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Thanks for the excellent comments about last week’s column on speed wobble.  As usual, I shared it on my Facebook page, and a lot of knowledgeable cyclists weighed in there, too, with additional issues that cause this phenomenon. 

So this week, I’ve updated my list of causes since there are quite a few more. And because it’s such a frightening issue – bad enough that some of you said you actually just bought a new bike to solve the problem!

Two industry gurus, Bill Farrell, the founder of New England Cycling Academy and the inventor of The Fit Kit and their frame alignment system (Bill sold the business); and Craig Calfee of Calfee Designs a pioneer in carbon bicycle technology said that frame and fork alignment issues cause speed wobble. I’ve added them to the list.

In case you aren’t a Facebooker, here’s part of Bill’s comment, “Whenever a cyclist described having “speed wobble,” I’d pull the components, clean the threads and face the bottom bracket. Upon inspection, the culprit was always a misalignment in the tracking plane. Once the frame was “cold set” (i.e. bent) back into alignment, the “speed wobble” issue was resolved. When the newer carbon fiber materials integrated into production, cold setting this type of material was impossible.” [Bill talks about how he helped find and fix carbon frame alignment issues, too – with machining not cold forging.]

And, here’s some of Craig’s comment, “Fork alignment is a very different animal than frame alignment. When the steering axis is projected to one side of the tire contact patch on the pavement, it forces the rider to make a correction. This sets up the speed wobble and the rider continues with an asymmetrical response, making it worse.”

To read Bill and Craig’s comments in full plus a lot more, visit my page here: https://www.facebook.com/langley.jim.

Here’s a graphic from Sheldon Brown showing some steel frame and fork alignment tools:

Last week I mentioned my riding buddy Tom’s speed wobble. Thanks to the comment from Melissa about her Roval wheels having bad bearings that caused a wobble, Tom is now looking into that possibility on his Rovals. Thank you Melissa!!

Along with the causes, here are some additional techniques recommended

In closing, probably the most important thing is to have a strategy for dealing with speed wobble if it happens to you. Based on my own experience and the fact that it’s the most commonly offered tip, if you can only remember one technique, you should remember to bring your knees together to squeeze the top tube of the frame to stabilize the bike and hopefully stop the wobble. And once you know your bike may wobble, keep in mind that if you get in the habit of resting one knee against the top tube as you start picking up speed downhill, that that action could prevent the speed wobble from happening in the first place.

Thanks again readers and Facebook friends for all the help!

Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s cycling streak ended in February 2022 with a total of 10,269 consecutive daily rides (28 years, 1 month and 11 days of never missing a ride). Click to read Jim’s full bio.

Thanks for this article Jim. I also had a friend that had a speed wobble/shimmy when doing downhill fast. He thought for sure it was something with his frame or fork, but he said it started when he put new tires on. Sure enough I gave him some other tires to use and his problem went away. As stated in your article, the tires were somehow defective and caused the shimmy. Moral of the story: It might not always be a major frame or fork issue. Check the small things first.

You’re welcome, Karl! Thanks for the tip to take care of the small things first.

For what it’s worth, this wobble is a common problem in engineering. It’s hard hard work to design a system — a bike, a bridge, a speaker, a helicopter, a car — that doesn’t oscillate somewhere. (Look at the Puget Sound bridge that oscillated until it fell into the water.)

And then come the field modifications to the system. Your list mentions some. The best design sometimes starts to oscillate again those modifications.

Your number one remedy, lay a knee on the frame, is a classic engineer’s remedy: dampen the oscillation. “Damper” is the engineer’s word for “shock absorber”, and a knee is a good damper. It’s a perfect way to stop oscillations, hopefully before they get out of hand.

(Your list also mentions a bunch of possible bike-system defects. If somebody’s bike has that kind of defect, they should FIX IT, especially before attempting a 45mph descent.)

Thanks very much, Ollie! In case anyone hasn’t seen the bridge videos, here are 2 good ones, the first archival, the second, an engineer looking at why it failed: https://youtu.be/lXyG68_caV4 https://youtu.be/mXTSnZgrfxM

I had a wobble that showed up on one of my first spring rides. Ended up I had a “wad” of congealed latex in my tubeless tire…..should’ve know better!

That’s a great tip and a something else to be aware of and to avoid, Gary. Thanks so much for sharing!

I had a wobble on my touring bike when loaded, changed the weight distribution several times trying to make the bike happy, no luck. Then I noticed a faint sound, like something rubbing, looked all over, nothing was rubbing, then I thought it could be the spokes, so I tightened all the spokes a 1/2 turn…no more wobbling!

Another great one, thanks, Fred!

I just bought my first Carbon bike at 79 & I like it just as much as I knew I would. That being said, I believe that the bike and all “modern” road bikes are much more “dynamically unstable” than a road bike needs to be. It took me more than a couple of rides to get comfortable removing my hands from the bars, especially at low speeds and the same for very tight 180s and my regular bike is a decade old Giant TCX AL. modified with a tripple chain wheel and flat bars. The new one is another Giant TCR ADVANCED II. I still ride my Aprilia Dorsoduro motorcycle to the edge of the tires and do tripple numbers regularly, where it’s safe of course. Headset tightness is easy to check; just brake hard front wheel only and if there’s ANY shimmy, get it fixed. If you can’t ride your bike hand’s off at ~20K because of instability there a problem somewhere on the above list that needs to be fixed. If you ride downhill at 80K on a bicycle you have more guts than me.

Thanks for the comment, Robert. I’m surprised that your TCR Advanced doesn’t feel more stable. A few of my teammates have those bikes and none of them say anything but great things about them. It makes me wonder if something might be amiss?

I hope not but it might be worth asking the shop about, Jim

Thanks for commenting Jim. I’m fine now, completely relaxed and comfortable on the bike hand’s on or off and 180s in the driveway width EZ. However the older road bikes had curved forks and the rake trail was more stable. Kinda like the difference between a Gold Wing and a crotch rocket. My current motorcycle is a super Moto with stability between the two. I love them ALL.

Jim, Here’s a cause not yet listed on your updated speed wobble causes. Wheels with woefully insufficient lateral stiffness. I have owned & built up over 40 bicycles (& wheelsets) of all types since working at a bike shop in my long youth & only experienced speed wobble one time on a 2000 Litespeed Appalachian Cyclocross framed bike, which I originally built with aftermarket components including drop bars, a very rigid straight bladed chromoly steel unicrown fork & an early carbon fiber wheelset. After visiting the Aerospoke wheel factory in South East Michigan back in 2000, I impulse purchased a set of their 700c 5-spoke carbon fiber wheels with glued on aluminum rims that looked promising. On the initial ride it became immediately apparent that the wheelset had insufficient lateral stiffness as evidenced by the rims scraping the rim brake pads at the slightest turn of the handlebars. Throwing caution to the wind, I brought the bike up to speed (about 25 mph) & experienced my first ever speed induced wobble. I held on for dear life & the wobble did not dissipate until my speed was down to a walking pace. Out of morbid curiosity I tempted fate multiple times by gradually increasing speed to determine where there wobble would start, which varied depending on how far forward I was leaning. The more weight on the front end the faster I had to go to induce wobble. I immediately removed the wheels, hung them up in the garage & purchase an ultra-rigid custom built 36 spoke wheelset with Mavic rims & Phil Wood Hubs from Joe Young Wheels in Texas. Never experienced speed induced wobble again.

That’s a good one, Bob. Thanks so much for sharing your story about those wheels producing the speed wobble due to insufficient lateral stiffness.

I ride fairly large frames (58-60cm) and in years (decades, actually) gone by, it was easy for me to induce speed wobble in steel frames with their skinny tubes. and even in first generation aluminum frames if the forks weren’t particularly stiff. I never experienced speed wobble with the Ti bikes I’ve owned, which were somewhat stiffer and had carbon forks, but there was enough flex in them that I was somewhat uncomfortable at speeds approaching 50mph. With modern carbon frames, with their increase lateral and torsional stiffness and larger diameter, stiffer steerer tubes, I can’t make make them wobble no matter how hard I try. The fact that I can be free of speed wobble and still have a comfortable ride means I’ve found the holy grail!

I’m glad you’ve found the holy grail in modern carbon bikes, Brian!

In 47 years of biking (150,000 miles), I had one episode of speed wobble. It was coming down Bear Notch in the White Mountains. I don’t believe the speed itself (around 45 mph) caused it, as I have descended at 52 mph on previous rides with no problems. What was unique on that occasion was that my bike (Cervelo R5) had mismatched carbon wheels. Up front were low profile Bontrager Paradigms (tubeless) and on the rear I had only recently put on a deep profile Bontrager XXX 4 TLR. I don’t know for a fact that the mismatch between low vs. deep profile caused the problem, but I swapped both wheels for a symmetrical XXX 2 wheelset and have not experienced a similar problem. Nevertheless, the wobble was so frightening that I routinely practice clenching my knees against the top tube just in case I ever experience another wobble.

Thanks for sharing your wobble and what may have caused it, Jeff. Another good one for us to know about!

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