Repairing and reinforcing a chain guard
- Thread starter olly
- Start date
sfc vintage
Hero member
Hi.
I have one for sale: SF1.
I have one for sale: SF1.
I fear unless I strengthen the original design that anything will be temporary but if the chrome is in mint condition then please let me know how much you'd like. I'm in Aylesbury, UK.
It's £100 more than I really want to spend given it's recently already been rechromed. I'm wondering if stainless steel welding and some spot welding of a support might work out without the need to rechrome.
The Sock
Hero member
- Location
- London, England
It’s not stainless steel so stainless welding would be problematic.
You could plate and rivet/glue it.
Any kind of welding/brazing will make a mark on the chrome plating.
sfc vintage
Hero member
Ah right - it needs chrome - cheers for the offer but no thank you.
Reunited Chris
Senior member
- Location
- Sydney
Hi Olly, I would be inclined to make up a replacement piece out of 2mm or 3mm stainless and plug weld it to the original guard.Look Olly, given its location I wouldn’t be too fussed about damaging the chrome. I would get it welded and strengthened and put it back on. Then I would just keep on riding it
Tom
Plug welding would be by drilling holes in replacement and then after placing in position filling the hole using a Tig welder.
Stainless steel has a high nickel content which would help to adhere it to the mild steel. The weld will hold. If a damp cloth is held against the guard immediately after the welding of each plug to remove the heat. Wouldn't bother about attaching broken piece.
Aylesbury, I was born and bred there. lived there for 26 years before emigrating to sunny Sydney in 75. Rode Velocettes in those days.
Dellortoman
Hero member
- Location
- Tasmania, Australia
That's something of a design flaw with laverdas. Breakages like that are pretty common. It really needs some kind of flexible mounting.
Good idea from Chris, but I'd suggest a cold repair to avoid any heat discolouration of the chrome. Make up an overlapping quadrant-shaped corner piece from stainless steel as in Chris' recipe above, but rivet it to the chrome chain guard with stainless rivets rather than plug weld. That'll also allow you to drill or grind out the rivets to replace the stainless corner if (when?) it work hardens and cracks. You can polish the stainless to resemble chrome so it won't be an obvious repair to the casual observer.
If you want to get really clever and improve the design, you could make a new corner piece that attaches to the chain guard via flexible mounts, like the rubber grommets on the mudguard stay. If any rivet counter spots it, you can tell them it's an upgrade.
Good idea from Chris, but I'd suggest a cold repair to avoid any heat discolouration of the chrome. Make up an overlapping quadrant-shaped corner piece from stainless steel as in Chris' recipe above, but rivet it to the chrome chain guard with stainless rivets rather than plug weld. That'll also allow you to drill or grind out the rivets to replace the stainless corner if (when?) it work hardens and cracks. You can polish the stainless to resemble chrome so it won't be an obvious repair to the casual observer.
If you want to get really clever and improve the design, you could make a new corner piece that attaches to the chain guard via flexible mounts, like the rubber grommets on the mudguard stay. If any rivet counter spots it, you can tell them it's an upgrade.
CLEMTOG
Hero member
"It’s not stainless steel so stainless welding would be problematic."
wrong again McStrap, stainless can be very successfully welded to mild steel, and doesnt need skills greater than are needed for welding S/S to S/S
Mine own on TOG has been broken like that for years and years, I just dont see the point in repairing it, just let it do its own thing quite happilly. I have a NOS stainless item, but have never fitted it, because S/S is even more prone to stress related/vibration, fractures. You dont wanr that cracking and falling apart when you are 2,000 miles from home.
CLEM
wrong again McStrap, stainless can be very successfully welded to mild steel, and doesnt need skills greater than are needed for welding S/S to S/S
Mine own on TOG has been broken like that for years and years, I just dont see the point in repairing it, just let it do its own thing quite happilly. I have a NOS stainless item, but have never fitted it, because S/S is even more prone to stress related/vibration, fractures. You dont wanr that cracking and falling apart when you are 2,000 miles from home.
CLEM
hmmmm...my dad has a TIG welder but I've no idea how to use it and he's not had much practice.
I will have to fit on again and see what's what - I seem to remember on one of my bikes there was very little clearance to strengthen with more metal but can't recall if it was the Laverda.
If there is space then I think I'll rivet some substantial reinforcement in and grind the backs of the snapped-off pieces. I can use the same drill holes for the rivets to weld it up one day so I would have been making those holes anyway one day. I will probably glue the snapped pieces onto the reinforcing bit.
Thanks for all the replies by the way.
On an aside - anyone tried something like this? https://eplating.co.uk/product-category/brush-plating-kits/replica-chrome-brush-plating-kit/
I will have to fit on again and see what's what - I seem to remember on one of my bikes there was very little clearance to strengthen with more metal but can't recall if it was the Laverda.
If there is space then I think I'll rivet some substantial reinforcement in and grind the backs of the snapped-off pieces. I can use the same drill holes for the rivets to weld it up one day so I would have been making those holes anyway one day. I will probably glue the snapped pieces onto the reinforcing bit.
Thanks for all the replies by the way.
On an aside - anyone tried something like this? https://eplating.co.uk/product-category/brush-plating-kits/replica-chrome-brush-plating-kit/