Ksyrium ES + Conti GP 4000's

craigenty

Is there an issue with this wheel / tyre combo?

We just had an a couple of incidents where a tyre blew off the front wheel twice in 3 days. Admitedly this occured on long Alpine descents so bad braking practice could be a factor.

The second occasion it happend proved to be quite costly (and a little sore)

Thanks in advance


Craig

nick hanson

I would think that the braking was almost certainly at fault.If the tyres were being run at the top end of their recommended pressure,then it wouldn't have helped,as anyone will get some temperature build up on the rims on descents,the heat will transfer to the tyre/inner tube & if the pressure is already on the high side,that pressure is only going to increase due to the heat build up.I haven't used the Conti 4000's,but are they an easy fit on the rims?.the only Conti's i rode ( & did descend the ventoux on them) were on the very light side,so maybe flex on/over the rim with the excessive pressure build up?.
Best make sure the clients don't go too high on tyre pressures,they really don't roll any better,just a more uncomfortable ride.

bigal.

I was the unlucky rider involved in this incident and the one factor not mentioned is that the inner tubes were Continental Race Supersonic's which weigh in at 50g's. Not sure if they factor in at all but they were one item that was a new addition to any Alpine descending that I have done before.

I am a bit curious about "bad braking practices" as my braking hasnt changed over the years and I have never experienced blow out's like this before. Last year I did similar descents in the Alps and never had any bad braking practices then so not too sure how this has developed out of the blue.

The tyres were sitting at 100psi approx and again this is what I have always ran at and also what other riders were using so I am more inclined to think the fault is either with the tube's or the sizing combo of the rim & tyre. Any other experiences or thoughts.????

APIII

I've been using the same combo most of this year without any problems. Apart from a descent of Ventoux, they haven't been subject to any prolonged braking though.

craigenty

bigal. wrote:

I was the unlucky rider involved in this incident and the one factor not mentioned is that the inner tubes were Continental Race Supersonic's which weigh in at 50g's. Not sure if they factor in at all but they were one item that was a new addition to any Alpine descending that I have done before.

I am a bit curious about "bad braking practices" as my braking hasnt changed over the years and I have never experienced blow out's like this before. Last year I did similar descents in the Alps and never had any bad braking practices then so not too sure how this has developed out of the blue.

The tyres were sitting at 100psi approx and again this is what I have always ran at and also what other riders were using so I am more inclined to think the fault is either with the tube's or the sizing combo of the rim & tyre. Any other experiences or thoughts.????

Hello there,

How did the Missus take the Road Rash??

I don't think it was bad braking personally. I think the tolerances on the front wheel or tyre must be a bit slack. Try some Michelin Pro race 2's. never had any problems with them on Mavics for years.

Craig

Brian B

Craig,

Hope you had a good time. Me and George are running with Es wheels and Conti black chilli tyres. I have not had any probs this summer with this set up but as you said long alpine descents and the heat generated might be a factor.

I had a similar problem a few years back when i was using light weight tubes but switched to Specialised tube which are not the lightest but do seem to be very robust.

bigal.

Hi Craig,

Missus was alright although at first I reckon she thought it was down to cornering to fast but she has been quite sympathetic seeing as I have been moping about with sores groaning about the crap weather back here.

The bike is back together with everything straightened and just got the forks to get checked. Definitly going to try a different tyre and tube combo although not likely to have any 20km 40mph descents to have to worry about back in sunny Scotland.

I will be in touch via e-mail regarding bottles etc.

Anyone want to buy some reasonable new conti 4000's and lightweight tubes.