650b 25c Tyres - Where to Purchase.

[ianbarton]

Last year we bought my daughter a Decathlon road bike in one of their sales. It's a nice bike, but as it has a small frame the wheels are 650b. It has 23mm tyres, but she would much prefer 25mm ones. My Google fu is failing badly and I can't seem to find any 650b x 25c tyres. She doesn't cycle much, so I don't really want to spend a fortune on the tyres as she will probably outgrow the frame in about another year. Can anyone recommend some suitable tyres?

 

[Spiderweb]

http://www.acycles.co.uk/schwalbe-m..._produit_cpc&gclid=CMi0oeSLucwCFTUW0wodsJoPaQ
These are the only ones I can find, a super tyre but not cheap at £25 each.

 

[DCLane]

@ianburton - are you sure they're 650b and not 650c. 650c is the road tyre and my youngest used Rubino Pro 650c's on his bike.

 

[MichaelW2]

http://www.acycles.co.uk/schwalbe-m..._produit_cpc&gclid=CMi0oeSLucwCFTUW0wodsJoPaQ
These are the only ones I can find, a super tyre but not cheap at £25 each.

Those are neither 650B or 650C but English 26"/650A ETRTO 25-590

Look on the tyre for the ETRTO number which should be either
650C: 571
650B: 584

 

[andrew_s]

There are three 650 sizes - 650A, 650B and 650C, which have bead seat diameters of 590, 584 and 571 mm respectively, and which are not interchangeable. Your existing tyres should have the size marked on them somewhere, such as 23-571.

650A is mostly wheelchairs now, but there are tyres from 28 up to 42 at St John St.
650B was traditionally French touring bikes, with tyres around 37-40mm, but there's a recent revival as the 27.5 mountain bike size, with tyres available down to 28mm (at least).
650C(571) are mostly small racing bikes, and used to be common on TT/Triathlon bike front wheels. Anything other than 23mm is hard to find, but there's a 25 mm version here

 

[ianbarton]

650C(571) are mostly small racing bikes, and used to be common on TT/Triathlon bike front wheels. Anything other than 23mm is hard to find, but there's a 25 mm version here

Spot on! The tyre is marked as 23/571 650/23c. Thanks very much!