Bicycle Mechanics - Trek seat binder bolt

I want to replace my seat binder bolt on my 85 Trek 760 as the head is stripped making tightening difficult.The original is a Matrix 5mm.Totally screwed together it is about 29-30 millimeters.I can't seem to find anything matrix on line.What would be comparable.I'm especially interested in what length to order.

if your binder is the style with a nut and screw section going into a plain hole, brand doesn't matter, just diameter and length.

Most have 8mm diameters, and the length is measured between the inside of the heads when fully closed, ie 30mm like yours. 30mm seat binder bolts (http://www.buycheapr.com/us/result.jsp?ga=us15&q=seat+binder+bolt) are very common, and you shouldn't have any trouble finding one.

BTW- if yours was running out of thread (fully closed) when tightened, you might buy a 25mm bolt instead.

If I recall that frame correctly the seat post binder bolt was double allen and fully recessed. So the outside diameter of the bolt head is more important than it would be on other frames. I would try one FB suggested and probably just file down the OD of the bolt head if they are too large.

Thanks guys.I ordered one for 5.25 on ebay and am hoping it'll fit.