What the devil is this?

I borrowed a seventies Puch Super Sprint from a friend after my commuter died. It has down tube friction shifters but the rear mech kept gradually going up through the gears by itself, particularly over bumps and things so I concluded the shifter needed tightening up. I'm not very familiar with road bikes but the shifters on it are tightened via a screw with a hexagonal head and around the head they have a plastic bracket (pictured) that looks kind of like a wingnut and allows you to tighten the shifters with your fingers. The problem is they're both cracked, which I wasn't aware of, and the moment I tried to tighten one of them (whilst cycling) it just crumbled off.



The guy who owns the bike plans to sell it as soon as he gets it back so obviously I'd like to try and replace the broken part but I can't figure out what this thing is or where I could get another. I took it to my LBS and they didn't have a clue but they're never been very good with old bikes.

Any suggestions? I just need to know what to google for.

I think that is from an old Simplex gear lever such as the Prestige. Like you say, the hex shape fits around a hex headed screw that secures the lever to its boss either on a clip or the frame. Acts like a wingnut though for the life of me I can't see why they didn't just supply a wingnut in the first place!

I would have thought that an ordinary slot head bolt would do the job - although it may be a weird French thread! Probably metric.

I think it acts like a washer too.

Just found this
http://www.oldbicyclejunk.com/zencart/index.php?main_page=product_info&cPath=3_15&products_id=481

SantaHul":2wpexp8r said:

I think it acts like a washer too.

Just found this
http://www.oldbicyclejunk.com/zencart/index.php?main_page=product_info&cPath=3_15&products_id=481

Click to expand...

I reckon those are the ones - although why you would need to buy 10 of them goodness only knows.

Perhaps it's because they keep breaking!

Frankly I'd stuff on a big washer and a Nyloc nut. It won't keep loosening either! You could also but a wingnut from B&Q. While they won't be exactly right, they won't be $30 for 10 either. :shock:

im currently rooting through my old spares boxes
having a bit of a clear out if i have any will let you know

hi mate
i found one in my spares box . pm me your address
and i will stick it in the post
think its off an old huret lever its a bit gnarly and looks like some ones
adjusted it with a pair of pliers but its intact and the screw is with it so will probably get you out of a hole
i made a mental note i need to get out more
wtf any one would want a bag of 10 is beyond me!
cheers
bowser

Bowser you have pm you legend

My Huret ones have these. They act like a friction washer as well as a wing nut so you can adjust the friction on the shifters. When they're in good condition they work fine but when they get worn and oily they have a habit of not gripping.