I experienced this for the first time a couple of months ago. Going downhill 30mph, over some railroad tracks, in the drops. Once it started I just knew I was going down, I had accepted it. Felt like it was never going to end, but I managed to get it under control and keep the rubber down. I don't think my bike was to blame for this, neither does my mechanic. I feel it was the combined effects of having too much weight on the handlebars, unbalanced weight on the bars, not weighting the pedals, legs far apart away from the TT. I seriously wanted to quit cycling all together after that experience. Did a lot of research, heard a lot of possible explanations. Put all the suggestions in practice and now have zero fear of it happening again. On descents I know keep my hands light on the bars, upper body relaxed, pedal down and leg braced against the TT if I'm coasting. When I'm in the drops, my hands are on the curve closer to the shifters, not on the bar ends. I have done many miles since then and my confidence is 100% back.
It was good to read this. It happened to me doing over 40mph. I think I'm to blame for it; the only thing I remember is I went in the drops and I started to pedal but still trying to put a lot of torque in to the pedals because I wanted to show off about how fast I can go downhill. I managed to get control of the bike during the wobble by easing the pressure off the front, then applying some back brake (I have discs) and then some front by which time the wobble eased off. Following this I lost all confidence and started to brake on descents. I'm starting to re-gain confidence now and being more lighter with the bike going down hill.
The idea to squeeze the top tube during a speed wobble is to add mass to change the resonance frequency of the wobble so you can regain control by not having the wobbles magnify each other each oscillation. The reason this differs on a bicycle than on a motorcycle is how the mass is distributed in the system. Rider on a motorcycle is less than half (down to a quarter probably) the mass of the system so the rider is more along for the ride if it happens and the only way to affect the wobble is reducing the mass that's wobbling. On a bicycle the rider is 80-90% of the system mass (or 8 or more times the mass of the bicycle) and can greatly affect the resonance just by absorbing the energy into the lower body mass. If the head and shoulders start to get moved around you follow your advice and try to disconnect the body mass from the bike (body bike disconnect) and ride it out again just trying to change the resonance and magnitude of the wobble until you can regain control. At least this is my understanding of it as I've fortunately only experienced it once.
I’ve had this happen 3 or 4 times now. Again 35-40mph, downhill, slight turn in the road and a cross wind (or car overtaking me!) and it’s the scariest thing to ever happen. Have managed to correct it by slowing, but of course, the wobble gets bigger before you stop. Have wondered whether it’s me, so will make sure I’m light on the bars, but will check alignment of the front end too. Scary stuff, that I dread happening again!
Great show guys, I experienced a terrifying speed wobble less than a week ago whilst descending at 60 km/h and genuinely thought my bike was collapsing under me. This was the first time I had ever experienced this (in my 30 years on a road bike). Generally, my BMC Teammachine rides beautifully and I cannot fault it. This one experience has got me terrified of descending now but I have taken the bike out a couple of more times and descended at 50-55 km/h without any issue. I have done a bunch of reading on this now and have found a really good article explain the physics of how this happens and some good suggestions on how to control it (link below). The bike is set up in fairly aggressively that puts the weight towards the back of the bike and, on top of that, the frameset is considered and known to be 'twitchy'. So for me, it's about weight distribution on a particular frame geometry. So far, when descending, slightly lifting my ass and putting the weigh into the bottom bracket (instead of the seat) seems to centre up the weight on the bike and, fingers crossed, this holds off the wobbles.
This happened to me and now it’s impossible to avoid. It has to be an anxiety thing causing uneven pressure. It’s not even speed related and it’s now happening on a 2nd bike. I think it’s the fear of it that is causing it.
many years ago with a steel frame I had this often, and could not do anything against it; with my modern bike I never had that experience - until one week ago, when I rode a fast descent and suddenly got heavy crosswind; I instantly touched the brakes (smoothly...) but things got much worse until I was ~20 kph slower... scary moments!
I've had speed wobble issues from time to time on my road bike too... perhaps once a season. When it happens, it starts when going downhill usually when I hit about 60 kph. The bike is in the shop now. Hopefully the mechanic can spot if there is anything wrong with the bike. Otherwise, I'll need to reassess my position on the bike and level of tension when descending.
This is one of the best explanations I have heard, thank you Jonathan for the motorcycle knowledge. I don’t know why you singled out the propel (maybe that was his bike?), along with the aeroad they are the stiffest bikes made, because of the 1 1/4” steer tube. I’m talking head tube stiffness (but they also have a lot of BB stiffness because they are both BB86 which is the stiffest bb shell design).
I only get them … and very violent ones , when I’m going downhill and take my hands off the bars and sit up … every time . If I do the same on a flat road zero wobble. I attribute it to the forces being put on the front on a downhill… al the weight pushing forward with no stick weight over the wheel. And THANK YOU for the pro tip! Hughes me such anxiety every time I have to align my stem
guys thanks :) got a new tri bike and fit. i took it out for a first ride and at about 24 mph got a speed wobble and that was in the base bars not aero bars. this bike is quicker handling than my prior (Cadex tri bike now vs my 2021 shiv disc). head tube angle is 73 on cadex vs 72 on shiv, trail on cadex is 63 mm, on shiv 62 mm, wheelbase on cadex is about 6 mm longer. not large differences but i feel like i'm right over the pivot point for turning rather than back behind it. and my position is much more aero (7 cm lower in front)... and i feel a lot more weight/ down pressure on my hands in the base bars. we checked headset, wheel axles and bearings, wheels being true, and even frame alignment. no harvest from any of those. there were wind gusts that day to about 20 mph and i was on 64mm deep wheels. could tighter handling, being more over the pivot point rather than behind it, combined with more weight upfront be causing the wobble that may have been set off by a wind gust?
I experienced speed wobbles on the Blue Ridge Parkway while descending from Peaks of Otter on a Trek 520 touring bike with relative wide tires, 28 mm or 32 mm. It was repeatable. I went through at least three cycles of speeding up and then having to slow down when the steering became unstable. I returned to the same stretch of road with the same bike with 25 mm tires and did not experience any recurrence. The speed wobbles were highly speed sensitive. They went away almost immediately when I hit the brakes. Since geometry and weight distribution don't change with speed, I highly suspect that aerodynamics are involved. Perhaps the wider tires created more drag at the leading edge of the wheel, which caused the steering to become unstable.
I got speed-wobble on my road bike, on my first carbon frame about 8 months ago. It was my first decent on that bike & as i say my first decent on a carbon frame, as my other road bike is aluminum. As I'm more a MTBer than a road biker, & i got into road biking as a art of PCL rehab, i didn't know how crucial bike fit was, & i didn't know you had to use the drops, i always thought drops were for wind & aero.. So anyway i was descending a 350m local decent, on the steep side of the hill, about -12% gradient, & i got to 65kmh & coming up to the first switchback my bike got speed wobbles & it literally felt like i was riding jelly, it was absolutely terrifying! But i stayed calm, rear braked gradually & managed to slow down to a stop just before i ran out of straight road. And had a breather & a scream lol.. So i looked into it & obviously the bike fit was a big cause, as was riding the hoods, & the hoods were Campy instead of Shimano so they were smaller, so maybe i had to grip a bit harder, plus my aluminum bike had Oval bars with cushier bar tape, where my carbon bike had faux leather & i felt the vibrations.. The bike itself was quite aero too, & built more for regional racing on moderate terrain, than for steep & windy descents & uneven surfaces.. All of these factors contributed to the wobbles at lower speeds than had been fine on my aluminum frame.. But the wobbles were so terrifying, that even a year later almost, I'm way more scared to get the speed on my road bike, than doing technical descents on my Downhill MTB, despite having had a PCL injury from MTB.. So even with a new road bike, another carbon frame, potentially better geo & maybe stiffer & set up better, I'm still riding with the top tube between my knees to dampen the frame, to avoid wobbles, rather than just get in the zone & enjoy the descents like a i used to.. I think experiencing speed wobbles just create trauma, like being in a devastating earthquake, & I've been in a a devastating earthquake, & eventually i got over that too. Just like now I'm more relaxed on my Downhill MTB now I've got all clear from my physio.. So since nerves themselves can add to the oscillations that create speed wobble, as you get over the experience, you can increate the speed because your more relaxed.. I think when it comes to speed wobble, there's not one cause, but a layer of causes that create a negative system that results in speed wobble. No somewhat what those causes are & you can avoid it i guess.. Here's hoping haha!
On modern bikes it is most likely to be rider mistake than bike. I experienced it on 3 different bikes. Now I am more relaxed on bike and it doesn't hapend anymore.
Speed wobble happens at high speed, relative to the bike’s construction and the load that it’s bearing. When one’s bike starts to shimmy at speed, slowing down a bit (in a nice, controlled manner with both brakes) is probably the best thing you can do. Knees on top tube help dampen frame vibration, and can help a lot in minimizing wobble should it occur. I’d suggest if it happens on an unloaded bike, shop for a new bike. If it happens on a loaded touring bike, (but not on same bike when it’s not loaded) look into weight distribution all your touring gear (don’t put it all in rear or in front).
I had an incident where I had a speed wobble. I came out of it by applying a little pressure on my back brake. I'm fairly sure it happened because I had different air tires. However my front rim isn't perfectly straight either. I tested it out but I don't have a speedometer so I don't know if I was going to the same speed. Also there were other variables that may have been different. When I experienced the wobble I was going downhill around s curves but the next time I stopped after only going around one curve.
Going down a 4 mile decent yesterday with a strong tailwind. Road turned 45 degrees which resulted in a strong cross wind. Full tuck hands right up against the stem at 40 mph. Bike started to shake. Moved to the drops. Bike started shaking violently water bottle flew out of the cage. I thought that was it. Started breaking, tried to get my weight evenly on the pedals. It seemed like the bike continued to shaked until i got it down to about 20 mph. Very scary. The violence of the shaking was incredible. Relax, stay calm, slow it down evenly, and ride it out. Good luck.
I did not have this problem with my alloy frame bike. Started to have speed wobbles with carbon frame bike. Not sure if frame material makes a difference!!
I had my first race in 2 years yesterday and this happened to me doing 45mph down the first hill. I didn't go down but didn't continue either. Dropping the bike off at the shop now.
The only time I get a mild speed wobble is going 35-40 MPH down a hill with a crosswind. Every single time it's happened, which has only been a few times, it has been in this scenario.
Great show guys! If the wobble is happening at a certain speed causing resonance that amplifies making handling worse, then one of the key things to do is get the bike to a speed where resonance doesn’t occur. Sometimes it can be just a little slower or faster. Of course if the wobble is happening at all different speeds, then it is likely a different issue altogether.
I been expirencing speed wobble on every long decent over 40kmph, checked everything. Could it be a defective frame, is it a warranty issue and how do i suggest it? Super6 evo disc ultergra
I keep getting speed wobble after I installed a basket on my rear tire. I already had a rack and saddles but to get the basket in, I had to shift everything further back. Now, the center of gravity of the saddle, rack and basket sit behind the rear tire. Now I get speed wobble on every single ride, at low speeds. I go on average at 10-13 MPH so it’s not like I’m speeding down hills. It also happens while going on slight incline, so when I’m going considerably slower. It only happens if I let go of the handle bars and even more so if I lean back. Is shifting all that weight to the rear plus my own weight when leaning back causing this? I never get it if I’m even barely grasping my bars, so it takes little dampening to stop it. It’s just scary.
The OD2 headset on the propel has a design flaw in that the bearings on the headset are too small. In particular the top bearing. Gradual wear will make them loose. Loose headset or hub will give speed wobble. I have a propel and get wobbles in crosswind descents at 45mph+ (front range in Colorado - lots of places where this can happen). Weight distribution absolutely makes a difference. It can happen when I'm on the hoods but rarely in the drops. Leaning down low is the best way to prevent them. Once they start you are in trouble. A slightly longer and lower stem will help, a front wheel with a good profile and non-bladed spokes, plus putting in new headset bearings. Speed wobble is a forced oscillation driven, in this case, by gravity and crosswind. If you can induce wobble repeatedly you can experiment by placing weights in saddlebag or backpack to see if it makes it worse or lessens it. Fill water bottle with shot and see what happens when you place it in different positions.
@@hebrews11vs5 Cat 1 guy, with 30 years racing experience, behind me told me it was the worst he had seen and was surprised I kept it upright. I stopped doing that particular race because of it - mainly because of fear of crashing others.
@@carlosflanders518 I raced on Sunday with a scary incident. But now I am understanding my situation a bit more. I hit a rock and got a small buckle on the front wheel. Hitting the front brake caused uneven brake pressure when the bump hit my brakes ( that's your forced oscillation ) then with my head set bearings smaller than the hole for them, those 2 aspects double teamed me. In the pouring rain my back carbon brake did not work that well and I thought I'd go down into the oncoming traffic. I hope you were able to sort out your bike. As fir me I finished my race but after that thing, I was more riding than racing because I could not stop well and I did not want to compromise the safety of others.
I was struck by speed wobble last summer going downhill and hitting a rough patch of tarmac. I guess bad surface was the reason. Hope to never experience this ever again.
I reckon any discrepency be it faulty weak fork, slightly worn bearings, wheel or headset. Once you get a small repeat oscillation its gonna start amplifying and then its scary time
Way too complicated an explanation guys, It's a lot simpler than that. It's normally caused by flex between the head tube and the seat tube (alignment also has a role). The top tube is primarily responsible for controlling that flex which is why most modern bikes have horizontally ovalised top tubes. Modern, beefed up down tubes also help.
Wobble and reason why ? By pro bicycle mechanic : Centering of the front Axe is not correct !! Today i test my custom race bicycle Wobble with 55mph I'm verry happy becouse i don't push bicycle to the limit and this can be serious crash with £10 000 bicycle..
I experienced this for the first time a couple of months ago. Going downhill 30mph, over some railroad tracks, in the drops. Once it started I just knew I was going down, I had accepted it. Felt like it was never going to end, but I managed to get it under control and keep the rubber down. I don't think my bike was to blame for this, neither does my mechanic. I feel it was the combined effects of having too much weight on the handlebars, unbalanced weight on the bars, not weighting the pedals, legs far apart away from the TT.
I seriously wanted to quit cycling all together after that experience. Did a lot of research, heard a lot of possible explanations. Put all the suggestions in practice and now have zero fear of it happening again. On descents I know keep my hands light on the bars, upper body relaxed, pedal down and leg braced against the TT if I'm coasting. When I'm in the drops, my hands are on the curve closer to the shifters, not on the bar ends.
I have done many miles since then and my confidence is 100% back.
It was good to read this. It happened to me doing over 40mph. I think I'm to blame for it; the only thing I remember is I went in the drops and I started to pedal but still trying to put a lot of torque in to the pedals because I wanted to show off about how fast I can go downhill. I managed to get control of the bike during the wobble by easing the pressure off the front, then applying some back brake (I have discs) and then some front by which time the wobble eased off. Following this I lost all confidence and started to brake on descents. I'm starting to re-gain confidence now and being more lighter with the bike going down hill.
The idea to squeeze the top tube during a speed wobble is to add mass to change the resonance frequency of the wobble so you can regain control by not having the wobbles magnify each other each oscillation. The reason this differs on a bicycle than on a motorcycle is how the mass is distributed in the system. Rider on a motorcycle is less than half (down to a quarter probably) the mass of the system so the rider is more along for the ride if it happens and the only way to affect the wobble is reducing the mass that's wobbling. On a bicycle the rider is 80-90% of the system mass (or 8 or more times the mass of the bicycle) and can greatly affect the resonance just by absorbing the energy into the lower body mass. If the head and shoulders start to get moved around you follow your advice and try to disconnect the body mass from the bike (body bike disconnect) and ride it out again just trying to change the resonance and magnitude of the wobble until you can regain control. At least this is my understanding of it as I've fortunately only experienced it once.
I’ve had this happen 3 or 4 times now. Again 35-40mph, downhill, slight turn in the road and a cross wind (or car overtaking me!) and it’s the scariest thing to ever happen. Have managed to correct it by slowing, but of course, the wobble gets bigger before you stop. Have wondered whether it’s me, so will make sure I’m light on the bars, but will check alignment of the front end too. Scary stuff, that I dread happening again!
this was a great episode. i used to struggle with speed wobble, but i think it has to do with being too tense on the bike.
Great show guys, I experienced a terrifying speed wobble less than a week ago whilst descending at 60 km/h and genuinely thought my bike was collapsing under me. This was the first time I had ever experienced this (in my 30 years on a road bike). Generally, my BMC Teammachine rides beautifully and I cannot fault it. This one experience has got me terrified of descending now but I have taken the bike out a couple of more times and descended at 50-55 km/h without any issue. I have done a bunch of reading on this now and have found a really good article explain the physics of how this happens and some good suggestions on how to control it (link below). The bike is set up in fairly aggressively that puts the weight towards the back of the bike and, on top of that, the frameset is considered and known to be 'twitchy'. So for me, it's about weight distribution on a particular frame geometry. So far, when descending, slightly lifting my ass and putting the weigh into the bottom bracket (instead of the seat) seems to centre up the weight on the bike and, fingers crossed, this holds off the wobbles.
I have gotten the speed wobbles twice, the second time I braced my top tube with my legs and that fixed the wobble.
This happened to me and now it’s impossible to avoid. It has to be an anxiety thing causing uneven pressure. It’s not even speed related and it’s now happening on a 2nd bike. I think it’s the fear of it that is causing it.
I'm with you bud, I am scared to death descending now.
many years ago with a steel frame I had this often, and could not do anything against it; with my modern bike I never had that experience - until one week ago, when I rode a fast descent and suddenly got heavy crosswind; I instantly touched the brakes (smoothly...) but things got much worse until I was ~20 kph slower... scary moments!
I've had speed wobble issues from time to time on my road bike too... perhaps once a season. When it happens, it starts when going downhill usually when I hit about 60 kph. The bike is in the shop now. Hopefully the mechanic can spot if there is anything wrong with the bike. Otherwise, I'll need to reassess my position on the bike and level of tension when descending.
This is one of the best explanations I have heard, thank you Jonathan for the motorcycle knowledge.
I don’t know why you singled out the propel (maybe that was his bike?), along with the aeroad they are the stiffest bikes made, because of the 1 1/4” steer tube. I’m talking head tube stiffness (but they also have a lot of BB stiffness because they are both BB86 which is the stiffest bb shell design).
I only get them … and very violent ones , when I’m going downhill and take my hands off the bars and sit up … every time . If I do the same on a flat road zero wobble. I attribute it to the forces being put on the front on a downhill… al the weight pushing forward with no stick weight over the wheel.
And THANK YOU for the pro tip! Hughes me such anxiety every time I have to align my stem
guys thanks :) got a new tri bike and fit. i took it out for a first ride and at about 24 mph got a speed wobble and that was in the base bars not aero bars. this bike is quicker handling than my prior (Cadex tri bike now vs my 2021 shiv disc). head tube angle is 73 on cadex vs 72 on shiv, trail on cadex is 63 mm, on shiv 62 mm, wheelbase on cadex is about 6 mm longer. not large differences but i feel like i'm right over the pivot point for turning rather than back behind it. and my position is much more aero (7 cm lower in front)... and i feel a lot more weight/ down pressure on my hands in the base bars. we checked headset, wheel axles and bearings, wheels being true, and even frame alignment. no harvest from any of those. there were wind gusts that day to about 20 mph and i was on 64mm deep wheels. could tighter handling, being more over the pivot point rather than behind it, combined with more weight upfront be causing the wobble that may have been set off by a wind gust?
I experienced speed wobbles on the Blue Ridge Parkway while descending from Peaks of Otter on a Trek 520 touring bike with relative wide tires, 28 mm or 32 mm. It was repeatable. I went through at least three cycles of speeding up and then having to slow down when the steering became unstable. I returned to the same stretch of road with the same bike with 25 mm tires and did not experience any recurrence. The speed wobbles were highly speed sensitive. They went away almost immediately when I hit the brakes. Since geometry and weight distribution don't change with speed, I highly suspect that aerodynamics are involved. Perhaps the wider tires created more drag at the leading edge of the wheel, which caused the steering to become unstable.
I got speed-wobble on my road bike, on my first carbon frame about 8 months ago. It was my first decent on that bike & as i say my first decent on a carbon frame, as my other road bike is aluminum. As I'm more a MTBer than a road biker, & i got into road biking as a art of PCL rehab, i didn't know how crucial bike fit was, & i didn't know you had to use the drops, i always thought drops were for wind & aero.. So anyway i was descending a 350m local decent, on the steep side of the hill, about -12% gradient, & i got to 65kmh & coming up to the first switchback my bike got speed wobbles & it literally felt like i was riding jelly, it was absolutely terrifying! But i stayed calm, rear braked gradually & managed to slow down to a stop just before i ran out of straight road. And had a breather & a scream lol..
So i looked into it & obviously the bike fit was a big cause, as was riding the hoods, & the hoods were Campy instead of Shimano so they were smaller, so maybe i had to grip a bit harder, plus my aluminum bike had Oval bars with cushier bar tape, where my carbon bike had faux leather & i felt the vibrations.. The bike itself was quite aero too, & built more for regional racing on moderate terrain, than for steep & windy descents & uneven surfaces.. All of these factors contributed to the wobbles at lower speeds than had been fine on my aluminum frame.. But the wobbles were so terrifying, that even a year later almost, I'm way more scared to get the speed on my road bike, than doing technical descents on my Downhill MTB, despite having had a PCL injury from MTB.. So even with a new road bike, another carbon frame, potentially better geo & maybe stiffer & set up better, I'm still riding with the top tube between my knees to dampen the frame, to avoid wobbles, rather than just get in the zone & enjoy the descents like a i used to..
I think experiencing speed wobbles just create trauma, like being in a devastating earthquake, & I've been in a a devastating earthquake, & eventually i got over that too. Just like now I'm more relaxed on my Downhill MTB now I've got all clear from my physio.. So since nerves themselves can add to the oscillations that create speed wobble, as you get over the experience, you can increate the speed because your more relaxed.. I think when it comes to speed wobble, there's not one cause, but a layer of causes that create a negative system that results in speed wobble. No somewhat what those causes are & you can avoid it i guess.. Here's hoping haha!
Thank you.
On modern bikes it is most likely to be rider mistake than bike. I experienced it on 3 different bikes. Now I am more relaxed on bike and it doesn't hapend anymore.
Speed wobble happens at high speed, relative to the bike’s construction and the load that it’s bearing. When one’s bike starts to shimmy at speed, slowing down a bit (in a nice, controlled manner with both brakes) is probably the best thing you can do. Knees on top tube help dampen frame vibration, and can help a lot in minimizing wobble should it occur. I’d suggest if it happens on an unloaded bike, shop for a new bike. If it happens on a loaded touring bike, (but not on same bike when it’s not loaded) look into weight distribution all your touring gear (don’t put it all in rear or in front).
I had an incident where I had a speed wobble. I came out of it by applying a little pressure on my back brake. I'm fairly sure it happened because I had different air tires. However my front rim isn't perfectly straight either. I tested it out but I don't have a speedometer so I don't know if I was going to the same speed. Also there were other variables that may have been different. When I experienced the wobble I was going downhill around s curves but the next time I stopped after only going around one curve.
Going down a 4 mile decent yesterday with a strong tailwind. Road turned 45 degrees which resulted in a strong cross wind. Full tuck hands right up against the stem at 40 mph. Bike started to shake. Moved to the drops. Bike started shaking violently water bottle flew out of the cage. I thought that was it. Started breaking, tried to get my weight evenly on the pedals. It seemed like the bike continued to shaked until i got it down to about 20 mph. Very scary. The violence of the shaking was incredible.
Relax, stay calm, slow it down evenly, and ride it out. Good luck.
I did not have this problem with my alloy frame bike.
Started to have speed wobbles with carbon frame bike. Not sure if frame material makes a difference!!
I had my first race in 2 years yesterday and this happened to me doing 45mph down the first hill. I didn't go down but didn't continue either. Dropping the bike off at the shop now.
The only time I get a mild speed wobble is going 35-40 MPH down a hill with a crosswind. Every single time it's happened, which has only been a few times, it has been in this scenario.
I had an old cheap bike in the 80's that wobbled on a downhill.. damn that was scary.
Squeez top tube with legs worked for me. It was absolutely horrific experience but thank God I stopped it by squeezing top tube.
Great show guys! If the wobble is happening at a certain speed causing resonance that amplifies making handling worse, then one of the key things to do is get the bike to a speed where resonance doesn’t occur. Sometimes it can be just a little slower or faster. Of course if the wobble is happening at all different speeds, then it is likely a different issue altogether.
a long dowel in the fork dropouts checked against the handlebars gives better accuracy
I been expirencing speed wobble on every long decent over 40kmph, checked everything. Could it be a defective frame, is it a warranty issue and how do i suggest it? Super6 evo disc ultergra
If you're ever concerned there may be a defect in your frame, its best safety-practice to reach out to the manufacturer to confirm.
I keep getting speed wobble after I installed a basket on my rear tire. I already had a rack and saddles but to get the basket in, I had to shift everything further back. Now, the center of gravity of the saddle, rack and basket sit behind the rear tire.
Now I get speed wobble on every single ride, at low speeds. I go on average at 10-13 MPH so it’s not like I’m speeding down hills. It also happens while going on slight incline, so when I’m going considerably slower.
It only happens if I let go of the handle bars and even more so if I lean back. Is shifting all that weight to the rear plus my own weight when leaning back causing this? I never get it if I’m even barely grasping my bars, so it takes little dampening to stop it. It’s just scary.
Good question, baskets can really throw off the weight distribution the bike was designed for. Be safe!
check your wheel bearings.
The OD2 headset on the propel has a design flaw in that the bearings on the headset are too small. In particular the top bearing. Gradual wear will make them loose. Loose headset or hub will give speed wobble. I have a propel and get wobbles in crosswind descents at 45mph+ (front range in Colorado - lots of places where this can happen). Weight distribution absolutely makes a difference. It can happen when I'm on the hoods but rarely in the drops. Leaning down low is the best way to prevent them. Once they start you are in trouble. A slightly longer and lower stem will help, a front wheel with a good profile and non-bladed spokes, plus putting in new headset bearings. Speed wobble is a forced oscillation driven, in this case, by gravity and crosswind. If you can induce wobble repeatedly you can experiment by placing weights in saddlebag or backpack to see if it makes it worse or lessens it. Fill water bottle with shot and see what happens when you place it in different positions.
Sounds like your speed wobble incidents were never very severe.
Because I'm not inclined to experiment with speed wobble. I just want it gone
@@hebrews11vs5 Cat 1 guy, with 30 years racing experience, behind me told me it was the worst he had seen and was surprised I kept it upright. I stopped doing that particular race because of it - mainly because of fear of crashing others.
@@carlosflanders518 I raced on Sunday with a scary incident. But now I am understanding my situation a bit more. I hit a rock and got a small buckle on the front wheel. Hitting the front brake caused uneven brake pressure when the bump hit my brakes ( that's your forced oscillation ) then with my head set bearings smaller than the hole for them, those 2 aspects double teamed me. In the pouring rain my back carbon brake did not work that well and I thought I'd go down into the oncoming traffic. I hope you were able to sort out your bike. As fir me I finished my race but after that thing, I was more riding than racing because I could not stop well and I did not want to compromise the safety of others.
I was struck by speed wobble last summer going downhill and hitting a rough patch of tarmac. I guess bad surface was the reason. Hope to never experience this ever again.
surprise there was no reference to a bad fork. I had a bad fork and replaced it, problem solved.
I reckon any discrepency be it faulty weak fork, slightly worn bearings, wheel or headset. Once you get a small repeat oscillation its gonna start amplifying and then its scary time
Way too complicated an explanation guys, It's a lot simpler than that. It's normally caused by flex between the head tube and the seat tube (alignment also has a role). The top tube is primarily responsible for controlling that flex which is why most modern bikes have horizontally ovalised top tubes. Modern, beefed up down tubes also help.
Hey Randy would even a small crack in the top tube then therefore potentially destabilize a bike and cause wobble?
Wobble and reason why ?
By pro bicycle mechanic : Centering of the front Axe is not correct !!
Today i test my custom race bicycle Wobble with 55mph I'm verry happy becouse i don't push bicycle to the limit and this can be serious crash with £10 000 bicycle..
Pro tip, don't say pro tip.