RailGun GT Performance Seat

RailGun Photos, Cross Florida 2014. Cross Florida 2015.

Barends, Spy Buttons and mesh seat covers

RailGun GT mold development

The pioneers of high-performance, low seat-angle seats on short wheelbase recumbents brought our famous carbon-fiber seat and tailbox to a new performance and usability level. We are seeing about a two mph increase in speed over the original RailGun at 30mph.


The GT is intended for ultra distance events and speed-touring. It has around eight degrees of recline. When used properly, this seat should do away with the need for "bridging" when at high power as it more properly positions and supports your body by supporting the spine and pelvis so the the sacrum floats slightly off of the seatpan when under power to prevent hamstring irritation and damage often seen on other carbon seats. It doesn't flex in the middle of the seat as all other seats do, for much quicker acceleration, faster/easier climbing and better power transfer and is far more aerodynamic.


The seat has integrated headrest tubes for a built-in headrest that weighs less than 6 ounces. It doesn't need a clamp but just slides in and out easily yet stays at your correct height. It is very flexible and can comfortably handle rough roads and most bumps without having to lift your head from the headrest.

The tailbox has two integrated bottle holders that are located directly behind the seat and a hinged lid that opens backwards for holding essentials. While the GT tailbox is only slightly larger than the original, it has almost twice the usable space inside and is much stronger.

Check the RailGun FAQ and Howto

for more information about our seats; how to pedal, climb and breathe; seat angles, tailboxes. etc.

This RailGun seat follows the contour of the M5 CHR frame and is extremely stiff for fabulous power transfer yet a comfortable ride when under power. Accelerating, climbing and just running under power on this ride is so remarkable and fun it likely has to be experienced to be believed.

By design, the tire interferes with the floor of the tailbox for an M5 CHR by almost three inches with the eight degree seat angle so we made a shaped tunnel insert to fit in the bottom of the tailbox to clear the wheel.


The end goal of all of this work is to produce the first Fast Touring bike, the RailGun Ultra. A touring bike that is extremely comfortable, easy to ride for miles on end and is very fast. One of the project goals has been to include some tube panniers to aid in travelling. We hacked up some rough experimental carbon fiber tube panniers to test some of our hypotheses just before the Sebring 2019 24 hour race and I rode with them:

Between the RailGun GT seat and the SpeedRail tube panniers, this M5/RailGun is a very, very fast bike. It managed to set a new 65-69 age 24-hr non-drafting record at Sebring 2019 and the panniers work so well I would rather ride with them and their extra weight than not ride with them. We are still discussing the pannier design but it will likely be two-part panniers with the front part bonded to the seat which will receive a rear section which will also attach at the rear of the tailbox.

Oven Cured

All new RailGun GT seats are fully oven-cured. The above photo is of the first fully oven-cured RailGun seat. The seat is lighter and stronger. It weighs about 3 lbs total, with all mounting hardware and headrest (not including the panniers).

The curing oven was made per my specifications by Jen Ken Kilns. Mike at Jen Ken selected an excellent controller and did a fabulous job designing the oven. It is very easy to use, very controllable and efficient. We use the curing and post-curing schedule as specified by the epoxy manufacturer.


While we have many great testimonials from our RailGun riders, the GT seat surprised us a bit by reducing turbulence behind the seat so much that it creates a better draft at faster speeds than we expected. Our strongest drafting riders just love the new seat now so we thought we would include some of their testimonials this time, instead.

While the GT allows faster speeds so it's even more fun to chase down cars while playing in the road, there is one drawback: the reduced turbulence makes it easier for strong riders to draft at faster speeds than they could before and makes it more difficult to drop a strong rider who has latched on...

Please Note:

While our non-competetive riders tell us that their RailGun seat has brought new comfort and life to their riding, we would like to remind people that this seat is not really designed for comfort at low power levels, such as just cruising around. It is a performance seat, designed to provide proper support while under power and might possibly become a bit tedious otherwise. The lumbar support is designed to assist and support the lower back when it is under tension, whether for short sprints or 24 hr ultras. If you ride with your lower back relaxed and not under tension, this seat may not be the best choice for you.

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June 5, 2019