chrome rim pinch/dent fix ?

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hoogerbooger
Posts: 673
Joined: 14 Jun 2009, 11:27am
Location: In Wales

chrome rim pinch/dent fix ?

Post by hoogerbooger »

Any suggestions on how I remove dips in chrome rims ?

I have a BSA 20 that is all original and I want to keep it that way ( It's as a nostalgia thing.....my brother wanted a chopper when we were kids.....but seemingly our dad misheard !). Obviously the braking, by olde style naff design is not up to modern standards, but it also has a nice unnerving judder as each wheel has one location where there is an inward depression on both sides.......I think from a predecessors partial success in addressing dents. They seem to have managed to get parallel sides at the outside where the rim meets the tyre.....but higher up the rim wall it dips inward. Otherwise I've managed to straighten both wheels and the chrome is pretty good.
Rim Dent.jpg
example above. Shinny parts show parts brake blocks engage. Also you might just be able to see a horizontal line which I guess is the result of using an adjustable spanner to bend the rim.

My best guess is I will need to lay the rim on a perfectly flush block of hardwood and find/make some sort of flat ended drift that is about the same size as the dent and whack it....from inside of rim....... starting off gingerly...building to bold ...as necessary.

Advice welcome. If I could fix these... I could improve the ride quality to bearable ( Can't work out how I had so much fun on a 20 as a kid/teenager ?...must have been very bored !.......although stripping down the SA AG has been fun now I'm a tad older...and it's running very well )
old fangled
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531colin
Posts: 16083
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: chrome rim pinch/dent fix ?

Post by 531colin »

If they are both opposite the valve hole, then they are the rim join.
In any case, beating them out is going to be tricky!
rjb
Posts: 7200
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: chrome rim pinch/dent fix ?

Post by rjb »

Rim distortions similar to that come about by riding with soft tyres over the edges of pavements etc. Block of wood and gentle tapping with a soft hammer is probably the way forward, varying the hammer treatment as required. :wink:
Probably not dissimilar to my Raleigh 20 stowaway.
Image
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
hoogerbooger
Posts: 673
Joined: 14 Jun 2009, 11:27am
Location: In Wales

Re: chrome rim pinch/dent fix ?

Post by hoogerbooger »

Oh!!!! :oops: wish I had taken the tyre off again to investigate. 531Colin is correct. "pinches" are at the welds and looking at the rim construction no easy way to correct, particularly higher up the rim as it's a double wall section:
rim weld.jpg
Front wheel "pinch" was about 1.25mm narrower than either side on rim, at the outermost rim edge. I had a go at "correcting" this and it is now about 0.4mm out at the rim edge ( but no/less change to the "dip" higher on the rim) ....................and the judder is no better . I think my attempts at correcting end here. Too much risk of making things worse rather than better. So the best course of action is probably to wear a helmet and hone nerves of steel via braking practice.

For the sad persons record here's my memory lane steed ( minus the rack wot is on a shelf):
BSA 20.jpg
old fangled
iandusud
Posts: 1577
Joined: 26 Mar 2018, 1:35pm

Re: chrome rim pinch/dent fix ?

Post by iandusud »

This was very common back in the day of chromed steel rims. It might help if you toe in your brake blocks.
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