Seat Mast Cutting, Conversion and Topper Fitting

All Ritte Vlaanderens and Ritte Bosberg models through '2013, use an integrated seat mast and seat topper system that increases rider comfort and road feel. This performance comes at a price, however; the mast cutting and mast seat topper/mast interface can be tricky. 

Note on ZERO SETBACK: If you're looking for a Zero setback topper that will fit a Vlaanderen or original Bosberg, KCNC makes a nice selection of compatible toppers that you can buy here.

IF YOUR MAST IS CUT TOO SHORT there are a few options: We have longer toppers available for purchase, and KCNC also makes a longer topper. We can also convert any seat mast frame to accept a standard seat post. We are happy to do this free of charge but you will need to pay for shipping to and from Ritte HQ.

Mast Cutting: 

Please Note: This procedure should only be performed by a professional mechanic with experience cutting seat masts. 

You will need an oversized saw guide. We recommend using Park Tool SG-7 

Know your exact saddle height beforehand and be aware that changing saddles will effect the height.

Place the topper fully on the uncut mast and measure the saddle height.

Subtract your desired saddle hight from the uncut saddle height. The difference between the two is the amount of mast that needs to be cut off.

Once cut, the topper can only be raised 15mm. 

Securing the Topper:

The outer diameter of the seat mast can vary by a few fractions of a mm. Likewise, the inner diameter of the seat topper can vary by a few mm. Properly fitting your topper to your frame is not simply a matter of torquing the bolt to 5mm, it requires an awareness of how tight or loose the topper is on the mast.

There should always be some kind of interface between the topper and mast. If the topper already fits snugly on the mast, you should use a carbon friction paste. But some toppers will fit more loosely. In these cases, we recommend using a wrap of thin painters' tape to help the topper bite into the mast.