quill stem sizing
 

I'm trying to figure out what sort of stem I need to get. I had ordered a Nitto Technomic (the one with the 225mm quill), but just recently found some threads which report that this stem does not work on small frames. I'll be mounting this stem in a 51cm frame --- a 1985 Pinarello Montello. Can anyone confirm this?

It would be nice if I could adjust the stem to get the handlebars anywhere from level with the seat to 2-3" below. If I've done my math right, that means I need between 66mm-145mm stem extension above the top of the headtube. I'll be using a Ritchey Logic Comp headset, which has a stack height of 37.9mm. I'm not sure if this is the stack height for the upper races/bearings/cap or the lower or combined. I'm guessing it's total stack height? I got the numbers here:

http://www.bikepro.com/products/head...table_top.html

So, assuming that the stack height above the headtube is on the order of 27-28mm that would mean I need a stem with an 38-118mm extension range. Obviously, this is a wide range, so I wouldn't expect a stem to cover the entirety of it, but is there a stem that would be comfortably in the middle, or maybe a bit towards the top of that range? Am I overthinking this?

A typical 51 cm frame will have such a short steerer that there's no way you could get 2-3 inches of height adjustability.

The general rule is that you want 2 1/2" of stem insertion, thoug light riders can cheat a bit on this. The entire length of the steerer is not available for stem insertion, because they are generally butted at the bottom, so the stem can't insert all of the way. Indeed, it's very dangerous to push the stem in so far that the wedge is entering the tapered butt zone.

Assuming your bike has a level top tube (bikes with sloping top tubes usually have longer steeerers for their size, but that style wasn't around in '85) it is unlikely that you'll have as much as 1 inch of height adjustability with any stem.

The Nitto Technomic is a GREAT product, we sell hundreds of them. Try it and see how you like the height.

I have occasionally cut these down for shorter riders, it's not too difficult just cut along the same angle as the wedge and file it smooth.

Sheldon "Technomic Fan" Brown

That is a bit of a bummer. Do you know how much stem extension I can expect out of other stems that don't have such long quills? It's tough finding measurements since everyone has gone to threadless stems.

What sort of cutting tool should be used? Some sort of hacksaw and a miter box?

Thanks for the info!

fwiw nitto is putting out a new revision of the tech stem, it is called the deluxe technomic stem and is 190mm long instead of the 225mm of the regular technomic stem...to me it has a cleaner look to it also..

The Technomic Deluxe has a nicer finish than the Technomic. I like the Dirtdrop.
http://www.rivbike.com/webalog/handl...ape/16044.html

I ride 52 and 53 cm frames, and have the same problem with Technomics, I call it the Giraffe Effect. I found the Technomic Deluxes get the 'bars to a nearly level (with teh saddle) position. Adjustment is limited because steer tubes are thicker at the bottom with smaller ID, so the wedge bottoms out not far from where the insertion limit disappears.

This doesn;t get me much adjustability, but for me that's ok, since my sizing/adjustments are stabilizing. For you, one of those Look stems with adjustabiilty might be a real good idea. Heavy, but adjustable. Then when you figure out where your 'bars need to be, you can get a stem that really fits and save some ounces.

Ken

Are you talking to me?

The LOOK stem seems to be a really cool device. The problem is, at $200 (the best price I could find with a quick search), I could buy 6 normal stems.

One of the reasons I want adjustability is not only because I'm not exactly sure what I want my position to be (but I'm pretty sure I'm close), but also because my cycling fitness varies greatly through the year due to my run training schedule, and the unpredictable demands of work.

I'll think about keeping a Tech. Deluxe on hand, though. Thanks for the datapoint.

It's easy really and I've done a few of these. Remove the wedge and bolt. Now with a hacksaw and using the original slant as a guide just cut off the amount required and remove any rough edges with a file. Do make sure you leave sufficient amount of stem in the steering tube for safety reasons.

Kalloy, and probably others, make an adjustable quill stem, for around $20 - $25 (Your LBS might have a used one or even loan you one). While not perfect (It's got a fairly long post and a wide range of angle adjustment), it should get you plenty close enough to decide what you'll finally need. Good luck.

Any Nitto stem, but especially the Technomic, is fantastic, and they do cut down nicely for the perfect fit.

If you cut the stem, be sure that you don't cut it so short that you run out of threads on the bolt before the wedge can tighten. I made that stupid mistake recently. Luckily, I had a shorter bolt on hand that worked.

PM sent.

not specifically. is there a significant problem?