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Measuring Handlebar Force Input?


rikker
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Has anyone ever tried to measure the countersteering force input on the handlebars?

Maybe using a straing gauge or something...

 

Right now I'm struggling with myself on the quick flick method because I always feel like I can't push/pull hard enough without washing my front out.

 

So, I was wondering how much Newtons is needed to achieve a quick flick rate of 5~10.

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I suspect that you don't need instrumentation, you just need faith. According to CSS (as I understand the issue anyway) if you are off the brakes and turn it hard enough to break a tire loose, it will be the rear, not the front. It was a major step forward for me in my riding when I finally found the courage to steer it really hard - I bet you'll find the same if you just screw up your nerve and push the inside bar much harder that you do now.

 

It's really not a matter of working your way up to a certain strength of steering input, but then no farther. You can steer it as hard as you like, unless you are trail braking.

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rikker,

 

Your concerns are common, don't worry. You couldn't put a specific number on the force required because it would be different at different speeds. As you go faster, the gyroscopic forces of the wheels turning increases, increasing the steering resistance. How much force does it take to quick flick the bike? It depends but probably much more than you'd expect. If I had you as a student at a school I'd demonstrate how much force is required at higher speeds (60+ MPH) by pushing on your shoulder with you leaning against it. I have yet to see a student be able to resist being pushed back quickly when I push, even big dudes. Keep in mind it's not how FAST you push (don't punch the bar), it's how HARD you push. The harder you push, the faster the bike leans over.

 

I recommend you find a controlled environment like a clean/dry parking lot, set a constant speed and push a little harder each time you steer. This will give you some feeling for how much bar pressure it takes, and will build your confidence in the traction the front tire has when quick steering. Let us know how your exploration goes!

 

Cheers,

Benny

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rikker,

 

Your concerns are common, don't worry. You couldn't put a specific number on the force required because it would be different at different speeds. As you go faster, the gyroscopic forces of the wheels turning increases, increasing the steering resistance. How much force does it take to quick flick the bike? It depends but probably much more than you'd expect. If I had you as a student at a school I'd demonstrate how much force is required at higher speeds (60+ MPH) by pushing on your shoulder with you leaning against it. I have yet to see a student be able to resist being pushed back quickly when I push, even big dudes. Keep in mind it's not how FAST you push (don't punch the bar), it's how HARD you push. The harder you push, the faster the bike leans over.

 

I recommend you find a controlled environment like a clean/dry parking lot, set a constant speed and push a little harder each time you steer. This will give you some feeling for how much bar pressure it takes, and will build your confidence in the traction the front tire has when quick steering. Let us know how your exploration goes!

 

Cheers,

Benny

 

This is an awesome post, but let me just add one point - make sure you have room to set a decent speed, 25 mph or higher, otherwise quick-flicking can be unnerving since the bike feels less stable a very low speeds.

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I believe the concept of measuring the amount of force applied to the bar's has been mentioned at least once or twice before on these forums

 

The actual measurement you're after isn't force, its torque

 

you could probably design a system for a bike with handlebars and strain gauge between a custom bar mount and the triple clamp to measure the torque applied at the steering stem, but I don't think the data you would be able to collect would be all that useful, though it would be kinda neat to compare with other riders and see how "aggressive" your steering input.

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I would so LOVE to get this data!!!!

 

It could be even simple, like PSI on the bar.

 

Turning a bike aggressively at high speed, takes significant bar pressure. So much, that in some turns we have riders pushing and pulling...hard!

 

To one of the original questions: we've never had anyone throw a bike down the road by turning too quickly, there are a few provisos: not on the front brake, tires are warm and in good condition, not slippery conditions on the asphalt. Tons of good data on this in Twist 2.

 

I had wondered if a pressure sensor on the bar(s) could be done. I suppose someone really good at engineering could figure this out, but I wouldn't envy trying to sort that out.

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wow, thanks guys!

well, now I'm quite overwhelmed (or I must say frightened?) by benham's post... I never thought that SO much force is needed to quick flick the bike.

I always watch WSBK, MGP, BSB, AMA SBK and brazilian SBK but I NEVER saw any handlebar movement when the rider initiate his corner approach...

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still can't see the countersteering, especially these hard inputs we are discussing here.

 

hey, I'm not arguing the only way to steer (countersteer, always, off course) I just don't see this huge amount of force applied to the bar.

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still can't see the countersteering, especially these hard inputs we are discussing here.

 

hey, I'm not arguing the only way to steer (countersteer, always, off course) I just don't see this huge amount of force applied to the bar.

The bars don't move a whole lot but there is a LOT of pressure on the inside bar when they're going in to fast corners. At speed, it doesn't take much front wheel deflection to make the bike lean quickly so you'll barely see it. A couple of months ago, I went into a 120 MPH 45 degree kink and I slipped a little bit when I moved my lower body setting up for it. I didn't have time to re-adjust before having to push on the bar to turn it in. That little slip affected how well I could lock on to the bike and when I pushed on the bar, my lower body just slid backwards preventing me from getting the bike steered as quickly as I needed. I ended up having to keep pushing and also pull on the other bar to make the corner. I was able to stay on track but it completely blew my exit on to the straight. It felt like trying to push a brick wall and all it did was push me back. It's not as dramatic at lower speeds because the gyro forces are less. I think you'll discover this on your own if you experiment a bit. Obviously, start around 25-30 MPH as Hotfoot suggested.

 

Cheers,

Benny

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SO, if you can change the leverage by extending or re positioning the bar's, that means the pressure applied at the bar is a variable in the system, but not the "answer"

 

The real data you want is the actual torque applied at the steering stem, where Torque = Force x Distance, so the pressure or force applied to the bars x the length of the lever arm it is applied to. The transducers and electronics to measure this are a bit pricey, but the design of the system would be rather simple actually.

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This is such an interesting discussion guys.I wonder if u could have like a " Steering meter " just like you can see how much throttle and brake is applied in the CSS coach videos for example or the lean angle meter in MotoGP.

 

I just got me a new bike and have to work a good deal on my steering.The toolkit arrived and i will get around to setting up my handlebars and position of the levers etc.I want to try different positions and settle on the best.Any guidelines for this [ sorry if this is hijacking the thread ] ? I want to make the steering process as easy as possible.Shall i put the bars as wide as possible for the best leverage?

 

Benny, you mentioned you have to push HARD to steer the bike at higher speeds.I guess this is my problem.I could steer the bike fine at 60 KPH and was doing the same thing quicker at 100 KPH.The bike would change direction quick but less.Could you explain how to correctly practice pushing harder on the bars? I fear it could upset the bike.Can i practice while the bike is stationary to get a feel of it first? How do i progressively learn to steer the bike accurately and quickly?

 

Also you spoke of maintaining pressure on the inside and even outside bar.I have heard you maintain pressure on the inside bar to keep the bike turning and maintain pressure on the outside bar to keep from crashing.I did not understand this fully.Can you verify this statement? Can you explain how what exactly maintaining pressure is, it's uses and how to cultivate this?

 

Thanks

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SO, if you can change the leverage by extending or re positioning the bar's, that means the pressure applied at the bar is a variable in the system, but not the "answer"

 

The real data you want is the actual torque applied at the steering stem, where Torque = Force x Distance, so the pressure or force applied to the bars x the length of the lever arm it is applied to. The transducers and electronics to measure this are a bit pricey, but the design of the system would be rather simple actually.

Tyler,

 

I completely agree with Eirik's answer to your earlier post... leverage. I think from a technical perspective you're exactly right about torque. However, I wouldn't necessarily know how to translate a torque number into something my brain could translate into useful data. Given that we're not normally changing the geometry (distance) of our bars, at least during a ride, I think that being able to know how much force/pressure goes into the bar to get a given steering result for a given speed is much more easily translatable into data most of us can relate to.

 

For example, if I were told it took 400 foot/pounds of torque to get that particular steering result on that ride it would mean very little to me. If I were told it took 250 pounds of force on the bar, I could relate to that.

 

Cheers,

Benny

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I also think that if people could actually get a feel of just how much force they could use without overpowering the steering response, it could help remove the fear many have of steering quickly. A bar fitted to a stationary bike with a torque scale could do do that. Most would probably be surprised just how much force can be used.

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This is such an interesting discussion guys.I wonder if u could have like a " Steering meter " just like you can see how much throttle and brake is applied in the CSS coach videos for example or the lean angle meter in MotoGP.

 

I just got me a new bike and have to work a good deal on my steering.The toolkit arrived and i will get around to setting up my handlebars and position of the levers etc.I want to try different positions and settle on the best.Any guidelines for this [ sorry if this is hijacking the thread ] ? I want to make the steering process as easy as possible.Shall i put the bars as wide as possible for the best leverage?

 

Just set it up for what's most comfortable & easiest to work the controls without having to contort your wrists/hands, or anything else. Anything else won't much matter until you start approaching track records (unless something is completely out of whack with the bike, in which case, see a reputable mechanic). -Benny

 

Benny, you mentioned you have to push HARD to steer the bike at higher speeds.I guess this is my problem.I could steer the bike fine at 60 KPH and was doing the same thing quicker at 100 KPH.The bike would change direction quick but less.Could you explain how to correctly practice pushing harder on the bars? I fear it could upset the bike.Can i practice while the bike is stationary to get a feel of it first? How do i progressively learn to steer the bike accurately and quickly?

 

I guess the simple answer is attend a school if you can. The bottom line is you lean the bike by counter-steering (pushing forward on the inside bar). The harder you push for a given speed, the faster the bike will lean over. The faster you go, the harder you need to push to get the same rate of lean (to overcome the greater gyroscopic forces of the wheels). Conversely, as you observed, if you use the same force at a higher speed, the bike will lean more slowly. As soon as the bike is at the lean angle you want, all you have to do to stop it from leaning further is to STOP pushing (nothing else), relax ALL bar pressure & begin your throttle roll on. If you do anything else, you can add instability and the bike won't go exactly where you want. To practice it, you just have to go do it until you can consistently get it right. From there you can start trying to do it quicker. -Benny

 

Also you spoke of maintaining pressure on the inside and even outside bar.I have heard you maintain pressure on the inside bar to keep the bike turning and maintain pressure on the outside bar to keep from crashing.I did not understand this fully.Can you verify this statement? Can you explain how what exactly maintaining pressure is, it's uses and how to cultivate this?

 

To clarify, I didn't speak about MAINTAINING pressure on the inside & outside bar. I was talking about a brief moment during the steering phase (while making the bike lean over) when I used both bars (push/pull) to get more counter-steering force because I wasn't able to get enough force by just pushing on the inside bar in that particular case. Once the bike was leaned and on line, I did what I said above... relaxed and rolled on. It sounds like you are confusing the steering/leaning part with the rest of the corner. I don't know where you heard to maintain pressure on the inside bar, etc. Read the section in Twist 2 about "Relax" and this should clarify. -Benny

 

Thanks

Stroker,

 

My replies are imbedded above. I hope they help.

 

Benny

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For example, if I were told it took 400 foot/pounds of torque to get that particular steering result on that ride it would mean very little to me. If I were told it took 250 pounds of force on the bar, I could relate to that.

 

400 Foot pounds of torque is 250 Lbs of force applied to a 1.6 foot lever arm, or 25 Lbf and a 16 foot lever, or 4800 Lbf at 1" .. etc. etc.

 

You might have a better understanding of what 250 Lbf is, but I seriously doubt you can sense or tell how much force your actually applying to the bars on the fly. Using both arms to steer even further complicates that, is it 200 lbs of push and 50 lbs of pull or 150 and 100.

 

Regardless of if you were measuring the force applied to the clip on's, or the torque at the steering stem, your going to have to go and and get a feel for what the #'s are a few times before you can even begin to look at the data, and since many many factors affect the "flickability" of a bike the exact numbers wont translate from bike to bike, so while the data would be neat, and it could serve as a tool to help someone overcome some fear's related to aggressive steering inputs by showing them what they are doing and demonstrating what its possible on the same machine, I doubt the data would be as useful as one might think.

 

If it was truly useful telemetry, MotoGP teams would be collecting it, and while I know they are recording a ton of stuff, I don't think this is on that list

 

 

Tyler

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I've listened to about the first 10 minutes of the Corser video. Thanks for posting it Eirik. It's tough to hear well but here is my interpretation of what I heard:

 

I believe Troy is talking about moving your body early, before having to steer the bike, so you don't move and steer at the same time which introduces instability. I agree with this and we teach that as well. However, I then think he's saying that while you are moved over to the side approaching the corner the bike will lean in the direction you are hanging off (basically what CSS calls body steering), and THAT is what he is saying you have to counteract with the bars. In my own personal experience, when I set up my body early (before getting off the gas & on the brakes) I don't feel a tendency for the bike to begin to lean in. Perhaps it does a little bit and I just automatically compensate without noticing. Maybe I'm not as far off the side as he is. It would be interesting to get him on the No BS bike to see if he would still think the same way after riding it. Myself too, for that matter.

 

If anybody understood what he said differently or if the issue you're concerned about arises later in the video, please speak up.

 

Cheers,

Benny

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