Front Tire Wear 1100RT

[jbedone]

I bought my 1100RT with about 7500 miles on it 3 years ago. The first set of tires were worn out at about 8500 miles and I noticed the left side of the front tire was worn to the cord. I replaced the tires (front and back) two times now with Michelin Pilot Road. Same thing each time, front tire wears on the left side. This most recent set the front is gone after about 3500 miles and back is still in great shape. I have the tires installed and balanced by a local bike shop, not BMW as there are none within 100 miles of my house. They said there was nothing wrong with the rim when I had the tires installed. To my knowledge the bike has never been wrecked or dropped. I did a Carfax when I first bought the bike and no problems showed up. My friends say I push the front on left handers too much but I do not buy this. Any ideas from anyone?

[alien_hitchhiker]

jbedone - my 1100 RT does the same thing & in fact, every bike I've owned has tended to wear quicker at the left side of the front tire, though I think it is more pronounced on the R-RT.

My theory? Three things conspire to do this:

- roads in my area tend to have a high center crown, so I'm often riding on a slight camber.
- I probably lean a little further & go faster on left hand curves due to the increased line of sight on most lefts.
- my RT is a little off balance. I know this because if I ride no-handed I have to shift my weight slightly to the left to maintain a straight line. (I could worry about this & try to correct it - but it's so subtle I'm never aware of it with normal riding)

BTW - I mounted up my first pair of Metzler 880 Marathons over the summer. 5,000 miles so far - with ~3000 of loaded, 2 up riding - and they look great. I even think they handle better than the Bridgestone Battlax BT 020s I ran for the previous 3 years (the BTs only last around 8000 miles)

[cjack]

I bought my 1100RT with about 7500 miles on it 3 years ago. The first set of tires were worn out at about 8500 miles and I noticed the left side of the front tire was worn to the cord. I replaced the tires (front and back) two times now with Michelin Pilot Road. Same thing each time, front tire wears on the left side. This most recent set the front is gone after about 3500 miles and back is still in great shape. I have the tires installed and balanced by a local bike shop, not BMW as there are none within 100 miles of my house. They said there was nothing wrong with the rim when I had the tires installed. To my knowledge the bike has never been wrecked or dropped. I did a Carfax when I first bought the bike and no problems showed up. My friends say I push the front on left handers too much but I do not buy this. Any ideas from anyone?

Tire pressure?
I use about 39 in the front and 42 in the rear. I don't think it matters what model except maybe the LT you could add a couple of pounds/insq.

[DarkCloud]

The reason the front tire wears unevenly is due to frame geometry. The solution is to set about three inches to the left, or directly behind the speedometer. Optimum tire pressure 36/38.

Jon

[Boxerkuh]

During my oilhead days I remember to have the same issue. What I did is two fold. I packed my left saddlebag with weight to "even" the weight of the bike out. However, I found that different tire manufactures would wear differently. I loved the Avon Azorro's: they are Z rated and soft, absolute fabulous grip, but only 6K out off the front and rear; just a soft compound tire. I ended up riding with a set of Metzler's that gave me the best of all worlds, price, handling and 15K; I hated the Michelin and the Dunlops, only about 10K and cupping on the front tire.
My two cents anyway....

[bmwmick]

I bought my 1100RT with about 7500 miles on it 3 years ago. The first set of tires were worn out at about 8500 miles and I noticed the left side of the front tire was worn to the cord. I replaced the tires (front and back) two times now with Michelin Pilot Road. Same thing each time, front tire wears on the left side. This most recent set the front is gone after about 3500 miles and back is still in great shape. I have the tires installed and balanced by a local bike shop, not BMW as there are none within 100 miles of my house. They said there was nothing wrong with the rim when I had the tires installed. To my knowledge the bike has never been wrecked or dropped. I did a Carfax when I first bought the bike and no problems showed up. My friends say I push the front on left handers too much but I do not buy this. Any ideas from anyone?

Put a pair of Metzeler ME-880's on it. I've been using these (in the bias ply versions) for 15K or so and they wear absolutely even across the width of the tires.

Unless your bike was crashed, there is no 'geometry' problem causing the wear. It is the fact that we ride on the right side of the road. Almost every US road is built with the crown in the center.

[sportridertex]

My 1999 RT does the same thing, left side of the front tire always shows more wear, and if I release pressure from the handlebars, it has a tendency to go Right,

I think BMW just builds them out of line from the factory

I put 880's on last spring, seems like this tire is going to last longer than any tire i've had on before.

[Mr. Frank]

Another variable in left side wear is the fact that left hand curves involve greater distance than right hand curves. You actually have more mileage on the left side of the tire.

[GeneT]

My R1200C has the most wear on the left side of the front tire also , as a matter of fact it even looks like there is a slight cup or uneven wear pattern between the tread groves. Local dealer says there is nothing to be concerned about.

:dance

[gnavecky]

jbedone - my 1100 RT does the same thing & in fact, every bike I've owned has tended to wear quicker at the left side of the front tire, though I think it is more pronounced on the R-RT.

My theory? Three things conspire to do this:

- roads in my area tend to have a high center crown, so I'm often riding on a slight camber.
- I probably lean a little further & go faster on left hand curves due to the increased line of sight on most lefts.
- my RT is a little off balance. I know this because if I ride no-handed I have to shift my weight slightly to the left to maintain a straight line. (I could worry about this & try to correct it - but it's so subtle I'm never aware of it with normal riding)

BTW - I mounted up my first pair of Metzler 880 Marathons over the summer. 5,000 miles so far - with ~3000 of loaded, 2 up riding - and they look great. I even think they handle better than the Bridgestone Battlax BT 020s I ran for the previous 3 years (the BTs only last around 8000 miles)


I agree with “Alien Hitchhiker” both my 2000 RT and Honda SuperHawk (VTR1000) do the same thing, for the same reasons.

[Rollifahrer]

I bought my '98 RT with 68K and now have almost 95K. It came with a new Pilot Road on the front, and I've put 2 on since. I found that shifting my butt over to the left until the bike tracks true with hands off bars (thanks to Throttlemeister) saves my tires. I load the left side heavier than the right, and watch tire pressure (31 psi is working really well). After 2,000 miles tire is as round as new with even wear.

[Panhead_Jim]

I just went and looked, and darned if it isn't evident on my 96 RSL. I think I know what it is despite other theories on the subject. It is the rotation of the engine and the associated torque. If it were road crown, as others have stated, then my Harleys would suffer the same fate. NO! My Harley tires wear true throughout their lives, over and over again. The first thing I noticed when I first rode my RSL was during downshifting, when you rap the throttle to sync the tranny for the downshift, the bike pitches noticeably to the right, due to the unreal torque in the engine and the associated weight shift in the bottom end. I am sure that this persists in all driving conditions, and that unknowingly we are always pulling back on the right bar to compensate for the "open left" front fork. This results in a constant wear on the left side of the front tire, much like a slight pull in a car's front set. Ya'll think about this and reply. Any motor that spins in the wheel plane will NOT do this, as evidenced by my Harleys.

[alien_hitchhiker]

It is the rotation of the engine and the associated torque. Ya'll think about this and reply. Any motor that spins in the wheel plane will NOT do this, as evidenced by my Harleys.

Jim - interesting thought. I think you are on to something.

It's my impression that the lateral torque effect of the boxer engine does contribute to the front tire wear pattern, but only slightly.

Try this experiment: Stradle your stationary boxer with the engine idling, rapidly open the throttle and let it rev to 3-4 K,
hold the revs constant for a moment
abruptly close the throttle.

What did you feel?

I'll bet you felt the torque effect as the crank accelerated up to 3-4 K, no torque effect while you held it constant, and then a reciprocal torque effect as the crank deaccelerated.

So the impact on tire wear is definitely there, but probably tends to balance itself out as it occurs with accel & deaccel, and is probably not a huge factor.

The real reason the tires on your Harley wear differently is that they rotate at a much slower speed and rarely lean :bolt

[DarkCloud]

I'm not an engineer, but under load wouldn't the torque be present?

JON

[alien_hitchhiker]

Jon, I'm thinking, I'm thinking...
(Hey, it's hard for me :huh )

I'm no engineer either. Maybe someone with a better understanding of physics will pipe-up.

Jim - it just might be that your explanation is on target.
(Though I still think that the real difference with the Harley tires is....)

Next time I ride I'll play out my little experiment to see if my theorem is correct. I'll report back - unless I'm wrong - in that case I'll just be quiet.

[blackNwhite]

Probably more info than you wanted but still good info none the less.
Tom

http://www.rattlebars.com/valkfaq/tirewear/

[Panhead_Jim]

The real reason the tires on your Harley wear differently is that they rotate at a much slower speed and rarely lean :bolt

LOL!!!!! :D

[glwestcott]

Brother's Gold Wing - both hands off and it tracks straight. Friends Harley - Both hands off and it tracks straight. My 1100RT - Both hands off and I'm heading for the shoulder. All three bikes, however, wear tires more on the left. I vote for it being caused by something with the road such as crown and length of left vs right hand turns. :gerg

[Troutluck]

I wonder if the telelever front end might contribute to this phenomenon by deflecting more (laterally) than a traditional suspension during cornering? Actually, I take that back; I think it's the synthetic oil causing it. Or surging. :)

[nrpetersen]

No - The "roll torque" you feel on engine acceleration/deceleration of a longitudinal axis crankshaft is due to inertial reaction effects caused by accel/decelling the engine flywheel. It is not due to steady state engine torque delivered to the wheels. All the forces and moments required to maintain the bike at speed areself reacted within the chassis, except of course the thrust needed to overcome drag and hills etc.

If you accelerate a bike, only that same flywheel component will appear as roll torque on the bike chassis. This roll torque will make you have to apply a slight torque to the handlebars to maintain direction as you accelerate away from say a stop sign. (I can't remember which way, but the effect is consistent)

If you change the direction of the bike (go from say westbound to northbound), assuming a longitudinal crankshaft axis, there is a minor gyroscopic moment caused by the flywheel on the bike chassis which wants to slightly pitch the bike.

If you go from straight and level, to going uphill, that same gyroscopic moment will apply a slight yaw torque to the bike frame.

These last two effects are probably undetectable to a most drivers. The direction change one applies to both longitudinal and lateral crankshaft bikes. The second one doesn't apply to transverse crankshaft axis bikes.

MNEngineer (retired)

[Panhead_Jim]

OK. So my theory about the engine's torque is not substantiated. So I guess I'm wrong. I guess I'm wrong. That explains why my Harley doesn't experience the phenomenon. Neither of my Harleys do. I guess I'm wrong. Boy, that's tough. I'm glad that's over with... ;)

[gsinmaine]

DO NOT high tec.This Roads tend to have a high crown Thanks Alien hitchhiker

[Panhead_Jim]

DO NOT high tec.This Roads tend to have a high crown Thanks Alien hitchhiker

Anyone care to attempt a translation? :stick

[alien_hitchhiker]

DO NOT high tec.This Roads tend to have a high crown Thanks Alien hitchhiker

I speak gsinmaine's language, allow me to translate. He says:

"High tech explanations are full of ground pig flesh encased in intestines. The road we all travel wears a crown at its highest point. When the tire touches the road, it too wears the crown. The alien who picked me up while I hitchhiked on the road expalined this to me. Thank you very much."

I'm telling you, I know about these things!

[DarkCloud]

OK. So my theory about the engine's torque is not substantiated. So I guess I'm wrong. I guess I'm wrong. That explains why my Harley doesn't experience the phenomenon. Neither of my Harleys do. I guess I'm wrong. Boy, that's tough. I'm glad that's over with... ;)

You're not wrong, your Harley's engine is mounted so that the torque resistance is the same direction as the motorcycle, not causing a lateral movement when the rpm's are increased.

My question, is the RRT balanced left to right? If on level ground, could an RRT stand perpendicular without support, or would it have to lean to the left to stand without support?

JON
ABR

[alien_hitchhiker]

My zwei phenigs:

I did some riding today (temp ranged from 38-48 degrees - brrrr). I did my little stationary experiment and also payed close attention to the torque effect while underway. My impressions fit with the rattlebars link provided by Tom.

While stationary, the torque effect was noticeable when the throttle was bliped. The bike wanted to rock slightly to the right. It was not noticeable with the throttle held open at a fairly constant rpm.

While underway it was not noticeable with acceleration or deceleration. If I pulled the clutch in and blipped the throttle while coasting, I did notice the torque effect.



Jim, I do think that you have identified a quirky trait of Boxer handling dynamics, but in line with the rattlebars piece, I can't imagine torque effect ever pulling the bike over enough to have a significant effect on front tire side wear.

[Panhead_Jim]

I speak gsinmaine's language, allow me to translate. He says:

"High tech explanations are full of ground pig flesh encased in intestines. The road we all travel wears a crown at its highest point. When the tire touches the road, it too wears the crown. The alien who picked me up while I hitchhiked on the road expalined this to me. Thank you very much."

I'm telling you, I know about these things!

That's funny right there. I don't care who you are. :blah

[Panhead_Jim]

You're not wrong, your Harley's engine is mounted so that the torque resistance is the same direction as the motorcycle, not causing a lateral movement when the rpm's are increased.

My question, is the RRT balanced left to right? If on level ground, could an RRT stand perpendicular without support, or would it have to lean to the left to stand without support?

JON
ABR

This is even funnier than the last. I'm standing beside myself. :dunno

[Panhead_Jim]

but I've got to get my post count up to a respectable number. I have a solution to the whole problem. Stay in the passing lane! That way, the crown is to your right side, and the left side wear problem should disappear! Of course, this requires that you consistently drive faster than everyone else, but that's normal, right?

Bah hah hah!

[Rollifahrer]

I'm not an engineer, but under load wouldn't the torque be present?

JON

Also not an engineer, but I believe it's the change in revs and subsequent change in torque that causes the noticeable side forces. Car engines twist on mounts, strong single-speed drills or grinders will twist when you hit the gas/trigger, then settle down when they hit a contstant RPM, there is still torque, but it's absorbed by the motor mounts, frame/wrist, ect...could be that agressive acceleration and blipping the throttle create a side force countered by leaning the bike slightly to the left. I found myself sitting slightly crooked and to the right (high side) after reaching cruising speed in 5th. I was then pushing slightly on the left bar to track straight, which accelerated the rate of wear on the left due to "scrubbing". I think it's worse with dual compound tires that are not properly , or ideally, inflated. At any rate, I now load my gear with this in mind and routinely check tracking and shift my weight accordingly. I also quit blipping the throttle on upshifts after I learned to sync. foot/clutch hand on this bike. It seems the bike stays more centered and I don't find myself scooting up to the high side.

1100RT gas tanks are asymetrical, the right side being bigger. The wear problem was REALLY bad after I took out the radio, untill I put a bunch of tools and a 5# weight in the "glovebox".

I'm not sure I really know the reason, but the things I tried work for me.

Good luck figuring out what works on your bikes!

[Godfather]

Gheez! Information overload...My 2000 Suzuki SV 650 wore the front tire asymetrically too! The left side looked as it were beveled then the center wore flat and the right side semi round. This happened with two different brands of tires (michelin,bridgestone) at about the 7000 mile mark. I used the bike for traveling and recreational riding. The engine is a V twin mounted laterally similar to that in a Ducati. The SV boards just accept it as wear from the crown in the road...There, my two cents. :dunno

[Rollifahrer]

I get 14K now instead of 8. Thought it might help someone to know what I did. Sorry the why I did it got too confusing.

[bdiver]

I agree with Panhead Jim, engine torque is the culprit. The entire road crown idea is a bunch of bunk IMHO, (do car tires wear out on the left side too???)

I've put about 150K on my 3 Hondas (magnas & sabres) in the last 23 yrs and they've worn good all around (except for cupping), The RT is a different story. I have about 11-12K on my Pilot roads and they were pretty good until the last 2K miles or so which I'm fairly happy with so I'll probably get another set. Thats my 3 cents