Paawpabear
Ken Morse
Please let me know which rotation direction you have installed your BT45 and why. I want to get mine mounted the best way the first time.
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Sent from my XT1254 using Tapatalk
To whom are you posing that question?What size did you go with ?
130/70-18What size did you go with ?
Ditto the quote.I've ran rears on front both ways and have found little difference. I normally mount them arrow backwards first and then rotate them when the scalloping gets bad.
Very helpful. Thanks everyone for your input and help with this topic, I very much appreciate it.I contacted Bridgestone about this when I spotted that half way through the life of my BT020s, the front tyre had been fitted the wrong way round.
The issue is nothing to do with the tread pattern or the wear life, it is to do with the way that the tyre is constructed. The 'rubber' compound is laid onto the carcass in a spiral, somewhat similar to the way that insulation tape is wound onto a roll. At some point there is an 'end' to the layer of compound. The direction of tyre rotation is set so that this presents a trailing edge to the road surface.
If the tyre is put on the wrong way round there is a chance that the end of the spiral layer of compound could get rubbed up.
I asked if I needed to have the tyre refitted. He said that it was up to me, but that I should keep an eye on the tyre in the meantime. I asked what I should be looking for.
He said that if the end does get rubbed up then the rubber compound will start breaking off in chunks. It will be very obvious.
I took it back and had the tyre refitted properly, not least because I wanted to point out to the people that did it that they had screwed up.
Which is why a rear on front should be backwards. Maximum force against the splice joint is placed on the tire during heavy braking.I contacted Bridgestone about this when I spotted that half way through the life of my BT020s, the front tyre had been fitted the wrong way round.
The issue is nothing to do with the tread pattern or the wear life, it is to do with the way that the tyre is constructed. The 'rubber' compound is laid onto the carcass in a spiral, somewhat similar to the way that insulation tape is wound onto a roll. At some point there is an 'end' to the layer of compound. The direction of tyre rotation is set so that this presents a trailing edge to the road surface.
If the tyre is put on the wrong way round there is a chance that the end of the spiral layer of compound could get rubbed up.
I asked if I needed to have the tyre refitted. He said that it was up to me, but that I should keep an eye on the tyre in the meantime. I asked what I should be looking for.
He said that if the end does get rubbed up then the rubber compound will start breaking off in chunks. It will be very obvious.
I took it back and had the tyre refitted properly, not least because I wanted to point out to the people that did it that they had screwed up.
Isn't the force applied to the front tire under heavy braking in the same direction as the force applied to the rear tire under heavy acceleration? Looking from the left side of the bike, I'm picturing the front tire rolling counter-clockwise, with braking forces opposing in the clockwise direction. Same with rear wheel acceleration, the pavement is providing a counter-force in the clockwise direction, which if overcome results in a rear wheel spin in the counter-clockwise direction. So it seems that the maximum force against the splice joint would be the same in both cases if the tire were mounted in the same direction for both cases.Which is why a rear on front should be backwards. Maximum force against the splice joint is placed on the tire during heavy braking.
That's why I mounted my BT45 backwards on the front of my ST1100.Which is why a rear on front should be backwards. Maximum force against the splice joint is placed on the tire during heavy braking.
Try imagining that the front is locked up and sliding. Now back to the rear, I picture the splice as a 45 degree cut going up from the pavement towards the back of the bike on the arrow forwards rear tire. During a "peel out" you would be swiping across the rear splice no problems. Now move that tire to the front (still arrow forwards) and lock it up while moving forwards. You're now sliding that tire with the 45 angle digging down towards the front which could make that 45 splice unwrap from the carcass. That's what I make of the whole arrow and rotation thing.Isn't the force applied to the front tire under heavy braking in the same direction as the force applied to the rear tire under heavy acceleration? Looking from the left side of the bike, I'm picturing the front tire rolling counter-clockwise, with braking forces opposing in the clockwise direction. Same with rear wheel acceleration, the pavement is providing a counter-force in the clockwise direction, which if overcome results in a rear wheel spin in the counter-clockwise direction. So it seems that the maximum force against the splice joint would be the same in both cases if the tire were mounted in the same direction for both cases.
I thought about this about long enough to type this reply, so please correct me where I'm wrong.
That seems logical to me, but think of it another way. Elevate the front wheel and spin it. Then from below apply a frictional force to the bottom of the tire, which I think would be similar to the pavement forces being applied. As the tire rotates while slowing down, the swiping motion you described for the rear still applies to the front if mounted in the same rotational orientation. It goes across the splice. If reversed, the swiping would be against the splice.Try imagining that the front is locked up and sliding. Now back to the rear, I picture the splice as a 45 degree cut going up from the pavement towards the back of the bike on the arrow forwards rear tire. During a "peel out" you would be swiping across the rear splice no problems. Now move that tire to the front (still arrow forwards) and lock it up while moving forwards. You're now sliding that tire with the 45 angle digging down towards the front which could make that 45 splice unwrap from the carcass. That's what I make of the whole arrow and rotation thing.
To counter that argument, I would claim that the braking forces have to be opposite the direction of the wheel rotation, otherwise they'd make the wheel turn faster, not slower. And a skid is different from normal braking forces. If you crash, anything dragging along the ground is skidding, and the force is opposite the direction of travel, but its not due to braking.Okay one more thought for you. If you apply the front brake and the tire is under enough friction to leave a skid mark as the tire turns which way will that skid mark go towards? The front tire tread force load under braking is opposite what you are picturing I think.
The tire rotates and slows and slides forward while the bike is forcing it's mass forward above the front contact point. The friction point at the bottom of the front tire is to the rear. Just like if you lock up the tire and drag the pavement under the front towards rear.