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Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 18 Oct 2020, 9:09pm
by johnstclarky
Hey everybody - I got given a very beaten up Jamis Nova Sport recently and have been eyeing it up as a good project frame to improve my bike building/maintenance skills. Only thing is there’s quite a large dent on the bottom tube of the frame which makes me doubt whether or not it’s worth it. I was wondering if anyone had any ideas whether or not I’d be stupid to try and ride a bike with a dent like this or whether I’d be stupid not to, seeing as it was free.... I’ve searched this a lot so I understand that technically any dent could structurally compromise an aluminium bike but just thought I’d see if anyone had any experience with this or any expert knowledge. Have checked it’s alignment and it’s all still straight so at least that’s good. Anyway, any help would be much appreciated Thanks

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 18 Oct 2020, 10:37pm
by Steve O'C
I think the standard reply on bike forms to this sort of question is to say it will be fine to ride.
PS can I have your shoes when you die.

Seriously this looks like it has been in a high impact front end shunt. As well as the creased downtube the forks will have sustained a significant impact. This could lead to sudden catastrophic failure and you will then hit the ground. How seriously you are injured depends on how fast you are going and what traffic is around you.

Start again with another frame and put that one in recycling.

Steve

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 18 Oct 2020, 11:50pm
by peetee
I agree with Steve. It’s more than just a dent and should be binned.
The way I look at that sort of damage is like this:
Find two empty drinks cans. Put a crease in the side of one. Now push down evenly on both.
Ride that frame downhill and brake hard and that tube could fold up like the creased drinks can.

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 5:10am
by The utility cyclist
Ride it and ignore the usual types who suggest death will come to you and then want to steal the shoes off your feet :twisted:
Keep checking the frame, if you hit some hard bumps it might well crack at some point, until that happens you won't die :roll:
As for comparing coke cans, again, more insane nonsense!

But, your bike, your call, if it isn't worth a lt to you then take it to the scrap metal recycling and get another alu frame for not very much via ebay/gumtree, there's loads.

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 5:18am
by pwa
If you want to be riding something you have to keep inspecting to see if cracks are developing, use it. But if you want a bike you don't need to constantly worry about, get something else. I may be considered alarmist for pointing this out, but I did know someone locally who finished up in A&E having lots of stitches on a knee wound when their ally frame fractured down the middle and the sharp ends dug into them in the crash. None of us know whether, when that frame fails, it will be polite enough to give you a visible crack some time before, or whether it will just become two pieces as you hit a pot-hole. There is a skip at the recycling centre waiting for that frame. Get another.

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 6:10am
by mattsccm
Try it. If thats had a front ender the whole front end has come back a bit and it won't feel right. Also check anything else for clues. My first reaction was that it had been dropped on something or something on it. I would use it for the planned excercise but if it handles badly extract the forks to keep and bin the rest.

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 6:21am
by Brucey
If you had some knowledge of exactly how the damage occurred you might be better off. The dent in the down tube is bad but some folk would ride that, if they absolutely had to. How often should you look for cracks..? About once every five miles sounds about right...

However as the first reply mentions, the prang which caused that damage may well have involved overloading the fork too. If the fork is damaged in the steerer area you won't be able to see it, and if it fails it can kill you. Life is short enough as it is, there is surely no need to take risks with shonky frames/forks that might fall apart beneath you, is there?

This frame is probably fit for the skip or maybe a 'turbo bike' perhaps. However you could still fall flat on your face if it breaks whilst attached to a home trainer....

cheers

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 7:33am
by yostumpy
But, in all honesty, why would you even ask?

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 8:14am
by fausto99
The fork, where the steerer tube joins the fork crown, is the crucial bit. I'd be surprised if that wasn't seriously damaged if the down tube has that much of a crease. You don't want to be riding when the fork parts company with the steerer!

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 8:35am
by merseymouth
Hi, I wouldn't even re-use the head-set! Total scrapper!! MM

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 8:47am
by rogerzilla
Down tubes are loaded in tension and in torsion, so a sudden collapse is unlikely but it will probably crack quite soon. Bin it.

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 9:28am
by peetee
rogerzilla wrote:Down tubes are loaded in tension and in torsion, so a sudden collapse is unlikely but it will probably crack quite soon. Bin it.


They are also subject to compressive bending loads during heavy braking and impacts on the move such as potholes and ridges. The same, though lesser, than they would when the front wheel is involved In a catastrophic collision such as this bike. That’s how the classic creased down tube is formed; the head tube tries to rotate around a point mid-way between the head and down tube joints.

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 9:38am
by johnstclarky
Thanks guys - you’ve confirmed what I thought would be the most sensible approach but the longer I looked at it the more I thought “mayyyyy e...?” But yeah definitely not looking for stitches in my wounded knee or a face plant on the tarmac any time soon!

Salvage the parts and scrap the rest it is!

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 1:10pm
by iandusud
johnstclarky wrote:Thanks guys - you’ve confirmed what I thought would be the most sensible approach but the longer I looked at it the more I thought “mayyyyy e...?” But yeah definitely not looking for stitches in my wounded knee or a face plant on the tarmac any time soon!

Salvage the parts and scrap the rest it is!


Good call. I'm honestly surprised that there are people here suggesting that you ride it and keep an eye on it. Apart from the fact that something could fail catastrophically (and bear in mind if it did it would probably be at high speed or when braking hard) the steering geometry will have been altered which may well result in dangerous steering.

Re: Is my Dented Jamis Nova Sport aluminium Frame salvageable?

Posted: 19 Oct 2020, 2:16pm
by scottg
fausto99 wrote:The fork, where the steerer tube joins the fork crown, is the crucial bit. I'd be surprised if that wasn't seriously damaged if the down tube has that much of a crease. You don't want to be riding when the fork parts company with the steerer!


That fork is the exciting bit, if you live near an airfield, you could find an A&P* with composite inspection
equipment. An ultrasonic inspection would be in order. In the old days you put a piece of broom handle
in the steerer tube, so if steer came adrift, you'd have chance to stop before the fork fell apart.
Ahhh, the good old days, they're to be missed. :)

Airframe & Propulsion Technician.