All about bicycles, electric-assisted bikes, technology and safety in the press

The most common safety risks that we come across in our daily work around bicycle safety, technology and operating instructions are also published by us in articles in the leading German special-interest magazines TOUR (Europe's road bike magazine no. 1), BIKE (Europe's mountain bike magazine no. 1), MYBIKE and EMTB in order to make this information, which is important for the industry, available to a wider public.

For many years now, the Eurobike Show Daily, trade fair magazine of the annual Eurobike Show, has also given us the opportunity to publish our view of major developments in the cycle industry in full-page articles.

We also speak regularly in independent expert presentations about all areas of bicycle technology and the bicycle market. In addition, we are quoted by further special-interest magazines of the industry and the trade as well as increasingly by radio and television in their media reports, which shows us that we are spot on with our advice. The section "News" informs you about the latest news from our specialist areas. The reports and publications of this section are listed chronologically or according to areas of interest.

TOUR 08/2012
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"Carbon seat post with shim"

Reader’s question

I'd like to upgrade my aluminium road racer with a comfortable carbon seat post. But as the seat tube measures 31.6 millimetres and 27.2-millimetre seat posts are more yielding, I'd like to mount such a seat post with shim.
Is this something you can recommend in the case of carbon seat posts?

Reply by Dirk Zedler, TOUR technology expert and bicycle expert

Experience has shown that nothing speaks against it if you use good components.
Mounting a carbon seat post with shim in a frame requires, however, special skills from the person doing the mounting.

The shim must be absolutely free of burrs and at a length of 75 millimetres at least long enough to reach inside the seat tube below the top tube.
The seat post itself must also have the same minimum insertion depth. This is the only way to ensure that it provides a reliable hold in the frame.

The clamping slots must be flush and the combination must match perfectly, i.e. you should feel a little drag while sliding the seat post into the shim. There must be neither play, nor should it be hard to insert the seat post.

In the case of aluminium frames, the seat tube must be lubricated, the inner shim as well as the seat post must however remain grease-free and provided with a thin coat of carbon assembly paste. Use a low torque value which is just high enough to tighten the seat post. Do not exceed the maximum torque value indicated for seat post or frame.

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