bike geometry question.

[Barrydanzig]

hey,


i'm currently building a 19in rockhopper frame for racing (when i'm all better of course) and i am starting to get bogged down in the geometry. being an average sized rider (6foot-ish) i need to know what type fo stem i would need. would a 120mm stem with a 0 degree rise be suitable? or would i need something shorter/longer with a few degrees of rise? i am planning on running a flat bar with bar ends on the bike.


anybody know whats best for me?

[Morgan]

Hard to say really. Depends on your height, the length of your arms, the length of the frame, your saddle height, your fork length, the number of spacers you can fit on the steerer, how far forward you want to lean, the amound of layback on your seatpost and your shoe size.


Your best bet is to use any old stem - whatever you have or can borrow and use that as a baseline to determine the ideal stem size for the bike.

[diamondG]

speaking of "how many spacers you can fit on the steerer"


if you're cutting the steerer stube on the fork, leave lots of room for spacers.

You can then raise and lower the stem/bars as needed to get it right, putting spacers above or below the stem.


I'd kill for some more height in my bars, the bike is too low on the front, I should buy a new stem with greater angle, but it would be so much handier if the steerer tube wasn't cut so short.

so if you're cutting it.. beware

[Barrydanzig]

yeah i am not gonna touch the steerer tube until i get it just right, even then i will be getting a bike shop to do that for me, just incase they have any words of wisdom on the matter. my coiler was a 20inch frame, and the stem was 90mm with a 12degree rise, and big freeride riser bars, so i'm thinking to get a similar position using flat bars i will need roughly 130mm with maybe a 10degree rise..? now as i have said before maths is not my strong point, but maybe this combination would work. i am thinking i will go into rip-off city...sorry i meant cycleways...and sit on a 19inch rockhopper and be "really interested in buying", that way i can get them to swap stems etc. to suit my riding style and get a position that is comfortable for me, as i've heard they do that.

[Oisin]

I wouldn't advise trying for a similar riding position on an XC race bike as your coiler. The coiler would be much more upright and a shorter reach which is good for DH and jumping but for XC racing you'd usually have a more stretched out position. Its better for efficiency and power over longer distances.