20" inner tubes

meic · Post by **meic** » 18 Oct 2008, 12:03am

I bought some Schwalbe AV6 inner tubes to use with 28 - 406 Stelvios.
The inner tubes are 28/47 - 406/451. Because they are for both 406 and 451, I have to fold them back on themselves inside the tyre which gives a significant bulge when blown up. This is like using 700C tubes in a 26" tyre.
Are there any proper inner tubes around?

Cunobelin · Post by **Cunobelin** » 18 Oct 2008, 8:58am

I have never had this problem, even when running the Marathon Racers on the Hurricane.

You may try another brand, but this is a fairly standard sizing range.

Apart from that I can't offer anything I am afraid.

byegad · Post by **byegad** » 18 Oct 2008, 9:41am

I have the same problem and am currently trying to source true 406-37 inner tubes with Schreader vavles. I do have some spares but in the long run the only alternative is to fit wider tyres as 406 50+ tubes are common.

thirdcrank · Post by **thirdcrank** » 18 Oct 2008, 11:59am

meic

You've lost me because if I look in the Schwalbe catalogue, all their Group 6 and all but one of their group 7 inner tubes are for 406. All the 451 size are in group 7A.

Sorry I can't post a link but the catalogue is a download from the main schwalbe site.

(I do appreciate that I am only looking at a catalogue and you are looking at real inner tubes.)

meic · Post by **meic** » 18 Oct 2008, 12:37pm

It could well be that I have old stock, as I cant see people buying any of these for a 28-406 twice. So hopefully they have modified the range.
I've got the box too and it also includes 28/37-440 which it alternativly calls 500A.

I think part of the problem may be that I want to use shraeder valves and narrow tubes will tend to have presta valves.

hubgearfreak · Post by **hubgearfreak** » 18 Oct 2008, 4:59pm

have you checked sjsc, they stock all kinds of stuff for nonconformists

these any use?

thirdcrank · Post by **thirdcrank** » 18 Oct 2008, 5:07pm

meic

Again, I am only going from the catalogue but it does say that groups 6, 6A and 7 are all made in both presta and schrader, with 6A also available in Woods and Regina.

As a ditto for SJSC, when I needed spare tubes for my Birdy (for which the tyres are a popular children's size but usually only available in the UK in schrader) SJSC had the right presta ones here by return - they were schwalbe.

(Edited to correct some awful spelling :oops:

)

byegad · Post by **byegad** » 18 Oct 2008, 6:18pm

I have ended up with 7As sold as 35mm 406.
I have seperately aquired 5 of these having ordered batches of 4 or more of size 37 406 only to find one or two of the the dreaded 7As in the batch.
Unfortunately I didn't check the whole batch at the time of purchase and cannot now remember where I got them! I stumbled on the error on the road and rode home with a folded inner tube, not too smooth a ride!

They all have schreader valves and the pack front gives the following information.

37 438 20 x 1 3/8ths
28 440 500 x 28A
37 440 500 x 28A
28 451 20 x 1 3/8ths
37 451 20 x 1 3/8ths