Tyre wear, should it be equal on both tyres?

Bubbabo
Bubbabo Posts: 26
edited October 2009 in Road beginners
Howdy roadies. I recently got a road bike 3 months ago, and I haven't been on a bike for many years, so I'm very rusty. I cleaned my bike today and noticed that the back tyre has much more wear than the front, and the front tyre still has the line on the centre. Is this natural? Or am I relying too heavily on my back brake, and not using the front enough? Because I was rusty I have tried to use the front with caution, but maybe I'm using the back a little too eagerly.

Bubba bo
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Comments

  • Smokin Joe
    Smokin Joe Posts: 2,706
    Nothing to do with your braking technique. You have most of your weight on the rear tyre and the drive is also going through there. I go through three back tyres to one front.
  • yogi
    yogi Posts: 456
    The back tyre will always wear more, it's carrying more weight plus all the drive goes though the back tyre. The rear tyres will wear flat too. Periodically swap your tyres around.
    http://yogi.terapad.com
  • Bubbabo
    Bubbabo Posts: 26
    Smokin Joe wrote:
    Nothing to do with your braking technique. You have most of your weight on the rear tyre and the drive is also going through there. I go through three back tyres to one front.

    I'm a big chap, so I guess that explains it :P Lot of weight going on my tyres, so they are taking a heavy ride.

    Thanks Joe
  • ride_whenever
    ride_whenever Posts: 13,279
    yogi wrote:
    Periodically swap your tyres around.

    So you have a lovely flat centered front tyre :roll:

    Run the rear into the ground, replace the front and move the old front (which is still almost new) onto the back. This way you keep the best condition tyre up front for cornering and braking grip.
    Neeermad
    Carbon 456
    456 lefty
    Pompino
    White Inbred
  • Smokin Joe
    Smokin Joe Posts: 2,706
    yogi wrote:
    The back tyre will always wear more, it's carrying more weight plus all the drive goes though the back tyre. The rear tyres will wear flat too. Periodically swap your tyres around.
    Waste of time, you won't get any more life out of the pair.

    Think about it.
  • edindevon
    edindevon Posts: 325
    Smokin Joe wrote:
    yogi wrote:
    The back tyre will always wear more, it's carrying more weight plus all the drive goes though the back tyre. The rear tyres will wear flat too. Periodically swap your tyres around.
    Waste of time, you won't get any more life out of the pair.

    Think about it.

    I don't think it is a waste of time if you want replace both tyres at the same time, thereby delaying further expense for as long as possible.

    Say for example we accept your guide that a rear tyre wears three times quicker than a front tyre and we say that a rear tyre will last for 3,000 miles. Obviously with no swapping, the rear will be worn after 3,000 miles and you will have to dip into your pocket to replace it. This applies even if you swap the old front on the rear and put the new tyre on the front as suggested by Ride Whenever. However, if you swapped your tyres over every 1,000 miles, you would still have life in both after 4,000 miles, as they would each have only covered the equivalent of 2,666 miles of rear wear.

    Edindevon
  • balthazar
    balthazar Posts: 1,565
    @Edindeveon

    By your rationale, a front tyre may last 9000 miles if left where it is. There's no way around it: if you replace tyres when they're worn out, you have wasted nothing. Replacing each tyre independently when it wears out is the sensible way to proceed – swapping the new one to the front even better. Why would you particularly want to replace both tyres together?
  • edindevon
    edindevon Posts: 325
    balthazar wrote:
    @Edindeveon

    By your rationale, a front tyre may last 9000 miles if left where it is. There's no way around it: if you replace tyres when they're worn out, you have wasted nothing. Replacing each tyre independently when it wears out is the sensible way to proceed – swapping the new one to the front even better. Why would you particularly want to replace both tyres together?

    I don't think one way is any more sensible than the other. I think it's just a case of each to their own.

    The strategy of swapping tyres was dismissed as a waste of time and I offered a reason why it might make sense for some people.

    Personally I can't be bothered to swap tyres, so I just replace them as they wear out, but that doesn't mean that people who choose a different way of doing things are wrong.

    Edindevon
  • John.T
    John.T Posts: 3,698
    Bubbabo wrote:
    Or am I relying too heavily on my back brake, and not using the front enough? Because I was rusty I have tried to use the front with caution, but maybe I'm using the back a little too eagerly.
    Bubba bo
    The tyre wear has been covered pretty well but you need to change your braking technique. Most braking should be done with the front brake as this one is most efficient. As you brake your weight is transfered to the front wheel so the available grip increases while the rear grip decreases causing skidding of the rear wheel. For hard braking brake as hard as you can on the front and just enough to nearly lock the wheel at the rear. This gives max brake power. It also avoids flat spots on the back tyre.
    My Fleet.
  • ride_whenever
    ride_whenever Posts: 13,279
    You don't get flat spots from using the rear brake, unless you're skidding a lot, and even then it'll be fairly even unless you just do one massive skid once.

    Flat spots come from fixies where you do skid-stops and always lock up in the same crank position, hence you're skidding on the same areas (dependent on ratios) and make flat spots
    Neeermad
    Carbon 456
    456 lefty
    Pompino
    White Inbred
  • careful
    careful Posts: 720
    Yogi wrote
    Periodically swap your tyres around
    I definately would avoid putting an ex rear tyre onto the front. The flat centre section that develops on the rear gives a very unsteady and low grip transition when cornering. I did this recently and am convinced that it was the cause of a nasty crash on a hairpin bend a few days ago. There could have been other factors of course, but the squared profile really messed up the handling for sure.
  • Smokin Joe
    Smokin Joe Posts: 2,706
    careful wrote:
    Yogi wrote
    Periodically swap your tyres around
    I definately would avoid putting an ex rear tyre onto the front. The flat centre section that develops on the rear gives a very unsteady and low grip transition when cornering. I did this recently and am convinced that it was the cause of a nasty crash on a hairpin bend a few days ago. There could have been other factors of course, but the squared profile really messed up the handling for sure.
    +1.

    A rear tyre will square off to a much greater extent than a front and swapping it over is a potentially dangerous practice.
  • keef66
    keef66 Posts: 13,123
    In my youth I used to favour the rear brake because the front was just too grabby and unpredictable Consequently I once created a spectacular flat spot on my rear tyre. Cast iron Raleigh racer, coming downhill in the Yorkshire Dales as fast as I could physically go. One of the horses I was about to pass decide to turn sharp right and do a Hi-ho Silver type rearing up manouvre. Grabbed the brakes and locked the back wheel for about 50 yards, accompanied by a kind of tearing noise as the rubber was stripped down to the carcass, and a kind of rattling noise, which was my anal sphincter opening and closing very quickly.

    Now some 30+ years later with machined alloy rims, and powerful dual pivot brakes with great modulation, I am perfecting the art of front-wheel braking
  • dilemna
    dilemna Posts: 2,187
    If braking hard you should apply the rear brake a fraction of a second before the front otherwise you risk going over the bars as all your weight is pushed forward or probably worse losing the front wheel if the road surface is slippery or you are turning otherwise you risk collecting some road rash. It is a whole let easier to control the rear end than the front. A front brake should always be used in conjunction with the rear if travelling at any significant speed.
    Life is like a roll of toilet paper; long and useful, but always ends at the wrong moment. Anon.
    Think how stupid the average person is.......
    half of them are even more stupid than you first thought.
  • Smokin Joe
    Smokin Joe Posts: 2,706
    dilemna wrote:
    If braking hard you should apply the rear brake a fraction of a second before the front otherwise you risk going over the bars as all your weight is pushed forward or probably worse losing the front wheel if the road surface is slippery or you are turning otherwise you risk collecting some road rash. It is a whole let easier to control the rear end than the front. A front brake should always be used in conjunction with the rear if travelling at any significant speed.
    Can't agree with that at all, it is always front brake first. The back brake is useful at slow speeds, in slippery conditions or if you need to scrub a tiny bit of speed off on a bend, but other than that it has the stopping power of a cream puff.

    Many motorcycle racers don't touch the back brake unless the surface is wet, and that includes braking heavily from 200mph.
  • Steve_b77
    Steve_b77 Posts: 1,680
    Surely when braking hard - really hard - it would make sense to move your weight backwards a little ti decrease the risk of going over you bars.

    Works on MTB, is it the same practise on the road?

    I know on my MTB I and many others use the rear brake to trim speed when descending quickly and the front to stop.
  • keef66
    keef66 Posts: 13,123
    You're right. If I need to stop really quickly and have time to plan it, I hang my @rse off the back of the saddle and over the back wheel.
  • ride_whenever
    ride_whenever Posts: 13,279
    Braking is a skill as well, keep your arms strong so your knees don't hit the bars and you can pull some pretty impressive rolling endos (as i found when a driver decided to turn without indicating)
    Neeermad
    Carbon 456
    456 lefty
    Pompino
    White Inbred
  • Steve_b77
    Steve_b77 Posts: 1,680
    Is it ever done in roadie circles to fit say a 25 or 28mm tyre up front and keep a 23mm tyre out back for minimal rolling resistance out back but greater cornering & braking traction up front?

    Feel free to tell me to bugger off back to MTB world if it sounds crazy :lol:
  • John.T
    John.T Posts: 3,698
    dilemna wrote:
    If braking hard you should apply the rear brake a fraction of a second before the front otherwise you risk going over the bars as all your weight is pushed forward .
    For any given retardation the weight transfer is the same regardless of which brake you are using. The difference is that you are transfering weight to the front wheel where it will help stopping and away from the rear one thus decreasing its stopping power.
    In the dry all stopping should come from the front brake and the rear only used to provide what it can without lock up. In the wet you use them much more evenly. It is a matter of getting the best balance and this comes with practice. If you favour the rear all the time you will never learn this.
    My Fleet.
  • John.T
    John.T Posts: 3,698
    Steve_b77 wrote:
    Surely when braking hard - really hard - it would make sense to move your weight backwards a little ti decrease the risk of going over you bars.
    Works on MTB, is it the same practise on the road?
    I know on my MTB I and many others use the rear brake to trim speed when descending quickly and the front to stop.
    It works just as well on the road but you usually can not hang your backside off the rear of the saddle as far. It is not such a problem as the C of G is lower on a road bike and you do not have the suspension dive.
    My Fleet.
  • Escargot
    Escargot Posts: 361
    dilemna wrote:
    ....or probably worse losing the front wheel if the road surface is slippery or you are turning otherwise you risk collecting some road rash.

    I think you/anyone would need to retake their cycling proficiency test if they used the front brake hard round a bend :wink:

    Ranks up there with pedalling round a sharp corner.
  • huuregeil
    huuregeil Posts: 780
    Escargot wrote:
    Ranks up there with pedalling round a sharp corner.

    People clearly need to get some fixed-wheel action to work out *exactly* how sharp the bend can be before pedal-strike becomes an issue :wink:
  • desweller
    desweller Posts: 5,175
    Further note on braking with the front:

    If you are stopping as hard as you can in the dry, then weight transfer will mean that the weight on the rear tyre is almost zero. As friction is a function of load, that means that the retardation offered by the rear is also almost zero, and applying the rear brake is of no use.
    - - - - - - - - - -
    On Strava.{/url}
  • balthazar
    balthazar Posts: 1,565
    Escargot wrote:
    dilemna wrote:
    ....or probably worse losing the front wheel if the road surface is slippery or you are turning otherwise you risk collecting some road rash.

    I think you/anyone would need to retake their cycling proficiency test if they used the front brake hard round a bend :wink:

    Ranks up there with pedalling round a sharp corner.
    I don't know how much emphasis you are putting on braking hard, but I brake fairly heavily right into the apex of corners, contrary to the swathe of advice from nearly everybody who sees motorsport racers as their model for fast progress on a bicycle.
  • Escargot
    Escargot Posts: 361
    balthazar wrote:
    Escargot wrote:
    dilemna wrote:
    ....or probably worse losing the front wheel if the road surface is slippery or you are turning otherwise you risk collecting some road rash.

    I think you/anyone would need to retake their cycling proficiency test if they used the front brake hard round a bend :wink:

    Ranks up there with pedalling round a sharp corner.
    I don't know how much emphasis you are putting on braking hard, but I brake fairly heavily right into the apex of corners, contrary to the swathe of advice from nearly everybody who sees motorsport racers as their model for fast progress on a bicycle.

    :shock: wow, you're a brave man.

    I think motorsport is used as the physics can be directly translated and is easy for most to understand. Personally (and possibly for your own safety) it might be advisable to either use your back brake (gently) round bends or not to brake at all (I don't mean literally :wink: ).

    I still believe in the old 'brake on the straights' philosophy as it's the most effective way of maintaining balance when the weight gets transferred toward the front of the bike.

    My fear is that your weight is moving toward the front whilst your front wheel is trying to turn round the corner.
  • balthazar
    balthazar Posts: 1,565
    Escargot wrote:
    :shock: wow, you're a brave man.

    I think motorsport is used as the physics can be directly translated and is easy for most to understand. Personally (and possibly for your own safety) it might be advisable to either use your back brake (gently) round bends or not to brake at all (I don't mean literally :wink: ).

    I still believe in the old 'brake on the straights' philosophy as it's the most effective way of maintaining balance when the weight gets transferred toward the front of the bike.

    My fear is that your weight is moving toward the front whilst your front wheel is trying to turn round the corner.
    We should be used to compensating for our weight moving forward, from braking on straight roads. I don't find it difficult to adjust my body position whilst cornering: it's hardly "patting your head while rubbing your tummy". The extra demands that moderate braking place on the tyre are minimal, as calculated by Jobst Brandt in this excerpt from this article:

    "Braking at maximum lean

    For braking in a curve, take the example of a rider cornering with
    good traction, leaning at 45 degrees, the equivalent of 1G centrifugal
    acceleration. Braking with 1/10g increases the traction demand by one
    half percent. The sum of cornering and braking vectors is the square
    root of the sum of their squares, SQRT(1^2+0.1^2)=1.005 or an increase
    of 0.005. In other words, there is room to brake substantially during
    maximum cornering. Because the lean angle changes as the square of
    the speed, braking can rapidly reduce the angle and allow even more
    braking. For this reason skilled racers nearly always apply both
    brakes into the apex of turns."

    I can't help but see the admonition, "Never brake in turns!! Ever!!"– which predominates – as one of the more baseless pieces of advice in cycling. It makes people go slower I suppose, yet it creates a boogeyman where none exist – and I like going down hills fast.
  • Escargot
    Escargot Posts: 361
    balthazar, I think you're missing that I said 'hard' braking i.e. wiping off a lot of speed mid bend.

    The general of this is true as under hard braking your weight wants takes a straight path, due to momentum. If this is done when you're trying to turn then I'm sure you can appreciate that your mass trying to go straight ahead, whilst you are wanting to change direction (possibly at 45 degrees) is not ideal.

    Interesting article but I believe he has slightly contradicted himself as a few paragraphs up he says:

    When approaching a curve with good
    traction, the front brake can be used almost exclusively, because it
    is capable of slowing the bicycle so rapidly that nearly all weight
    transfers to the front wheel, at which point the rear brake is nearly
    useless.

    However, he then says further down:

    In other words, there is room to brake substantially during
    maximum cornering. Because the lean angle changes as the square of
    the speed, braking can rapidly reduce the angle and allow even more
    braking. For this reason skilled racers nearly always apply both
    brakes into the apex of turns.

    You can't have it all ways. If you're braking substantially then your weight would transfer to the front. However, if the pros are using both brakes into an apex then it cannot be hard braking as the rear brake would be useless.

    At the end of the day most of us don't want to be decending at 100% efficiency so the regular rules of physics still applies. If that makes me average, by Mr. Brandt's standards, then fair enough but I'm going to stick with braking before a bend :)
  • balthazar
    balthazar Posts: 1,565
    Escargot wrote:
    balthazar, I think you're missing that I said 'hard' braking i.e. wiping off a lot of speed mid bend.
    Well, my first comment was to wonder just how much stress you were putting on that. If our dispute is over moderate or hard braking, then there is nothing to resolve as I think we're in agreement. I had the impression that you were taking the standard line of forbidding any braking at all during cornering, and it is that, commonly stated (often aggressively – as if to disobey it would result in disaster) position that I think is wrong.
  • Escargot
    Escargot Posts: 361
    balthazar wrote:
    Escargot wrote:
    balthazar, I think you're missing that I said 'hard' braking i.e. wiping off a lot of speed mid bend.
    Well, my first comment was to wonder just how much stress you were putting on that. If our dispute is over moderate or hard braking, then there is nothing to resolve as I think we're in agreement. I had the impression that you were taking the standard line of forbidding any braking at all during cornering, and it is that, commonly stated (often aggressively – as if to disobey it would result in disaster) position that I think is wrong.

    I thought that's what you were aiming at :D

    The chap writing the article is generally right (although he does contradict himself a bit) but by 'substantial' braking I think he means light adjustment, which is probably fine.

    I suspect we all brake round the bend to some extent, depending on speed, as it doesn't really matter if conditions are good. I just feared from your earlier comment that you were hanging on the brakes mid bend :shock: :wink:

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