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questions about steerer tube diam & stems, threadless vs. ?(5 posts)

questions about steerer tube diam & stems, threadless vs. ?Haiku d'état
Jun 7, 2001 3:28 PM
converting an old SS cruiser to some kind of crazy mutant bike. learning experience. questions:

stem: replacing comfort-angled quill/threaded stem with another, and the cruiser bar with a straight bar. getting whatever's on sale at nashbar (this is a beater).

how do i determine the steerer tube diameter? can the fork be removed and the top of the steerer tube rolled along a ruler to get an accurate diameter measurement (of 1/4 or 1/8)?

also, anyone have experience with threadless stem adapters?
check quill diameter...C-40
Jun 7, 2001 7:12 PM
Quill portion of a stem for a 1 inch steering tube is 22.2mm or 7/8" inch diameter. Quills are 25.4mm or 1 inch diameter for 1-1/8" steering tubes.

To get an approximate diameter measurement, use an adjustable (crescent) wrench, and set it to fit tightly to the quill. Use a ruler or tape measure to measure the distance between the jaws. Works like a crude caliper.
Crude caliper....Rusty Coggs
Jun 7, 2001 7:24 PM
...I like it. One to remember.
re: questions about steerer tube diam & stems, threadless vs. ?Rusty Coggs
Jun 7, 2001 7:22 PM
Pull it quill stem out.1" ones are usually marked 22.2mm ones for 11/8" are marked 25.something mm. Thoes numbers refrence inside diameter of steerer tube. Pull the steerer and measure diameter. A ruler across the top is good enough. Or just remove the top nut and pull the quill and then measure. If you have a caliper You can just measure the quill at the insertion mark. 22.2 or 25.something. Once you have seen several, you can tell the diff just by looking. I have used a few quill adapters. They are OK . Some are better than others.
thanks! i'll check this weekend.Haiku d'état
Jun 8, 2001 7:28 AM
funny how you lose this stuff from school if you don't use it often enough. i was thinking diameter was the full distance around the tube, but that's circumference...diameter is the distance across the opening, radius is 1/2 the diameter. ouch. head hurt.

thanks again for your input!