Handlebar Stem Size?

Srjeeper · #1 (**permalink**) 09-07-2009, 01:02 PM

Time has come to replace the stem on 'HuffNPuff", but I'm not sure what's the correct size. It's a Huffy Cranbrook frame and the stem I'm replacing is the orginal. The two sites I've checked for new ones, look to have them in either 21.1mm or 22.2mm.

Anyone know the diameter of the stem extending down into the frame neck?

All replies are appreciated........

BostonBiker · #2 (**permalink**) 09-07-2009, 01:08 PM

which end of the stem are you talking about? the end that clamps on the steerer tube or for he handlebars? most steerer tubes for MTBs are 1 1/8", for the threadless ones.. road bikes are generally 1" threaded or threadless... hope that helps... you can do the conversions... those are the current standards, for the last few years at least...

Srjeeper · #3 (**permalink**) 09-08-2009, 05:59 AM

Bump - Bump

ocscully · #4 (**permalink**) 09-08-2009, 12:45 PM

My best guess is that what you need is a 22.2 / 1 in. standard. The 21.1/.833 is a hold over from the old days when Schwinn made their bikes using non standard sizes and threads so you would have to go back to a Schwinn dealer to get replacement parts. There are also some older BMX bikes that used the 21.1/.833 stems.

ocscully

Nashville Kat · #5 (**permalink**) 09-08-2009, 01:59 PM

Stem quills, for threaded headsets come in 3 sizes: 25.4 mm (1 inch), 2.22 mm (7/8") and 21.1mm (smallest, not sure of inches, don't want to do math now)

This must not be confused with the fork steer tube diameter which is 1/8 inch larger- therefore a 1 inch stem quill fits in a 1 1/8 inch steer tube, a 2.22 mm 7/8" quill fits in a 1 inch fork steer tube- (Headsets are described as the fork tube they fit: a 1 inch headset fits a one inch steer tube, but takes a 7/8 inch stem to slide into the inside diameter)

22.2 (7/8") is the most common stem quill that fits a 1 inch steer tube and 1 inch headset,

but yes, most newer mountain bikes now have the larger 25.4 stem, which fits their 1 1/8 inch fork steer and they have a 1 1/8 " headset- Road bikes went from 22.2 in the 60's and early 70's to 25.4 when Campagnolo went to a wider stem quill.

After getting familiar with the sizes, I can usually tell on sight- most stems are stamped with their size doown on the quill-

the small diameter 2.11 quill is the more rare and usually on older bikes, but quite standard in BMX old school bikes as well- not really indigenous to Schwinn, but Schwinn did have them on a lot of their bikes when others had largely gone to 2.22 mm.

And all this then must not be confused with handlebar diameter- usually just one of two sizes, again 22.2 (7/8 inch) or 25.4 (1 inch)- if a handlebar is thicker at the stem point of contact, it is usually 1 inch, if it is the same diameter as the rest of the bar it is 7/8 inches. Most handlebars are 1 inch at the center, excet for BMX which is normally 7/8 inch.

smaller sizes of all this can usually be shimmed to the next larger size up with shims, cutt aluminum or tape, but obviously, the larger never can fit the smaller size

Nashville Kat · #6 (**permalink**) 09-08-2009, 02:17 PM

Heres a Schwinn World Traveller I built this summer with an annodized old school BMX stem usually available on bay - the Schwinn has the small 21.1 stem described, which is the size of this MX stem-

I also have one of these on my Peugeot PX10 road bike (circa 1970) which I just shim with some tape- because it replaceda 22.2 stem. Old fart with back troubles who can't ride drop bars anymore, and these BMX bars are lightweight and look great.