Seatpost diameter survey - min and max for fg/ss bikes

Greetings all,

I am trying to establish a rough min and max value for seatpost diameters, particularly among fg/ss and road bike riders.

Although Sheldon has a superb source of seatpost information, I am focusing on catagory and ultimately trying to see if there is a common seat post size (+/- 1mm) that covers a majority of ss/fg/road bike riders.

My Questions are:

1, What is your seatpost diameter?

2, Are there many examples of oversized seat tubing within this catagory? (i.e. over 27.4mm)

Kind Regards

FL

wow.

what an earth are you gonna do with the information?

sit on it?

I'm trying to design a kind of towbar that fixes onto seatposts. But just wanted to see how adjustable I needed to make it (what my range I had to cope with), also out of curiosity I guess:)

27.2 is the common size that blah blah

OS seatposts tend to be found on newer carbon road bikes.

I remember I had a gt timberline many moons ago, I think that had a 31.8 or something daft like that, From what I can gather, downhill and fold ups use the fattest as they need the extra strength?

31.8 mm would more than likely be the seat tube, not the seat post.

As hippy said the most common size is 27.2 mm

surely there's already trailers that you hook to the seatpost, how have they solved it?

31.8 mm would more than likely be the seat tube, not the seat post.

As hippy said the most common size is 27.2 mm

a few of aluminium MTB frame makers like klein, used to use 31.6mm seatposts

Yes your right, there are plenty of current market trailers with attachments and the simplest way would be to make an adjustable fastener (like on many mudguards), but I'm trying to approach this by making a cheap one piece molding, it may be that its not possible but I'm just interested to see what my range is really.

yep, but it's more likely to be a seat tube size, which is why I said likely and not defiantly was.

Surely if you found the largest common size, designed it for that then made shims for other popular sizes that would be an easy way to please everyone.

...or you could look at push seatposts and see what sizes they do. ie: 25.0mm > 31.sommit or another. And then make the clamp fit them all?

There will be no standard seeing as lots of people ride wanky old steel conversions from all over the world.

or what mick said

Of the bikes and frames I've got around the house, they take seatposts as follows:

2x26.8mm
1x27.0mm
8x27.2mm
1x30.4mm
3x31.6mm

http://www.lhthomson.com/elite_sizes.asp

The shim idea has indeed crossed my mind, and also a fully adjustable (catering for 25mm to 31.8mm) bracket too. Practically speaking, I should really make a silicone/flexible strap like knog lights which can stretch up to their largest size thus catering for all sizes.

1, What is your seatpost diameter?

I know I'm not to laugh, but the more I re-read the question..........

Anyway, 27.2 (x 2) is the non-comic answer from me.

wow, thats a large corridor you have!! Cheers for taking the time to get them. I guess I should phrase the question like so, If I was to present a bracket that fitted (27.2mm seatposts +/- 1.5mm) what percentage of bike would I be designing out.

29.4
more exclusive than all that NJS shit that plebs like to roll

I've got a 30.9 seatpost and a 32.7 seat tube, pain in the arse indeed.

Well it's quite the opposite, as it's a Thudbuster seatpost...

that's quite alright, when I read it back it does sound quite obtrusive. he he

so are these (30.9 and 32.7) seatpost diameters on track/fixed/road frames?

...just seen the thudbuster, looks serious!

25.0 on mine