frame size

Question
QUESTION: Hello

Have a small size mountain bike 17" that bought years ago from bike store. I think I should have had medium - 18".  I like the bike but only now I discovered that it may be slightly too small for me.  If I raise the seat so that my legs are almost fully extended, than I am too high from the ground.  Can ride like this maybe on asphalt but not on a trail.  On the trail, I thing that my legs are too bent.  I am 5, 10" inseam is 31".  Is there any corrections/parts etc. that I can make?  

Thank you,     Gabe

ANSWER: Dear Gabe,

Sorry for the delay, but I needed to have some more time to think about your question.
What I do understand is that with your bike you can reach the ground with your feet (flat?).
If you want a good position on your bike, you should loose that idea that you won't feel the ground anymore because you are more stable without hitting the ground when you stay on your pedals. For example when I'm on my regular bike without suspension I can reach the ground with my toes. But when I'm on my fully I can't reach it anyway.

The right way to adjust your height of the saddle, is to put your heel on the pedal. When you can't stretch it anymore without overstretching the leg your in the right position.
That is for all kind of bikes!


Take a look for more information at the following websites

http://www.google.nl/search?q=mountainbike+seat+position&um=1&hl=nl&biw=1366&bih

http://www.giant-road-bike.com/index.php/2010/06/19/how-to-adjust-your-bicycle-s

http://miamirally.com/cm/index.php?option=com_content&task=view&id=10&Itemid=1

Good luck

Best regards

Michael

---------- FOLLOW-UP ----------

QUESTION: Thank you, the problem is that when my seat is high and I am on the asphalt all is good ad my legs are bent correctly.  However, if I leave this position and go on a trail, I am much too high to feel comfortable when passing a dip etc.  If I lower the seat to a comfortable level to ride on the trail, I think that my leg ate too bent.  

Do you have anymore guidelines, please?

Thanks again,   Gabe

Answer
Hello Gabe,

It is impossible to sit low while your legs/knees are correctly bended.
It is a compromise between strength/feeling ok at your bike and guts.
The links I gave you before are the right ones to set/tune your bike perfectly.
You can take a much smaller bike, you will need a much longer seatpost and a longer stem.
But after all, if you want to sit down correctly, you still can't touch the ground.
A roadbike has a lower placed bracketarea, there where a mountainbike has a higher one to jump over rocks and trees.
And even worse, if you want a fully you will sit much more higher at that bike.

So adjust slowly your seatpost higher (by 0.5 centimeters) a month (you can do it faster but that depends how your body is reacting on that). And work on your stability on your bike. You can do that by practice riding circles slowly and pick up flagpoles or cones from the left side to the other while riding VERY slowly.

Hope that this will answer your question.

Thanks