Engineering Students Build Tool-Free Adjustable Head Angle Headset
A group of engineering students from California Polytechnic State University have developed, built and tested a headset which can adjust a bike's head angle in under twenty seconds, without tools. The product is the result of a senior engineering project by Ben Harper, Josh Martin, Dylan Prins and Glenn Petersen of Cal Poly Bicycle Builders, whose work we've reported on before.
The headset offers three positions: neutral, steeper and slacker. It changes the effective head angle of the bike by +/- 2-degrees relative to the mainframe. However, because the head tube of the bike drops as the fork gets slacker, so the angle of the frame changes, the overall change in head angle is around 1.5 to 1.6-degrees either side of stock, depending on the length of the frame, fork and head tube.
While angle-changing headsets are nothing new, existing designs require a long while in a workshop plus specialist tools to swap out or change the orientation of the cups. That makes them a "set-and-forget" product. And while head angle can be adjusted with flip chips, these usually provide a tiny change in head angle and also alter the reach, bottom bracket height and seat angle, making them of limited use. This headset can be adjusted on the trail-side with no tools in less than twenty seconds (the claimed average time is sixteen seconds). That means it could be adjusted to suit different trails, or changed between climbing and descending. The team suggest it could be rented out by bike shops to curious customers / bike nerds who want to feel the effect of different head angles with the most direct comparison possible.
A structural prototype without the Vecro strap or QR preload mechanism.
The headset fits tapered steerer forks and uses ZS44- and ZS56-standard cups. The lower cup allows the bearing carrier to pivot as the head angle changes. The upper cup has three pairs of holes which attach to the bearing carrier with pins to securely lock the steering assembly into one of three positions. To avoid having to loosen the stem and preoad bolt before adjusting, headset preload is provided by a quick-release clamp and a conical spacer from One-Up Components. When the clamp is released, the headset has enough wiggle room to be adjusted, then the preload clamp is re-tightened once the pins are in position at the chosen setting. A Velcro strap ensures the pins stay securely in place.
The headset was designed using Finite Element Analysis, machined in-house and tested on a purpose-built test machine to four times the calculated maximum loading case. Only then was it tested out on the trails. After around 200 miles, the team say it performs just like any other headset while riding, and it never became difficult to adjust.
I asked Andrew Kean, Professor of Mechanical Engineering at Cal Poly and project sponsor, if they had any IP or patents on the product, and if they intended to commercialize it. "The way senior projects work at Cal Poly is the IP stays with the project sponsor (me)," he said. "I left it up to the students to decide if they wanted to maintain any IP or secrecy, and they all declined. If they had wanted to commercialize the headset, I would have supported them. But I think they were just happy to have a successful school project and then move on with their lives. I would love if others learn about the project and maybe improve the project on their own. In its current form, it would be great for a demo bike where a shop could allow a consumer to try out different head tube angles easily on the trail. It would need to be refined before it could be commercially successful for consumer sales."
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that creates a production version of a "mule" bike
which allows a shop to replicate the travel and angles of 3-4 different bikes
might have an edge on the competition.
This headset would fit right in on a project like that.
Mongoose NX 9.7, 1999.
Imagine when they say "would be nice to have it just a bit slacker/steeper" they could actually confirm if that is what they want or if there is something else they don't like.
For the rest of us, I'm not sure.
That’s correct, I studied something in between underwater basket weaving and rocket science.
Give me a call when the slack, slacker and slackest version is available. (If Chris Porter hasn’t TM’d that already)
Not saying it's the case here.
While we're on the topic of head tubes and head sets - why do we still do Star Nuts? Argh...
The loose pins were replaced with some kind of spring-loaded pin solution, which means less chance of loosing pins and less steps to move position.
The preload system would be changed to something like a eccentric-concentric expanding solution which doesn't require a big QR lever, but can be solved with a smaller, locking solution.
I can see the solutions in my head, but it's hard to put into writing without drawing it out. Brilliant concept though.
Normally, we only need slack when turning down, and besides, with an upright headangle, it would be great to have less travel and harder suspension.
There are/were in the past bikes that could formshift with a button. Brands like Canyon, another german company that I don't recall that had an adapter above the shock and connected with the fork.
The way I see, is that complicated design although solving some problems, it creates others problems.
On the other hand, droppers are much more complex and today almost everyone wants it....
I would look forward to seeing it be sleeker/more stylish but equally as functional. Great idea and great design/implementation.
Because remember droppers? Wasn’t such a bad idea.
www.pinkbike.com/news/straitline-quickie-stem-2010.html
On a serious note, people are seriously downvoting me? I’m quite clearly joking.