Hi Everyone,

I am in the process of building a high end titanium Audax/ultra distance bike. The bike has been assembled and riding perfectly, beyond what I ever expected.

In the process of building the bike I borrowed the 27.2 diameter Ritchie seat post form my mountain bike and installed it with a 27.2-30.9 Crane Creek shim. The frame requires a 30.9 diameter seat post. I did this as a the frame geometry (seat tube angles) are different to my usual bike and I was unsure what set back I would require.

Now that the bike a assembled and being ridden, it is time to purchase a new seat post. I am primarily considering an aluminium seat post however will consider a carbon one.

My questions are;

• Should I purchase a 30.9 diameter seat post or continue to use the 27.2-30.9 shim and a 27.2 seat post?
• Will there be any noticeable difference between a 27.2 and 30.9 seat post?
• Have people experienced any problems with their frame when using a shim and a smaller seat post?

Kind Regards

Donnie Johnson