Stem advice
 

Hi
Would like to replace a 3ttt stem on my 30 yr old Trek with something longer...there is a "80" mark on it
which I assume is maximim height. Can I go with a 40 degree stem for more upright position? Comfort
is more important to me than maintaining "appearances"...

You can go with any stem that provides you a comfortable fit, provided the diameter is correct for your steering column, the clamp size matches your handlebar diameter and you do not exceed the insertion marks on the stem.

Most bicycles used a 22.2mm stem but some 22mm was used on European brands. 21.15 was standard for BMX and some very inexpensive box-store models.

Clamp diameter can be 25.4mm, 26.0mm, 26.4mm or 31.8mm. The latter is a modern standard. Most 3TTT bars use 26.0mm but measure yours to be sure.

The 80 you mention should be the extension or reach of the stem, in millimeters.

Most stems sold to-day are for threadless headsets and clamp directly to the steering column, which prtotrudes above the headset. You may have some difficulty finding an old, quill style stem, with sutiable rise, to fit a 26.0mm bar. Good luck!

You could either get a threadless stem adaptor and use a modern stem to get the rise you need, or go for a Nitto "Technomic" stem:

http://harriscyclery.net/merchant/37...technomics.jpg