650B - would it be daft?

[NickM]

I have a hankering to replace the wheels on my 700C commuter with the 650B size to allow the fitting of some nice fat tyres, the better to cope with potholed roads.

Conversions of this type are gaining ground in the USA. They are easily done, now that the Tektro R556 brake is available, are reversible, and cheaper than changing to MTB 26" (which for me would require a whole new bike - beside which, I cannot tolerate straight bars).

On the other hand... the 650B size no longer seems to be well supported even in its French homeland. I have yet to find a UK supplier of tyres in the light, supple (as distinct from heavy, soggy) category, nor any of good 650B rims such as the Sun CR18.

Would I just be laying myself open to a lot of frustration and aggro?

 

[Crackle]

Upping a mtn bike or downing a road bike. What are you going to use it for?

 

[mickle]

Don't bother, anything 650B is extremely hard to find. The resulting BB drop would scupper you on corners too.

 

[beancounter]

I have a hankering to replace the wheels on my 700C commuter with the 650B size to allow the fitting of some nice fat tyres, the better to cope with potholed roads.

I share your sentiments about the state of our roads, but I've got 32's on my 700 commuter wheels - how much bigger did you want to go?

bc

 

[NickM]

The bike in question only has clearance for 23C tyres in the 700C size, so fatter 700Cs are not an option. However, substituting 38-584 650B tyres would only drop the bottom bracket by 4mm, which I reckon I can cope with.

But if 650B stuff isn't getting easier to come by, it will probably just lead from initial joy to eventual despair and rending of garb...

 

[Crackle]

The bike in question only has clearance for 23C tyres in the 700C size, so fatter 700Cs are not an option. However, substituting 38-584 650B tyres would only drop the bottom bracket by 4mm, which I reckon I can cope with.

But if 650B stuff isn't getting easier to come by, it probably just lead from initial joy to eventual despair and rending of garb...

Would the brakes still fit?

Incidentally I have only ever seen one article on 650b which I was trying to find for you but without success. It must have been somewhere really obscure.

 

[jimboalee]

Definitey + 1 on Mickle.

One of my club mates has a 650B TT bike. Increasingly hard to find stuff.
Also +1 on the lower B/B. Pedals will clash the tarmac.

I have seen some very tastefull MTB conversions with 'drops'.

 

[NickM]

One of my club mates has a 650B TT bike.

I doubt it; the TT front wheel size is/was 650C

Also +1 on the lower B/B. Pedals will clash the tarmac.

I doubt it, when the bottom bracket is lowered by only 4mm.

I have seen some very tastefull MTB conversions with 'drops'.

I have done one, and agree they can be very nice... but I don't have a suitable MTB to start from, and I do have this rather boneshaking road bike.

 

[NickM]

Would the brakes still fit?

Yes, because they are a 55-73mm drop model, replacing 47-57mm calipers.

 

[mickle]

http://www.freewebs.com/650b/

 

[NickM]

Handy link, Mickle - thanks

I think I'll put the project on hold for a year, and hope to see whether 650B stages a big comeback or just fizzles out.

 

[NickM]

The results of this morning's research:
http://www.classicrendezvous.com/France/France.html
http://www.ece.ubc.ca/~gillies/singer/
http://www.cyclofiend.com/cc/index.html (and ctrl/F for "650")

But folding 559 Schwalbe Kojaks only weigh 295g, and you can (sometimes) get them...

 

[andrew_s]

I think it would work quite well, except that you would have to allow for keeping in stocks of wheel-related parts (rims, tyres, possibly tubes) as you wouldn't be able to just go out and buy a replacement tyre, and even ordering from an overnight web supplier like Chainreaction may well not be possible, as you may well have to go foreign.

Allowing for duty/VAT on foreign orders, and a couple of spare rims & tyres as well as those you intended to use would make your setup costs higher than you may currently be thinking of.

 

[NickM]

Allowing for duty/VAT on foreign orders, and a couple of spare rims & tyres as well as those you intended to use would make your setup costs higher than you may currently be thinking of.

Yup. Over $400 before the C&E people get their claws into me