Norco Factory Team Mechanic Lewis Kirkwood Thinks Mountain Biking Could be Giving us Bad Vibrations

Aug 7, 2019
by James Smurthwaite  
Lewis Kirkwood, the Norco Factory Team mechanic, conducted the study as part of his PhD.


We’re all used to the ‘mountain bike claw’ at the end of a long day of riding as we pry our semi-paralyzed hands from the grips. The feeling of being beaten up after a day of bike park battery is part and parcel of modern mountain biking, but just how much vibration are we getting through our handlebars? And is that safe for us in the long run?

A recent study from Edinburgh Napier University suggests that mountain bikers are experiencing more intense vibrations than a construction worker who has spent a day on a jackhammer. The study was carried out by Norco Factory Team mechanic, Lewis Kirkwood, as part of his Ph.D. He fitted accelerometers to the bars of two top-ten riders' bikes at a round of the Scottish Enduro Series and the British Championships. These are tracks that have hosted EWS rounds in the past and represent a typical, elite-level enduro race.

The data returned suggested that vibration levels the mountain bikers were experiencing exceeded the safe recommended levels according to ISO standards. ISO is a body that creates standards covering 164 countries with the goal of ensuring products and services are safe, reliable and of good quality. ISO 5349 - 1:2001, which monitors human exposure to hand-transmitted vibration, caps vibrations at 5.0 ms^-2, but Lewis found mean values of 5.84ms^-2 on the riders he studied, as well as values topping out at 6.61ms^-2.

Before you panic, we don't yet know if those standards are relevant to mountain biking. "Just because these numbers are over the arbitrary value that we label as being bad doesn't mean that the riders can't handle it," says Kirkwood. "We’ve still got a long way to go but I think it is important to quantify it." In the workplace, exposure to vibration has been linked it to musculoskeletal, neuromuscular, vascular and other types of pathologies such as hand-arm vibration syndrome.

We caught up with Lewis to talk about how the study came about, what it might mean for everyday riders, and how we can limit the vibrations we experience when riding.




How did this study first come about?


Lewis: We started out by looking at the physiological demands of enduro racing. We had 9 elite racers for a year, and one of the ways of measuring the demands of racing was using Catapults. Catapults are pretty basic GPS units that can start to look at braking and the distribution of speed on tracks, and they can tell you a lot about where the fast guys make their time.

With those, you can measure whole-body vibration and we saw some quite high values but the equipment didn't meet the specifications to measure at the ISO standard. This led us on to realising that we needed to measure vibration in accordance with international guidelines to fit it in with all the other research out there. At the moment, mountain biking is on its own path with how you measure things so we had to bring it back in line with the standard, it had to fit in somewhere.

bigquotesMy professor did a study at Fort William and you can lose around about 30% grip strength in one top to bottom run.


Where do these standards come from? What industries are experiencing the most vibrations?


Lewis: Construction, people that spend all day on jackhammers, lumberjacks, and joiners. The reason these guidelines are in place is that they're seeing hand arm vibration syndrome, an irreversible pathology. You can get white fingers syndrome, peripheral circulation, and nervous problems and musculoskeletal problems. So, there's a reason those guidelines are in place but we still don't know very much about how they come about and it's different for everyone. Some people can experience more vibration and be fine and some people can experience less vibration and not be ok. It's still early days but you have to put a number on it at some point.


Are there other reasons vibrations are important for mountain bikers?


Lewis: The more vibration you expose yourself to, eventually it's going to limit your grip strength. Vibration stimulates muscle and it makes the muscle tense, which is why you get arm pump because your muscle doesn't relax and it cuts off the blood flow.

My director of studies, Professor Geraint Florida-James, did a study at Fort William and you can lose around about 30% grip strength in one run top to bottom. Eventually, you'll hit a big hole and you can't hold on or you lose your posture. It's all energy; it has to be dissipated somewhere before it gets to your head. The more you can limit it at your hands, the faster you’re going to go but keeping that control and performance is the key part.

Lewis: We also had models for how much training the guys were doing and mountain bikers, going by heart rate, were doing roughly half of what the road riders were but they were still getting the same improvements in physiological parameters. You have to provide the same stimulus to get the same outcome, so we were obviously missing half the measurements. In mountain biking there's a lot more involved in terms of vibration, shocks, riding through holes and all of that stuff. That was something that pointed us towards vibration being a missing training load in mountain biking.

Should elite and everyday mountain bikers be worried about vibrations?


Lewis: Well, we don't want to cause panic with anyone and actually I've only got a hardtail so I don't want the warriors to come and eat me up for being some sort of fear monger, but it's concerning. It's at the point where we don't know what happens if we keep doing this for years and years. We don’t have mountain bikers that have grown really old yet.

As I grow up, I want to be healthy but the consideration for me is that I'm going to ride mountain bikes whether or not it's going to be harmful because I like riding bikes. We believe there are ways of optimising the design of components such as handlebars, grips or even gloves, tyres and spokes, and if we can look at ways to minimize vibration while still keeping the performance then that has to be a good thing.

Just because these numbers are over the arbitrary value that we label as being bad doesn't mean that the riders can't handle it. We’ve still got a long way to go but I think it is important to quantify it because if you can't do it reliably and in a valid way then how do you know if one handlebar is better than the other?


So what's next for you and this study?


Lewis: Professor Florida-James has just secured £19 million funding for an Innovation Centre and a bike park in Innerleithen with Edinburgh Napier University and with the Mountain Bike Centre of Scotland, which is a pretty massive deal.

This is just scratching the surface with handlebar vibration. This was to prove that we could do it, then with the Innovation Centre we can test different things. So if you had a component manufacturer with different layups of carbon handlebars and they wanted to know which was better in the field then we can put an actual number on it to reliably measure it. Then you go into seatposts, and frame material and spoke tension and that's what I want to do more of.


Lewis knows a thing or two about vibrations as a hardtail rider.


Lewis: It gets really interesting when you can measure it and then measure the response from the body too. At Napier, we have a big physiology department where we can take blood from people so we can link up vibrations doses and changes in the blood to see if there is a relationship with things like osteo-arthritis and all the other nasty pathologies that potentially go with vibration exposure. It has opened up more questions than it's answered at the moment!

The key thing I wanted to say is I'm not trying to scare people away from riding bikes by any means, it's just something that we've realised is potentially going to be an issue and to address it. You see products coming out all the time that flex for comfort and then other times it's all stiffness and strength. Ultimately we can measure these things and ultimately we would want to work with companies to develop such products to find the best balance.

The full study can be found here.


183 Comments

  • + 73
 This news really resonates with me.
  • + 12
 I converted my fork to a coil and increased travel to 170mm, carbon bars, 2.5 inch tyre, magura mt7 brakes, which are super powerful, and soft grips. It made so much difference and a lot less hand and general fatigue compared to my friends and my self on previous years.
  • + 6
 I'm tingling just thinking about it.
  • + 19
 One word answer: 'vibrocore'

I was suffering from the first stages of white finger from poorly damped chainsaws after years in tree surgery and forestry, but switching to Spank vibrocore bars and larger diameter Ergon grips has made numbness during riding almost non-existent.
  • + 2
 @landscapeben: I started getting white finger in my last few years of dh racing, half way down a track i wouldn't be able to feel my 2 middle fingers and they'd be ghost white. It was really concerning as I wasn't sure whether I'd lose my grip or not. It became more common until the point where I'd get it every ride on the dh bike. Over ten years since I raced dh now, and those fingers turn white the moment they get cold, say after I jump in a lake. A cold weather mtb ride really sucks as they go numb immediately. Haven't found much that helps but lots on here are recommending the Spank bars so they may be worth a try?
  • + 1
 @landscapeben: The Ergon GD1 dh grips in the fatter diameter are my favorite!
  • + 6
 @notenduro: a bit old school, but ODI Rogues for me...
  • + 2
 @notenduro: I've tried both the Ergon GD1 and the standard Ergon, both are nice but I preferred the GD1. Not sure that either made a difference to the Reynauds (white finger medical term). By the way, I have talked to my doctor about it, nothing you can do but wait and see if arthritis comes along, thats the interesting question.
  • + 3
 carpal tunnel is linked to vibration in industry already but you're looking at 8+ hour work days 5-6 days a week for those. This has been linked back to industries such as forestry, construction (equipment operators, etc), and shipyard.

You also have vibration disease which can impact peripheral nerves, blood vessels (Reynaud's Syndrome), and even bone/joints.

Again these have been linked to jobs with much higher exposure levels and durations much longer than what we get through mountain biking.
  • + 2
 @papapendrel: yea there’s a huge difference. So I have an enduro bike with carbon renthals and rev grips and a DH bike with vibrocore, rev grips, dvo onyx DC and atomikcarbon (high density foam core). I pretty much mitigate all lingering vibration.

At first ride you won’t notice the difference between the carbon bars and vibrocore. But for best results is to ride with one setup for a month, then change back to your old set up. You need to do this because you already programmed your mind into thinking one way is how it should feel.

Another think that people do not account for is bar width and grip diameter. I bummed up to the largest grip diameter and went from 800mm to 790mm.
  • + 1
 @landscapeben: i was wondering what the effect of the vibrations in this test if they switched to a vibracore bar? hope to see the real scientific data on a normal bar vs the vibracore under these same tests!
  • + 6
 @papapendrel: I'm almost 48 and been riding since I was a kid. Mtb specifically since '91. Been riding parks the last 5 or 6 years and really REALLY noticed a huge difference with arm pump and "the claw" when I switched to fat paw grips. The esi chunkies are good too but fat paws are the thickest, and I have relatively smaller hands for a 6' guy so the review information about them being only for guys with giant hands is a bunch of BS. I only tried them because I had a bad crash and bruised my palm so badly, I was trying any grip that would allow me to ride while I healed. But the difference was so noticeable at the park that I put fat paws on every DH bike since and all my Enduro rigs too. They're awesome. And while they may deteriorate faster when you crash, because theyre foam, they're cheap. So whatever. You can just buy a new set if a couple of small chunks out of the end bother you. I believe they show character. Good luck with the hands! May u ride as much as u love to.
  • + 1
 @notenduro: I've liked my other ergon grips, but found the GD1 Factory version has such a thin layer of rubber that it provides almost no dampening. They are also lousy when wet/sweaty if you're riding without gloves. I've got an extra set of new GD1 Factory (the fatter ones) if you need a back up pair, message me.
  • + 2
 @shredddr: Same here
  • + 2
 @papapendrel: The flexx bars with the soft elastomer will fix it... just be warned they feel super strange at first, and everyone who gets on your bike will ask how do you ride like that.
  • + 3
 @papapendrel: Yes, yes and yes again, the combination of the vibrocore bars (a good rise may also be helpful due to increased damping compliance in the bar itself I run the 50mm), with the larger diameter Ergon GD1 grips is the business. It won't sort it completely but will make a heck of a difference. Sounds like you had it a little worse than me, but for me I would say it's 80% improved with this setup. Beer
  • + 3
 @rockchomper: Yes it would be good to see on paper the improvements our hands are already feeling with these bars!
  • + 1
 @papapendrel: Has your doctor considered a shoulder injury of some type? Torn rotator cuff and unstable shoulders can cause similar issues as those nerves pass thru this area. There are a host of different things that can affect finger numbness such as cubital tunnel syndrome but that would likely affect different fingers, I think pinky and ring fingers. BUT what is important is nerve damage can become permanent. Find a better Dr... Wait and see is an excuse for incompetence in a lot of cases.
  • + 2
 @drjonnywonderboy: Yup, I am all about increasing compliance and absorbing shock.

I've been riding mountain bikes, starting with BMX, for forty-five years. As a 50+ guy I will tell all you young uns that a time will come when it becomes harder to hold onto those grips. No matter how strong you are, no matter how much you train, you will become less virile.

To compensate I am running coils, longer travel, flats, and thick 9mm Red Monkey grips.

And I still get at it, just take longer periods between poundings Wink
  • + 2
 @landscapeben: I was really hoping this was going to end with Spank bars on a chainsaw.
  • + 1
 @landscapeben: I wonder how much of this is placebo. According to this german article where they strapped vibration sensors to the handlebar there is no measurable difference www.bike-magazin.de/komponenten/lenker_vorbauten/test-2016-spank-vibrocore/a33999.html
  • + 1
 @shredddr: try the odi cush, same size/design as the rogues but push on for even more comfort. Used to be a rogues guy but cush is even better
  • + 2
 @Aptlynamed: Genuinely would be interesting to see a proper study and to factor in degree of rise in the bar. But as I have more than one bike set up but only one with the vibrocore and grip combo I've mentioned above, I can feel and certainly believe there is a genuine difference and that isn't just placebo. Seems to me that the strongest evidence at the moment is people like me with an actual condition who were previously suffering with numb sore hands that on most rides, just aren't suffering any more since installing these bars. Proof's in the pudding they say Wink
  • + 2
 @mark4444: I suspect Faast Company will start making money with reports like these coming out.
  • + 1
 @papapendrel: you may have a condition called Raynaud's based on your symptoms. Can be serious in cold regions and sometimes managed with medications.
  • + 1
 @chize: rad - I will check that. I have a set of push on rogue style atv grips I have yet to install - wonder if they're the same or similar
edit - just looked and they're single ply vs dual ply.
  • + 28
 Don't tell everyone! The suits will use it as an excuse to level out the trails, or some muppet will sue a trail centre for rsi. Aaaargh!
  • + 10
 Is anyone on PB familiar with hand pump?

I don't really get arm pump, but riding rough terrain like bikeparks with braking bumps will cause my fingers to seize up. It's like they become frozen in place, it's insanely painful to get them moving again and eventually my fingers even become painful to the touch, almost like I've bruised the bones. It doesn't seem related to how tightly I'm squeezing the bars, either, but the effects can last into the next day.

I've been considering those Revolution grips with suspension but they're an investment for sure.
  • + 3
 I put Rev grips on that new One Up bar; the difference in these 42 year-old hands is quite tangible. I had CushCore in last summer, but took them out because I couldn’t reconcile the weight....might put them back in.
  • + 4
 I ride park at least weekly and have the same issue. The ESI extra chunky grips have helped me, and they're cheap. I will try the Fat Paws grips next.
  • + 1
 YES. I ride the bike park daily, and it feels like the bones in my fingers are bruised quite often. Damn braking bumps!
  • + 4
 Bar roll makes a tremendous difference for me. I'm talking about not being able to ride for more than a minute versus doing full runs without pain. In my case pain comes from where the force is applied onto my palms. Brake lever position affects hand fatigue too. There are also other things that help a lot, like powerful brakes, proper tire pressure and suspension setup. I don't know if you have one but a pressure gauge made quite the difference for me (obviously, someone could say). Following my experience bar roll is the first thing i'll try ( along with proper brake lever position, of course).
  • + 1
 I used the Revgrips and like them enough to get a pair for my 2nd bike. However, as soon as they loosen, as all the lock ring type of grips do, the Revgrips explode. All the pieces fly out and the grip isn't just loose, it is free spinning and one of the scariest things that has ever happened to me on a bike. So, I have 1.5 pairs of Revgrips for sale if you dare.
  • + 1
 @Costigan76: Same here, and 44 y/o... that setup got rid of my hand pain. I was using foam grips to good effect but tired of replacing them so often. The OneUp bar is certainly more forgiving vs Race Face NextR/SixC.
  • - 25
flag youknowitsus (Aug 7, 2019 at 7:39) (Below Threshold)
 @wilbersk: Oh shit if that guy rides park weekly, and you ride it daily then you're DEFINITELY faster and better than he is. I actually ride park twice a day bro, so really anything I say is more true than what you do. Damn braking bumps!
  • + 8
 @youknowitsus: are you deranged? The guy asked a question about if people who ride park experience something, and the other guy explained that he rides park daily and experiences the same thing.

You need to find some more positivity in life so you don't come off as angry and dumb for no reason
  • + 3
 I can understand not wanting to change your current set up, but when i started riding a lot of bike park, I had the same issue and i was told to adjust my brakes in as far as i could comfortably. When you're on the brakes, your fingers will be closer to the bar, and it wont stress them out as much, which will calm your hand down. At this point in my riding, my brakes are in to the point where i can full lock and then touch the lever to my bars if i squeeze hard. This helped me out tremendously in the hand pain department.
  • - 23
flag youknowitsus (Aug 7, 2019 at 8:49) (Below Threshold)
 @Mntneer: I'm not downvoted so I must not be wrong. Chill your mill you fkin Canadian.
  • + 1
 @pbraunstein: Cool, this is kind of heartening. I just bought more powerful brakes; I will set them as close as possible and hope for the best! I use the DMR Deathgrips right now and the grip is so fantastic I don't want to change them if I don't need to.
  • + 2
 Mess with your brake bite point (I recommend making it closer to the bar), and move your levers more parallel with the ground. The people I see in WBP complaining about their hands have their levers slammed (old school technique)...flatten them out
  • + 1
 Do you ever stretch? Try some Cat-Cow to start. Focus on weighting all parts of your hand and fingers.
  • + 2
 @Rudy2455: I have the same problem. No arm pump, just pain in my hands articulations. I tried grips from ergon, it did not really help. I also tried to stretch and it did not help either. The only thing that helps is adjusting the brake angle.
Mark the position of your brakes and change only one of them. After half a day of park, you check if you feel a difference between left and right hand pain.

I have not yet ridden in a bikepark this year, and I'm still hoping to find a solution that reduce the pain. I remember people were saying that the OURY grips were the best to dampen vibrations. I have not tried them yet.
  • + 10
 Hey Guys, Johnny Arm Pump here.
I suffered from quite severe arm pump and thought you guys might like to know how I have improved it.
My first recommendation would be to get yourself checked by a hand ortho to discard you have medical issues like carpal tunnel, and also as a disclaimer, whatever I say is not to be taken as medical advice.

First of all, severe hand pump has a medical name, it's called Chronic Exertional Compartment Syndrome in the Forearm. What happens very simply speaking is the muscle groups of the forearm swell up beyond the fascia that sorrounds them (fascia is a fibrotic inelastic tissue that sorrounds muscle groups in the body), this increases pressure in the forearm which prevents circulation getting to both the nerves and the muscles, resulting in loss of strength, sensibility and pain. There are two solutions to the problem... you either stretch the fascia allowing more space for the swelling of the muscle, or you cut it surgicaly (if only tried the first one, but from what I've read surgical minimaly invasive resolution of the problem results in immediate resolution of the problem from reports both on professional dirt motocross and rowers).

So, what have I done to stretch the fascia (known as myofascial release, youtube it).
I copied the idea of a device sold for motorbikers (4arm-strong.com) and improved it a little. I actually bought the device and it helps a lot. Watch the tutorial video to get an idea of the concepts (www.youtube.com/watch?v=x2SHY0l35x0)
This is what I built www.pinkbike.com/photo/17574271
It's a lacrosse ball cut in half, using a crank extractor tool kept in place by a vice, so that it prevents the ball from moving forward when I do the myofascial release exercises. Could also nail it to a table I guess.
I do two exercises:
1.- www.pinkbike.com/photo/17574273
Stretch your elbow and flect your hand and fingers, look for the thickest part of the muscle group on the back of your forearm (it's a little to the lateral side in that position). Press it as much as you can on the ball while at the same time maintaining a forward push on the ball, and at the same time maintening the flex on hands and fingers. Hold for 20 seconds, repeat 3 times.
2.- www.pinkbike.com/photo/17574275
Same thing but working on the other side of the forearm. Look for the thickest muscle group (a little on the medial side on that position) extend hand and fingers (help yourself with the other hand), press the ball on the muscle group while pushing. Maintain for 20 seconds repeat 3 times.
If you find your forearm sliding too much on the ball clean both with alcohol.
Afterwards I use a complete (not cut in half) lacrosse ball, and press on those muscle groups and following their direction while moving the ball against a table or wall. Start easily, too hard at the beginning with any of these exercises could irritate the nerves more.
Other recommendations.
DONT TRAIN FOREARM STRENGTH on the gym. Train Pecs arms and back, so that they handle the biggest part of the load, use forearm only as stabilizer to your arm and pec exercises. Consciously relax your hands and grip when riding.
Gear improvements: coil the shock it if you can, 29" if you can, vorsprung luftkappe if you cant coil it, and re-shim it to your weight and riding stile (vorspung, push, avalanche customize the damper side of shocks). Rev Grips, Oneup components handlebar.

edit: I forgot to mention, use brakes that need the less force possible both in the free stroke and while squeezing, and put the levers in the Yoan Barelli position because it relaxes the posterior muscle group of the forearm wich is the one that I've found to be more stressed. Don't down vote me on branding but unfortunately I've found shimanos fit better this description, same goes with 29" wheel size
  • + 2
 @zede: I used to have a real problem with losing feeling in my hands. It would start with pins and needles and riding up I would have to shake my hands. I worked out a formula to set up my bike properly and ended up raising my bars 30mm. No more hand problems. Same grips, brakes etc. Also had problems with my bits- you know- down there, on long climbs. This is fixed now too. If your bike has a low stack height, your bars are probably too low putting too much weight on your hands. Had a mate having the same issues and he has fixed it too.
  • + 1
 @MTBgeometryguru: Going to a slack 9'er I lowered the bars vs my previous bike, it helped me adapt to the new bike but was ultimately too low for good posture and I had some issues. Raising the bars only 10mm makes a big difference!
  • + 1
 @davec113: Yeah 10mm makes a big difference. Problem is the latest 2020 bikes are getting really long in the front end meaning you need to get your weight forward more to weight the front wheel. It won't be so bad on smaller bikes but taller guys will notice it. Just read a review on the latest Reign where tester noted lack of weight on the front wheel was an issue on anything other than really steep stuff.
  • + 2
 @youknowitsus: wtf is wrong with you? Seriously.
  • + 2
 @MTBgeometryguru: Yup, I also think the steep seat angles may put the rider's butt too far forward wrt the BB, which will result in more weight on the hands on flats and gradual climbs. Even with my Trek Slash it feels like I need to get my chest right over the bars to weight the front end enough to rail turns with maximum speed, and some coaching with an EWS pro and watching some vids confirmed this is proper technique. So, raising the bars to achieve better climbing posture has it's practical limits. It's definitely doable on my Slash. On a bike like a Pole, idk... I've never been on a bike like it yet. Dropper handlebars? Bring back bar ends? Smile
  • + 1
 @davec113: I just put a -20 degree 50mm stem on my Daughters Devinci to try and get her weight further forward. High stack height on them. You are definitely limited with raising bars on bikes with long front centres as you'll run in to front wheel traction issues. Pole bikes - yeah I think they will suit someone with shorter arms. I can't get the numbers to work for me. Same story with geometron. I have studied some photo's of Chris Porter and it looks like he has shorter arms compared to his height and torso. My elbow is below my hip bone. His look like they are 2/3rds of the way between his armpit and hip. So his bikes probably work really well for him but won't be everyones cup of tea.
  • + 1
 @MTBgeometryguru: For me the problem is not I lose feelings, just pain in the articulations of the fingers. I grip really tight the handlebar and I think it's the problem. My handlebar is already higher than it should be, but I do it just to please my back.
  • + 1
 Lots of solutions on here, but most seem to be focused on muscluar pain in your hands. For me (and the OP I think), it feels like my finger bones are bruised from being vibrated against my grips. The only thing that seems to help at all in the moment is to squeeze my grips harder to keep my fingers from getting vibrated on my grips.

I run virtually flat brake levers, and I use the ODI rogue grips, but neither has helped too much. Maybe time to try a vibrocore bar.
  • + 1
 @wilbersk: maybe time to speed up your fork's rebound ( turn down the damping).
  • + 3
 @McNinja: If you haven't tried the new Hayes, the lever pull is smoother than Shimano or SRAM, but they provide more power. I'm able to keep less pressure on the lever than any other brakes I've tried.
  • + 1
 @shinook: I love my Hayes! Best brake I've ever used.
  • + 1
 @shinook: Thanks for the tip! I'll be looking around to see if I can demo a set
  • + 11
 The only solution to this is obviously a new Marzocchi Super Monster.

You can’t get shaken by what you can’t feel.
  • + 2
 A Super Monster with Fasst Flexx bars and Rev Grips wrapped in Fat Paws oughtta do it!
  • + 8
 On a completely different topic, it's interesting that he is using a Dvo fork when his team is sponsored by rockshox...
  • + 17
 Lol.. Takes the money from sram and buys a good fork..
  • + 5
 @BeerGuzlinFool: that would be research grant money. Even better.
  • + 1
 Is he riding a honzo?
  • + 4
 At least they're putting independent science behind the concepts that drive Spank's vibrocore marketing spiel. The grant to make improvements to Innerleithen is awesome, and for facilities to properly test new kit, rather than relying on snake-oil and sales patter
  • + 7
 Super, I have a new excuse for riding a £10k 160mm enduro bike on XC trails.
  • + 7
 Vibration is fun though...
  • + 3
 Just my personal experience, but 2 years ago used to get the claw so bad that I couldn’t even finish a full day at the bike park. Thought I was gonna have to give up DH riding. I was riding a carbon bike with carbon wheels and a 35mm carbon bar with a Fox 36 fork. I tried every grip out there and nothing made a difference. Then I ditched all the carbon. I got a steel bike, aluminum wheels, 31.8 aluminum bar. I no longer have any hand pain. I can even run super thin Renthal ultra tacky grips that I like. Just did a trip to Big Sky and Grand Targhee and logged 80k of vert without any hand issues. I think most stuff is just built way too stiff for the average DH rider. I’m not looking to be the fastest guy on a single run. I just want to be able to ride laps all week and be comfortable.
  • + 2
 Interesting article. I guess it´s at the vry beginning of putting numbers down as standards as he said.
In some areas vibration is used as a stimulus, for example with stem cells for cartilage growing, but it´s all about the right parameters. To little stimulus and nothing happens, to much and the cells die.
Just like everywhere else - it´s about finding the right balance.
  • + 7
 *laughs in Twostroke*
  • + 1
 lol
  • + 5
 @LJp253: More like braHaHaHaaaap!
  • + 2
 Ive been riding all disciplines of MTB for over 25 years including as a guide so thats a lot of riding. When I started riding road a few years ago I was in agony and ended up at the docs who suggested carpel tunnel. Onwards from that I now have dupatrons on my palms now which is mildly irritating. In the last year I got into motorbikes and had a bit of a revelation. Being tense. This sounds balls and obvious but unless you consciously relax your shoulders, chest and arms, you get pummelled to crap and are not in control. This becomes way way more obvious at 80mph! I was not a particularly bad rider before but this has made a massive difference. BUT you only relax if you consciously tell yourself to. It wont happen otherwise. This is all on top of properly adjusted levers etc. What a difference in terms of arm pump, lower back, etc.
  • + 2
 Excellent study and great to see the correct standards being translated over from the construction industry.

I'd just like to point out though that the 5m/s-2 acceleration is quite low for typical working conditions. Construction works use tools like hammer scabblers or road breaks that can be in the region of 20m/s-2 although by all means far less exposure.

Since hand arm vibration syndrome is an accumulative effect a life long multiple ride a week MTB'r is at higher risk than your average joe. However, the actual time descending on a typical day (for myself at least) is around 25mins/30mins on a 4hr ride for example, which according to the H&S exec (See below) @ ~6m/s-2 you would need to have around 45mins of descending to reach the exposure action value (minimum to hve lasting effects). There is an argument that on a day with lots of bike park laps and uplift you can get well above this 45mins descend time but even still you would be nowhere near the maximum limiting exposure time of 4hours @ 6m/s-2.

I think this is something we need to be aware of and certainly advances in technology will help us, but unless you are actively working with these kinds of tools as an occupation, the additional vibrations from riding shouldn't be anything to worry about from a long term health stand point.

Table 2 Simple 'exposure points' system
Tool vibration (m/s2) 3 4 5 6 7 10 12 15
Points per hour (approximate) 20 30 50 70 100 200 300 450

100 points per day = exposure action value (EAV)
400 points per day = exposure limit value (ELV)

Source: I'm a civil engineer and www.hse.gov.uk/vibration/hav/advicetoemployers/assessrisks.htm
  • + 2
 I think you are missing a big point of why a race team mechanic is studying this. After 2 minutes of the vibrations, you have lost XX% of your grip strength, affecting your performance for the next 90 seconds of track (which might be 80 seconds of track if you could mute the vibrations possibly).
  • + 5
 @Rubberelli:
Sort of missing part of the point. I feel like the larger point is the possible nerve damage from vibration. Hes gone thought the dosage math to show that while the levels of vibration could be dangerous for longer rides but likely most riders aren't going to see issues. Id be curious to see where gravel riders end up on this with their rigid bikes. Id think they'd be in more danger than your average rider plowing your average chunder.
  • + 3
 @Rubberelli: I'm not really concerned with grip strength and neither is the OP's study. This is to review the lasting impacts on MTBr's due to hand arm vibrations.
  • + 3
 @tbev: I remember the days of fully rigid MTBs, my hands used to itch at the bottom of descents.
  • + 1
 @SNKYbsn: when asked the reasons studying this is important to mountain bikers, he replied,
"The more vibration you expose yourself to, eventually it's going to limit your grip strength. Vibration stimulates muscle and it makes the muscle tense, which is why you get arm pump because your muscle doesn't relax and it cuts off the blood flow.

My director of studies, Professor Geraint Florida-James, did a study at Fort William and you can lose around about 30% grip strength in one run top to bottom. Eventually, you'll hit a big hole and you can't hold on or you lose your posture. It's all energy; it has to be dissipated somewhere before it gets to your head. The more you can limit it at your hands, the faster you’re going to go but keeping that control and performance is the key part."
  • + 1
 @tbev: you are worrying yourself for nothing. They didnt do this study to scare you into not riding. They did it to see if they could measure the vibrations so components can be made to mute it better. He even said, "This was to prove that we could do it, then with the Innovation Centre we can test different things. So if you had a component manufacturer with different layups of carbon handlebars and they wanted to know which was better in the field then we can put an actual number on it to reliably measure it."
  • + 2
 Last year, I rode 3 days at the Whistler Bike Park, in late August when the brake bumps were at their worst. I had significant arm pump by the end of the trip, which took about a week to feel better. But I still had weakness in my hands and pain while riding. I could not ride a tech trail without stopping several times to shake out my hands and arms. I was also too weak to open jars. Six months later I sought out medical treatment. My doctor sent me for a nerve conduction study, and I was diagnosed with carpal tunnel syndrome. It took about 3 months of therapy to recover. Luckily, no surgery was required. Now when I ride rough trails, I stop more often to "shake out" the arm pump.
  • + 1
 I worked in as a carbon moulder for 8 weeks last year and one of the parts of the job was using an impact wrench to open the moulds for about 3 hours a day. The intense vibrations from that gave me carpal tunnel syndrome. The Alps this year was insane. I genuinely couldn't hold on in some of the roughest parts and like yourself I had to shake my hands out even mid run. An exercise you could try is clenching your hand into a fist then stretching your fingers all the way out. 10 or so times and that helps
  • + 2
 You will get old and you will hurt. If you're lucky you will still ride. If I had a way back machine, I would bring some Vibrocore bars and those suspension grips along to way back then. Guess I'll wince and read the study.
  • + 1
 I would be interested to see the waveform of the vibrations experienced on a mtb compared to a chainsaw or jackhammer. Even if the amplitude is similar, i would guess that with tyres and suspension involved the vibrations on a mtb are much less harsh. A sine wave rather than a sawtooth or square wave. This is pure speculation though.

Oddly i very rarely get arm pump while riding. I used to when i rode bent and very stictiony 888's. Got better forks however and it went away. Even on loooong rough alpine descents.
Other variables are that I use push on grips and coil springs at both ends. On a recent riding holiday i noticed that the guys on air springs spent a lot more time complaining of arm pump/hand pain. Not exactly a scientific test though...
  • + 1
 I think the tires and suspension would dampen the worst of any impacts while on the bike, the injuries suffered from crashes and the long term impacts of them are a much more concerning consequence of mountain biking. With a jackhammer you are in the same position all day long and not moving your body around all the time in different positions like on a bike. It's the repetitive movement of the jackhammer that causes the carpal tunnel and other problems, mountain biking isn't like that at all. The variety of movements on a mountain bike is mostly great exercise for all parts of your body and keeps them conditioned and lubricated, including your wrists and arms. At least until until you inevitably crash.
  • + 1
 Ride a rigid single speed for a few seasons and you'll figure out how to set up a regular bike to reduce vibration. ENVE Carbon 31.8 bar and ESI extra chunky grips with 2.4 Ardents at 19/20 psi. Ergon saddle. Problem solved.
  • + 1
 Carbon bar + ESI xc FTW! My friends make fun of my "foam grips" but I'm the only one who's hands feel fine after back to back bike park runs in Colorado. ESI or some other vibration absorbing grip is stage 1. Stage 2 is learning to grip the bars less, no death grip or it won't matter what grips or bars you run.
  • + 1
 I'm curious how the vibration pattern would affect us. With a jackhammer, it's pretty fast vibrations for long periods of time. For most rides (outside of a bikepark covered in braking bumps), the vibrations are varied from short and fast to long and slow and everything in between. Maybe some have worse effects than others, I'd be curious to know.

On another note: it's not always the vibration size that matters, it's how you use it Wink
  • + 2
 Vibration is dampened by your body and can cause premature wear of body components. Particularly the shoulder and elbow joints as they support a large amount of your body weight in certain situations. Shoulder/Clavicle rank in the top 5 most commonly experienced by a cyclist. These areas also provide a path for the nerves associated with forearm, wrist, hand and finger use. Swelling can increase pressure on the nerves passing through these areas and effect in other parts of the body.
  • + 1
 Shock absorber. Shocks those things on your bike. We used to tune shock absorber to be super plush. Now forks and rear suspensions have platform for that aggressive feel. The opposite of shock absorber. Same with 29 inch wheels. Faster yes but you will be beat up at the end of the ride. Making parts and frames stiff. The bike market calls these improvments. Now we are starting to engineer compliance. There is still room for improvement.
  • + 1
 Another MTB sports abuse injury you might want to investigate is trigger shifter thumb. I'm old and abused my hands rockclimbing for 25 years. So that could be a factor but after hanging up the climbing shoes, and after about 10-12 years mountain biking I developed arthritis in the basal joints of both thumbs. I suspect its from trigger shifters and if you search the problem you'll find a lot of other riders think so too. The left hand started first but after switching to 1x drivetrain that went away mostly. The right got worse until I switched to SRAM GripShift and that has helped a lot.
  • + 1
 Well as hitting gnarly trails with a bike that transfers bumps into the parts of your body that are connected to the bike one has to simply look at roadworkers problems when they use jackhammers on roads... it is even a registered occupational disease in Germany!
  • + 1
 honestly i am a heavier stocky guy at about 235 LBS riding DH and i have been struggling with gripping the bars some times at the end of the day. its a strange soreness that makes me feel like im losing grip completely or at least the strength to hold on. Now im definitely not riding anything elite. Did some laps at trestle one time and the brake bumps were so bad with my grip (not arm pump) that i had to call it a day so i didnt get hurt. I switched grips to something larger and that made it worse.

I have since built a new DH bike with an air sprung fork instead of the coil i was previous using. being able to adjust the air pressure and fine tune it seems to have helped quite a bit but i did experience my grip issue at the end of the 2 day ride at MCBP NJ. It didnt happen as quickly as the year previous but it did eventually happen. I dont believe my brake levers are set up incorrectly, i do believe having a more fine tune-able fork has helped me quite a bit.

I have not experienced it riding any XC or DJ type stuff.
  • + 1
 I'm in a similar boat. I weigh 230 lbs and ride aggressive enduro style riding. I've experienced very similar hand pump and even had had a couple close calls. I installed cushcore and rev grips and it has virtually eliminated the problem. I was able to drop my tire pressure roughly 10 PSI each and I was able to drop shock pressures too.
  • + 1
 same boat. im using the sensus meaty paws. I'm also at the gym every day after work doing complexes. Medium weight, high reps, short rests, and most importantly never put the weight down. This has helped so much with my core and grip strength. highly recommend.
  • + 1
 @ampb100: YES to gym time! Spent a lot of time lifting in the off season and it def made a difference.
  • + 1
 Considering that they measured the vibration on pros going pro speed down pro tracks, does this really apply to everyone else? Sure everybody suffers from arm pump and such, but we aren't all pros who are sending it at ridiculous speeds down the roughest trails in the world. If the pros suffer this much then fix that problem for them first, then we can benefit from the trickle down in a few years
  • + 1
 The issue is that the pros want to get down the track as fast as they can and the bikes are set up to optimise that. Realistically, they are only riding for 5 mins at a time, with 20-30 mins rest before the next run. I have experienced very short term tingling in my hands after using an sds drill in hammer mode knocking off plaster for 30 mins, which was a lot worse. New coil conversions for enduro forks make a huge difference. I have a smashpot in my 36 and it's amazing.
  • + 3
 Not sure but I could also argue the opposite and say that maybe pro riders, with their level of ability and skill actually smooth the trail out at those high speeds, gliding and dancing the bike on top of a lot of the chatter that a regular rider would feel.
  • + 2
 @NotDeadYetMTB I had similar thoughts. Also, the folks for whom these vibration exposure guidelines were developed ("lumberjacks," construction) run their equipment for 6-8+ hours a day, everyday, for 35 years. No one rides a bike that much at race pace.

Interesting research though and I look forward to following how it develops.
  • + 6
 Bad vibes for sure!
  • + 1
 "The reason these guidelines are in place is that they're seeing hand arm vibration syndrome, an irreversible pathology. You can get white fingers syndrome, peripheral circulation, and nervous problems and musculoskeletal problems. So, there's a reason those guidelines are in place but we still don't know very much about how they come about and it's different for everyone. Some people can experience more vibration and be fine and some people can experience less vibration and not be ok. It's still early days but you have to put a number on it at some point. "

f*ck. i was gong to ask my doctor what was up w/ my right hand/forearm. not excited to see the word "irreversable" there. Looks like i need to invest in some super vibration-reducing grips if want to keep riding and try not to make this worse
  • + 1
 So you are telling us we are tired on the bottom of a lap and we have less strenght and a mistake is more possible? And we will be possibly damaged by years of shredding? Hot news, really. I had no idea.
  • + 4
 You should worry more about ticks!
  • + 5
 I'm shaken by this news
  • + 0
 Also this study really didn't reveal much. You can't just say "oh no, this might be bad, but we actually don't know because we haven't actually studied enough to have all the answers."

Thus is the history of medicine, so what can you do about it...
  • + 1
 Have you ever replicated a pro fork setup you can occasionally find here on pb? they're stiff af, especially the compression settings so i don't know if this translates to normal riders.
  • + 0
 Quite often people doing research studies come up with findings that prove their theory.
It's not very often years are spent researching something for someone's career where there is nothing so say or publish at the end of it.
How much unpublishable data (doesn't work with the theory) was collected to end up with the required amount of published data to meet a chosen theory is a question I often ask myself when I read 'latest research shows..' type articles across all media.
  • + 8
 The answer to that is peer review. I wouldn’t discredit research on a whole, scientific ethics definitely exists.
  • + 2
 You don’t have a clue. Research is an attempt to test a hypothesis. It doesn’t matter to the scientists whether they prove or disprove the hypothesis. It’s the answer they want.

Classic example being the guy that invented the glue for post it notes. That was supposed to be super glue. It was still useful.
  • + 1
 @yzedf:

This is a bit of an oversimplification. There is a big problem in academia where negative results are not seen as publishable because they do not add anything new to our collective understanding of a subject. In theory researchers should only be motivated by finding the truth about something, but in reality there are financial incentives to find exciting new results, and negative results are not exciting (even though they might be informative). Researchers may then be motivated to produce more publishable findings by questionable means (e.g., looking for correlations between dozens of variables, p-hacking, etc).

Also, scientists don't prove or disprove a hypothesis. If they find an effect they reject the null hypothesis (sort of a baseline assumption that there is no effect). That is, they conclude that the null hypothesis is not representative of reality (though, the accuracy of this conclusion depends on the quality of the research). They then offer the alternative hypothesis as a possible explanation about what is happening, and it should be accompanied by some kind of rationale. They DO NOT ever prove the alternative hypothesis. That is just not how hypothesis testing works.
  • + 2
 @c0-w: my wife has had her research published multiple times, including her PhD dissertation (that’s not so common in her field). Please tell me more about how it works...
  • + 1
 @yzedf: Well clearly I don't have a clue either...
  • + 3
 There is a Journal called Journal of Science and Cycling?

Thats an impressive grant the supervisor got.
  • + 1
 Maybe incorporate more rest in between, and some handgrip & forearm exercises in addition to using tech such as carbon or Vibrocore bars...
  • + 1
 I think I like you.. “I need to buy £200 carbon bars, they’re healthier”.
  • + 1
 Carbon bars ( and other products made of this material) in vast majority of cases, if anything, increase your fatigue.
  • + 1
 @tobiusmaximum: The vibrocore bars are quite reasonably priced. Don't know if they make a difference but those who have them swear by them.
  • + 1
 @WAKIdesigns: I find them to be quite nice over alloy bars- but I have an alloy frame with carbon wheels...
  • + 1
 @DangerDavez: I have vibrocore on my dh bike and like them... carbon frame in this case...
  • + 2
 Guess I'll sell everything , sit at home, drink beer, and get rid of my sonicare electric toothbrush....
  • + 3
 So we have to weigh up the bad vibrations against the excitations.
  • + 2
 Roadies probably have it way worse no? Or adult film stars.. Basically, people who shave their legs often..
  • + 2
 "My fingers hurt" - Whats that grandma? Oh, well now your back's gonna hurt, cause you just pulled landscaping duty.
  • + 1
 Anyone else feel like they're blasting Marky Marky and the Funky Bunch to these experiments?

Its such a good vibration
Its such a sweet sensation!
  • + 1
 Not really bothered above living longer. Just wana ride longer on park days. Just upgraded to cushcore , vibrocore bar and rims, rev grips, now looking for wrist absorbers
  • + 1
 Noticed a pretty large difference when switching from Odi to Oury grips on a friends recommendation. Vibrocore sounds like it might be next on the list.
  • + 1
 Solution discovered decades ago in the 1990's: Use Oury Grips (not a paid comment!)

www.ourygrips.com/mountain-grips
  • + 1
 Considering how many gnarly crashes I have on any given weekend I don’t really think the vibrations from my bars means shit
  • + 2
 I guess I need a unionized Mtb club to keep me from riding my bike too much. Maybe I’ll get paid more money to!
  • + 2
 Rev Grips and Cush Core!!! Added them this year and haven't gotten hand pump once this season!
  • + 2
 Those nutjobs selling anti vibration stickers are going to love the marketing opportunity here.
  • + 1
 give me a good masculine vibrator. It seems working well for other but not for me.
  • + 2
 I'm here for a good time not a long time
  • + 1
 If riding my bike gives me bad vibrations reckon it is time I headed down to the beach boys instead
  • + 2
 This article makes me feel kind of blue velvet.
  • + 1
 Pretty sure I just found the graduate program I want to do! I guess I should start learning German? How fortuitous.
  • + 2
 Suprised nobody mentioned Vibrocore yet...
  • + 2
 In other words, the sky is blue.
  • + 1
 Could things like Powerplate training and those powerball gyro trainers help (in strengthening) ?
  • + 1
 MTBer complains of sore hands, MXer says, Hold my beer whilst I move your brake levers up.
  • + 2
 Newsflash, repetitive sports motions are hard on your body!
  • + 2
 Was this study sponsored by Girvin Flex Stem?
  • + 1
 Been riding hard since 1982 and Vibrocore bars and Ergon grips have really worked for me. Smile
  • + 2
 Easy solution: more manuals
  • + 2
 What bike is that?
  • + 4
 Pipedream Moxie
  • + 1
 this article really shook me
  • + 1
 "and actually I've only got a hardtail"

We should be friends.
  • + 1
 Well, this has really dampened my day!
  • + 1
 But I’m going to get too shaken up by it just yet
  • + 1
 Intense hand vibrations don't mean shit to me. Yes, I'm single.
  • + 1
 E-Bikes give bad vibes to me.
  • + 1
 DGAF... Still gonna ride \m/
  • + 1
 So the guy riding on a hardtail is worried about vibrations?
  • + 0
 I don't agree with the study. I've spent days with a jackhammer and it is much rougher.
  • + 1
 I think I know who you speak of...
  • + 1
 What’s bad vibration? Like a bad vibe?
  • + 1
 I'm trying to get vibrated into the next dimension.
  • + 1
 Says the guy riding a hardtail
  • + 1
 The post is just here to rattle us a bit.
  • + 1
 Nice one Lewis!
  • + 1
 yikes
  • + 1
 30 laps a day..
  • + 1
 It is very gripping
  • + 1
 Revgrips. Done
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