Headset adjustment is also important... Any mis adjustments will effect handling ... Stem length, short is skid ish long is slower and more controllable . It's definitely not a pleasant experience.
I rode the same bike, a Trek 520, down the same descent on two different occasions. Speed wobbles occurred during the first occasion, but not the second. The only significant difference in the bike between the two occasions was the tires. I vaguely recall they were 28 mm when the speed wobbles occurred, and 25 mm when the speed wobbles didn't occur.
High speed wobble is caused by rotational wheel imbalance. The reason your bike wobbled with one size tire and not the other is by pure Luck... You see, there are three heavy spots on your wheel. One, is on your tire, two is on your rim, and third is your air-valve. The rim and air-valve are fixed, but the tire heavy spot can be anywhere. Here is where the magic happens.... If by LUCK the heavy spot on the tire is located together with the rim & tire heavy spots, you end up with a big lump of weight on one side of the wheel causing the wheel to be very un balanced. And if by LUCK if the heavy spot on the tire is located opposite of the rim & tire heavy spots you end up with a fairly well balanced wheel.. It is the bike industry that refuses to understand wheel balance and does any research on this very dangerous matter of wheel balance. All they care about is aero... Don't worry they'll soon find out.
Happened to me too. Both times in Orange NSW. But on different bikes. Both with 45 mm rims. Most recently on Sunday 10 September 2023. A guy lost his bidon going downhill rapidly at about 75kmh. I swerved to avoid it and probably braked as well then kicked in the most hair raising experience I’ve ever had on a bike (that includes falls). A massive death or speed wobble where I was certain I was to crash big time. It was like the bike was trying to throw me off. I veered away from others to avoid peril to them. Fortunately I somehow managed to keep it together and survived without incident but it scared the absolute s**t out of me. I thought I was lucky to have survived. I put it down to a cross wind as another rider had the same thing on a Trek Madone. I think that you can keep peddling and get through it and only apply rear brake because of aero issues.
So crazy. Actually happens again to me on the same downhill a few weeks back. Guy on a f12 Pinarello had same issue. He went down and fractured pelvis 😢
It happened to me two times. I have a carbon frame Tarmac with Zipp 303 wheels and 28mm tires. There was cross wind both times. I think it is a combination of those things. My handlebar is also a bit high wich may help as well. I need to find a solution or I will end up kissing the asphalt soon 😞
Never, on any bike until Dogma F. Stable on flats but a strait descent. Probably set iff by a crosswind. Moving saddle position forward seemed to help, not cure, but notably, haven't had it since balancing front wheel and reducing tire pressure... used to run max for tire, 115psi. Now, 105-110. C60 wheels and all other roadbikes have been rim brake, so the winds really affect the quick frontend handling of the Dogma.
Happened to me. Carefully inspect your tire to ensure it's seated properly. An un-properly seated tubeless tire with definitely make your wheel wobble. If you didn't hear a "pop" when you placed the tires on your rim then it's an improperly seated tubeless tire possibly causing your wobble. Spin your wheel, everything even? If not, take the tire off and re-seat. Thanks!!
Thanks for feedback. I use latex and clinchers and it’s seated properly. I even wondered if it was too low tire pressure. Or if the wheel was not balanced but it only happened once. Never again.
I had it last week, but it’s hard to tell why exactly. Tyre pressure on the front tubeless was definitely low, but the tyre ran straight in terms of beading after the installation.
Happened to me on my Ostro during the Bear Mountain Classic last season. Super rainy, cold, and windy. I was on the BI45’s. I’ve actually moved to the Bontrager RSL 37’s. Feels much more stable.
Yep I second that. ,its a wheel balance thing. The deeper the wheel the longer your valve needs to be which unbalances the wheel the longer the valve is(more weiggt) I used those golf club sticker weights in opposite side of valve and cover it with black electrical tape. Prob solved. Keep adding the weights until the wobble in the stand goes away
What you and others are finding is the bikes natural resonance. You hit the sweet spot of vibrations constructively adding and re-enforcing themselves. The right combination of frame geometry, material characteristics, rolling speed, road vibrations, and maybe wind speed and other factors create slight shimmies in the bike. Normally they simply dissipate but at resonance they strengthen. How to fix? Send your bike to a lab for full engineering analysis... otherwise experiment with changing things. What on your bike might possibly affect road shimmies / vibrations? Change that and see if it makes a difference. Wheel stiffness might do it. Tire size and air pressure might do it. Shifting position on the bike might do it. Altering weight of the bike might do it. Etc.
I am just tired of getting the speed wobbles, tried everything regarding positioning CoG and different frames. I have had +20 speed wobbles in the last few years. I got rid of an old Boardman frame but then had a slight case on a brand new Basso Diamante SV with 404 Firecrests. I have a new winter bike now, and put my old Knight Composites 35 TLA on it. I had another terrying case of it on a long descent the other day. Started to shimmy so bad, rocky outcrops everywhere, but managed to take the speed out of it and bale out by landing it in a verge with some scathing thank god. I think the KC wheels are the cause, and about to swap them out and retest my winter bike.
I’ve been trying to figure it out for two years. Happens on Moots Routt RSL gravel bike. It’s happened with gravel wheelset (Mavic aluminum and 34mm tires) and road wheelset (Enve SES AR 34 with 28mm tires). LBS checked headset, hubs, etc. Last fall Moots replaced the carbon fork. All to no avail. LBS just removed 20mm from stem stack height, which I’m now checking out. Moots said they’d look at frame but if they find nothing I’ll have to pay for shipping, which could be $800+. I may just replace the frame.
I have had people in comments and messages on IG that is a phenomenon across all brands wheels and frames. From s works, to Pinarello to trek. Don’t replace your frame. Seems just it a happens with a perfect recipe of wind direction, road condition, and position / grip on a decent.
I experienced this on the descent from coal bank pass on the iron horse this past weekend. Scared me more than crashing on my mtb. One of the guys I rode with also had it. A few people blew past me with obviously no issue. I also passed a few people who may have been having worse issues. It does seem like it may be a recipe rather than just 1 thing potentially.
After reading many comments I believe different things attribute to it. I had about 5-10 wobbles always around 50 or more km/h and sidewinds in the last months on my new Canyon Aeroad SLX. I swapped the rims from 62 to Shimano C50 but that seemed to have been an unhelpful decision. Just yesterday at a grand fondo I had to brake and my friend crashed into me. Resulting in broken bones, a lot of pain and many months to come to recover. This years summer riding is over. It’s very sad. And every time I get more afraid to ride. In my opinion the manufacturers are not taking this issue serious enough.
Wow. Very timely video. Exactly same issue happened to me on my ostro this past Saturday. Coming down the other side of a bridge and the wobble started and scared the crap out of me..I slowed the bike down as much as I could until I got safely down onto flat road. I’ve had this happen to me twice on my Cannondale SystemSix also. So I’m thinking its me (fear/descendophobla?) vs an issue with the bike. Both bikes are size 58 with deep section wheels so that may be a factor. I knew what to do, but didnt. Should have been in the drops, weight back and maybe pinching top tube with my legs, but panic set in and I forgot all the techniques. Anyway, the bike is great and fast. I do recall there was a bit of crosswind so that may be contributing. I have the deepest blackinc wheels so that didnt help. Next time, I’ll think tactics before letting this happen again.
I had an incident a speed wobble at slower speeds due to mostly having different pressures in my tires I think. It wasn't that bad and I got out of it by just applying a little bit of rear brake.
Hi, had the same scenario happen a few weeks ago on a descent at 35mph on a Lauf. This is probably the smoothest most stable bike I have owned. Like you said it was terifying!!
I'm turning blue in the head trying to tell the whole Hi-End enthusiast, fast riding world that "High Speed Wobbles" is caused by rotational un-balanced wheels!!! To the publishers of Addict Cyclist all I ask is for you to send me your contact info and I will explain in detail the chain of events that happens to a light weight bike & rider with carbon wheels as speeds increase... You will be shocked, I promise. Sincerely Dan Sotelo
I suspect, at least front wheel, this IS a significant cause. Less for back wheel because it really can't move side-to-side. One reason to think this is that, at least in my case, wobble only occurs above 25+mph. I suspect set off by a crosswind, then the balance adds up with flex, wind, harmonics to be pretty nasty and won't stop until under 10mph....feeds itself.
happened to me three times on two different bikes. once on aluminum frame and twice on carbon Emonda. out of three times two times it happened after i started to brake gently over 40 rm/h.
I have the FACTOR VAM 02 Experienced the same thing descending many times. Had to slow down to walking pace. I have ZIPP 303's. Am looking to change to a climbing wheels. Another UA-camr call 'The diabetic cyclist' actually came off with the Zipp 303's, and stopped using them. He says he changed to Black Inc. - same depth 45 - and that resolved the problem.
Thanks for feedback. Seems the BI 45 are a good all around option. It only happened to me once and never again. My front wheel was also not true. Just has that fixed this week.
I had two high speed wobbles on a giant propel with 65mm wheels in the same week totally put me off fast descents. Found some advice about wheel balancing turned bike up side down spun it up to speed and the bike was jumping of the floor. I balanced the wheels using small golf club weights under the rim tape and now the wheels spin smooth. Did this over a year ago and not had an issue since and yes I’m descending like a mad man once again 🤣
Just experienced this on a 45mph descent after I had to avoid a branch and squeeze between it and a trailer. Kinda windy day nothing crazy that I haven’t experienced. State aluminum frame, quite stiff, 60mm Elite wheels. Hadn’t really done a lot of climbing on them so couldn’t compare to if it was them or not. Just switched back to vittoria wheels. We will see. The State aluminum frame has never felt comfortable quite honestly might just have to go back to specialized
Speed Wobble One time in a race going down hill not to fast , 4 Or 5 rider all got speed wobble around me, It was cold out about 45 deg, Going down hill, on chip seal, With the temperature and the chip seal created a frequency in the Frames Some tried to control it buy putting a knee on their top tube . This was about 2008 so we where all on 23 or 21 wight tires. most only had Alum Wheels as it was a hilly course Only one time had I seen any thing like that.
Hapend to me on new Factor ostro vam 2 almost every ride. Before that I rode Look 795 rs 6 years and never experienced that. Happened at 85km/h and I almost crash. I am scared of this bike…. Wheels are Black inc 48/58
Wow! Crazy you said this. I always felt that the wide fork and the D shape steer had something to do with turbulence or resonating frequency causing the wobble at certain wind angle with maybe road conditions.
Same with me. New Factor Ostro Vam2 with 48/58 wheels. Seems like crosswinds are always involved. I bought Enve SES 3.4 and thought I had it solved but it still happens depending on wind. Bike had me so scared I switched to my Colnago C64 using the same Enve wheels. Was on a steeper decent yesterday not even much over 30 mph and it happpened now on that bike. I’ve ridden for 20 years and only had a couple wobbles on other bikes which was above 40 mph and those were more of a wobble at the seatpost that you could dampen with your knees. These latest ones are front steering wobbles and has me afraid to go downhill. I’m getting dropped from my groups on the downhills and I’m 220lb I’m used to going flat out downhill. My previous bike a Specialized SWorks Roubaix I never had this problem. That bike is a couple lbs heavier so I don’t climb quite as fast but going downhill I always feel like I could go faster. I’ve spent way too much trying to solve this. About to try buying a new Roubaix since it’s lighter but I’m also wondering if that’s the problem. These lighter bikes are the ones giving me issues. Just not sure the lower weight is worth the instability
@@matevzlapanja3335 Yeah later in my ride the wind was behind me and I hit 42 mph….cant say I felt confident though I felt like I was a wind gust away from crashing. My cycling coach is a Factor dealer and he thinks I should lower my handlerbars…I’m just hesitant since that’s a one way trip. I hate this I used to love bombing down hills
Headset adjustment is also important... Any mis adjustments will effect handling ... Stem length, short is skid ish long is slower and more controllable . It's definitely not a pleasant experience.
My wheels are better balanced now and going on the annual ride where it happened to me 2x. Hope this year is better
I rode the same bike, a Trek 520, down the same descent on two different occasions. Speed wobbles occurred during the first occasion, but not the second. The only significant difference in the bike between the two occasions was the tires. I vaguely recall they were 28 mm when the speed wobbles occurred, and 25 mm when the speed wobbles didn't occur.
High speed wobble is caused by rotational wheel imbalance. The reason your bike wobbled with one size tire and not the other is by pure Luck... You see, there are three heavy spots on your wheel. One, is on your tire, two is on your rim, and third is your air-valve. The rim and air-valve are fixed, but the tire heavy spot can be anywhere.
Here is where the magic happens....
If by LUCK the heavy spot on the tire is located together with the rim & tire heavy spots, you end up with a big lump of weight on one side of the wheel causing the wheel to be very un balanced.
And if by LUCK if the heavy spot on the tire is located opposite of the rim & tire heavy spots you end up with a fairly well balanced wheel..
It is the bike industry that refuses to understand wheel balance and does any research on this very dangerous matter of wheel balance. All they care about is aero... Don't worry they'll soon find out.
Happened to me too. Both times in Orange NSW. But on different bikes. Both with 45 mm rims. Most recently on Sunday 10 September 2023. A guy lost his bidon going downhill rapidly at about 75kmh. I swerved to avoid it and probably braked as well then kicked in the most hair raising experience I’ve ever had on a bike (that includes falls). A massive death or speed wobble where I was certain I was to crash big time. It was like the bike was trying to throw me off. I veered away from others to avoid peril to them. Fortunately I somehow managed to keep it together and survived without incident but it scared the absolute s**t out of me. I thought I was lucky to have survived. I put it down to a cross wind as another rider had the same thing on a Trek Madone. I think that you can keep peddling and get through it and only apply rear brake because of aero issues.
So crazy. Actually happens again to me on the same downhill a few weeks back. Guy on a f12 Pinarello had same issue. He went down and fractured pelvis 😢
It happened to me two times. I have a carbon frame Tarmac with Zipp 303 wheels and 28mm tires. There was cross wind both times. I think it is a combination of those things. My handlebar is also a bit high wich may help as well. I need to find a solution or I will end up kissing the asphalt soon 😞
Yikes! I’m sure it’s a combo of wind, road condition.
Never, on any bike until Dogma F. Stable on flats but a strait descent. Probably set iff by a crosswind. Moving saddle position forward seemed to help, not cure, but notably, haven't had it since balancing front wheel and reducing tire pressure... used to run max for tire, 115psi. Now, 105-110. C60 wheels and all other roadbikes have been rim brake, so the winds really affect the quick frontend handling of the Dogma.
Happened to me. Carefully inspect your tire to ensure it's seated properly. An un-properly seated tubeless tire with definitely make your wheel wobble. If you didn't hear a "pop" when you placed the tires on your rim then it's an improperly seated tubeless tire possibly causing your wobble. Spin your wheel, everything even? If not, take the tire off and re-seat. Thanks!!
Thanks for feedback. I use latex and clinchers and it’s seated properly. I even wondered if it was too low tire pressure. Or if the wheel was not balanced but it only happened once. Never again.
I had it last week, but it’s hard to tell why exactly. Tyre pressure on the front tubeless was definitely low, but the tyre ran straight in terms of beading after the installation.
60mm is to much for Crosswinds. Move to 40mm wide rims
Running Roval Rapide clx2 with a 51mm front and super wide profile and it is helping tremendously
Happened to me on my Ostro during the Bear Mountain Classic last season. Super rainy, cold, and windy. I was on the BI45’s. I’ve actually moved to the Bontrager RSL 37’s. Feels much more stable.
Thanks for feedback!
Yep I second that. ,its a wheel balance thing. The deeper the wheel the longer your valve needs to be which unbalances the wheel the longer the valve is(more weiggt) I used those golf club sticker weights in opposite side of valve and cover it with black electrical tape. Prob solved. Keep adding the weights until the wobble in the stand goes away
@@evanwilliams4920 Silca makes a balance kit.
@@addictcyclist No kidding. Must be fairly new. Thanks!
What you and others are finding is the bikes natural resonance. You hit the sweet spot of vibrations constructively adding and re-enforcing themselves. The right combination of frame geometry, material characteristics, rolling speed, road vibrations, and maybe wind speed and other factors create slight shimmies in the bike. Normally they simply dissipate but at resonance they strengthen. How to fix? Send your bike to a lab for full engineering analysis... otherwise experiment with changing things. What on your bike might possibly affect road shimmies / vibrations? Change that and see if it makes a difference. Wheel stiffness might do it. Tire size and air pressure might do it. Shifting position on the bike might do it. Altering weight of the bike might do it. Etc.
Thank you for the feedback!
I am just tired of getting the speed wobbles, tried everything regarding positioning CoG and different frames. I have had +20 speed wobbles in the last few years. I got rid of an old Boardman frame but then had a slight case on a brand new Basso Diamante SV with 404 Firecrests. I have a new winter bike now, and put my old Knight Composites 35 TLA on it. I had another terrying case of it on a long descent the other day. Started to shimmy so bad, rocky outcrops everywhere, but managed to take the speed out of it and bale out by landing it in a verge with some scathing thank god. I think the KC wheels are the cause, and about to swap them out and retest my winter bike.
Wild. On a charity ride on a fast 45mph downhill a Pinarello with dt Swiss arc wheels and I on my factor experienced it. Asked around, no one else.
@@addictcyclist Typical. I feel your frustration!
I’ve been trying to figure it out for two years. Happens on Moots Routt RSL gravel bike. It’s happened with gravel wheelset (Mavic aluminum and 34mm tires) and road wheelset (Enve SES AR 34 with 28mm tires). LBS checked headset, hubs, etc. Last fall Moots replaced the carbon fork. All to no avail. LBS just removed 20mm from stem stack height, which I’m now checking out. Moots said they’d look at frame but if they find nothing I’ll have to pay for shipping, which could be $800+. I may just replace the frame.
I have had people in comments and messages on IG that is a phenomenon across all brands wheels and frames. From s works, to Pinarello to trek. Don’t replace your frame. Seems just it a happens with a perfect recipe of wind direction, road condition, and position / grip on a decent.
I experienced this on the descent from coal bank pass on the iron horse this past weekend. Scared me more than crashing on my mtb. One of the guys I rode with also had it. A few people blew past me with obviously no issue. I also passed a few people who may have been having worse issues. It does seem like it may be a recipe rather than just 1 thing potentially.
After reading many comments I believe different things attribute to it. I had about 5-10 wobbles always around 50 or more km/h and sidewinds in the last months on my new Canyon Aeroad SLX. I swapped the rims from 62 to Shimano C50 but that seemed to have been an unhelpful decision. Just yesterday at a grand fondo I had to brake and my friend crashed into me. Resulting in broken bones, a lot of pain and many months to come to recover. This years summer riding is over. It’s very sad. And every time I get more afraid to ride. In my opinion the manufacturers are not taking this issue serious enough.
Oh wow! So sorry to hear about the accident. Hope you all recover fast!
Wow. Very timely video. Exactly same issue happened to me on my ostro this past Saturday. Coming down the other side of a bridge and the wobble started and scared the crap out of me..I slowed the bike down as much as I could until I got safely down onto flat road. I’ve had this happen to me twice on my Cannondale SystemSix also. So I’m thinking its me (fear/descendophobla?) vs an issue with the bike. Both bikes are size 58 with deep section wheels so that may be a factor. I knew what to do, but didnt. Should have been in the drops, weight back and maybe pinching top tube with my legs, but panic set in and I forgot all the techniques. Anyway, the bike is great and fast. I do recall there was a bit of crosswind so that may be contributing. I have the deepest blackinc wheels so that didnt help. Next time, I’ll think tactics before letting this happen again.
Hey Jay, good feedback! Can happen any time and I feel the condition have to align… wind direction, road conditions, tense rider…
I had an incident a speed wobble at slower speeds due to mostly having different pressures in my tires I think. It wasn't that bad and I got out of it by just applying a little bit of rear brake.
Wow. That's scary. I have black inc 45's and I have been lucky to never have experienced this.
Hi, had the same scenario happen a few weeks ago on a descent at 35mph on a Lauf. This is probably the smoothest most stable bike I have owned. Like you said it was terifying!!
So crazy! Just a perfect storm of conditions. Wind, speed, road conditions
I'm turning blue in the head trying to tell the whole Hi-End enthusiast, fast riding world that "High Speed Wobbles" is caused by rotational un-balanced wheels!!! To the publishers of Addict Cyclist all I ask is for you to send me your contact info and I will explain in detail the chain of events that happens to a light weight bike & rider with carbon wheels as speeds increase... You will be shocked, I promise. Sincerely Dan Sotelo
Look me up on Instagram
I suspect, at least front wheel, this IS a significant cause. Less for back wheel because it really can't move side-to-side. One reason to think this is that, at least in my case, wobble only occurs above 25+mph. I suspect set off by a crosswind, then the balance adds up with flex, wind, harmonics to be pretty nasty and won't stop until under 10mph....feeds itself.
happened to me three times on two different bikes. once on aluminum frame and twice on carbon Emonda.
out of three times two times it happened after i started to brake gently over 40 rm/h.
I have the FACTOR VAM 02 Experienced the same thing descending many times. Had to slow down to walking pace. I have ZIPP 303's. Am looking to change to a climbing wheels. Another UA-camr call 'The diabetic cyclist' actually came off with the Zipp 303's, and stopped using them. He says he changed to Black Inc. - same depth 45 - and that resolved the problem.
Thanks for feedback. Seems the BI 45 are a good all around option. It only happened to me once and never again. My front wheel was also not true. Just has that fixed this week.
I had two high speed wobbles on a giant propel with 65mm wheels in the same week totally put me off fast descents. Found some advice about wheel balancing turned bike up side down spun it up to speed and the bike was jumping of the floor. I balanced the wheels using small golf club weights under the rim tape and now the wheels spin smooth. Did this over a year ago and not had an issue since and yes I’m descending like a mad man once again 🤣
Thanks for feedback! The wheels already jump, esp the front. Silca makes a balance kit. I will consider.
Just experienced this on a 45mph descent after I had to avoid a branch and squeeze between it and a trailer. Kinda windy day nothing crazy that I haven’t experienced. State aluminum frame, quite stiff, 60mm Elite wheels. Hadn’t really done a lot of climbing on them so couldn’t compare to if it was them or not. Just switched back to vittoria wheels. We will see. The State aluminum frame has never felt comfortable quite honestly might just have to go back to specialized
Thanks for sharing!
Speed Wobble One time in a race going down hill not to fast , 4 Or 5 rider all got speed wobble around me, It was cold out about 45 deg, Going down hill, on chip seal, With the temperature and the chip seal created a frequency in the Frames Some tried to control it buy putting a knee on their top tube . This was about 2008 so we where all on 23 or 21 wight tires. most only had Alum Wheels as it was a hilly course Only one time had I seen any thing like that.
Wild! My instance was on rough chip seal in the Pocono Mountains. Didn’t happen again for rest of the ride. I hit over 50mph a few times too.
Hapend to me on new Factor ostro vam 2 almost every ride. Before that I rode Look 795 rs 6 years and never experienced that. Happened at 85km/h and I almost crash. I am scared of this bike…. Wheels are Black inc 48/58
Wow! Crazy you said this. I always felt that the wide fork and the D shape steer had something to do with turbulence or resonating frequency causing the wobble at certain wind angle with maybe road conditions.
We will see I will try with different wheels….but definitely frame has to absorb this…
Same with me. New Factor Ostro Vam2 with 48/58 wheels. Seems like crosswinds are always involved. I bought Enve SES 3.4 and thought I had it solved but it still happens depending on wind. Bike had me so scared I switched to my Colnago C64 using the same Enve wheels. Was on a steeper decent yesterday not even much over 30 mph and it happpened now on that bike. I’ve ridden for 20 years and only had a couple wobbles on other bikes which was above 40 mph and those were more of a wobble at the seatpost that you could dampen with your knees. These latest ones are front steering wobbles and has me afraid to go downhill. I’m getting dropped from my groups on the downhills and I’m 220lb I’m used to going flat out downhill. My previous bike a Specialized SWorks Roubaix I never had this problem. That bike is a couple lbs heavier so I don’t climb quite as fast but going downhill I always feel like I could go faster. I’ve spent way too much trying to solve this. About to try buying a new Roubaix since it’s lighter but I’m also wondering if that’s the problem. These lighter bikes are the ones giving me issues. Just not sure the lower weight is worth the instability
@ I will contact customer support at Factor and we will see what they will say about this. I think this mustn’t happened cause it is so dangerous…
@@matevzlapanja3335 Yeah later in my ride the wind was behind me and I hit 42 mph….cant say I felt confident though I felt like I was a wind gust away from crashing. My cycling coach is a Factor dealer and he thinks I should lower my handlerbars…I’m just hesitant since that’s a one way trip. I hate this I used to love bombing down hills
Jabba cat 🐈 approved
1.25k Subs and you have a 15 second unskippable AD?!
I don’t make the rules around here 😂
@@addictcyclist I mean that was really impressive
@@anakinskymonke3670 thanks for the watch!
shimming effect...easy to solve, ride faster!