Spot the difference: good bike fit, bad bike fit

One's a recipe for disaster, the other's set for success – but which is which?

Published: April 2, 2014 at 9:09 am

Can you tell when someone has a perfect fit for their tri bike? Try to spot the difference between these two positions, courtesy of our staff writer Mike Anderson, who went in search of the perfect fit at Bristol's Bike Science for the latest issue of 220 (on sale now).

Mike's bike fitting cost £149.99 at the Bristol branch of Bike Science – for more info head to www.bike-science.com.

A:

B:

Think you know the answer? Click here to find out the verdict from Andy Sexton, top fitter at Bike Science…

:

Position B (above) is the correct one

Bike Science's Andy Sexton said the following about position A (below):

Saddle too low

“Insufficient leg extension means power output will be compromised. There’s less stress on the knee when the saddle is higher, especially on the initial phase of the pedal stroke.”

Saddle too far back

“This closes the hip angle, which is how close the thigh comes to the torso at the top of the pedal stroke. It compromises power output and requires a high level of hip flexion, which can cause the knee to track outwards as the hip angle closes. Also, lack of saddle support means the rider is ‘perched’ on the narrow nose of a conventional road saddle. The more forward position combined with an ISM Adamo Road saddle will encourage the rider to sit 2-3cm further forward and allows for a more open hip angle.”

Reach too long

“Here, the rider’s weight isn’t supported skeletally through the upper arm. The rider will need to engage the lower back and shoulder muscles to support the body, which isn’t sustainable. Shorter reach means the rider can relax onto the pads.”

Unnatural wrist position

“S-bend bars require a high level of wrist flexion. It’s difficult for a rider to establish a relaxed hand position or gain any purchase on the bars. Upturned bars allow the wrists to sit more comfortably.”

For the full report on how to get the perfect fit for your tri bike, pick up a copy of the May issue of 220 Triathlon, on sale now. You can subscribe to the mag here.

PLUS this month's digital edition includes lots of bonus content, including video of our staff writer Mike getting his fitting at Bike Science – available via the iTunes store, Google Play and Zinio.