Re: Substitute shells for Sturmey FM
Thanks for the information. I knew 650A existed but didn't realize that it was common and offered a wide variety of tires.
The rims appear to be essentially the same width as 650B and given the tiny difference in BSD they ought to be useable on my 650B frames. Functionally the same OD for frames going forward, high quality fat tires available, about 50% the cost of 650B equipment, CR-18 available in 40 holes.
Is 650A is still common and healthy in the marketplace? It's not on the way out for some reason? That seems implicit in your comments. If that's the case, it's kind of difficult to argue with the logic.
--- In Geared_hub_bikes@yahoogroups.com, "aarons_bicycle_repair" <aaron@...> wrote:
> The CDLV tire does come in a 650A size.
> And since there are more rims and tires available for 650A, it might be wise to "standardize" on 650A.
> It is interesting that 10 years ago, before 650B became fashion, there was only one tire readily available in 650B and no rims. The only real source was France and maybe Japan.
> Had Jan Heine and Grant Petersen looked at their history, they would have seen that 650A was really really common. Grant paid for rims and tires to be made. Fat tires could have been made for 650A. Right now the fattest tire I can find for 650A is the Schwalbe Marathon Plus in 26 x 1 5/8"
> The whole 650 A/B situation reminds me of the 1980s when touring bikes had 27" wheels and racing bikes had 700C. For all purposes the same size wheel! And the difference between 584 and 590 is smaller than between 622 and 630.
> --- In Geared_hub_bikes@yahoogroups.com, "John" <jmedclay@> wrote:
> > Aaron - Do you have any 650B rims with 40 holes? That would save me some trouble and since I make my own frames, CS clearance isn't an issue. I very much like the CdlV tire.
> > Thanks,
> > John
- I think discussing wheel sizes applies to this forum because it affects your gearing.
For example most 700C bikes can accept smaller wheels which will give slightly lower gears and fatter tires.
Also like Alex W. said, 590 is a very common 3 speed size and almost everyone has or has seen or will get a Raleigh 3 speed!
There is some confusion about the 700D size. Sheldon Brown lists it as 587mm, http://sheldonbrown.com/rim-sizing.html as does my Black edition of Sutherland's Handbook for Bicycle Mechanics BEFORE the correction. A sticker sheet was sent out with corrections that you cut out and stuck over the errors. I have that correction in my copy of the book. It says 583mm is the correct size for 700D. BSDs within 2 or 3mm should be interchangeable!
I used to have a spare set of the GT knobbies for their 700D bike.
I finally sold them some years ago. They were NOS. I fit them on a 584mm rim and they fit just fine. They did NOT fit on a 590. When I had them and I was counseling Grant and Jan to push for more tires for 590 instead of 584 I created this page: http://www.rideyourbike.com/650b.shtml there is a link to a picture of the 700D on a 584mm rim.
This leads me to believe that Sutherland's is correct and 700D is 583 and Sheldon is wrong and 700D is NOT 587. Does anyone have a tire with the Bead Seat Diameter printed?
I think 587mm tire size "standard" might have problems since bead seat diameter varies from rim to rim and tire to tire. I mean, I think it would work most of the time, but no manufacturer is going to make them because of liablility, unless they also make 587mm rims. So we are stuck with 2 good tire sizes. Maybe the industry will adopt one over the other like they did with 622 over 630.
At this point, I would vote for 584 only because it is a smaller size and will fit more bikes. BUT, and this is a big BUTT, 584 tires would need to come in narrower sizes! Just like 700C now comes in every size from 18mm to 65mm+. Most 622 bikes cannot be retrofit to 584 unless a narrow tire like the Col de la Vie is used.