Frame dent

Orinoco

Orinoco

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Anyone know about frames? After I'd had my cycle frame stripped and powder coated I noticed a dent/crease at the top of the down tube, looking back on photos it was there before, I'd just not noticed it, I was more concerned with removing the rust. It's a bit late to try and sort out now, , I'm hoping it will be fine to ride with, any thoughts?

IMG_7185.jpeg

IMG_7184.jpeg
 
If it was like that before, why worry now?
 
Hi Adrian. Looks like a road bike frame, vintage with downtube shifters. That’s a very minor dent and steel frames like that are very strong. I would not worry about it at all, unless you are planning to convert it to a CX (gravel) bike…and even then I wouldn’t be too concerned.

Whilst it’s apart, I’d probably wire brush inside that steerer tube, and spray some ACF into the frame for good measure. I see it has a grease nipple, from a time when things were built properly. Pls send a pic of the completed bike, some of us like vintage bikes.
 
I assume it’s a steel frame. I had a similar issue many years ago when I was in my teens. My local bike shop mechanic told me to ignore it and if I was going to repaint it, fill it and then paint it. I think he said fill it with lead like car bodies used to be filled, but I just repainted the frame leaving the 2 dings in the top tube. Structurally it will make virtually no difference.
The only time I would be concerned is if the damage was severe enough to alter the geometry of the bike.
I seem to remember Mercian Cycles offered a tube replacement service for their steel frames. It used to be something like £70 per tube plus any paintwork afterwards.
Your frame looks like it’s been brazed with lugs supporting the tubes.
Ps it would be interesting to know what caused it?
 
AdrianS said:
I assume it’s a steel frame. I had a similar issue many years ago when I was in my teens. My local bike shop mechanic told me to ignore it and if I was going to repaint it, fill it and then paint it. I think he said fill it with lead like car bodies used to be filled, but I just repainted the frame leaving the 2 dings in the top tube. Structurally it will make virtually no difference.
The only time I would be concerned is if the damage was severe enough to alter the geometry of the bike.
I seem to remember Mercian Cycles offered a tube replacement service for their steel frames. It used to be something like £70 per tube plus any paintwork afterwards.
Your frame looks like it’s been brazed with lugs supporting the tubes.
Ps it would be interesting to know what caused it?
Click to expand...
The cause could be
possibly the front end had been subject to the front forks been forced backwards.
I caused similar damage to steel Marin mountain bike frame after a jump went wrong.
Unless suplight steel Columbus SLX or Reynolds 853 I am it will be fine even if the head angle has been slightly adjusted?
 
parkys100 said:
The cause could be
possibly the front end had been subject to the front forks been forced backwards.
I caused similar damage to steel Marin mountain bike frame after a jump went wrong.
Unless suplight steel Columbus SLX or Reynolds 853 I am it will be fine even if the head angle has been slightly adjusted?
Click to expand...
Interesting if a forward knock would do that damage. I would have thought the forks would have gone first. Is there any evidence of crash damage elsewhere on the frame?
With regard to the effect on steering and riding, if the wheels are still aligned which it looks like they are with the position of the damage, the steering angle could have very slightly increased which would make the bike slightly more “twitchy “ and quick to react, a bit like a race bike compared to an endurance bike.
I’ve seen many an aluminium frame with dents and dings in them, without causing any problems if minor. If major in ally, that’s a different matter. But steel is far more forgiving and as long as you’ve not bent it past it’s elastic limit, will be fine to leave.
 
AdrianS said:
Interesting if a forward knock would do that damage. I would have thought the forks would have gone first. Is there any evidence of crash damage elsewhere on the frame?
With regard to the effect on steering and riding, if the wheels are still aligned which it looks like they are with the position of the damage, the steering angle could have very slightly increased which would make the bike slightly more “twitchy “ and quick to react, a bit like a race bike compared to an endurance bike.
I’ve seen many an aluminium frame with dents and dings in them, without causing any problems if minor. If major in ally, that’s a different matter. But steel is far more forgiving and as long as you’ve not bent it past it’s elastic limit, will be fine to leave.
Click to expand...
If was aluminium frame I would not ride it.
Dental bill would possibly be to expensive?
 
parkys100 said:
If was aluminium frame I would not ride it.
Dental bill would possibly be to expensive?
Click to expand...
I’ve seen worse in an ally frame that never caused problems.
The trouble with ally frames is that they cannot easily be repaired, whereas steel can be repaired.
 
Thanks All, I bought the bike unseen, daft really, but it was an opportunity, as I fancied an old school touring bike, turned out a bit grubby, frame rusty in parts, so decided I'd rebuild it with a view to some camping :) It's a Thorn Club Tour, built by Robin Thorn in Bridgwater, one of his very early bikes from 1995, and yes, steel, 531 throughout, https://thorncycles.co.uk/bikes.

Here's a photo os the bike just after buying, will post another once I get it all back together...

IMG_6993.jpeg
 
Orinoco said:
Thanks All, I bought the bike unseen, daft really, but it was an opportunity, as I fancied an old school touring bike, turned out a bit grubby, frame rusty in parts, so decided I'd rebuild it with a view to some camping :) It's a Thorn Club Tour, built by Robin Thorn in Bridgwater, one of his very early bikes from 1995, and yes, steel, 531 throughout, https://thorncycles.co.uk/bikes.

Here's a photo os the bike just after buying, will post another once I get it all back together...

View attachment 468344
Click to expand...
Ideal.
Once repainted/powder coated .If possible inject frame saver wax or ACF 50 into the inside of the tubes.
Steel frame can suffer if water gets trapped .
I know a chap who had a very nice Columbus tubes frame rust through on the right had chain stay .
I had several steel frames years ago and always dosed with wax internally .
I have titanium now, so no need .
 
Nice, thats newer than I had anticipated. A 531 frame can be all day comfortable, something lovely about the way a quality steel frame rides.

All this chat makes me realise that my current frame is not protected internally, I will sort it!IMG_0383.jpeg
 
We use T9 chain lube to protect steel frames and forks on this side of the pond. It's wax.
I had a Schwinn homegrown that had a BIG dent in the down tube. It never seamed to be a problem, despite being AL.
It may be the slight dent or crease in your frame was caused during the fitting and brazing of the frame tubes and lugs. And it might have been gently put there by the frame maker to help clear the fork crown. I agree it probably won't be a problem and often frame makers would intentionally put a big dent in the right chainstay to clear the chainring .....
Nice looking ride .... I run 29ers mostly converted dirt bikes from just before the boost period started.... TI is my fav, brooks saddles and Thompson cockpits ....
 
Last edited:
Well here it is, fresh from the powder coating and rebuild, yet to commission some new decals/stickers, though quite liking the 'Q' bike status! Weighing in at 12.8kg with all in, I coated the inside of the frame with rust converted, followed by XCP Professional as I had some handy, should do the job for another 30 years... it'll see me out. I just need to ride it now... and get the clearance of the rear mudguard a bit better...

IMG_7222.jpeg
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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