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Tank Grips & Being Front Heavy on Braking

Discussion in 'New Riders and Riding Tips' started by VCM, Aug 21, 2008.

  1. After searching I failed to find specifics to a question I have. So I am once again turning to my NR pals for a little input.

    Two issues here :
    The first being 'tank grips'. I found that trying to 'grip' my knees into the tank when cornering/braking to be impossible because my legs are short, hense the knees 'try' unsuccessfully to grip the slippery plastics just under the tank. In an attempt to fix the problem I attached a strip of velcro ( the fuzzy side ) to the plastics.


    It feels better, but still not 100%. Not sure if you can buy 'tank grip' material.

    Second Issue : Too tight on the bars under brakes.
    Since day dot, I've read and tried to incorporate 'good' riding habits.
    One in particular being 'loose' on the bars. I am confident in saying that I have this down-pat 99.9% of the time, whether I am battling winds, cornering, or just cruising along .. EXCEPT under brakes.
    I find that under brakes ... a large portion of my weight is being transferred to the front of the bike, which I believe is undesirable for tyre traction? My elbows stay bent but not loose. If I left em loose, I feel I'd slide to the front.. over the tank and exit over the bike :p

    I have tried to grip the 'plastics' with my knees in order to take up some of the forces, but whether it's tank design or my short legs, it achieves nothing and I end up getting 'knackered' under heavy braking, whilst weight is once again thrown to the front. Do I need to excercise my thigh muscles ?? Or is it perhaps the lack of some form of tank grip that I am unable to prevent this weight from shifting to the front tyre??

    At a Loss
  2. Have a look at stomp grips - from any store. They're not as aesthetic as the techspec stuff though.

    You're on the right tram, under heavy braking, gripping the tank allows you to take some load off the bars. The lower the loading, the better the front suspension can handle the road bumps.
  3. Less pressure on the bars is always good, but I don't believe it takes any load off the front wheel unless you change your body position. I think it's another one of those fallacies like "weight the pegs to lower the COG".
  4. It will stick to plastic provided it is not textured too heavily. :wink:
  5. What do you base this on Devo?

    I wasn't talking about the wheel, I was talking about the suspension. BIG difference.
  6. We're talking about the same thing, I just don't agree. :)

    My logic: think of the bike and rider as a single static unit, which essentially is the case once you're in position and under brakes. Where the load is transmitted internally through this single system is irrelevant. It's about where the mass is.
  7. I think in a straight line you are probably right, but as soon as the weight is off centre there is a difference.
  8. Devo, I think you have a point. You're definitely right about the CoG.

    Directionally, if the suspension doesn't have to try and resolve the rider's inputs through the bars as well as the road's inputs, then it can do a more efficient job. Gripping the tank lightens the load (note, not remove it) on the bars and the magnitude of the additional inputs through the bars.

    But I guess the size of the inputs a rider can put in is small compared to the total intertia type loading towards the front under heavy braking... especially if vertically upright, so on a practical level, we're not really disagreeing by much :)

    Have a look at any good ebraking advice though, they all recommend getting out of the way of the handlebars... why do you think that is?
  9. Fundamentally, I agree with Devotard that the bike can be treated as a (relatively) simple free body for the purposes of weight transfer - the suspension will compress the same no matter how the rider's inertia is transferred to the bike.

    I think it's important to keep the weight off of the bars because that stops you from "locking" your arms and turning your steering to crap. But dat's just me. :)
  10. When braking in a straight line - let your body fall into the tank - that way you have less pressure on your arms

    When braking into a corner - weighting, body position, suspension, etc all make a difference. Do you want your body sticking to the bike when shifting body position going into a corner :eek: Could be interesting :eek: :LOL:

    On a motard - all rules are off.......... :LOL: :LOL:
  11. In a practical sense I think the only concern is if you're either adding random steering inputs, promoting head shake, or compromising your control/finesse by having too much/uneven load on the bars (almost certainly). By that alone it's a good idea to stay off the bars as much as possible.

    I still maintain it makes no difference on (for example) the amount of dive, load on the tyre, ability for the suspension to soak up bumps under brakes. Leant over or upright.
  12. Bike and person as single entity...... Sorry, 30 years of riding and 15 years of racing tells me otherwise. :)

    Dirt - Body position has a huge impact on the working of the bike - you hardly ever sit and you always keep your arms loose and let the bike dance beneath you - so youa re definately not a single unit - you are hanging on for the ride with your knees against the tank :grin:

    Motard - As above. You weigh say 80kg with gear and the bike weight say 105kg.... Think about it. Breaking into a corner and adjusting body position to continue breaking into the corner. The best riders are clean, tidy and agresive and definately shift their position - watch the races :)

    Road - Peron weighs less but there is more dive into the front and the more exeperienced riders continue breaking going into the corner and shifting body. :)

    So, yes, body weight and position does impact the bike and its ability to function.
  13. Come to think of it, I disagree, even in a straight line. Imagine yourself on the bike, contact points are bum, bars and boots. Now without really moving any of your mass, take your feet of the pegs, just by 1mm, that extra weight you just released from the pegs is taken up by a combination of your other two contact points, meaning extra weight distributed over the rear of the bike and at a higher point, making it more likely to shift forward under braking than a lower weight bearing point.

    Another way is just try to ride with only your left hand and foot actually bearing weight, but the right ones just 1 mm obove their usual contact point. What does the bike do? The mass of your body is still in the same place, but the weight distribution of that mass is concentrated on less, uneven, points.
  14. Rightio Spots... now you've introduced steering! :LOL: uh oh.... :eek:hno:

    I've been very specific about my words. I've not once referred to rider induced inertia or bike dive or whatever. I've referred to rider input into the bars. I agree, whether you're holding on or not, the bike will dive just as much.

    If you're leaned over though, 99.5% of the time that means steering/cornering. It's widely understood that if you're tight and stiff on the bars in a corner (non motard style - front and rear wheel basically aligned), the bike will tend to go wide? Why's that?
  15. Thanks Guys .. will look into your suggestions.
    I understand that tight on the bars can aggravate situations like 'head shake', overload the front suspension and amplify inputs a rider receives .. . ( all way over my abilities ATM ), my main concern was hard braking and the cons of being tight on the bars as a result of not being able to brace myself to the bike. So I am correct in assuming you all recommend bracing the bike via knees or chest to reduce weight transfer to the front suspension under heavy brakes? in which case I will enquire about some form of grips to apply to the side plastics.
  16. Robslav wrote ; "If you're leaned over though, 99.5% of the time that means steering/cornering. It's widely understood that if you're tight and stiff on the bars in a corner (non motard style - front and rear wheel basically aligned), the bike will tend to go wide? Why's that?"

    I will try to answer this......

    If you are assuming your arms are tight and then i guess it is assumed your whole body is tight. By being tights and dont moving over with the bike (leaning off, shifting your head, moving your bum, etc...) then the main portion of mass is "centralised" as a single unit - as somone put it - and the bike will go wide as that is where its mass is directed. Where-as if your mass moves into the corner (on the inside of the turning radius) you are creating a central pivot that assists the bike with changing direction.

    Here is a simple exercise for people. Ride down the fwy and when safe, keep your body in a rigid position - then, move your head only - meaning leaning it left and right - guess what, the bike will also change direction. So, if such little imput changes direction, imagine what else could change the direction.

    Phew - hope tnat helps. :grin:
  17. I had the same view and the same argument over on msgroup.org ...the CoG doesn't change so the system behaviour doesn't change.


    Double springing the rider's weight like Skuffy said, does make some big differences to bike handling... however, it doesn't change anything about the system CoG (well... technically it moves a bit based on the relative position of the rider's body... we're talking millimetres though), so the system still behaves the same.

  18. No, no, some are saying it, does not make it right...... Moving mass forward is not going to impact your bike. When you go through a corner, you want your body over the front wheel.... this is riding 101 :) :grin:

    Let your body slide into the tank and hold onto the bike with your thighs whilst braking, not your arms. So, strengthen your thighs, back and stomach muscles. :grin:
  19. :?
    Ok .. so bracing myself via my thighs will help whilst braking in a straight line?
    Am I right in assuming some form of grip attached to the side will help?
    ..apart from going to gym