1994 Stumpjumper Seat tube question???

[tommid]

Hello,
Very bad form I know a nubie coming straight in with a stupid question..
I have had my 1994 Stumjumper Tange Prestiege since 1999 when a mate gave it to me. Had it resprayed and originally had a USE post with a shim. Thing is I cant work out what size the seat tube I need is. I have had a go with the calipers that measure it as 26.4 (an odd size. Worked in the bike trade for years and dont come across many of this size) and when I fit a 26.4 post it seems to have some space to wrattle ariound and slip down in...

I have a feeling it may be a 26.8, but i dont want to buy a post only to find out thats not the case...

Any help you can give will be greatfuly accepted.

 

[cchris2lou]

My 1991 Stumpjumper is 26.6 .

 

[tommid]

26.6 even odder size.... umm Curious...

 

[Andy R]

26.6 even odder size.... umm Curious...

Not that odd - my 1988 Explosif takes that size post

 

[one-eyed_jim]

My 1992 is 27.0, and I thought that was the same as the 1991...

Is it possible your seat tube has been pinched by using a too-narrow post at some point, cchris2lou?

 

[Inigo Montoya]

my 1993 stumpjumper's seat tube dia is 27.0mm too.

 

[one-eyed_jim]

Well that's a confusing set of responses. FWIW I was pretty sure steel Stumpjumpers were 27.0 from 1991 until they went oversized briefly before disappearing, so a 1994 would be 27.0mm

Mine's certainly 27.0mm, and it's unlikely they went narrower (which would imply a heavier, thicker-walled seat tube) later on.

Have you measured the diameter at several points to check for ovalising? Does the slot look pinched?

 

[velomaniac]

Look up http://www.sheldonbrown.com

He has a table of seat tube sizes which include many specialized models, my Rockhopper 1994 frame is 27.2mm for example.

Cheers

 

[ededwards]

My 1991 is also 26.6 so with Chris there but doesn't really help Tom with his 1994.

Could you take it to an LBS as they may have a few old ones you could try for size? Alternatively, stick with the USE or similar 25.0 post and use a shim?

 

[one-eyed_jim]

Look up http://www.sheldonbrown.com
He has a table of seat tube sizes which include many specialized models, my Rockhopper 1994 frame is 27.2mm for example.

It's here:

http://www.sheldonbrown.com/seatpost-sizes-m-z.html#s

but because it's user-submitted, it's full of errors and incomplete information. For example it says:

Specialized Stumpjumper 1994 31.0

That's clearly an aluminium frame, and should be 30.9mm. It lists a Nitanium Rockhopper in 1988, which is probably just a typo for 1998. Interesting that the 1991 Stumpjumper is listed as 26.4 ...