Wednesday, December 9, 2015

There's an App for That: Suspension Forks

Let me just make it clear at the beginning of this. I don't ride bikes with suspension. I know - heresy, right? The way I figure it, I'm one of the many, many people (the majority of cyclists, probably) who never rides in the kinds of conditions that make it necessary. And that for most of us, suspension is just a heavy complication.

Complication? Read enough on forums about mountain bike suspension, and you'll get the sense that proper suspension tuning is some surreal combination of art, science, and voodoo. And the ideal adjustment can change constantly, even during a single ride, depending on trail conditions.

Well, if any aspect of cycling screams out for computer-assisted intervention, I guess it's suspension tuning. And it looks like somebody is making that happen.

SussMyBike is just wrapping up a Kickstarter campaign (ends on Dec. 11) for a suspension fork setup tool that uses an electronic sensor and a smartphone app that analyzes suspension activity and recommends improved settings.

The fork-mounted sensor has a spring-loaded tether line.
Such sensor units are sometimes called "yoyo sensors."
The system consists of a box with a spring-loaded retractable tether cord - the box mounts on the lower fork stanchion, while the other end of the tether cord mounts to the upper part of the fork. Movement of the fork up and down causes the tether to pull or retract, which operates sensors in the box, where data signals are collected and sent via Bluetooth to the smartphone. Though the SussMyBike Kickstarter page never states it explicitly, some readers might recognize the fork sensor unit as something called a "string potentiometer" or more colloquially, a "yoyo sensor."

"Suspension has evolved!" shouts the SussMyBike ad. "We live in a world where (nearly) everything can be measured. We have an appetite for numbers and data. We want figures that will help us optimize results. Strava, MapMyRide . . . it's everywhere!"

Yes it is. It's everywhere. Like viruses. And when I get out on my bike, the last thing I want is more data. Riding is where I get away from it all.

There's the yoyo sensor mounted on the fork stanchion,
with a smartphone analyzing the data. (photos from SussMyBike)
So, why would somebody need all this technology to set up their fork? SussMyBike says: "The problem is that fine tuning your bike suspension for best results can take hours of trial and error and lots of head scratching. Ask your biking friends how to set up suspension and they will all give you a different answer! . . . They are not riding your bike and do not know how it is reacting. SussMyBike measures what actually happens so you do not need to be an expert rider to adjust your suspension." The crowdfunding ad goes on to cite professional mountain bike team mechanics, saying "Even professionals find this stuff hard!"

Actually, I have no problem believing any of that. But what it says to me is that I'm glad I don't bother with suspension.

I have no doubt that there are people who will find a suspension tuning app very useful. I'm just kind of happy not to be one of them.


  1. It seems that would only help tune your suspension for how it was ridden on that one trail (maybe even just that one time) the day you measure the ride. If you ride on a different trail, or change the size of your tires, or your normal route is all muddied-up, etc. then all measurements will change. Not that I can't imagine a benefit for this thing, but it seems awfully narrow.

    I am no mtn biker, but when I do pretend to get a little dirty on a bike, I like a rigid frame. Forks add weight, complication, expense, etc., and that isn't beneficial to me. My rides aren't "epic" enough.


    1. Good points -- like you say, every trail would be different, and I assume this isn't something one is expected to keep mounted all the time for constant "real time" reevaluation of settings. Anyhow, it's not meant for us.

    2. Suspension setup really isn't all that hard. I returned to off-road riding after a long period of inactivity (during which time suspension evolved from "using your elbows" to the mess that we have today) and, although I was initially intimidated by the numerous ways a suspension fork needs to be set up, by my second serious off road ride I had it down. Really, it's no more complicated than learning to shift friction shifters for those people who have always click-shifted. My point is that the technology in the article is totally unnecessary, since forks really can be set up by "feel" alone.
      Still, 99% of my riding is done on the road, making my suspension fork a somewhat ugly, after-the fact accessory. But, and I say this as someone who was quite dubious of the technology - for serious off-road riding, there's no comparison between a rigid fork and a suspended fork. Well, I'll qualify that - hats off to you rigid fork folks in the woods - you're die-hard! But for my old bones I appreciate the gains that have been made in suspension during the last 20 years. Really, only one "improvement" (if you're into that) I can think of during cycling technology during this timeframe.

    3. Certainly, if someone is doing some pretty serious trail riding in the woods and mountains, suspension can be a good thing -- and I just don't do that kind of riding.

  2. I confess: I did have two bikes with suspension. Actually, the frames were hardtails, but they both had suspension forks. I actually did ride in conditions where they were useful. I don't anymore, so I, too, see suspension as an unnecessary complication.

    I'll admit that I never got it adjusted quite right. Everyone, it seemed, had different ideas on how to do so. If I'm reading this post right, it seems that unless you're doing exactly the same ride (same trail, weather conditions, tire width, etc.) as you were doing when the measurements were taken, the data will be of little or no use.

    This makes me think of a story a co-worker told me: A wealthy man takes up hot-air ballooning. One day, when he is aloft, a storm hits, blowing him off-course and forcing him to make an emergency landing.

    When he emerges from his cabin, he sees another man. He calls out, "Excuse me, sir. Where am I?"

    "Why, you're in a field."

    The ballooner thought for a moment. "Are you an accountant?"

    "Yes! How did you know?"

    "The information you gave me is completely true and completely useless."

  3. I have a Specialized Crossroads of some variety (they made so many) from the early oughts with a suspension fork. It's the front half of my Xtracycle. Honestly, I didn't know it was adjustable. It's just dead weight as far as I can tell. :-\

  4. Rented a couple of bikes on a recent trip to San Fran. Both had suspension forks. The first outfitter's business was almost exclusively aimed at urban tourists and M.U.P. riders, the second expected that we'd be doing the fire roads of Marin. We stuck to paved roads and paths, with only one brief jaunt through a park in Mill Valley. i found no benefit in the front suspension-in fact i found it disconcerting, especially when starting from a dead stop. i suppose that the suspension forks may have made sense on a single track or a rutted fire road, but for most conditions with the average rider of these type bikes, it seems to be a case of a solution in search of a need. A recent post on Mr. Moulton's blog, "Selling the Benefit" comes to mind.

    What is the expected life span of a suspension fork and frame? How long is it before it becomes a boat anchor or doorstop?

  5. Mike W--My favorite mechanic tells me that the suspension forks found on today's $500-$600 bikes will last about two years, or a year of hard use.

    I never found out how long either of my suspension forks held up because I sold them--one after two years, the other after five (when I sold the last mountain bike I owned). The last one was the latest version was the latest (when I bought it) version of the Rock Shox Judy (the yellow one); the one I had before it was a Rock Shox 21. Both were considered among the best at the time I bought them.

    I'm guessing the Judy probably lasted a few more years, if person who bought it maintained it (or just didn't ride it very much). I think, though, that even if it's a high-quality suspension fork, I'd retire it after about a decade, especially if I'd been doing a lot of technical (or simply hard) riding.

  6. Really big tires at low pressure can take the place of a suspension bike much of the time. Thats the concept Jeff Jones uses with his bikes. Riding a bike without all the bouncing and floating is more about using technique and skill. It asks more from the rider than a suspended bike does, but riding a non-suspended bike with fat tires in challenging trail conditions can be a lot of fun!

    Sometimes a trail is just meant to be hiked. Hiking while walking with the bike (hike-a-bike) can be pleasant and perhaps a better way to experience the trip. Inflate the tires hard again when on the transit/pavement part, where all the suspension stuff is just an albatross around your neck.

    I think those who need or want to drive a car to where they ride a bike are more suited towards using a suspended bike.