Don’t Ride Like Pee Wee

Posted by on May 6, 2011 in Daily Blog | 1 comment

 

Today I took the kids to ride their bikes on some dirt trails.  They’ve only just started riding, so technique isn’t very important to them just yet.  But, just to make sure they get off to the right start, I made sure their seats were just the right height. Not too high so they can’t reach the ground, and not too low that they’re standing.  Just right.  Perfect seat height for them is more a matter of safety than anything else.

As I’m scrambling behind them, I hear the tell tale sound of a mountain bike fast approaching.  Here he comes…and quickly we get off the trail to let him by.  As he passes, I admire his well built calves and spotless cycling apparel, watch the full-suspension work under the aggressive pedaling and burst into laughter at the overall spectacle.  Here’s a guy who’s got some cash, and has a nice bike and the best clothes.  He obviously rides a lot,  but his seat’s way too low.  With each revolution of the pedals, his knees form a 90 degree angle.  The overall impression is that he’s a big guy riding a kid’s bike.  Not only does he look ridiculous, but he’s frantically peddling in the granny gear on only the slightest of inclines.

 

Now, so you don’t look like Pee Wee Herman on your ride, here’s some info to help you get positioned correctly.

 

Technique: How to get your seat height right

By Nick Morgan

One thing all the experts agree on however is that if you get the height wrong, the effects can be catastrophic. A brand new study suggests that setting the height too low can decrease time to exhaustion by as much as 12 per cent.

Consequently cyclists with limited time on their hands might actually get more out of a shorter session by lowering their seats to a sub-optimal level so as to make it harder.

It’s an interesting theory, but even knowing how to get it wrong presupposes that you know how to get it right, and many don’t.  Read on to find out exactly how to do it.

1 The Heel method

The heel method: the heel method

This is the one every bike shop owner or gym assistant will tell you whenever you clamber onto the saddle. You place the heel of your shoe on the pedal and set the saddle height so your leg is straight at the bottom of the pedal cycle with the pelvis remaining in a horizontal position.

Despite this commonly heard method, there is virtually no scientific evidence to support it and it often leads to the saddle height being adjusted too low.

Professor Will Pelever of Mississippi University for Women has written several papers comparing methods for finding the best seat height and says, “The main problem is that this method does not take into account individual variations in femur, tibia and foot length.”

2 The 109% method

A more robust method was developed by Hamley & Thomas in a 1967 paper. They experimented with different saddle heights and found that the ideal was achieved when the saddle was positioned at 109% of your inseam length when measuring from the pedal axle to the top of the seat height.

Your inseam measurement is basically the length from your crotch to the floor. To calculate this, face a wall and put a thick-ish book between your legs as if it were a saddle. Ensuring that you are standing straight with your heels on the floor, mark a line along the top of the book edge touching the wall.

The distance from the floor to the height of the mark is your inseam measurement. It’s best to measure it several times and take an average.

This has proved an extremely popular method and is recommended by many top-level coaches. Yet a recent study by Professor Pelever found that it was inferior to the Holmes method (see below) both in terms of power output and economy.

3 The LeMond method

This is a popular variation on the 109% method and pioneered by the three time Tour de France winner Greg LeMond.

Also using inseam length as a guide, this formula calculates 88.3% of your inseam length and uses it to measure the distance from the centre of the bottom bracket to the top of the seat height.

Interestingly, Pelever has shown that this often produces a different seat height from the 109% method and although it seems to work for many people, it may not be ideal for someone with particularly long femur bones.

4 The Holmes method

 

This was originally developed to reduce over-use injuries in cycling and takes a different approach entirely from the other three. 

It uses a device called a goniometer for measuring the angle of the knee joint at the bottom of the pedal stroke. Holmes recommends an angle of between 25 and 35 degrees and closer to 25 for those with a history of patella tendonitis.

This may all sound a bit technical and if so it’s probably best to go with one of the two inseam methods, but you can pick up a goniometer for around £20 from medical suppliers.

Pelever’s research has shown that setting your seat height based on a knee angle of 25 degrees outperforms all other methods (including an angle of 35 degrees). “Using a goniometer and a 25 degree angle is definitely the method I’d recommend,” he says.

Don’t rely on simply feeling comfortable either. “If you’ve been pedalling at a much lower saddle height than is optimal, it may feel awkward in the beginning,” says Pelever.

“However, as your body adapts (usually in two to three weeks) the new position will not only feel comfortable, but will improve performance in the long run.”

Of course, if you still feel uncomfortable after a few weeks then you will need to make changes. It’s best to use the 25 degree knee angle as a starting place. Have someone watch from behind to ensure that your hips do not rock back and forth across the saddle due to over extension at the bottom of the stroke. If that is the case then the angle may need to be adjusted upwards slightly for comfort.

“When I finish fitting someone on their bike, their knee angle is usually somewhere between 25 and 30 degrees, but much closer to 25 on most all occasions,” says Pelever.


Credits: BikeRadar.com

Photo Credit: amidnightrider

 

One Comment

  1. Suspension is an important part of your dirt bike, that’s the reason why you have to adjust it so it suits you well. Should you be driving on suspension that does not feel right to you it could give you bad performance on the track. Adjust it!