Is it acceptable and safe to repair a small-ish hole in a frame? The reason I ask is that having rubbed down the frame on my Domi 99 project, I’ve discovered that the bottom rail has a hole in it about 8mm long by 3mm wide. It appears to be the result of corrosion as the metal around the hole is very thin. I am hoping that I can get the hole opened up a bit to remove any thin metal and then get a plate welded over the hole. Does that sound a sensible thing to do or is my frame just scrap metal now?
If anyone has any advice how I can repair the frame I’d very much appreciate that information.
That sounds serious. Unless there was a very valid reason that rail was corroded due to special circumstances I would suggest the other is in similar condition.
A good paint/ engineering shop will be able to measure the tube wall thickness. Get the whole thing checked before you go further. Then if necessary, get the tube replaced by a competent engineer..
Don't skimp on it Tony, a repair is cheaper than another unknown quantity frame and a bad repair out in the market place is an accident in the making.
I'm sure someone will give you details of the right "goto" company.
It does sound serious. However, see here:-
That is a comprehensive service, I think your answer is there Tony >
Thanks for that link - I’ve emailed Andover Norton to ask if the lower tubes will fit a slimline frame. I don’t have sufficient knowledge to know if the lower tubes are the same on wideline and slimline frames (but I hope they are as I found two holes in the other lower rail this afternoon).
If they do fit, the next problem will be finding a suitably skilled engineering person who can weld the new tubes in place and get the lug and bracket positions correct, but that’s ‘step 2’, I need to get the right answer from Andover before I worry about finding an engineer.
Thanks again for your help.
Yep that certainly looks promising - I just hope the wideline tubes are the same as slimline ones as my frame is a slimline.
I think if you had blasted the frame, rather than rubbed it down, more holes, or larger ones, would have appeared. I seem to recall it is not unknown for Featherbed lower frame rails to rot out from the inside. Somehow moisture gets in there, and of course that is where it will end up, at the bottom..
Hopefully AN will provide the answers. I suspect they may suggest bronze welding, rather than MIG or TIG. It may require the services of a specialist frame builder, to whom no doubt it would not be a problem.
Do keep us posted. Good luck with it.
I would highly recommend approaching Norman White at Thruxton. He can do anything with frames - he replaced distorted sections of my Mk3 Commando frame front down tubes, the entire rear loop and shock absorber mounting plates. Impossible to spot the repairs!
Thanks for that recommendation- sounds like Norman White is worth a call.
I had exactly the same problem with my Slimline frame about 15 years ago. At the time I had a brazing attachment for my arc welding set and was able to add metal patches over the large holes and small blobs over the pin holes. This worked fine to start with but the internal rot was well established and most of my repairs fell off within a year. I then headed off to see Dave Degens who had jigs to hold my frame firmly inline while the worst sections of tubing were cut out and replaced with new chunks. The repairs needed were extensive and expensive but done by an expert. I would suggest speaking with him first or Norman White as a good second choice. Attachment shows the weak areas of the Featherbed frame which apparently had a design fatigue life of only 150,000 miles.
Dave Degens would be the man, for sure. I didn't realise he is still in business. Still in Horsham, is he?
Thanks for the info re Dave Degens - I didn’t realise he was still building bikes.
That drawing you attached showing the frame’s weak points is interesting as my frame has holes in most of the locations indicated, but luckily no crack near the headstock. That point of water ingress by the rear footrest bracket is strange because on my frame it looks like those brackets are simply but-welded to the frame tube so how does water get into the tube? Having said that though, on one of the frame tubes there is a crack just at the point where the top of the footrest bracket is welded to the tube - I guess that would allow moisture into that tube. However, the other side of the frame also has holes on the lower rail but there is no crack at the footrest bracket or anywhere else in that tube so I don’t know how the moistures got in on that side. Worrying that the service limit of the frame is 150,000 miles as my frame looks like it’s already got a high mileage on it.
Water is weird stuff. On a certain bridge the crash barrier posts were toe to toe welded steel 6" ×3" channels instead of square hollow sections. One winter, some of the posts split. They were full of water and froze overnight. Water vapour must have got in, and condensed, simply through the weld defects (which are always there...). Over a long time some had filled up. On a cold day, those with water could be seen by the dew on the outside. Some were completely full of water even though they were fully sealed by welds.
Which bridge Dave?!
As PH has mentioned, is it totally critical to get the whole frame cleaned back and the whole of it inspected. Since my time in AN I have heard of a few Commando frames that have 'suffered light frontal' thankfully two were found once stripped back, one was straightened and coated and being used to build a bike, thankfully noticed that when the cradle was fitted the wheel alignment was wrong further investigation found the frame had cracked away from the repair area. All three were scrap.
Just because the front is not that badly damaged does not mean the rear of the frame is not, check the loops behind the gearbox, they may look OK, but may well be cracked.
Another good tip, if and when you have the parts off your bike for minor repairs / maintenance check the frame and welds that are normally hidden.
..a big one from England to Wales...
about 2 years ago I took a twisted frame over to him, he was still working from behind his house with an assistant.
He's attended a couple of NOC "do's" this year so I guess he is still active.The place is quite tucked away...still has a website but very little info here...http://www.dresda.co.uk/