It looks like I’m getting a CF base and rail adapter. What is a good (cheap, strong, light) post to go with them? I need 27.2mm by 350mm approx. Does anyone have one they want to sell?
Is this any good? Eb*y link
i have that post on my road bike and it works nice
Are you sure you want a CF seat post? Bike seat posts (esp. for road bikes) don’t get as much “action” as unicycle seat posts, since bikes have handlebars. For the unicycle, as you know, the seat is the handlebar… so the rider is constantly applying torques and forces to the seat post.
Carbon fiber has a high tensile strength for forces applied along the fibers (along the length of the seat post) but a relatively low strength for forces at angles to the fibers (along the radius of the seat post). What this means is the CF seatpost is great if the only force you apply to it is up/down, but it isn’t as good for the case when, say, you biff a stair set and push down hard on the handle, or the uni goes flying and the seat hits something. The CF seatpost won’t bend in these cases, it’ll crack, at which point it will be completely useless.
Now, I don’t have any direct experience with CF seat posts, but my common-sense-o-meter tells me it wouldn’t last very long on any of my unis… I have a tendency to biff landings and the seatpost takes a good amount of abuse.
Your results may vary.
The guys at the bikestore i work in say that a CFpost is bad for any bike or uni that will take any impact. Maybe for a road bike or Coker but for a trials they said they wouldnt recomend it because it will snap. You’d be much better of getting a Thomson post in my opinion even if it is more expensive.
<EDIT> Maestro beat me to it…
For a unicycle I recomond only an easton
Easton makes the best carbon fiber you can get and the only stuff I’d run on a uni.
All other carbon posts, tend to shater when the break, but easton, if it ever does break, will break clean.
if you go carbon go easton. if you dont go thomson
Ah, Well its always good to know your parts will break in a clean way.
I’ll third the motion to not get a carbon fiber seatpost.
In addition to the downsides for a CF seatpost that have already been mentioned, there are issues with scoring, being able to take high clamping forces, and the need for a high quality frame that has good seatpost clamping.
When you insert a CF seatpost you have to be careful not to cause any scoring (scratches) in the seatpost while putting it in the frame, removing it from the frame, adjusting it, or twists from general use. Surface scratches will reduce the strength of the seatpost and are bad for CF bike parts.
You also need a high quality frame that has a well machined seat tube that clamps the seatpost well and is smooth inside so it won’t score the seatpost. No stock unicycles fit that bill.
Then there is the problem that CF seatposts don’t handle high clamping forces. Unicyclists tend to use high clamping forces to keep the seatpost from twisting. That’s not compatible with a CF seatpost.
I can’t think of a single good reason to get a CF seatpost for a unicycle. I don’t even like them for bikes.
Thanks everyone for the heads up!
Is a Thomson post the way to go? What are the other options?
i’m putting one of these on my schlumpf
http://raceface.com/components/seatposts/evolve-xc-post.htm#
How much is that gonna cost?
prolly only like $50-70 give or take
A Thompson seatpost is pretty much the gold standard for Muni. Many of the guys I ride with got them second hand off ebay. Still touch you for around 40 or 50 bucks (80 bucks new) but I’ve never once heard of a Thompson breaking.
JL
Following John’s advice, I’ll say the Primo Rod post is the silver standard for street and muni. It’s a bit heavier than most seat posts but it’s available in a lot of sizes (including 22.2 mm), it’s cheaper than dinner for 2, and it’s so strong you could probably use it to bash a parking meter open if you needed some spare change.
HAHAHA That made me laugh so hard!