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Old 02-02-13 | 07:57 AM
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cny-bikeman
Mechanic/Tourist
 
Joined: Apr 2007
Posts: 7,522
Likes: 12
From: Syracuse, NY

Bikes: 2008 Novara Randonee - love it. Previous bikes:Motobecane Mirage, 1972 Moto Grand Jubilee (my fave), Jackson Rake 16, 1983 C'dale ST500.

Originally Posted by goldfinch
My primary road bike is a Trek Madone, 43cm with 650 wheels, effective top tube of about 48cm IIRC. I am very short, shy of 4'11". The stem on that bike has next to no rise that I can see and it measures from center bolt of the headset cap to the center of the handlebar slightly less than 60mm. I assume it is a 60mm stem.

I recently bought a used Terry Symmetry (44cm, 650 wheels, effective top tube just short of 50cm IIRC) as a bike I can ride anywhere and park anywhere and toss on the bus racks, that kind of bike. The Symmetry is slightly too long in the reach for me as compared to the Madone. I will say it is a nice and stable bike and not near as twitchy as the Madone. I measure the stem at 70mm. I would like a shorter stem to bring in the reach a bit. I am riding both bikes with the saddle about level with the handlebars.

Questions:

1. How short of a stem can you go without a big negative on handling?

2. Neither the Madone nor the Terry have any angle to speak on on the stems. If I get one with a certain amount of rise, does that change effective stem length? Or, is stem length measured differently if the stem is angled?

3. Unrelated to the stem question, I have another minor question. The tires on the bike are 650 x 28, made by Terry. I like the wider tires. The side of the tire reads inflate to 110 but doesn't give a minimum. I put 90 pounds in them. Can I go lower? I weigh about 105 pounds.
  1. The shortest you can go is 40mm, which will make the handling slightly quicker, but not very noticibly. People sometimes exaggerate the effect of changing stem length on steering. The difference in steering is proportional to the change in distance from the center of the fork colum to your hands, and in the case of going from 70 mm to 40/50 mm that is a 3.5/2.5% change. Perhaps you have looked already, but to see the options from 40-50mm use this Google search threadless stem (40mm OR 45mm OR 50mm) (28.6 OR 1 1/8) -bmx
  2. Distance and height from saddle to bars are related but separate issues. That being said geometry would indicate that more rise would put the bars slightly more toward you as well as putting you more upright. (use the calculator in the post below)
  3. http://www.dorkypantsr.us/bike-tire-...alculator.html (you can Google bicycle pressure calculator for other pages and even apps).

Last edited by cny-bikeman; 02-02-13 at 09:07 AM.
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