how do you measure a stem?

[jim55]

my road bike(that ive just got ),it feels like too much of a stretch and im always fidgeting ,the hoods feel a bit far away and i have to stretch for them ,,so im thinking move the bars a bit closer to me ,,,(iv tried the seat as far forward as it goes and its still not enough (doesnt feel right either ),,the stem thats fitted puts the bars too far forward ,it has a long top part ,,iv seen a nice used stem on ebay (btw the bike has an old style threaded headset ,,with a big lockring ,so the stem can just b loosened and changed ,not affecting the forks at all)with a shorter "projection "(eh?),,what i need to know is changing this is quite straight forward ,,but ,,as far as i know theres two diff sizes ??do i remove the existing part and measure across the existing hole or what?how do i know which size i need ?

btw the bike is an older road bike made with reynolds 753 tubing on original forks if thats any help

 

[jim55]

if this helps

 

[accountantpete]

The stem reach is measured from centre to centre - ie centre of the steerer bolt to the centre of the bar clamp.

I'd make sure your seat is correctly positioned first though.

 

[jim55]

its not the reach i need measured its the diameter of the whole (ooer missus )that the stem fits into i think

 

[youngoldbloke]

Measure the diameter of the existing stem - if you haven't got calipers use an adjustable spanner tightened to a sliding fit and measure the gap. Sheldon Brown has lots of information about quill stems and the various diameters used, (but it is probably 1").

 

[jim55]

thanks ,,, thats a good tip

iv seen a good one on ebay ,,,hope its the right size ,,the "throw/reach is spot on ,if the steere fits ,,game on

thanks