I just got a carbon seatpost for my bike. After reading the installation instructions, however, (and having the occupational hazard of being a mechanical engineer) I'm a little hesitant to install it. (it's filled with waivers such as "don't look at the seatpost wrong when installing it"😉 A friend of mine had a carbon seatpost fail on him. Not sure if he installed it correctly, but he's a pretty sharp guy and does most things by the book.
If I'm willing to folllow all of the guidelines (no twisting, clean clamping, obey the torque spec) am I worrying for nothing? It's an Easton EC70. The bike is an '03 Cannondale R2000.
I just got a carbon seatpost for my bike. After reading the installation instructions, however, (and having the occupational hazard of being a mechanical engineer) I'm a little hesitant to install it. (it's filled with waivers such as "don't look at the seatpost wrong when installing it"😉 A friend of mine had a carbon seatpost fail on him. Not sure if he installed it correctly, but he's a pretty sharp guy and does most things by the book.
If I'm willing to folllow all of the guidelines (no twisting, clean clamping, obey the torque spec) am I worrying for nothing? It's an Easton EC70. The bike is an '03 Cannondale R2000.
thanks for any comments
PS I'm a larger rider, about 6' 1" 195 lbs
Install away. I'm 175lbs and plant my cheeks on a 127g seatpost that sticks about 215mm outta my seat tube. Heck, I even greased it. All you really have to do is follow the torque specs. If you're worried about it slipping, then use some dynamic paste instead of grease. Some folks use no grease and end up finding their CF posts stuck in the seat tube as a living example of galvanic corrosion. Some don't.
Install away. I'm 175lbs and plant my cheeks on a 127g seatpost that sticks about 215mm outta my seat tube. Heck, I even greased it. All you really have to do is follow the torque specs. If you're worried about it slipping, then use some dynamic paste instead of grease. Some folks use no grease and end up finding their CF posts stuck in the seat tube as a living example of galvanic corrosion. Some don't.
FWIW, my post has never, ever slipped.
Is it true that some grease will attack the CF and degrade it? So is there a special grease for the purpose?
If I'm willing to folllow all of the guidelines (no twisting, clean clamping, obey the torque spec) am I worrying for nothing? It's an Easton EC70. The bike is an '03 Cannondale R2000.
When I read these posts I often wonder, is the frame designed for a carbon seat post? :eek:
How do you design a seat tube to accept CF seat post? 😕
You offset the slot at the rear of the seat tube that the seat post clamp squeezes together. Or the other option for us is to spin the seat post clamp 180 degrees (bolt sits towards front of bike) so that both the slot and seat post clamp are not pinching the seat post at the same point.
Stay away from seatposts where the clamp glues into the post itself (Deda Elementi style). They can come loose. Better to get something like the FSA K Force one piece. The Easton's look good too.
I've seen grease react with resin on carbon seatposts.....
Alienator, did you have to sand down your AX? I've heard of a few people having to do that.
There's nothing in grease to react with carbon fiber or the resin. If that were the case, then everyone on a CF bike would be in trouble because the BB shell and the headtube are areas likely to come in contact with grease.
Craig Calfee as well as other CF manufacturers have gone on the record as saying that grease does no harm to CF. Leonard Zinn has also addressed this at Velo News and had responses from manufacturers saying the same.
Yeah, I did have to sand my AX post. I forget how much, but I think it was on the order of 30 thousandths of an inch. My memory could be way off though.
It may have been the grease used or te resin, but Orbea branded carbon posts do blister if greased. After 6 weeks it was pretty evident on a string of first-service bikes at a previous bike shop.
KCNC Ti Pro Lite seatpost all the way. 143g of metal.
I have greased (with Texaco wheel bearing grease) both of my Campagnolo Chorus carbon fibre seat posts. One is in a Litespeed Ti frame ame and the other is in a Douglas carbon frame that has an aluminum sleeve inside the seat tube.
Neither seat post has slipped and the grease has not attacked the seat post clear coat. The Litespeed has been used for one year and at this point there are no issues in this area.
Install away. I'm 175lbs and plant my cheeks on a 127g seatpost that sticks about 215mm outta my seat tube. Heck, I even greased it. All you really have to do is follow the torque specs. If you're worried about it slipping, then use some dynamic paste instead of grease. Some folks use no grease and end up finding their CF posts stuck in the seat tube as a living example of galvanic corrosion. Some don't.
FWIW, my post has never, ever slipped.
Thanks a lot for the info. I believe some greases will attack the epoxy matrix, and the Easton instructions say not to use grease. They also say not to twist in as you put it in, which makes sense (lateral scratches will act as stress concentrations as the seatpost is in bending). Such is the problem with carbon: brittle, brittle. I'll clean the inside of the seattube well and see how it goes...
