Bottle bosses pulled out of frame

[surreypete]

My newly acquired project bike is an '84 Peugeot Premiere, it's got one big fault that might be annoying to fix, the bottle bosses have pulled out of the frame, there appears to be no damage to the tubing and I cant see any cracks or fatique so the tubing is still in good condition.

What's the easiest way to replace them?

I'm thinking along the lines of Rivnuts, the holes already exist so no drilling the frame and getting someone to weld or braze new bosses in, that sounds expensive and also means a new paint job and I'd like to keep the bike as original and retro as I can.

Cheers

[GeorgeET]

Sounds like the threads got stripped. Get the next size tap and retread them than use a larger screw for the cages. The rivnuts would require a largerer hole.

You could also use a short sheet metal screws but nor as neat as retreading.

[nfmisso]

George - I have a different interpretation.

Pete - If I understand you, the bosses themselves pulled out of the frame; not that the threads in the bosses stripped. Do you still have the bosses, or can get replacements the same outer diameter? Test fit the bosses in the holes, hopefully they are a tight slip fit. Clean the bosses and the holes in the frame with a solvent (isopropyl alcohol is good enough, the wipes the medical industry uses to wipe the skin before giving a shot works well). Wear medical gloves. Use a good slow setting (1 hour) epoxy, and bond the bosses in place, apply the epoxy to the holes and surrounding area inside the tube (be generous on the inside), and push the bosses into the holes. Immediately wipe off any excess. From a water bottle cage, and some rubber bands, fashion a compression clamp to hold the bosses in place while the epoxy sets up - leave the clamp in place for 48 hours (I am conservative) put the frame in a position such that the bosses are upside down; after 24 hours, if you can heat the area up to 60°C for an hour, all the better (a personal heater blowing on it). Lubricate the screws that you use to hold the bottle cage, so that the epoxy does not stick to them, nor fill the threads.

[surreypete]

Thanks for the replies guys.

It looks to me like the bosses have pulled out the frame.

Nigel your idea sounds good, I may go down that path but I am still thinking of getting some rivnuts and squeezing them up in the frame, the holes in the frame should be the same size as they were or very close, in my mind a rivnut will compress up to take up any slack and I intend getting large flange with a spline on them so they pull tight and shouldn't rotate in the hole.

I did find the following link after a search on the web, a chap makes a rivnut tool out of an old wheel hub and spindle and says the size of rivnuts for a bicycle should be M5 X 0.80, he recommends aluminium ones should be used as they will compress up easier then a stainless rivnut.

http://barndoorcycling.wordpress.com/2012/09/12/installing-a-bottle-cage-bosses-using-riv-nuts/

[GeorgeET]

Cool info. Never seen one pull out like that. Hope I never will......

[nfmisso]

Is the frame aluminum? Then no problem with aluminum rivnuts - if steel then there is a corrosion potential - but the aluminum will be the looser.

Do NOT use stainless with the aluminum.

[Painkiller]

(04-10-2013, 08:14 PM)nfmisso Wrote:  Is the frame aluminum? Then no problem with aluminum rivnuts - if steel then there is a corrosion potential - but the aluminum will be the looser.

Do NOT use stainless with the aluminum.

I understand where you are coming from Nigel about the stainless to the aluminum and quite the debated subject, however I always use stainless bolts for mounting rear/front racks, have for many years and have never ever had a problem, in fact I have had more issues with the cheesy bolts that come with the bike racks. In the 30yrs I have been doing bicycles I have installed a couple hundred at least.
I think as far as bicycles go it is ok to do and recommend it, for the mere fact they polish nice, are strong enough, and never have unsightly rust in the socket head

[surreypete]

Thanks for the feedback guys.

I think the frame is steel, it says on a little sticker "Peugeot Carbolite 103"

[surreypete]

Finally got round to fixing this on the bike, well I didn't fix it personally, I was cycling home from work and made a detour and popped into the local bike shop to ask if he had the rivnuts to buy so I could fix it.

The guy on the counter went round the back to speak to the mechanic guy and he appeared with a little tray of bits, he dug out some rivnuts and gently tapped them into the frame and got out the rivnut tool and squeezed them up.

I was expecting this to cost me a bit of cash, what with the labour of the guy fitting them but the grand total of all this came to £2. Total bargain and it restored my faith in the shop somewhat.