Almost every week I know I can count on two things: Someone is going to ask me about seat sizing and I will see a rider on a hardshell seat that is too small for them.
Fit on a hardshell seat is a very personal preference. Most performance riders love the feel of a fully supportive seat behind them. If you are one of them, then read on! This article is for you.
There are a variety of seats on the market today. We build our own Carbent HPV seats in-house and they are based on the Velokraft seats of old. Bacchetta supplies a seat that has the same shape but slightly different sizing. HP Velotechnik's BodyLink seat is the only adjustable hardshell seat on the market. Finally, ICE makes a beautiful seat designed specifically for trike use.
(The process we use to build our seats in-house is almost identical, but we vacuum bag the pieces to get rid of excess epoxy.)
In terms of fitting, the general guideline is that when the pad is on the seat, the top of the seat should sit right at the base of your neck. Note, the seat pad needs to be installed. So, changing your seat pad can also change the fitting of your seat. For example, if you are ordering a Carbent HPV seat and plan on using the basic foam pad, we will suggest a seat size that is one size larger than if you are using a Ventisit pad.
Bacchetta seats are approximately 1/2 size smaller than the Carbent HPV seats, and are available in medium and large. The Carbent HPV seats are available in medium, large and extra large. So, between the two brands, we can supply five lengths of seats in half-sizes.
The ICE seat has a similar size to the Carbent HPV seat, but in has built-in wings to provide lateral support for trike riders. Unfortunately, the ICE seat will not work on other brands as some of their mounting hardware is built into the seat and is not removable.
The beauty of the BodyLink seat is that it is adjustable. So, one size fits 95% of the riders out there! The BodyLink seat uses three supporting points that are built into the HP Velotechnik seat. It may work on other bikes, but we haven't tried to know for sure.