School me on 650B wheels
 

I'm working on a 650B classic touring bike project. Can someone school me on wheels? The current plan is to get a used 70s/80s steel road bike of decent quality off ebay and then retrofit to 650B.

I plan to ride mostly on paved roads--maybe occasional a gravel road? I weigh 140 lbs and will be carrying up to maybe 20 lbs of gear for overnight camping. Probably not much more than that.

I have the following decisions to make:
1. Hubs - stick with the original hubs that came with the bike and build up a new 650B wheelset around these, or buy new hubs? What are your thoughts on a rear internal hub with 8-10 speeds?

2. Which rims? Here are some options:
Rims
Grand Bois Rims - Longleaf Bicycles

Looks are important--I'm trying to keep a classic look if possible. Durability and quality are probably equally important. Are the Grand Bois rims worth the cost?

3. How many holes - 32 or 36? I want a decently strong rim. But what do I really need?

I think that's about it for now. I'm sure though I'll have more questions.

I'm curious, why 650?

One of my current projects has a lot of overlap with your plans. My wife's mid-80s Trek 720 was in dire need of being repainted. Since the original cantilever brakes that came on that bike are awful and she really, really, really likes to take her descents slowly, it seemed like a good time to change the brakes to the Big Squeeze brakes from R+E. (They are also doing the painting.) I also decided to change from 700C to 650B. This will allow her to either keep the same level of toe overlap, if she goes with 48 mm tires, or to reduce the overlap by 5 mm or so with 42 mm tires. Granted, she could drop it more if she wanted to go to narrower tires, but going to wide, supple tires was part of the reason for the change; putting wide tires on a 700C rim caused too much over lap for her. There are other changes afoot (nine-speed cassette with 10-speed Ergo shifters and changing to the carbon handlebars she has enjoyed on our tandem), but those aren't exactly consistent with the classic look.

I went with the Grand Bois rims, 32-hole. Why would a light rider need more spokes? I'm 185 pounds, ride hard, often carry a boatload of gear (inclement weather tours), spend a lot of time off-road and use 36-hole 700C wheels on my touring rig. Any more than 32-holes for someone under 150 pounds on a 650B just seems like an overbuild to me. Even our tandem, which is on a fairly deep 26-inch rim, is only 36 spokes and we roll that thing over many a gravel road and odd trench without worry. Sure, the smaller spoke length gives some extra strength there, but fully loaded we can weigh in at over 400 pounds.

I honestly couldn't say if the Grand Bois rims are worth the slight cost premium. I went with the advice of people I trust, including the awesome crew at R+E, and figured this was a one-time purchase. Besides, if Jan Heine can successfully roll these things on the terrain he rides, which is very, very similar to what we ride, then they are probably up to the job.

[MENTION=185425]B. Carfree[/MENTION]
That sounds like an interesting build. I don't want to thread jack, maybe you could post some build info in it's own thread?

I have 32-hole Grand Bois rims. My decision was influenced by Jan Heine’s explanation of how and why they were redesigned: https://janheine.wordpress.com/2014/...mered-fenders/ . I can tell you from experience that it is very easy to get Compass tires on and off of Grand Bois rims.

A classic touring bike will have cantilever brakes with 27" or 700c wheels.
Cantis are pretty much a no go for 650 conversion since the adjustment is (almost)always not enough to fit the new wheel size.

So now you need to go with a touring bike from before about 1983 or a sport touring bike since either design will have side pull brakes.
Pre 81 or so will limit the odds of a frame having bottle and rack mounting points.


Regardless- if the hubs that came with the bike were good, i would consider using them. If they were generic from 30 years ago, id probably pick up some new hubs.
I would use 36h rims, but i am not a lightweight. To me, there is no downside at all to have more spokes. Most wheels from touing bikes will already have 36h or 40h rims, so might as well keep it going with your conversion.

Interesting thoughts about brakes.

I'm running 700c on my 26" frame, and the cantis are definitely in the wrong spot. Wheel clearance isn't bad though.

http://bikeforums.net/attachment.php...hmentid=503392

However, I'm seeing notes of people running 650b wheels with cantis using a 26" frame, so that would be an option.

The one warning with 650b on 26" is shocks bottoming out. Fender clearance?

Disc brakes would allow swapping wheels, but would require a much newer frame.

If you're painting, you could probably move the canti posts.

I suppose that depends on one's definition of classic. There were an awful lot of 650B-based bikes used for touring back in the 1920s, '30s, '40s and '50s.

True. I was limiting my response to the OPs desire for a 70s or 80s bike.

Going back another half century from what he wants though?...im couldnt begin to imagine the workarounds and unknowns that could come up.

By internal hub, do you mean the newer style of freehubs and cassettes as opposed to the older freewheels threaded onto the older hub style?

Or, do you mean internally geared hub? I assume this is not what you mean, but I was not sure.

I like the newer freehub design for hubs, but for your weight and expected gear weight the older hubs with 5 or 6 speed clusters would be strong enough.

The older frame you are looking for is likely 126 mm rear droput spacing, the newer frames for newer hubs need 130 mm or 135 mm. If the frame is steel using a frame with 126 mm dropout spacing is not a problem, but it does mean you are looking for steel instead of Aluminum.

A lot of the older frames used centerpulls or sidepull brakes instead of cantilever brakes. I am not sure about fitting brakes to the older frames but you might be able to find a set of long reach centerpulls or sidepulls that would work with 650B, but maybe might not???

Avoid the older 27 inch wheel size frames, I am reasonably confident that you will not be able to fit brakes to a 650B rim. This was a common size in the 1970s.

For your weight and luggage weight, there would be nothing wrong with 32 spokes.

You will find spares in 650B in France , That is where the tire size came from.

A classic 27" frame should be able to fit moderately large 700c tires.

Weinmann or Diacomp 750's will probably work. They do on my Univega and Trek 630 conversions.

There are a lot of threads on 650B conversions on the Classic and Vintage Forum. There is an active thread there now. The Google 650B discussion group might also be helpful.

I built my wheels with 36 spokes because I had some 36 hole hubs.