Are folding tyres reliable?

PJPenrouz

I've bought new tyres for my commuter - Schwalbe Marathon Supreme 32mm - much lighter than the original Marathon Plus and still supposedly pretty flatless. So I put them on, one with a brand new inner tube and the other with an old one, (it was quite hard to seat the beads in) and starting pumping them up - they both exploded at 85psi (although they should take up to 95) - each time the tyre went off the rim. It never happened to me before with wire beads. So I put in another set of inner tubes, took more care with placing them in the tyre and they now seem to be OK at about 80psi. Should I be worried that they might burst during riding? I'm scared to increase the pressure now. Any similar experience?
Cheers

meagain

Shouldn't happen with NEW tyres IMO/E. Did you take more care with seating properly on the rim second time? I sort of inflate 'em in stages, pausing to "bounce" evenly into place all the way round at say 20/40/60 psi.

Just a thought.

pete.whelan

Yours rims need to have hooked edges for them to grip onto when inflated.

[___] and not \__/ or |__|

meagain

If they were sprint rims then surely wouldn't hold at all?

maddog 2

good drawing pete 8)

PJPenrouz

The rims are heavy duty Sun ME14a, I haven't checked but I'm sure they have that ridge so nicely drawn by Pete.

Gary D

PJP,
Interesting!

I had a very similar problem recently with non-folding Schwalbe Marathon's (standard sort).
See thread: http://www.bikeradar.com/forums/viewtop ... t=12559868

I think if you do a search for "Schwalbe" you might also throw up some more relevant threads.

I put my problem down to tyre/rim incompatability. Since I've put the Gatorskins back on there hasn't been a problem so I guess that rules the wheel out.

Unfortunately I'd had mine for too long, and they had also been on another bike, so I couldn't send them back - but I would have done if I could!

In answer to your question, yes they could suddenly go bang while you are riding. That is exaclty what happened to me twice :twisted: :twisted: Second time was just after I had bombed down a nice hill and just touched 40mph
Rest assured, those tyres will never be going anywhere near that bike again.
I would change them straight away if I were you!!

Hope this helps.

Gary.

combat_wombat

it may just be thar your rims are not designed to take tyres as wide as 32mm

pete.whelan

Looking at the data for the Sun ME14A rim, it would suggest it is OK for cross (cyclo-cross), so 32mm would be OK, but not to the pressure you were going for. It isn't much different in profile to a Mavic Open Pro rim

alfablue

I wouldn't expect the pressure to be too much for the rim, it is rated for road racing, triathlon. They are the same width as my Open Pro's (19.8mm), which are rated to 140psi, (although the wider the tyre, the lower the pressure they will be rated for) however the Open Pro's are recommended for tyres up to 28 (not saying 32 wouldn't work).

On my tourer (26" wheels) I have rims of 22mm width and these take my Schwalbe Marathon 1.5's (equivalent to 37's) fine (indeed will take tyres up to 2.1, pressures up to 113psi for 1.0). Maybe the rims are just too narrow in your case for the particular combo of tyre width and pressure, maybe try 28's?

PJPenrouz

Thanks for all the thoughts.
I actually ran the rims with Marathon Plus 35mm over the winter and never had a problem. But they had wire bead.
Now I'm having a dilemma what to do with these - try them on lower pressure, use them on different rims or just get rid of them - they are brand new and were quite expensive.

alfablue

PJPenrouz wrote:

Thanks for all the thoughts.
I actually ran the rims with Marathon Plus 35mm over the winter and never had a problem. But they had wire bead.
Now I'm having a dilemma what to do with these - try them on lower pressure, use them on different rims or just get rid of them - they are brand new and were quite expensive.

Well, kevlar beads do make the tyre much more flexible (obviously) and it seems that doesn't work in your situation. It may be that the rim diameter is slightly small, maybe just by 1 or 2mm, as well or instead of it being a rim width issue. There does seem to be variability in the actual diameters of similar sized rims, usually the issue we read about on here is tyre / rim combos that are too tight and a bugger to fit, so your issue is a bit unusual.

Running on lower pressure may not give a satisfactory ride or performance, and getting different rims to suit the tyre is a bit extreme unless you want some anyway.

I think your best bet is to eBay them, they go for good prices (I was after some but the prices were always a bit rich for me). If they were 26" ones I'd probably make you an offer!

There is a weight advantage from kevlar beads, but I wouldn't choose that over reliability, but of course the biggest advantage is the ability to carry a spare tyre easily if on tour, however its not much use if it wont stay on the rim.

John C.

A mate of mine had the same problem with Schable Blizzard tyres. He ditched them in the end.

mr-ed

Try taking them back to where you got them, they'll probably exchange them for different tires and even more so if they say they should fit the rims your using. Then you don't loose any money selling them and getting new ones.

PJPenrouz

OK, I've had a chat with a well trusted guy from my LBS and he said the tyres weren't seated in properly. He knew the model and indicated I was unlucky it happened twice. Then he checked the tyres, pumped them up to 95 psi and was quite certain it would be fine. So I'm riding them now - I'll let you know if I end up regretting it!