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 Access, Sport, Race and Zoomer products have adjustable booms so one size fits all per the chart below. The Edge has a fixed boom that is not detachable. The Path, Cruiser, Tour, and Tandem have 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. Also, if you're ordering a Path, Cruiser, or Tour and you're in-between sizes, you may want to order a spacer. The spacer lengthens the boom tube one inch which is half of the typical two inch difference between boom sizes. The spacer works great for those riders who measure in the middle of two sizes. It also provides more crossbar clearance for riders with very long feet. The spacer costs just $9.95.
Frame Size |
Path/Cruiser/Tour X-Seam |
Zoomer/Zoomer Elite X-Seam * |
Sport/Race X-Seam ** |
The Edge X-Seam |
Extra Short |
34.5 - 39 |
36 - 46 |
38 - 49 |
26 - 31 ** |
Short |
36.5 - 41 |
31 - 42 |
||
Medium |
38.5 - 43 |
33 - 44 |
||
Long |
40.5 - 45 |
35 - 46 |
||
Extra Long |
41.5 - 46 |
46 - 50( $199 custom charge) |
N/A |
| Frame Size | Tandem Front (Captain) X-Seam (in inches) |
Tandem Rear (Stoker) X-Seam |
| 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 | Note: there is no long option in the rear. The larger rider should captain the tandem for optimum handling. |
| Extra Long | 42.5 - 44.5 |
* The Zoomer, Zoomer Elite, Access, Sport, and Race frames are one-size-fits-all within the X-seam range but we ask for your measurement so we can set up the boom position and chain length to fit you.
** This range is possible on The Edge but requires a custom frame with shorter main tubes, shorter handlebars, a shorter boom tube, longer seat stays, and possibly a shorter crankset. This is a custom build so call for pricing and lead time.