In this article I’m going to delve into the specifications of the Headshok stem, and how to find a proper alternative if you’re looking for one. Like I am.
I have two Cannondales with a Headshok stem. A Cannondale Killer V from 1998 and a Cannondale Super V from 1994. I’m at least looking to replace the 15cm.
Headshok stem for the Killer V and might also opt for a different one for the Super V. So what should I be looking for? That’s what we’re going to find out in this article.
Video
Headshok Stem specifications
Head tube diameter
Headshok stems came in just one head tube diameter, which is 1.56″, 1 9/16″ or 39.68mm.
The diameter is used only for Headshok forks and is a Cannondale proprietary standard.
I read some people say old-style headshok stems have a 1.5″ head tube diameter, but based on the fact I measured it myself with a clear reading of 39.7 I don’t see why that would be the case.
Stem finish
Headshok stems come in two finishes: black and silver. The silver versions we’re only mounted on mountain bikes from 1992, which was the year the Headshok fork was introduced, to 1994.
Stem length
I don’t know for sure what specific lengths were onto the market. Only the 1998 Cannondale catalog featured all of the available stems.
Two sets we’re featured: for mountain bikes and for the Cannondale Silk Road bike, which was a road bike with front suspension.
Stem rise
Based on measurements I took from the catalog and the fact that Headshok stems are reversible, you could go from -30° to a 30° rise
Clamp type
old-style clamp 
The first Headshok stems featured a single bolt clamp. This meant the handlebar had to be inserted into the clamp from the side, possibly damaging it, especially with riser bars that had a pronounced curve.
With the single-bolt system you could also see if the stem was inverted. The bolt would be pointing upwards if you did.
They were soon replaced with a front-loading clamp with a 2-bolt faceplate, called the Ahead-style. This style clamp enabled the front of the clamp to be removed, which made the stem much more user-friendly to quickly swap out without removing bar-ends, grips, brakes, and shifters.
All available Headshok stems
Based on the previous information, you can make up what type of stems were available.
All stems can be inverted. So a 135mm. -8° stem can be changed into a 135mm. 8° one.
All of the entires in the following table are offered with the 2-bolt clamp system. Since stems with single-bolt clamps were never featured in the catalog I don’t have more information on them.
Length (mm.) | Rise | Handlebar Diameter (mm.) | Clamp Type |
|---|---|---|---|
115 | 20° | 25.4 | 2-bolt |
175 | 25° | 25.4 | 2-bolt |
175 | 15° | 25.4 | 2-bolt |
145 | 6° | 25.4 | single bolt |
145 | 4° | 25.4 | 2-bolt |
135 | -8° | 25.4 | 2-bolt |
130 | -16° | 25.4 | 2-bolt |
125 | -30° | 26.0 | 2-bolt |
120 | -20° | 26.0 | 2-bolt |
115 | -8° | 26.0 | 2-bolt |
115 | 4° | 26.0 | 2-bolt |
120 | 15° | 26.0 | 2-bolt |
Alternatives for a retro Headshok stem
The original stems came from an age where long stems were all the rage. So the shortest option available was 115mm. Luckily, there are a number of newer alternatives available.
All of these alternatives use 31.8mm handlebar diameters! So be sure to buy a couple of shims for your skinny bars as well.
Cannondale Headshok Stem
Cannondale offers new versions of the Headshok stem. Starting from 80mm. to 120mm. in increments of 10mm. They come in a 5° and 20° angle.
They do have a 31.8mm. handlebar diameter. That means older-style 25.4mm. will need a shim to fit.
The stem has been discontinued in 2014. So getting the size and rise you’re looking for can be quite the challenge.
Length (mm.) | Rise | Handlebar Diameter (mm.) | Clamp Type |
|---|---|---|---|
80 | 5° | 31.8mm | 2-bolt |
80 | 20° | 31.8mm | 2-bolt |
90 | 5° | 31.8mm | 2-bolt |
90 | 20° | 31.8mm | 2-bolt |
100 | 5° | 31.8mm | 2-bolt |
100 | 20° | 31.8mm | 2-bolt |
110 | 5° | 31.8mm | 2-bolt |
110 | 20° | 31.8mm | 2-bolt |
120 | 5° | 31.8mm | 2-bolt |
120 | 20° | 31.8mm | 2-bolt |
Reverse S-Trail Stem
Reverse has created a Headshok compatible 1.56″ stem called the S-Trail. They offer it in a single 8° / 60mm. version to accommodate riders who want a very short stem.
I found the Reverse S-Trail to be the only stem readily available.
Thomson X4 Stem
Thomson also made a 1.56″ stem, which is no longer available. They were all 0° stems. Apparently in four different lengths.
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