stem indentations on carbon steerer
MidlandsGrimpeur2
Posts: 2,127
in Workshop
Had a slight crash at the weekend, took the fork out to check it and noticed that the stem has scored some indentations into the steerer tube.
Stem is a Deda Zero 2 which has cutouts at the rear of the stem on either side. The sharp edges where material has been cut away has obviously now scored the carbon (clear pattern on the steerer which is identical to the cutout outline). Max torque is 5nm and I have never tightened it beyond 4.5 with a torque wrench. Seems to me an inherent design flaw with this stem, plus both pinch bolts are on one side only, which does not help to spread the load when tightening.
It is not a major issue as I actually ordered a new bike to replace the caad but I wanted to keep hold of it for travelling abroad, sportives etc.
After my long preamble, is the fork safe to ride? There are no cracks but I don't know what kind of damage these score marks are going to do long term.
There is no chance Cannondale will warranty it and I am unlikely to get anything out of deda as they will just claim it was overtightened I am sure. So basically my only other option is to stick the bike on the turbo if it is no longer safe to ride.
Stem is a Deda Zero 2 which has cutouts at the rear of the stem on either side. The sharp edges where material has been cut away has obviously now scored the carbon (clear pattern on the steerer which is identical to the cutout outline). Max torque is 5nm and I have never tightened it beyond 4.5 with a torque wrench. Seems to me an inherent design flaw with this stem, plus both pinch bolts are on one side only, which does not help to spread the load when tightening.
It is not a major issue as I actually ordered a new bike to replace the caad but I wanted to keep hold of it for travelling abroad, sportives etc.
After my long preamble, is the fork safe to ride? There are no cracks but I don't know what kind of damage these score marks are going to do long term.
There is no chance Cannondale will warranty it and I am unlikely to get anything out of deda as they will just claim it was overtightened I am sure. So basically my only other option is to stick the bike on the turbo if it is no longer safe to ride.
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Comments
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Carbon fibre is actually quite soft... think about it as some really hard wood... which in essence is very similar, fibres (cellulose) + resin (lignin). You can indent CF fairly easily, but that won't result in a dangerous steerer. It's only when you develop fractures that strength is compromisedleft the forum March 20231
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Pictures would help, but as Ugo said I wouldn't be overly worried about indentations as long as they're shallow and there's no evidence that the steerer has started to crack near the indentations.1
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Not something I would worry too much about .Worth keeping an eye on after a few rides to check it .1
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Cheers all.
Had another closer look at the steerer. Definitely no cracks and it is a bit of mild scoring so it looks okay. As I said, it will not be in regular use from now on so I think it will be okay for the occasional ride and to use as the turbo bike.0
