Mountain Biking - Seat Height

I am new to MTB, been riding road for a while. I was curious about seat height and bike fit. My understanding that your MTB should be a little bit smaller then your road bike. I ride a 59CM road bike and have a 20" MTB. I usually adjust my seat on my MTB so that my legs are extended properly like I do when I ride my road bike. I am beginning to think my seat may be too high as I feel a bit uncomfortable in my shoulders and arms because they are carrying more of my weight then my arse. What would be the effects of lowering my seat? Would my pedal stroke lose some power? Would me legs/knees be under some different strains?

To be sure, there's a happy medium in there somewhere. I have my MTB seat lower than my roadie so I can get off the back of the saddle if necessary (with the pedals leveled). I'd suggest trying it down slightly.

Of course, the geo of both bikes will play a factor in what you find is comfortable. Some MTBs have much longer top tubes than others which, in turn, affects how much you are leaning over the bike and pressure on the shoulders too.

One thing about the road v. mtb set-up too is that on the MTB, even with my full suspension, I'm out of the saddle more than on my roadie.

The lower your seat the more you climbing ability is affected. Do you use flat or riser bars? Riser bars may help you put weight back on your arse since you won't have to lean forward as much.

Flat. I was told the higher the bars the harder it would be for me to keep the front wheel on the ground while climbing. Where I ride there is a lot of climbing. I guess I need to find a happy medium.

FWIW, I often adjust my seat at the "top" of a ride. Most of my rides are nearly all uphill on the way out, and nearly all downhill on the way back. I set my seat higher (1 - 2 inches) than the bars on the way up, and level on the way down.

Where I live it is very hilly also. I use riser bars with no trouble. You just have to remember when climbing to tuck your elbows in toward your body that way if you pull on the handlebar during a climb your are pulling back and down instead of pulling the front wheel up. If you still pull the wheel up when climbing then you should be in the next harder gear.

raise your front end with a riser bar and stem, don't' compromise your pedaling efficiency by lowering your saddle.

Play with your saddle height and find a happy medium. It will be more about personal feel on a mountain bike as compared to maximizing efficiency on the roadie.

...I ride a 59CM road bike and have a 20" MTB. . .

Granted it comes down to personal preference but a 20" may be a bit on the larger side for you. It will work great if you ride smoother fireroads/single track but if you do any steep and/or technical descents/trails you may find that you feel out of control because you can not move around enough on the bike.


I am beginning to think my seat may be too high as I feel a bit uncomfortable in my shoulders and arms because they are carrying more of my weight then my arse. . .

Road bike ? Do you run a flat bar or drop bar? Would seem to me that you are leaning over more on a roadie then a MTB unless you are on more of a commuter/hybrid style set up on the road bike.
Try a riser bar and possibly a shorter stem depending on the length that it has now. If you are worried about the front lifting on steep climbs then be sure to sit on the "tip/nose" of the saddle, lean forward a bit and do not pull UP on the bars AND keep a smooth spin going.



...What would be the effects of lowering my seat? Would my pedal stroke lose some power? Would me legs/knees be under some different strains?

Yes and yes. With the seat set like you have on your roadie (if it is adjusted properly) you will have a more efficient stroke but you will be giving up some maneuverability on the MTB.

Having the knees in a new a different position will change the stress on them and you may even feel a bit of soreness because they are used to the roadie position. If you feel pain rather then soreness give it a rest, see if it happens again and you just may need to keep that higher setting.

Also remember, it is not bad form to mount and dismount a MTB to adjust the seat before and after a climb or technical section though it can become a pain in the arse depending on the trail.

DBD:beer:

Get a Gravity Dropper and have the best of both worlds.