TerraTrikes use a sizing measurement called an X-Seam. This measurement helps us to determine which size will best fit you. Here is how we you determine your X-Seam size.
Wear shoes you would typically use for riding. Sit very tight against the bottom of the board, lean back, and stretch your legs out straight with the soles of your shoes perpendicular to the floor. Measure the distance in inches from the front of board to the bottom of your shoe. This is an important measurement so have an assistant help you get an accurate number. Use an ironing board, a piece of plywood or whatever you can find. Lean it against a wall at the recommended angle or as close to it as you can eyeball.
The boom tube is the front part of the frame that holds the bottom bracket, crankset and pedals. It attaches to the frame where the outrigger tubes meet the main tube(or where the arms of the frame meet the body). The Rover, Rambler, and Sportster products have adjustable booms so one size fits all per the charts below. The Tour II has a detachable boom tubes of different lengths but they are not a sliding adjustable piece.
The boom tube length guidelines listed below are merely suggestions, this is by no means an exact science. For those of you who are on the fence, here are some guidelines. If you're the serious racing type who likes to recline the seat all the way back and go fast, add an inch to your x-seam measurement. If you're more inclined (no pun) to sit very upright and just cruise around town and be cool, you might need to subtract an inch.
|Frame Size||Rover||Rambler||Tour II||Sportster|
|Short||29" - 47"||33" - 45"||36" - 42"||36" - 49"|
|Medium||38" - 44"|
|Long||40" - 46"|
|Reccomended Rover Boom Positions|
|X-Seam Range - Optimal||33.5" - 41"||41" - 43.5"||43.5" - 47"|
|X-Seam Range - Full*||29" - 45"||36" - 47"||38" - 52"|
|* Full range of adjustability can cause heel strike in the shortest position (Boom in, seat all the way forward) and will change handling dynamics in the longest position (Boom out, seat all the way back).To determine the X-Seam measurement, use the sizing diagram located above.|
|Frame Size||Tandem Front
|Short||37.5" - 39.5"||35.5" - 42" One Size fits both short and medium|
|Medium||39.5" - 41.5"|
|Long||41.5" - 43.5"||**|
|X-Long||42.5" - 44.5"|
|** There is no long option in the rear. The Larger rider should captain the Tandem for optimum handling|