Absolutely the same. I've made this mistake in the past and wondered why my knee was fine after six hours on the road bike but ached on a two hour ride on the MTB.
General rule of thumb is that all of your bikes should be setup the same from the hips down. Also - generall speaking - pain in the front of the knee indicates your seat is too low, pain in the back indicates too high.
Of course, for an aft, seat position, top tube length, etc. means a bike fit is the only way to be sure.
Here's more info that you wanted:
Knee Pain
Knee Pain Location
One way to classify knee pain (and identify possible solutions) is to look at the location of the pain.
- Anterior (see chondromalacia below)
- Reasons
- patellar tendonitis
- patellofemoral syndrome
- Causes
- pushing BIG gears - cadence too low
- saddle too low or too far forward
- foot too far forward on the pedal
- crank arms too long
- leg length discrepancy with seat set for shorter leg
- Possible solutions
- ride at 75 rpm or higher
- raise seat (in small increments of less than 5mm) or move seat back
- move cleat forward 1 to 2 mm
- shorten crank arms by 2.5 cm
- set seat for longer, not shorter, leg with correction for the shorter leg
- Posterior
- Reasons
- hamstring/gastrocnemius
- neurovacular bundle
- Causes
- saddle too high or too far back
- too much pedal float
- leg length discrepancy with no correction for shorter leg
- Possible solutions
- lower seat (in small increments) or move seat forward
- limit float to 6 - 8 degrees
- set seat for longer, not shorter, leg with correction for the shorter leg
- Medial (inner side)
- Reasons
- medial collateral ligament
- pes anserenus
- Causes
- cleat position too wide - foot held externally rotated (toes point out)
- excessive knee frontal plane motion
- too little pedal float
- Possible solutions
- narrow foot position by moving cleat towards the outside of the foot (thus your foot moves nearer the bottom bracket)
- orthotic or wedge to correct foot alignment
- pedal float should be 6 - 8 degrees
- Lateral
- Reasons
- iliotibial band
- degenerative lateral meniscus
- Causes
- cleat position too narrow - foot held internally rotated (toes pointed in)
- too little pedal float
- excessive knee frontal plane motion
- Possible solutions
- widen foot position by moving cleat away from the bike
- pedal float should be 6 - 8 degrees
- orthotic or wedge to correct foot alignment
Saddle Adjustment
A simple seat height adjustment may ease the forces placed on the knee. If the seat is too low, stress is placed on the knee from the patellar and quadriceps tendons and is generally felt anteriorly below the patella where the tenson inserts on the tibia. If the seat is too high, pain may develop behind the knee.
There are several different ways to determine proper seat height. The easiest way is to allow one pedal to drop to the 6 o'clock position and observe the angle of the knee joint. There should be a 25-30 degree flexion in the knee when the pedal is at the bottom most point. Another is to measure your inseam (in centimeters) and multiply this measurement by 0.883. This should be your distance from the top of the seat to the center of the bottom bracket. If you place your heels on the pedals, have someone else hold the bike, and pedal backwards, your hips should not rock back and forth. Likewise if your hips rock when you are riding, lower your saddle until you achieve a smooth pedal stroke.
Seat fore/aft position and cleat position may also contribute to knee pain. Saddles that are too far back cause the cyclist to reach for the pedal and stretch the IT band with resultant knee pain. Saddle position can be evaluated with the "plumb bob technique". Seated with the pedal in the 3 o'clock position, a "plumb" hung from the most forward portion of the knee, should intersect the ball of the foot and the axle of the pedal. |