650B / 27.5" ,,, are there (usually) any major differences?

[DougC]

I'm considering obtaining a wheel this size for the tire-making project.
Not so much for the belted radials I'm currently working on, but for
other future projects.

A lot of sites note that these two sizes (650B and 27.5") are the same
ISO size (584mm) but are the rims usually the same general widths? I
have noticed that places selling 650B wheels tend to use more-expensive
parts, while many places selling 27.5" wheels have much cheaper offerings.

For one example, the cheapest front 650B wheel listed on Amazon costs
about $90, while the cheapest front 27.5" wheel costs about $35.

I think at least part of this is because the 650B wheels are usually
made for allowing rim brakes, while the MTB wheels are often
disk-only... And disk-only wheels have shifted from being more-expensive
than the old style to less-expensive. (I've seen Wal-Mart bikes now with
disk-only rims! so if you like the concept or not, I think it's safe to
say that it has arrived)

Also note that these wheels won't ever get put on a bike and actually
-used-, they're just for assembling tires on. So the general parts
quality doesn't really matter as they won't see any loads other than
test-inflating tires. They just need to be clean and straight.

[Gregory Sutter]

On 2016-10-12, DougC <dci...@norcom2000.com> wrote:
> I'm considering obtaining a wheel this size for the tire-making project.
> Not so much for the belted radials I'm currently working on, but for
> other future projects.
>
> A lot of sites note that these two sizes (650B and 27.5") are the same
> ISO size (584mm) but are the rims usually the same general widths?

650b is the road size, and 27.5 the mountain, so in general I'd
expect the 27.5 rims to be wider. There are probably enough
exceptions to this statement to make it worthless, though. The
market is evolving rapidly. A little Internet research or a trip to
***mart with some calipers would be a better way to determine the
width of a specific rim.

--
Gregory S. Sutter Mostly Harmless
mailto:gsu...@zer0.org
http://zer0.org/~gsutter/

[AMuzi]

In that case just get the cheapest 584mm front wheel.

Rims/wheels for Waterford Audax bikes (650B) are different
in width from wheels for bottom end XMart MTB type bikes
(27.5 inch) although both and many inbetween are offered in
584mm.
Current tire sections for that run roughly 28mm to 55mm,
much like 559 series.

Check this out:
http://www.velocityusa.com/product/rims#sizes-tab

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[DougC]

On 10/11/2016 10:38 PM, Gregory Sutter wrote:

> 650b is the road size, and 27.5 the mountain, so in general I'd
> expect the 27.5 rims to be wider. There are probably enough
> exceptions to this statement to make it worthless, though. The
> market is evolving rapidly. A little Internet research or a trip to
> ***mart with some calipers would be a better way to determine the
> width of a specific rim.
>

There's not a lot of reason to covet any parts on Wal-Mart bikes, since
you generally can't get them separately of buying the whole bike anyway.
It's super-cheep OEM stuff. You'd be lucky if you could even track down
a manufacturer from the name on the part.

What I was wondering is if the MTB types were drastically wider. And
some are, but not all... On the Velocity site Mr Muzi linked to, the
650B rims varied from 18 ~ 25mm wide, and the MTB rims were 25 ~ 40mm wide.

I did get the 27.5 wheel on Amazon, since it was less than half the cost
of the next-cheapest ones I had seen. And it is 21.4mm wide (a Weinmann
rim) so it is more in the 650B-width-range as I wanted,,, and this
perhaps explains its cheap price. It's listed by Niagra Cycle but it did
not appear on their own website.

I may have something interesting to 650B riders and their ilk, but I
don't really have a way to make good knobby treads yet so I've got no
plans for MTB tires as it is.

And once again....... I am waiting for parts in the mail from China, so
I can finish building the two automatic cable reels.