HeadShok Stem Project — Quick Poll Inside

[cannondalefanatic]

Is there any progress on this? I just now saw it and am very intrigued.

Thanks for the interest! Yes, here's an update. If you filled out the survey (above), you should be subscribed to the newsletter that will be coming in 2026.

Current Status: Testing​

Current configurations under test:

• HeadShok — 1.56” steerer | 31.8mm bar | 60mm length | 0° rise
• Standard — 1.125” steerer | 31.8mm bar | 40mm length | 0° rise

Testing to date includes real-world riding on my own bikes:

• Super V (MTB use)
• F700 (road / gravel crossover use)

These rides include rocky singletrack, sustained vibration, and typical trail impacts. So far:

• No stem slippage observed
• No visible signs of fatigue or deformation

To expand coverage beyond my own setups, a small group of local riders has begun testing the standard steerer version. This helps validate broader usage scenarios while supporting continued development of the Cannondale-specific variants.

Local MTB trails used for testing

What’s Next​

A dummy steerer test fixture has been sourced and is currently in transit. Once received, final samples will be prepared and sent to a certified lab for ISO 4210-5 testing.
This will provide standardized data on strength, fatigue, and safety, and represents the final major validation step before any production decisions are made.

 

[Kenright73]

Yup, filled out the survey before I posted. My preferences are a little different as I'll be working with early '90's geometry; longer stem (110 or 120mm) and a small rise (5°). Steerer tube diameter will be 1" threadless.

If all goes well with testing and feedback, will the stems be built on custom measurement requests?

 

[cannondalefanatic]

Yup, filled out the survey before I posted. My preferences are a little different as I'll be working with early '90's geometry; longer stem (110 or 120mm) and a small rise (5°). Steerer tube diameter will be 1" threadless.

If all goes well with testing and feedback, will the stems be built on custom measurement requests?

Great question, and thanks for the detailed context and survey participation.

One thing that’s important to understand up front is that any meaningful change in geometry or interface still needs to go through the same validation and certification process. Length, rise, steerer interface, clamp geometry, and materials all matter, and once you step outside a tested configuration, it’s effectively a new design from a safety standpoint. So certifying one stem doesn’t automatically open the door to other sizes or variants.

There are two slightly different communities here. The restoration crowd tends to want period-correct lengths and geometry, while the resto-mod crowd is optimizing fit and handling with more modern setups. Based on the survey feedback so far, the initial development has leaned toward the resto-mod side, which is why the first configurations skew shorter. That doesn’t mean longer, original-style geometries are off the table, just not the priority based on initial feedback.

I am open to going down that path if someone is genuinely serious about getting exactly what they want. In those cases, it’s less about a one-off part and more about funded development of a new variant, engineered, tested, and potentially certified the same way a production part would be. It’s not inexpensive, but if there’s real intent behind it, there are creative ways to approach it so the effort isn’t wasted.

Right now the priority is getting the first configurations fully tested and validated. Once that baseline exists, it becomes much easier to explore additional geometries responsibly.

If you’re interested in pursuing a specific geometry and understand what’s involved, feel free to send me a DM. Happy to talk through what that could realistically look like.

 

[cannondalefanatic]

A few people have asked how I'm handling updates as this moves along.
I'm posting design & test updates to a single mailing list.

Anyone who participated in the original survey is already included. This is mainly for folks who want updates without tracking every forum post. I'll still be posting updates here as things come along.

Link here if useful:

A modern stem, thoughtfully developed for legacy Cannondale HeadShok bikes

xstemproject.kit.com

 

[cannondalefanatic]

I’ve posted a progress update on the XStem HeadShok project for those interested.


The latest newsletter covers current test status, design decisions, and next steps. Still very much an iterative process, but making steady progress.


Sharing here in case it’s useful or sparks discussion:

XStem Project Update - New 2026 Surveys, Testing Progress & What’s Next

ISO testing is underway for the XStem project. See progress updates, rider feedback, and what’s next for vintage Cannondale HeadShok bikes.

xstemproject.kit.com

 

[cannondalefanatic]

Been deep in XStem development lately, but another small part keeps coming up:

HeadShok lockout knobs / stem caps.

A lot of originals are cracked or missing. Before producing anything, I put together a short 3-minute survey to gauge real demand and preferences (period-correct vs modernized, additive vs CNC, pricing, etc.).

Not a preorder. Just collecting input before moving forward.

If you’ve got a HeadShok fork, I’d appreciate the feedback:

Take Survey Here

I’ll share what comes back once responses are in.

 

[cannondalefanatic]

Wanted to share a proper update here for those following the XStem project. Some of you may have seen the short version on Facebook, but I'll provide a little more detail here.

The XStem has completed ISO 4210 mountain bike stem validation. Here's what was tested:

• Full MTB fatigue cycles, in-phase and out-of-phase
• 1600N and 2600N forward bending stages
• 1000N lateral bending
• 50Nm torsional security

All completed successfully under controlled conditions. 6061-T6 aluminum, all three variants (Heashok 2-piece/1-piece clamp & Standard 1-piece clamp) validated.

Important note on intended use: validated to MTB load levels, but positioned for cross-country and recreational trail riding consistent with ASTM Condition 3. This is not designed for aggressive enduro, downhill, freeride, or bike park use. The geometry and intent respect the original HeadShok platform with modern validation behind it.

Design is locked. Now comes manufacturing.

For the HeadShok variant, I'm planning a limited initial run of 25 units:

Black anodized. 60mm / 0 degree / 31.8.

I'm finalizing production quotes right now to lock in retail pricing for this first batch. I've been talking to CNC shops in the US, UK, and Taiwan, and the learning curve on small-batch production economics for a part with this many tight tolerances has been steep. Steerer bore, clamp fit, deburring, anodize stack-up. Each one adds real cost at low volume.

A few things I'd welcome input on from this community:

1. Has anyone here been through a group buy for a bike component? What made it work or fall apart?
2. Know a CNC shop with experience machining bike parts? I'm actively qualifying production partners and would appreciate introductions.
3. For Lefty owners specifically: I've had a question come up about 60mm stem length compatibility with certain Lefty forks. If you're running a Lefty and have thoughts on minimum stem length, I'd like to hear from you.

If you want priority access when pricing is announced, let me know in the thread or send me a message. I'll reach out directly when the numbers are final.

If you'd like to further weigh in on manufacturing and pricing paths for this project, you can fill out this survey here:

Feedback on XStem Manufacturing and Pricing Paths – Fill out form

I'll keep updating this thread as production moves forward. Thanks again to everyone providing feedback and guidance. Appreciate it! -Bruce