Help: seatpost clamp/bolt for Trek 520 1992/1993 - looking for a photo

[red_mike]

Dear colleagues,

I've recently turned into the owner of Trek 520, year 1993 - nice bike! However, the seatpost (clamping) bolt is missing - the former owner used just a generic bolt and nut with a spacer. On my other steel frames, the clamps of this type has a "nib" (like a "nose", or a small tooth) which should fit in a special notch on a frame to prevent turning of the nut inside the frame. However, this frame has no notches of any type? and this puzzles me a bit.

Would it be possible, if somebody has Trek 520 1992/1993 around with original seatpost clamp, to make a photo of this mystical bolt? This will greatly simplify my search

Thank you in advance and have a good ride

M.

 

[jim haseltine]

Perhaps it uses a Campag style bolt - one with a knurled rather than keyed sleeve end. Until the bolt has been in place for some time you have to use 2 x 5mm Allen keys to tighten or loosen the bolt in the frame. One to hold the knurled end secure so it doesn’t move and the other to tighten or loosen the threaded part of the bolt.

 

[red_mike]

So, ladies and gentlemen. When I was thinking about fitting of Tektro cable hanger for a fork, I suddenly realized, that brake pivot nut can actually do the job as a left part of the clamp. Quickly measured everything, found a pivot nut from a broken Sram Force road brake (even holistically correct), cut normal bolt to approx 27mm of a total length - et voila, it seems to work The pictures of the end result are attached. Haven't yet tested it, but seems to hold just fine.

Overview:



Left side:



Right side:



I'll post the overall picture after few days of testing.