Stiff seatpost?
 

After a few months of being on only my CF and Ti bikes, I was riding my steel bike yesterday. It was handling the road imperfections fine, but I had this feeling of sitting on a pile bricks. Not the saddle itself, but like it was in direct contact with the ground with no bike in between. A previous Ti bike I owned felt the same. What the two bikes have in common besides the identical saddles is non-standard seat posts...at least non-standard for me. I have been riding very light 27.2 mm CF posts for several years except for the ones on those two bikes. On the old Ti bike the post was CF, but 31.8 mm instead of 27.2. And on the steel bike, since refurbishing it, I have been running a 27.2 mm aluminum Thompson Masterpiece post. I'm suspecting that lower compliance in those two posts is responsible for the feeling.

In order to test my theory I have inquired about the cost of another one of their lightweight, two-bolt CF seat posts. If it is cheap enough, I think I will buy one and put it on the steel bike. I would really prefer that to the Thompson anyway.

Stay tuned.

why not just pull the saddle and seat-tube from your CF or Ti bike to try in the steel bike?

Doh!

The Thompson post is one of the stiffest in the industry.
Setback, post diameter and even sta affect compliance.
Seatposts are not created equally in flex by any stretch.
FSA Kforce has always been my sweet spot....wonderful design, flex, lightweight and fanastic 2 bolt clamp.
As it turns out, choice of seatpost is a rather big deal for fussy riders. :)

Blasphemer!

Heathen!

Texan! :mad:

Reminded me of this test from Velo News. I have the Thomson setback that I've used on the CAADX build I had and on the Crockett right now. It does pretty well, mainly because there is a massive bend that gives it a small point of relief. It's been comfy overall, but both bikes have seen most of their miles on 32mm tires. A straight masterpiece? It was nearly at the top of the list. I have one on my frakenbuild right now, but I haven't gotten to put any miles on it, yet. It's going to have 26 x 1.5 tires anyway. I'm more worried about the steel frame and fork that weigh 8 pounds. :lol:

But just look at a straight masterpiece and a setback you can guess which will be more harsh. Imagine two carbon forks, but one is curved and the other is straight. Physics and all that jazz.

Says the Dallas Cowboys fan. :lol:

My Masterpiece is setback, but, as you know, only 20 mm, not quite as much as the more common 25 mm on other posts.

I just find that a stiff seatpost gives a bike a very particular feel and not pleasant.

So which CF posts are you running on the other bikes?

For a long time I was riding only the 152 g Performance CF post that was discontinued a few years ago. I had three of them. I sold the 31.8 mm one with the old Ti frame and one of the 27.2s got discarded by accident while I had the steel bike broken down for repainting. Don't ask how that happened. Anyway, now I have just one of those left. Except for the one-bolt clamp, thst was a great post while it lasted.

I've got the Workswell post on the Workswell frrame.

Check out a bike just recently posted in Hot or Not, #22515 (at the moment 2nd to last post in the thread). What are thoughts on stiffness of that 'seatpost' treatment?

Or ... best of both worlds? My two ti bikes have custom posts. Ti tubes with machined large setback heads and Thompson clamping hardware. The sweet Thompson setup and adjust-ability, lots of setback and clamps centered in the seat rails (reassuring for ti railed seats which are a boon in themselves for rough road comfort) and ti posts which are quite noticeably more compliant than aluminum posts.

Ben

That's an interesting idea. Who puts those together for you? Do you buy the whole Thompson posts and throw away what you don't need? Are you aware very light no-name clamping hardware can be bought separately off ebay?

TiCycles makes the posts. They machine the head from solid stock to the needed setback, drill for the seatpost diameter, glue and set-screw it in and put on the hardware they buy directly from Thompson. Apparently Thompson makes this very easy.

I have no desire to deviate from the Thompson hardware. Busting seatposts always messes up rides. (Turned a 100 mile ride into an epic when I broke a bolt at the halfway point of an out and back. 1970s, I was new to the area and had no phone numbers. Farm country.)

Ben

For anyone dealing with a seat post compliance issue, I can vouch for the Specialized/S-Works carbon seatposts with the zertz insert. I tried one out coming from a Thomson on my race bike and was blown away by how much less road chatter I felt. Too bad my training bike has a weird size that I can only get in an Elite, but HTFU, I guess.

Link, please..?