IbisTouche

We have just gone out of PBP Audax (peloton riding) because we had two faillures of two Continental Gatorskin 28 mm. The tandem is a Comotion Speedster from the easter with rims at 18-622 mm. We think we could have used a too thin rim - the standard which we seller as well as te constructor advised us to use. I am at 82 kg, my stoker is at 46 kg - saddlebag with 4 kg and the tandem. The tandem had been used for 800 km when the rear tire blast. We had gone though small towns in the first night where there where some heavy rain making the visibility difficult. The tarmac in these towns were very bad and with lots of holes. After inspection of rear tire I discovered that the front tire bulged our to the right side of the tire - same side as the blast had been on the rear tire.
Is there a production fault?
Are the ris too narrow for the tire?
The road conditions: should we have used wheels with wider rims for night riding on roads with poor tarmac.

PS: we used 115 psi

TandemGeek

That both tires had deformities seems unusual and in my mind would suggest a tire issue and not a rim incompatibility. That so many tandems run 18-622 rims with 28mm tires -- many of them being Conti Gatorskins -- also seems to suggest a tire-related problem.

As to whether or not it was a manufacturing defect or something that happened to your tires after they were produced, if others have reported Conti sidewall failures then manufacturing defect becomes more likely.

Absent that, perhaps the tires were mishandled before mounting (i.e., wire bead folded by accident) or is it possible that you ran through or over a road hazard with both front & rear tires that damaged the tire sidewalls? In regard to the latter, there would likely be some dings in the rim adjacent to the point where your tires failed.

Just some thoughts...

However, I would agree that if you expect a goodly amount of your riding to include rugged roads in all weather conditions and at night, a set of wheels that would support 28mm as well as 35mm tires would be a better choice, e.g., Velocity Dyad or similar.

Monoborracho

The Continental website states a max of 360 pounds (163 kg) with 95 psi recommended and 116 max.

With a 35# tandem you had 148 kg load, which 90% of max. It would seem to me that a hard bump on the road would put you above the manufacturer's recommendation for loading.

LWaB

I rode that event (on solo) and believe that the tyre sidewalls were damaged by road hazards, not manufacturing faults. Many USA-ian tandem teams seem to like Gatorskins (as does my partner) but I don't rate them at all, having effortlessly sliced through the sidewalls. Several Aussie tandem teams prefer Bontrager Hardcase tyres of various models. You'll always have to compromise between speed and durability.

Homeyba

Nobody had spare tires you could borrow? You were riding an Audax weren't you?? Were you riding on the traditional PBP route? It's been a couple years but I remember the roads as being pretty good for the most part. I'd suggest that you give your rims a look-see for dents like TG mentioned. If you damaged both wheels hitting the same hole it's very likely that you also dented the rim. On long distance rides bad things sometimes just happen. Bummer.