my 622 rims (I bought a ISO 622 westrick front wheel from them too, with a Sturmey Archer X-FDD hub) so far, though. They're almost as large, I can run standard 700c tires (which means I can get studs), and they're stainless steel instead of chromed. You might want to consider buying 622s.