Westwood rim size

[Tuckered Out]

Hi All, Quick question. With a Westwood rim is the O.D. of a 27.5" rim and a 28" rim the same but with a smaller profile tyre or are they a different diameter.
Thanks for your assistance, Trevor.

[WyvernRH]

OK, 28" rims are a bit of a minefield. You may want to see the discussion at:
viewtopic.php?t=42523
But a good summary is the post from BicyclePassion which I will quote:
<
Lots of confusion with 28" wheel sizes, but as stated above, 28 x 1 3/8 (642) was the most common size used in Australia, with 28 x 1 1/2 (635) coming a distant second in popularity. 642 was used on roadsters and road racing bikes.
The actual Conloys mentioned above, in 28 x 1 3/8, (642), 1930's Conloy Asp's, were in the Jack Hepher collection, are now on a bike in my collection, and were very uncommon when new, but listed in catalogues. I have seen one other set in the last 30 years.
28 x 1 3/8 x 1 1/4 Dunlop Speed tyres were available, these were a narrow tyre to suit the 642 rim. I have some of these on the alloy Conloys. Not to be confused with the current 28 x 1 5/8 which fits the 622 (700C) rims.
In the 1930's, if you could afford to buy 28" Conloy alloy rims to convert your 28" racing bike to the latest technology, you could afford to get a new bike built with the latest thing, which was 27 x 1 1/4" aluminum (Conloy Asp), or 27 x 1/4" Dunlop Special Lightweight rims, which were very light steel rims.
Warren
>
So, hope that helps

Modern marketing has not helped at all making up new nominal inch sizes to represent existing size specifications.

Richard

[Duck!]

Modern marketing has not helped at all making up new nominal inch sizes to represent existing size specifications.

Richard

Not modern marketing. For decades The Industry has cherry-picked bits & pieces from various regional sizing methods and mashed them into a nonsensical concoction that ranges through confusing, misleading, and inaccurate, to just plain bloody wrong!

I've been stewing on this mess for 20-odd years and am getting pretty close to a full-blown rant about it! Brace yourselves!!

[WyvernRH]

Modern marketing has not helped at all making up new nominal inch sizes to represent existing size specifications.

Richard

Not modern marketing. For decades The Industry has cherry-picked bits & pieces from various regional sizing methods and mashed them into a nonsensical concoction that ranges through confusing, misleading, and inaccurate, to just plain bloody wrong!

I've been stewing on this mess for 20-odd years and am getting pretty close to a full-blown rant about it! Brace yourselves!!

Yes, good point, I should have said 'Modern Marketing has added to the existing confusion'. Cos really, all these new 'inch' sizes for 650B and 700C tyres have just confused the scene more than it is already.
Recently I had to disappoint someone who thought they had managed to buy nice tyres for their old 27x 1 1/4 wheels - of course they were actually 27.5" i.e. 650B - not gonna fit.... Fortunately, they fitted my Cannondale Lefty so he was not out of pocket.

And we won't mention the quagmire that is 26" (nom)

Richard

[P!N20]

I've been stewing on this mess for 20-odd years and am getting pretty close to a full-blown rant about it! Brace yourselves!!

Subscribed

[warthog1]

Not modern marketing. For decades The Industry has cherry-picked bits & pieces from various regional sizing methods and mashed them into a nonsensical concoction that ranges through confusing, misleading, and inaccurate, to just plain bloody wrong!

I've been stewing on this mess for 20-odd years and am getting pretty close to a full-blown rant about it! Brace yourselves!!

It would be a pita as a bike mechanic I expect
I have been back on the bikes about the same 20 years and 700c exclusively, so no effect really. Just got wider and gone tubeless is all. Both positive changes ime.

[Duck!]

I've been stewing on this mess for 20-odd years and am getting pretty close to a full-blown rant about it! Brace yourselves!!

Subscribed

I'll make a new thread when I go off on it, it's too much for piggybacking on another.

So back to the topic at hand... I had not heard of Westwood rims until this thread, but after some research I realise that I had actually seen some in my life as a mechanic. Most commonly they were made in 635mm and 642mm diameters, confusingly both labelled as 28" (check your tyre width, 1 1/2" for 635 and 1 3/8" for 642mm), but were also made in smaller rim sizes. In the old French sizing system, some of which carries into the modern mess, 642mm rims fell into the 700A size, while 635 is also known as 700B. I saw both 635 and 642 on the one bike once! I have not seen the use of the term 27.5" for any of these older-style rims, only in the modern MTB usage.

[Tuckered Out]

Thanks for the reply's. looks like my quick question opened a can of worms. My 60s Malvern Star came with 1 Westwood 28" rim and 1 Endrick 28" rim. both are 1 3/8" 642 X 22mm. There is a pair of Westwood wheels on evil bay listed as 27.5 Inch. but the seller may have listed them incorrectly. Would be nice to have a set of matching rims. Will ask the seller to measure the rims with a tape measure to clarify the size.

[Duck!]

My limited understanding is that Westwood refers particularly to the cross-section design of the rim, as other manufacturers also produced this design.


The rim diameter is measured at the bead seat, or the flat section at the base of the sidewall, not the outer edge, so a bit of guesstimation will be required with the tape measure, but 7mm is a decent margin to play with.

The 27.5" listed by the seller is almost certainly an error.

[Tuckered Out]

Fixed one issue, created another. Bought a couple of Westwood rims and a set of forks for my Malvern Star. When they arrived I noticed that they both have 36 spoke holes. The wheels that came with the frame were 32 front and 40 rear. These rims where on an older Malvern Star as the paint matches the forks. Not that big an issue though, can do a different spoke pattern with 36 holes, just need to get another set of hubs. So it begins!