Early 70s OU8. Seat binder bolt/nut are pretty well rounded off, and can no longer be adequately tightened.

The rider would like a quick release, if possible. I tried this one (Sunlite 50-60 mm)

https://www.niagaracycle.com/product_...ducts_id=11823

but it was much wider than the 'ears' on the frame.

Sunlite also offers a seat binder that covers 40-50mm range. Does anyone know if this would be a better fit?

Otherwise, I am open to your suggestions about what binder/ binder bolts would work.

Thanks!

Around here quick release = stolen seat.
I would go to your local hardware store and get a stainless steel socket head cap screw and matching nut with locking insert.
Neat, easy to find, lighter, cheap, lower theft potential = done

Good suggestions, thanks folks! I'll head to the hardware to find a good match.

I've probably got a QR seat binder or two laying around, and I think I even have a UO-8 mixte frame to test it on - PM me if you want one, and I'll give it a try.

As much as I don't like the QR seat binder I used one on a late 60's Gitane and it worked fine.

Thanks for the generous offer! That said, in the interest of time (which is short, unfortunately), I'm going to go with the hardware store bolt suggested above. I do appreciate your offer, though.

I have used a polished up stainless steel bolt and nut - Just hacksaw the bolt flush then take a file and sand paper and polish up the nut and bolt head - They look fine and are strong and will last...

Don't forget the washers.

Just wanted to update folks. I did end up finding success using the Sunlite quick release binder for the range of 40-50 mm.

The binder does keep the post secured in the frame, but there is a slight bit of play side-to-side. Wondering if this is due to the shim and narrower seatpost situation?

Wondering what the diameter seatpost we could get that would eliminate the need for the shim, and if folks think that would help keep it better secured?

Thanks again!

If there is side to side play, it will eventually walk itself down under "load".

I am dealing with this right now and the answer is get the Peugeot shim and post. I can't find anything that is close enough to work. I tried a 25.3mm steel post but it was not tight enough. The next size I had in my pitiful inventory was much to big and I tried to find a 25.4 but even it might be too small. Anyway...

I went with the original post, shim and saddle clamp and works just fine. It sort of suits the Brooks mattress saddle that I am installing on the bike.