cumulo

Hi, I recently found a folding bike in a barn that I hope to bring back to life. I don't know what make it is as someone debadged it and part sanded it, and then obviously gave up. It seems to be a normal Raleigh Twenty/shopper type of bike that was a vintage late 70s/80s maroon colour and has 20" wheels.

Here is where it gets weird. I have never come across a bicycle where the rear seat stays are completely detached from the seat post. They are not broken. They were never brazed or welded in the first place. They have a bracket and holes where something, presumably a bolt, goes to join it all up. What on earth were the manufacturer thinking? Why make an unecessary weak/stress point point that doesn't help the bike fold or save on weight in any way?

Can anyone shed any light on this phenomena, and what can I do to fix it? Can I just find a bolt that fits and push everything together and tighten everything up with threadlock, or is there a special bracket that must be fitted?

Please take a look and have a guess,

Bog standard seat post - weird detached seat stays.

Different angle.
or maybe I'll strike lucky and find someone that has dealt with this before.
I

leob1

Going by the 'tab' in the seatstay hole, I'd say it was designed to use a seat binder bolt. So if you can find one that fits, that's what I'd use.
But by looking at the amount of rust on those tubes, I would question the reliability of the frame, and the safety riding the bike. That's more than surface rust. .

dedhed

https://www.bikeforums.net/classic-v...roadsters.html

https://www.bikeforums.net/classic-v...tay-bolts.html

GAtkins

I have no idea, but did that thing come from the wreckage of the Titanic?

Glenn

AlmostTrick

Keep form and function in mind here. You'll need to use a well rusted bolt so it matches.

subgrade

Many pre-war and soviet era bike frames I have seen have this design (seatstays are welded to the dropouts, but bolt-on at the seat tube, and one bolt both keeps them in place and tightens the seat collar). What was the thought behind design, I don't know, but it's not that uncommon.

delbiker1 

@cumulo, I can only say better you than me.

cumulo

Ha! I know it looks pretty bad but the rust does seem to be surface because the paint was previously removed down to the bare steel which always coats very quickly with rust if left alone. I sanded bits of the frame by hand. removing the rust, and it was shiny metal underneath. I will need to monitor the whole frame carefully of course, and maybe it may well be lost cause, but hey, it was in a barn behind some hay bales and old wooden furniture and cost me nothing. Any parts I buy can be reused on another similar project. I really want an vintage folder. The photos do look grim, though!

Thanks for the input, guys, I will be careful to check the integrity of the frame and chuck it otherwise.

It never occurred to me that it might be related to removing a chaincase or chain assembly, dedhed,. I guess that might make the bike older than I thought. Nice links.

Moe Zhoost

Seat stays are the least-stressed tubes on your frame. Those that you picture are plenty strong when bolted in properly (and when not compromised by rust). Makes for an easy conversion to belt drive, too.

Joe Bikerider

Very interesting. I’d like to get a belt drive bike but the “traditional” stay removal systems are A real turn off. Anyone know of other bikes built with this system? Please let me know. Thanks.