Help me find a seatpost!

[padawan]

I purchased a used bike which I am very happy with. Beautiful 6/4 titanium frame. Rides like a dream, comfortable, responsive.

The only thing I wasn't really keen on about the bike was a very heavy scratched up alloy seatpost. The problem I'm running into is finding one that fits the frame tubing.

The standard seat tube width measurements seam to be 27.2 mm or 31.6 mm. Mine seems to measure about 30 mm. Is that really uncommon? I'm not using a micrometer to make the measurement. Is there a "standard" size for seatposts that's close to 30mm? Help!

Thanks,
Pad

 

[gclark8]

Best to get a Vernier (inside) or Micrometer as Kalloy do a 350mm range:
29.2
29.4
29.6
30.0
30.2
30.4
30.6
30.8
31.0
31.2
31.4
31.8

 

[padawan]

Best to get a Vernier (inside) or Micrometer as Kalloy do a 350mm range:
29.2, 29.4, 29.6, 30.0, 30.2, 30.4, 30.6, 30.8, 31.0, 31.2, 31.4, 31.8

Thanks gclark8, even if it isn't the best news.

That's not very user friendly! The old seatpost is actually a Kalloy. Any advice on how much fudge room I can play with (i.e. if the tubing is meant for a 30.0, could I use a 29.6 or a 30.2)?

Pad

 

[gclark8]

The size will be written on the seat post, take it out, near the limit line, at the bottom.

 

[bobbyOCR]

I am sure there is a shim for seatposts. Then you can use a 27.2. If you know of a 25.4 then I would be happy

 

[gclark8]

I am sure there is a shim for seatposts. Then you can use a 27.2. If you know of a 25.4 then I would be happy

Shims I can get:
26.4-28mm OD, 25.4ID
28.0-30mm OD, 26.4ID
30.0-31.8mmOD, 27.2ID
These are tapered. Let me know if I can help.
I can get 25.4 seat posts if required.

 

[padawan]

Hey gclark8,

If I understand your last note you have a shim that is designed to make a 27.2mm diameter seat post fit a 30.0mm (inner diameter) seat tube. Do you happen to post as a seller on e-bay.ca? How much do these shims cost? You're halfway around the world from me, shipping cost (in comparison to item cost) my be prohibitive but I'd like to at least find out.

Thanks,
Pad

Shims I can get:
26.4-28mm OD, 25.4ID
28.0-30mm OD, 26.4ID
30.0-31.8mmOD, 27.2ID
These are tapered. Let me know if I can help.
I can get 25.4 seat posts if required.

 

[John M]

Hey gclark8,

If I understand your last note you have a shim that is designed to make a 27.2mm diameter seat post fit a 30.0mm (inner diameter) seat tube. Do you happen to post as a seller on e-bay.ca? How much do these shims cost? You're halfway around the world from me, shipping cost (in comparison to item cost) my be prohibitive but I'd like to at least find out.

Thanks,
Pad

If George can get the shims, a good local shop in Canada can also. You might also look at airbomb, aebike, Harris cyclery, or one of the other North American online sellers that carry the QBP catalog. Your local shop probably works with QBP as well.

Here is the link to Airbomb's page with the 27.2 to 30.0 shim. The have other sizes also.

http://store.airbomb.com/ItemDesc.asp?IC=ST0228

 

[gclark8]

If George can get the shims, a good local shop in Canada can also. You might also look at airbomb, aebike, Harris cyclery, or one of the other North American online sellers that carry the QBP catalog. Your local shop probably works with QBP as well.

Here is the link to Airbomb's page with the 27.2 to 30.0 shim. The have other sizes also.

http://store.airbomb.com/ItemDesc.asp?IC=ST0228

Exactly! Any LBS can buy these into stock. I believe they come from Taiwan, Kalloy is one brand name.

If Bobby OCR (or anyone in Perth) needed one, there is a spare here in my bike room.

 

[padawan]

If George can get the shims, a good local shop in Canada can also.

Thanks all for your feedback, I'll get it sorted out.

 

[melslur]

Thanks all for your feedback, I'll get it sorted out.

With all the talk about shims......why? My advice would be to just take your bike to the LBS and let them measure the seat tube exactly, and let them sell you the right post. I was looking to buy a seatpost and the LBS offered to measure the seat tube, but my seat post stated the size on it so the measurement was not needed. If you're planning on buying from eBay, the right post from the LBS may be cheaper and better than an eBay seatpost and shim combination.

 

[PeterF]

I purchased a used bike which I am very happy with. Beautiful 6/4 titanium frame. Rides like a dream, comfortable, responsive.

The only thing I wasn't really keen on about the bike was a very heavy scratched up alloy seatpost. The problem I'm running into is finding one that fits the frame tubing.

The standard seat tube width measurements seam to be 27.2 mm or 31.6 mm. Mine seems to measure about 30 mm. Is that really uncommon? I'm not using a micrometer to make the measurement. Is there a "standard" size for seatposts that's close to 30mm? Help!

Thanks,
Pad

I have a Pinarello with an oddball size too, (I believe it's a 31.0). The post that came with it is still ok, but most likely I'll have to get the same overpriced post if this one ever breaks. What a pain.

 

[bobbyOCR]

With all the talk about shims......why? My advice would be to just take your bike to the LBS and let them measure the seat tube exactly, and let them sell you the right post. I was looking to buy a seatpost and the LBS offered to measure the seat tube, but my seat post stated the size on it so the measurement was not needed. If you're planning on buying from eBay, the right post from the LBS may be cheaper and better than an eBay seatpost and shim combination.

That may be. But, from working at a LBS a while ago, it isn't the easiest task to get a light, brand name seatpost for a racing bike in a diameter like 31 or 30. They are very rare, as everyone either uses 31.6 or 27.2

 

[padawan]

That may be. But, from working at a LBS a while ago, it isn't the easiest task to get a light, brand name seatpost for a racing bike in a diameter like 31 or 30. They are very rare, as everyone either uses 31.6 or 27.2

My problem exactly!

I actually have a very nice K-Force Light carbon seatpost but of course it doesn't fit (27.2). I ordered a shim from my LBS (thanks to previous posters) so that should allow me to use it. Still, I'd rather have a seatpost designed to fit my bike. Thomson make some great seatposts in 30.0 (designed for mountain bikes) but they are 1) not the lightest and 2) zero setback.

Oh well!