# "Death Wobble"



## J_T_Buckley (Dec 31, 2009)

I bought a 08 Specialized Sequoia Elite last winter. I have recently started riding it. Yesterday, for the first time, I went on a fast paced smooth surface ride with some friends. On the first downhill of the ride we all took off. When I hit 37-38mph my bars/front end began shaking violently. I almost lost control and took out 1/2 our pack. I took it easy until we made our first stop. A few of the guys are avid cyclist and described what happened as "death wobble". They each said that they hit speed near 45 and 50mph and my bike should be perfectly capable of doing that. We did a quick lookover on the bike and everything appeared to be in perfect mechanical condition. I tried to pick up my speed a few more times on the ride and everytime I'd hit 35mph I could feel the shimmy start. Any faster than that and I would almost lose control. I tried different body positions and holding the bars differently and nothing helped. My friends directed me to contact Specialized customer service. I emailed them last night but haven't gotten a response.
Is there anyway I can fix this? Has anyone ever dealt with Specialized on an issue like this? What will they most likely do, if anything? 
This is my first raod bike and I am very new to it all. All comments and suggestions will be greatly appreciated.


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## b31den (Aug 23, 2008)

It is probably something to do with tires, tubes, or wheels. Either badly out of balance or the wheels are flexing too much. Also check that the headset is tight enough.


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## shoegazer (Nov 2, 2007)

This unexpectedly happened to me recently on a bike that I know well. After ruling out any mechanical problems, I removed my new Vredsteins from the rims, swapped tubes and reinstalled which resolved the issue. I hope it's that simple for you!


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## kbg (Jun 23, 2009)

I second the thought to check your headset. I recently had a little play in mine and it was causing some shimmy at about 35 mph.

Some thoughts on shimmy from the legendary Dave Moulton:

http://davesbikeblog.blogspot.com/2005/11/high-speed-shimmy.html


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## Fredke (Dec 10, 2004)

J_T_Buckley said:


> I bought a 08 Specialized Sequoia Elite last winter. I have recently started riding it. Yesterday, for the first time, I went on a fast paced smooth surface ride with some friends. On the first downhill of the ride we all took off. When I hit 37-38mph my bars/front end began shaking violently. I almost lost control and took out 1/2 our pack. I took it easy until we made our first stop. A few of the guys are avid cyclist and described what happened as "death wobble". They each said that they hit speed near 45 and 50mph and my bike should be perfectly capable of doing that. We did a quick lookover on the bike and everything appeared to be in perfect mechanical condition. I tried to pick up my speed a few more times on the ride and everytime I'd hit 35mph I could feel the shimmy start. Any faster than that and I would almost lose control. I tried different body positions and holding the bars differently and nothing helped. My friends directed me to contact Specialized customer service. I emailed them last night but haven't gotten a response.
> Is there anyway I can fix this? Has anyone ever dealt with Specialized on an issue like this? What will they most likely do, if anything?
> This is my first raod bike and I am very new to it all. All comments and suggestions will be greatly appreciated.


There are a number of extensive threads on this topic here. Search under "wobble" and "shimmy".

"Death wobble" is poorly understood. There are lots of arguments amongst experts about exactly what causes it. There are probably many different things that can contribute. Part of it may be your bike, but part of it may be your riding style, particularly since this is your first road bike.

If you get nervous on the descent and tense up, especially your arms, your body can amplify little vibrations or wobbles until they become big oscillations and the bike is veering dangerously from side to side. If you feel this happening, try to relax your upper body. Squeezing your legs gently together to grip the top tube may also help.

On your bike: one thing to check is your headset bearings. If they're loose your bike may be more prone to wobble (stand over your crossbar with your feet firmly planted on the ground. Grab the left brake lever and squeeze it. Gently try to roll your bike forward and back with the brake firmly squeezed. If you feel the handlebars wiggling relative to the head tube, your headset may be a bit too loose; take it to your bike shop and have them adjust it properly. You could do the adjustment yourself, but since you're new to this, let the bike shop do it). This is one possibility, but it's not the only one and it's not guaranteed to fix things, even if the headset is loose.

Different bikes handle differently on descents depending on their geometry. Changing forks to change the trail may have an effect. 

But trying to cure speed wobble can be a real exercise in witchcraft. For now, focus on the part you can most control: how you behave while descending. Get practice, relax, and work your way up gradually to high-speed descending.


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## Mr. Versatile (Nov 24, 2005)

Definitely check the stuff mentioned above. To stop or prevent a speed wobble clamp both knees to the top tube. It'll stop instantly. When I'm going fast, 30+, I always leave one knee in contact with the top tube.


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## Fredke (Dec 10, 2004)

Mr. Versatile said:


> Definitely check the stuff mentioned above. To stop or prevent a speed wobble clamp both knees to the top tube. It'll stop instantly. When I'm going fast, 30+, I always leave one knee in contact with the top tube.


Not always. One time I was descending about 50 mph with gusting crosswinds. I got a nasty speed wobble---especially because I was in reasonably heavy traffic. I clamped my knees to the top tube, but no dice. Wobble got better, but was still very dangerous. Only slowing to less than 40 did the trick on that particular day.


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## CleavesF (Dec 31, 2007)

Lighten up on your grip. Seriously.


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## J_T_Buckley (Dec 31, 2009)

Just got home from a ride a few hours ago. Checked the headset before the ride and it was tight as was everything else. Unfortunately I was only able to hit 35 twice on the short ride but the wobble was there. I tried to loosen my grip and it seemed to help but did not fix it. I also tried to clamp my knees but by the time I did that I had slowed down and the wobble left naturally.


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## Fredrico (Jun 15, 2002)

*A few more things to check:*

See if the wheels are in alignment, that is, track in the same line. That can be easily done by holding up a long straight edge against both rims in two places on each rim. If there's a gap on one of the points on the rear rim, the rear wheel isn't tracking the front.

Any kind of irregularity in the tires or rims can cause shimmy at high enough speeds. Check for side to side true, or "hop." The tire could have a slight bulge in it, or may not be seated evenly on the rim.

If wheels are true, round and rolling in the same line, then shimmy can be caused by too much weight over the front wheel. You'd feel this descending. Move way back on the saddle, and see if shimmy goes away, being careful to keep hands firmly planted on the hoods to hold the front wheel straight! As already suggested, relax on the bike and don't fight it.

Another way to check whether headset is too loose or too tight, either of which could induce shimmy: do the front brake on wheel pushing bike back and forth to feel "clicking" in loose headset, as Fredke suggests. If no clicking, then put the frame on your shoulder and hit the handlebars sideways. They should oscillate back and forth a few times and settle in the center without "binding." If they "bind," loosen the headset adjustment. It can be easily done by unscrewing the two allen bolts clamping the stem on the steering tube, and unscrewing the top allen screw a few turns. Then tighten the top allen screw until it stops, and back it off a half turn or so. Straighten the bars and tighten the clamp screws. The handle bars should rotate side to side smoothly without binding or having any play.


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## twinkles (Apr 23, 2007)

You notice that when you spin a front wheel, it always stops valve up, fairly quickly. I put 3 presta nuts on the front wheel and found it to didn't settle with the vavle up, essentially balancing the wheel/tire. An aluminium rim is pinned and welded opposite of the valve hole, which adds weight there. From what I understand, speed wobbles are quite often a combination of things. Eliminating one might be the answer.


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## fallzboater (Feb 16, 2003)

How tall and heavy are you, and what's the frame size? I have had several frames that would death wobble in certain conditions, mostly on the brakes at 35+ mph with gusty winds. I have been close to 60 mph with no trouble, if I don't brake. You might try other wheels, and the techniques suggested, but I think it's got a lot to do with frame geometry and stiffness, and rider cg location. I think the newer stiff carbon frames with tapered steerers are less likely to have problems, but unfortunately, you won't know until you give a bike a good test.


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## CleavesF (Dec 31, 2007)

Redo the quick releases, and check your preload on your wheel bearings. Other than that... ummm... I'm out of ideas because everyone else has them mentioned/covered.

Get a new bike?


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## Hooben (Aug 22, 2004)

Is there a chance that this is caused by the rider? Maybe find a person who rides the same size as you who is very experienced, and get them to try a descent on the bike. 

Could this be caused by too much of an upright stance on the handlebars?

Just a thought.


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## J_T_Buckley (Dec 31, 2009)

Thanks for all the input. I'm gonna keep working at it until something helps. 

I am about 5'9.5" and 185lbs to answer fallzboater. The bike is 58cm. It feels like it fits me well.


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## f3rg (May 11, 2008)

I skateboarded when I was a kid/teen, and this happened all the time when bombing hills. When I was 19 or 20, I finally crashed pretty hard and shredded most of the skin off my right forearm (still have the scar to prove it). I'd never considered it could also happen on a bike, but at least bikes have brakes to put the wobbles in check. At 33, I don't think I want to have any more skin eaten by concrete.


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## David Kirk (Mar 6, 2005)

f3rg said:


> I skateboarded when I was a kid/teen, and this happened all the time when bombing hills. When I was 19 or 20, I finally crashed pretty hard and shredded most of the skin off my right forearm (still have the scar to prove it). I'd never considered it could also happen on a bike, but at least bikes have brakes to put the wobbles in check. At 33, I don't think I want to have any more skin eaten by concrete.


A bike wobbles for the same reason a skateboard does oddly enough. On a skateboard both the front and rear wheels steer (as opposed to a bike) and a speed wobble occurs when the front and rear trucks steer is opposite directions from one another by twisting the board in torsion. The board winds up and releases and causes the trucks to steer in the other direction and it sets up a rhythm. The way one gets it to stop on a board to to move your weight as far forward as possible so that you are standing on just the front truck. This allows the rear to just track and not steer.

A bike is similar. A bump in the road, a cross wind, a dramatic wheel imbalance can start the wobble which twists the frame slightly in torsion causing the front wheel to flop to one side while the rear (through frame twist) steers to the other. This can't go on for long and the frame eventually resists enough that the frame then springs back causing the rear to steer in the other direction while the front steers in it's other direction. This oscillation is speed wobble. Many will tell you that it is a mystery but it just isn't. How come one bike does it while another doesn't is harder to quantify but the reasons behind wobble are well understood. Motorcycles do the same exact thing FWIW.

Very often a given bike will wobble under one rider but not another and this is because the riders weight is different and they sit on the bike differently. Tall riders tend to experience it more often than short riders because the tall guy's frame is longer and therefore less torsionally rigid and can more easily twist and start the process. I'm tall (6'4") and years ago I had a Merckx that was fine except at 18 mph when it would set up a wobble that would throw me to the floor if I wasn't careful. It was fine at 50 mph but 18 would kill me. It was easy to stop the wobble on that bike just like it is on most bikes and all one needs to do is damp the movement. Pressing a knee to the side of the top tube or, believe it or not stand up and it will immediately go away. Standing up shifts weigh to the front wheel and removes the resistance of the seat against your butt and allows the rear to just track and not steer.

In 30 years of dong this there are a few hard and fast things I've learned about wobble. It is almost never an issue of frame or fork alignment. In fact almost the opposite. If the frame and fork are perfectly aligned the bike will be more apt to wobble. The reason is that if the frame is poorly aligned it will pull to one side and the wobble will mean that it might pull a bit more then a bit less to the side but since it never comes 'over center' it won't start going right then left and so on. You can often take a bike that has bad wobble and cock the rear wheel to one side in the dropouts and the bike will be fine.

It is also almost never because of the headset or it's adjustment. In the old days of crappy headsets with loose balls one could over-tighten a headset and cause it to develop detents giving the bike indexed steering. This was a real problem. Now almost all headset designs prevent this from happening. Unless the headset is floppy loose it's not the cause.

Speed wobble is most often caused by the perfect storm of rider weight, frame torsional rigidity, rotating mass and balance, and road conditions it can be difficult to make it go away. Let me first reiterate that if you are heading down a hill and the bike starts to wobble the best thing you can do it to relax (hard to do while pooping your pants I know) and press one of your knees firmly against the side of the top tube. This will stop almost every wobble. But there are some things that can be done to a bike that is prone to wobble to help keep it from happening again - 

* don't waste your time on getting the frame/fork alignment checked - it's a red herring.

* don't waste your time overhauling the headset - if it has no knock and rotates smoothly it's not the issue

* do try a different front wheel. In a huge number of cases this will stop it. Your wobble wheel might be out of balance or slightly out of true and a different wheel can be different enough to break the cycle.

* do raise your rear air pressure and lower your front. The higher rear air pressure will stiffen the sidewall of the tire and help stabilize it and keep it from flexing side to side. Lowering your front will give it a bigger contact patch and a softer sidewall and give it more damping.

* do make sure you have as little crap in your saddle bag as possible and that it's securely fastened. If the bag can wobble back and forth it helps the cycle build. I had a friend once who had bad wobble on his trek and it turned out he had about $10 in coins in his bag. WTF? He emptied the bag and the bike was 'fixed'.

* do relax. A stiff and tight body give the bike something to wobble against soften and relax on downhills and you will go faster easier.


Lastly - this will make me sound like a crazy man but every bike made wobbles. Every single one of them. No exceptions. The thing is that, with a given rider weight and set of conditions it might not wobble at normal speeds. It might only wobble at 75 mph and since no one goes that fast it's a non issue. Or it might happen at 8 mph and it's so easy to control that we don't think about it. Ever have a bike that was hard to ride no handed at low speeds but was fine if you cocked your butt to one side and leaned the bike just a bit? In most cases that is wobble but in most cases it's worked around and a non issue.

Sorry for all the typing......... it's snowing here today and my wife is out or town and I just had coffee so I'm a typing mad man. I hope the above helps at least a bit.

dave


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## waldo425 (Sep 22, 2008)

It is either the frame being twisted (would surprise me coming from specialized, unless you bought it used and someone crashed the bike) or the wheels are out of true or out of dish. Either of those can cause a death wobble. Next time you have it happen you should pinch the top tube with you legs. This should even it out and help you retain some semblance of control.


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## medimond (Apr 26, 2009)

Your 5'9" and riding a 58 inch bike, is that effective TT? I'm 5'9" and I ride a 54. What length is your stem?

Did you buy this bike used or new?

Swap wheels with someone else and see if the problem re-occurs. 

Calfee claims that a non-symmetrical fork can cause this problem:

http://www.calfeedesign.com/forksymmetry.htm


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## mimason (Oct 7, 2006)

58cm sounds too big unless they call you torso.


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## George M (Sep 25, 2008)

I'm 5" taller than you and I ride a 58. I got a speed wobble at 32 mph once. The next day on a different road I relaxed more and held the TT with my knees and got it up to 35 with no problems. I have a Specialized Roubaix Elite with Open Pro wheels.


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## Kerry Irons (Feb 25, 2002)

*Wheel balance not the issue*



twinkles said:


> You notice that when you spin a front wheel, it always stops valve up, fairly quickly. I put 3 presta nuts on the front wheel and found it to didn't settle with the vavle up, essentially balancing the wheel/tire. An aluminium rim is pinned and welded opposite of the valve hole, which adds weight there. From what I understand, speed wobbles are quite often a combination of things. Eliminating one might be the answer.


Since the wheel is not suspended (except by the pressure in the tire) having a wheel out of balance is not an issue. Having a wheel out of true, out of round, or a tire that is out of round is an issue. Wheel balance is not.


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## dasho (Apr 8, 2002)

Excellent info, David Kirk - thanks!


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## J_T_Buckley (Dec 31, 2009)

It feels pretty good. I do have a long torso. I rode a 56 at a bike shop last year and I felt a little cramped.


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## speedyg55 (Jun 11, 2009)

I had speed wobble on one of my bikes at relatively low speeds (started at about 22 or so). I upgraded to different handlebars and stem and the wobble went away completely. I don't know if the old bars or stem were causing the problem, but I was happy it stopped.


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## George M (Sep 25, 2008)

speedyg55 said:


> I had speed wobble on one of my bikes at relatively low speeds (started at about 22 or so). I upgraded to different handlebars and stem and the wobble went away completely. I don't know if the old bars or stem were causing the problem, but I was happy it stopped.



That made me think about swapping parts as well. I read where a guy had a wobble on a Roubaix and he put a different fork on the bike and that done the trick. I wonder, if you have another bike you could try it out. I remember the fork the guy bought was an Easton.


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## robbyracer (May 30, 2007)

I had a bad wobble on my C'dale Synapse7 and changing tires fixed it.


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## ZoSoSwiM (Mar 7, 2008)

Try removing your tires.. Put a light coating of baby powder inside the tire and cover the tube with it as well. Reinstall the tube and tire. Sometimes when you put on a tire you can bunch up the tube.. The baby powder will prevent it or at least help limit it.


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## fallzboater (Feb 16, 2003)

Great post! I'm about 195 lb and ride a very large frame due to my long legs. I've owned more frames with an unacceptable wobble than without one, so once I find one that works, I tend to hang onto it. The torsional stiffness definitely seems to be the major factor. It used to seem to me that a relatively short wheelbase and steep HA (twitchy handling) caused the wobble, but I've since ridden an extremely stiff frame that had twitchy steering, but would not wobble. I think it's more a factor of quick geometry tending to initiate wobble in a frame that isn't torsionally stiff enough.


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## serious (May 2, 2006)

Kerry Irons: *Since the wheel is not suspended (except by the pressure in the tire) having a wheel out of balance is not an issue. Having a wheel out of true, out of round, or a tire that is out of round is an issue. Wheel balance is not.*

Yes the wheel has to be aligned, but the tire has to be balanced. In general balancing a wheel refers to balancing a tire that causes the imbalance. With cars you use some lead to balance uneven tires, with bikes you may have to change or re-install the tube/tire to get rid of the imbalance.


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## fallzboater (Feb 16, 2003)

serious said:


> Kerry Irons: *Since the wheel is not suspended (except by the pressure in the tire) having a wheel out of balance is not an issue. Having a wheel out of true, out of round, or a tire that is out of round is an issue. Wheel balance is not.*
> 
> Yes the wheel has to be aligned, but the tire has to be balanced. In general balancing a wheel refers to balancing a tire that causes the imbalance. With cars you use some lead to balance uneven tires, with bikes you may have to change or re-install the tube/tire to get rid of the imbalance.


A wheel being out of balance at speed would have a similar effect as it being out of round. For motorized vehicles, wheels and tires (and ideally, brake rotors) are balanced as a system. It doesn't make any difference to separate the two. Your statements imply that a balanced tire on an imbalanced wheel would be acceptable; that's not the case.


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## Kerry Irons (Feb 25, 2002)

*Understanding balance*



fallzboater said:


> A wheel being out of balance at speed would have a similar effect as it being out of round. For motorized vehicles, wheels and tires (and ideally, brake rotors) are balanced as a system. It doesn't make any difference to separate the two. Your statements imply that a balanced tire on an imbalanced wheel would be acceptable; that's not the case.


You guys are not understanding the issue. A car or motorcycle wheel is suspended, and if you see a car driving with an out-of-balance wheel, the car runs steady but the wheel is bouncing. This is possible due to the vehicle's suspension. There's no such thing on a bicycle. If the wheel is true and round, it would have to have a VERY large amount of "off center" weight to be felt. This is not going to happen short of a defective tire, which would probably not be round anyway. The amount of weight of a rim seam or inner tube valve is totally insignificant in the context of shimmy.


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## Tort (Nov 4, 2008)

I think it's all been covered, but if I missed it I would suggest you release the front wheel and then re-seat it in the forks to make sure it is aligned. 

I had this problem off and on and found it is due to me not seating the front wheel correctly each time I had to re-install it after removing it for travel to a my girlfriends house, and quite easily would get it clamped back in slightly off center, hence the crazy wobble when I got around 30+ mph.


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## serious (May 2, 2006)

fallzboater: *For motorized vehicles, wheels and tires (and ideally, brake rotors) are balanced as a system. It doesn't make any difference to separate the two*

I am not separating the two, just explaining the difference between alignment and balance.

Kerry Irons: *A car or motorcycle wheel is suspended, and if you see a car driving with an out-of-balance wheel, the car runs steady but the wheel is bouncing.*

You are only talking about vertical vibrations due to imbalance in tire mass. There is plenty of lateral imbalance, which will cause the wobble. A improperly seated tire (I saw plenty in mountain biking) will create a lateral imbalance and cause weird vibrations or wobbles at specific speeds.

The death wobble discussed in this thread may be cause by many things, but if it is the wheel's problem, then it is definitely alignment, balance (lateral) or both.


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## Kerry Irons (Feb 25, 2002)

*Clarifying the point*



serious said:


> You are only talking about vertical vibrations due to imbalance in tire mass. There is plenty of lateral imbalance, which will cause the wobble. A improperly seated tire (I saw plenty in mountain biking) will create a lateral imbalance and cause weird vibrations or wobbles at specific speeds.
> 
> The death wobble discussed in this thread may be cause by many things, but if it is the wheel's problem, then it is definitely alignment, balance (lateral) or both.


Which is exactly my point. The post by twinkles suggested that the imbalance which causes the wheel to stop at the same point each time you spin it could cause speed wobble. Not so. Lateral imbalance (out of true) or vertical imbalance (out of round) of the wheel can stimulate speed wobble, as can a tire that is deformed or defective and lumpy.

BTW, you will rarely find a road tire that is improperly seated on the rim, because the much higher pressure (compared to MTB tires) will blow it off the rim in short order.


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## WaynefromOrlando (Mar 3, 2010)

Not sure if this has anything to do with the OP, but motorcycles have what are called "tank slappers", which is when the front tire gets out of whack, wobbles, and the feedback grows until it is swinging from stop to stop. 

Happened to me after I hit a bad pavement seam on my 750 doing somewhere north of 90 MPH back when I was young and stupid. Motorcycle still came with spokes in those days, as my bike did at the time. The only way to stop them was to lightly, I'm talking LIGHTLY, press the rear brake to slowly increase the pressure on the front tire until it damps out the wobble.

It's an E ticket ride when it happens, and probably not much fun on a bike either. I have been up to about 60 MPH on a bicycle before (clocked by a CHP officer as I rode down from the Grossmont summit in San Diego), and never had so much as a hint of wobble.


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## bigreen505 (Jun 10, 2007)

What happens when you try to ride with no hands? If you can't ride with no hands at any speed, it's time to start looking closely at everything on the bike including your weight distribution.

I've run into speed wobble on two bikes now. The first was a cracked carbon rear triangle that took a while to develop. On the second (my current bike) it was a perfect storm scenario with several things off just a touch (headset, front wheel bearing, front wheel true, rear tire) including my position. Changing any one of the factors probably would have eliminated the problem.


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## davidmcnally944 (Dec 28, 2021)

fallzboater said:


> How tall and heavy are you, and what's the frame size? I have had several frames that would death wobble in certain conditions, mostly on the brakes at 35+ mph with gusty winds. I have been close to 60 mph with no trouble, if I don't brake. You might try other wheels, and the techniques suggested, but I think it's got a lot to do with frame geometry and stiffness, and rider cg location. I think the newer stiff carbon frames with tapered steerers are less likely to have problems, but unfortunately, you won't know until you give a bike a good test.


I have a few bikes that I ride frequently downhill, for some reason my cruiser which frame resembles a schwinn sting ray only larger never wobbles, no matter how steep the decline or how hard I pedal this is a multiple speed cruiser that will do 35 downhill with no problem. I dont know if the fact that this is a relatively heavy bike because it is mostly steel including the hubs, stem etc. I am thinking that most of the people with death wobble might just be too light in weight to handle intense speed because my other bikes 2 hybrids and 1 road bike also tend to wobble a bit and are both much lighter than my cruiser.


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## Peter P. (Dec 30, 2006)

davidmcnally944 said:


> I have a few bikes that I ride frequently downhill, for some reason my cruiser which frame resembles a schwinn sting ray only larger never wobbles, no matter how steep the decline or how hard I pedal this is a multiple speed cruiser that will do 35 downhill with no problem. I dont know if the fact that this is a relatively heavy bike because it is mostly steel including the hubs, stem etc. I am thinking that most of the people with death wobble might just be too light in weight to handle intense speed because my other bikes 2 hybrids and 1 road bike also tend to wobble a bit and are both much lighter than my cruiser.


I doubt that's the case. Professional riders almost certainly ride bikes on the hairy edge of being UCI legal, weight-wise, and front end shimmy is not widespread in the pro peloton.


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## eddie m (Jul 6, 2002)

Holy zomble thread!
If anyone is still interested, David Kirk's long post above is the correct answer.

em


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