seatpost vs clamp size

[IDB1]

does an xx seatpost diameter mean an xx clamp size??

Got a post size of 28.6 and (without proper measuring tools) the clamp looks like 33mm.. does that sound right?

 

[6.5x55]

It would depend on the wall thickness of the seat tube I reckon .

 

[fagin]

No and possibly, but 31.8 is more likely

 

[IDB1]

Would me saying it's for a '98 (probably) GT LTS 4000 help??

 

[fagin]

Would me saying it's for a '98 (probably) GT LTS 4000 help??

I would expect it to be the same as your front mech band.

 

[IDB1]

Ah!!.. .good idea

That's coming off soon so I will take a peek...

that didn't occur to me at all

 

[fagin]

I think most seatpost outside diameters are pretty standard 28.6 for steel or 31.8 for aluminium, same as mechs.
It's the seatposts themselves which are a bugger - I have a small collection of seatposts from before I realised they aren't all the same size and finally got one to fit.

 

[IDB1]

This is a steel frame with a seatpost size of 28.6 (according to the seatpost I took out..)

I'll check the mech tomorrow and see what gives

It'd be ok if I could get the other half of the bolt out of the original seatclamp which I had to cut because some tit had rounded it off

 

[IDB1]

31.8. . .

 

[IDB1]

Is it normal to have to hammer (rubber mallet) a seatpost clamp on?

I took the 31.8 collar off the Aggressor to try on the LTS and it's not even close.
Looks about 2mm smaller than the original one too (which had the cut bolt that I've now removed so can use the original collar until I need a nice one)...

The front mech clamp fits the top of the seatpost tube so it is definitely 31.8.