[photosbymark]

Well after a long search for a seatpost to see if I can get the Fuji Newest 3.0 rideable without either knee pain or spending a fortune on a seatpost.

I have an older Schwinn Rocket mountain bike, that didn't bother me nearly as bad as the Fuji. Took a look and thought, those posts look about the same size. It never crossed my mind that the seatposts would be the same size given the different uses. The Fuji is a 27.2. The Schwinn looks like a 27.2 J. Anyone know what the J means??? If I had to guess it is probably for a thicker wall and a stronger seatpost for off road use. It also looks like it has far more setback than the Fuji.

Now the Fuji is an aluminum frame, and I think the Schwinn is steel and probably a steel seatpost. The Fuji seat post is carbon fiber. Steel or aluminum will have to be greased, but the carbon fiber doesn't need it. Is it going to be a problem going back to carbon fiber with grease on the frame??

Oh well the Sunray for a while is definately the first choice of bikes. It just fits.

[flyingdog]

Click----> Grease on carbon fiber seatpost? - Cyclelicious

IMHO..I wouldn't put grease on CF or Aluminum as a person could over torque the collar. Theoretically, grease could give an unnatural feel to bolt tightening. But then again, it's usually a very, very, thin layer. Besides, greasing is only to prevent rust/sticking and CF or Aluminum don't rust.

[photosbymark]

Aluminum doesn't rust per sey, but it does corrode. It doesn't product iron oxide, but it does produce aluminum oxide. The grease wouldn't go on the carbon fiber seatpost, but it would need to be in there for any metal seat post and would leave a residue that could be difficult to totally remove. If the carbon fiber post ever went back in, it likely would come in contact. Wonder if the grease would react with the CF and weaken it.

Now add to the fact that steel in an aluminum frame probably would cause some dissimilar metal corrosion. Over time it could cause a weakening of both tube and frame. Hence my reluctance to just stick the post in and see if it fits.