Dented Aluminium Frame - Serious?

Mr Will

To cut a long story short, I was knocked off my bike at the start of last month by a van driver who turned across a bus lane without looking or indicating. I am fine but the bike has taken a bit of a knock, both shifters are scuffed and battered but there is also a small dent in the top tube.

Originally I was just going to ignore it as I doubt it can be fixed without replacing the frame, but I'm now starting to worry it might have long term effects. Is a dent in an Aluminium frame a problem, or will it likely be okay?

Pictures:


IMAG1147 by Mr_Will, on Flickr


IMAG1148 by Mr_Will, on Flickr

pastey_boy

you may get away with that but best to check with a cannondale dealer.

unixnerd

I think a dealer would tell you to replace the frame just to cover themselves, I'd be amazed if they didn't. If you can get a new frame from the driver or his insurance I would.

Failing that if it were my frame I think I'd take a chance on it.

thel33ter

My Trek 1000 has a dent about that big on the top of the top tube, it's been fine, even after hitting a car (again I assume)

I would be fine riding it, but keep an eye on it none the less.

desweller

Tricky. Some frames might get away with it, some won't. The top tube is in compression, so it is definitely a candidate for failure. I would definitely be claiming for a replacement.

Lagavulin

Definitely take it into the 'dale dealer dealer for their opinion.

Several months after purchasing my Allez I noticed a dent in the top tube when giving it a good clean. I'd never pranged it and to my knowledge it'd never fallen over. Dent was forward of the handlebar rotation so it wasn't the bars.





Took it into the local Edinburgh Bike Shop. First lad who looked at it said i was a goner and I needed a new frame. Then an older gent came over and asked what the issue was. He had a look at it and then had another member of staff to check it out. They then tried it in a jig for alignment. Came back all clear. Told me they thought it was fine to ride but if it worsened or I had any qualms to bring it back in.

Frame is still going some 6,000+ miles later.

Berk Bonebonce

"Take it to an lbs"????

I mean, what are you expecting them to see that you can't. Do the assistants in your average bike shop have x-ray vision or something?

It's a little dink in the top tube and will require nothing more than regular checking and keeping an eye on. Any sign of a crack propogating and it needs scrapping.

The top tube will have the thinnest walls of all the tubes in your frame because it is stressed the least.

MattC59

I've got what looks like a nasty ding in the aluminium top tube on my mtb. After lots of consideration (and a bill forabout £1400 to replace it) I decided to chance it and left it as is. That was two years ago and it's been fine.

It is an mtb though and has quite a complex tubing profile so it may be that, at this point, it has sufficient strength to handle it.

The LBS had differing views:
The younger guys barely looked at it and said it needed replacement. The more experienced guys played around, checked alignment and decided it would probably be ok.

As you were knocked off, I assume that you got his insurance details and reported it ? I'd claim if I was you.

Monty Dog

If you can't claim on the insurance, I'd just keep riding it - it's unlikely to just suddenly fail whilst riding along. Any failure would be clearly evident by a crack - but there's no real crease in the metal to create a stress-raiser to cause one to start.

kettrinboy

One of my bikes has an ally frame and if it had a dent like that i,d just carry on riding it, at least its on the underside where you cant really see it too much.

andy_wrx

Someone's just bought a Giant TCR frame on eBay for £137 with a big dent on the toptube...
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0553659206

MichaelW

Someone gave my brother an old Cannondale frame with a dented top tube. He rode it for years then gave it to me. I rode it a bit then passed it on. I think its still being ridden.

pastey_boy

Berk Bonebonce wrote:

"Take it to an lbs"????

I mean, what are you expecting them to see that you can't. Do the assistants in your average bike shop have x-ray vision or something?

It's a little dink in the top tube and will require nothing more than regular checking and keeping an eye on. Any sign of a crack propogating and it needs scrapping.

The top tube will have the thinnest walls of all the tubes in your frame because it is stressed the least.

they dont have x-ray vision but they do have experience. a well established shop will have seen many dings like this and also the outcome of riding such frames. if they have seen one fail catastrophically then they are in a position to advise on the best course of action.

cougie

I have a similar dent like that on my Alu bike - where the handlebars have swung into it. Its not quite as big as yours though. I've got no worries with riding it - but I think it makes sense to look after your bike - so check it when you clean it.

Did anyone see the photo of the cracked stem in the comic last week ? That would be nasty.

Buckled_Rims

I've just looked at my CAAD9 (assuming it's your CAAD9 as well).

It's fairly thin in that section but looks strong. The dent is longitudinal and none creased, so that's far better then a lateral dent with a crease. It's not on a high stress area, like a downtube. My guess is it'll be OK.

Take it on a very bumpy road and give it a hard pedal, if the dent changes then there's your answer. However, it's now an ideal frame for a winter bike :shock:

PS. try using 25mm tyres to help cushion the bumps a bit more if you keep the frame.

Mr Will

Thanks for the advice everyone, glad to hear that it'll probably be okay if I can't get it replaced on the van drivers insurance. The bike is now at an LBS again, I'll post again with their verdict when I hear back later today.

MattC59

Mr Will wrote:

Thanks for the advice everyone, glad to hear that it'll probably be okay if I can't get it replaced on the van drivers insurance. The bike is now at an LBS again, I'll post again with their verdict when I hear back later today.

Don't give in !! If you were knocked off and the van driver was in the wrong, there shoul dbe no question as to whether his insurance pays up !!

Berk Bonebonce

pastey_boy wrote:

Berk Bonebonce wrote:

"Take it to an lbs"????

I mean, what are you expecting them to see that you can't. Do the assistants in your average bike shop have x-ray vision or something?

It's a little dink in the top tube and will require nothing more than regular checking and keeping an eye on. Any sign of a crack propogating and it needs scrapping.

The top tube will have the thinnest walls of all the tubes in your frame because it is stressed the least.

they dont have x-ray vision but they do have experience. a well established shop will have seen many dings like this and also the outcome of riding such frames. if they have seen one fail catastrophically then they are in a position to advise on the best course of action.

Carbon fibre can fail suddenly, and with it comes the risk of injury. With aluminium the failure is a less likely to be a sudden one.

cougie

You should be able to get it replaced on his insurance. Take no crap if it was his fault.

If you dinged another car whilst driving you can be damn sure that the other motorist would end up with the dent pulled out or fixed.

Dont do it yourself - get the pros involves. Alyson France at Bikeline is great. You should always take photos of all the damage to you and yourself.

His insurance company will try to give you the run around.

sheffsimon

I ride an MTB in cross races with an ally frame I got for a fiver off ebay, with a big hole in the down tube where a bottle cage boss was ripped out by the previous owner, never give it a second thought TBH.

Your frame will be fine.

Down the Road

Mr Will wrote:

Thanks for the advice everyone, glad to hear that it'll probably be okay if I can't get it replaced on the van drivers insurance. The bike is now at an LBS again, I'll post again with their verdict when I hear back later today.

PM me for a legal team to solve this