Front Tire Cupping

[dmixon]

I was talking to a co-worker and we both have the same issues with the front tire cupping on the Left side of center line after 7000 miles or so. He rides a Triumph Thruxton and I ride a 1100RT. We have heard it is from the crown of the road, If this infact is correct does the front tires tend to wear on the right side of center line in places like England where they ride on the opposite side of the road then we do?

[Polo]

Although you have been around since 2005, you obviously don't even lurk that much around here.

 

There are countless threads discussing the left side wear issue. If you can count the hairs that form your eyebrows, you may approximate the number of different opinions and versions on the subject.

 

My $0.02 is that if the tire cups you're running pressure too low.

 

Regarding the left side wear, I'll stay out of the discussion.

 

Best of luck.

[GordonB]

The front tire will wear a bit more on the left side. Fact of life accept it. Cupping is due to low pressure, you should be running 36psi. IMO

[NumbHands]

Though the pressure chart suggests all kinds of pressure levels depending on load, I have found 42 Rear and 36 front are best for tire wear. Incidentally, that is the value stamped on the VIN number label on the frame under the tank.

 

Michael

[Mark K]

Ha!

 

I wish I had a tire that would last 7K!

 

 

[boatzo]

 

 

Hi Neighbor,

 

Agreed, there is a myriad of threads on the subject. As Polo says tire pressure is a big issue. I run 38 front and 42 back, ride 1 up and don't carry much gear. Mine used to wear like yours and a dealer service manager said "They all do that, its the crown on the road".

 

Well, after consulting a motorcycle race mechanic, I did a fork alignment (very simple to do) and I have had even wear on the front tire for thousands of miles now.

 

That is my 2 cents.

[Boffin]

My front tyre wears on the left. I must get round to re-setting the front fork legs.

 

Andy

[4wheeldog]

There is something innate (Or is it inane?) in the human psyche that encourages us to go faster turning left than right. Nascar, and indy/cart racing are all evidence of this.

[CoarsegoldKid]

 

Well'after consulting a motorcycle race mechanic, I did a fork alignment (very simple to do)

 

Sometimes I get left wear and sometimes I don't. What is this alignment you speak of?

[AndyS]

 

Sometimes I get left wear and sometimes I don't. What is this alignment you speak of?

 

This is alignment .....but for the 1150RT

[boatzo]

Thanks for that info Andy. In addition to that I would add:

 

The axle should slide freely from one side to the other. Mine was very tight when I went to remove the front wheel for a tire (or is it tyre ) change. It had previous been installed at a dealership. I loosened the bridge bolts and immediately could slide the axle easily from one side to the other.Get everything lined up and torque the bridge bolts.

 

When reinstalling the front wheel, get everything snugged up and then bounce the bike so the forks slide up and down before tightening the axle clamp bolt. I think also that it is recommended to run the front wheel against a solid wall a couple of bounces.

 

This whole thing has worked well for me.

[Polo]

Would you elaborate on the procedure? I am not visualizing what needs to be adjusted.

 

As I heard it once in a movie: "tell me as if I was a 5 year old"

 

Please.

[AndyS]

Hi Polo, I hope this helps:

If the fork set up is not correct, various things can happen.

1. a fork leg can me radially misaligned such that when the axle goes in, it doesn't slide perfectly right to left and may need to be forced to get it to go into the partnering fork leg. This will set up stresses in the forks effecting their operation and this will also have an effect on the wheel.

 

2/. Lateral misalignment. If the fork legs spaced incorrectly at the bridge, then once the axle goes in it will either have to spring the forks wider at the base to get the wheel to fit correctly - or spring the forks tighter together, again generating an undesirable effect on the performance of the fork (which will be passed on to the wheel).

 

3/. Fore & aft misalighnment. This will try and twist the forks all the time and may well accelerate all sorts of wear.

 

For this reason, those of our number that replace their fork seals simply by undoing the fork bridge and sliding the leg off. If you don't put the leg back exactly right it may well cause a small problem.

 

BMW recon this is important, as they start the assembly instruction with a stern attention notice instructing the user to do the job TO THE LETTER. (this sort of wording is unusual).

 

Andy

[Ian]

Though the pressure chart suggests all kinds of pressure levels depending on load, I have found 42 Rear and 36 front are best for tire wear. Incidentally, that is the value stamped on the VIN number label on the frame under the tank.

 

Michael

 

My understanding is that those are the higher values specified for two up and fully loaded riding

 

regards,

 

Ian

[David R]

Tire pressure is an individual thing. I put on a new set of Z6 and set the pressure according to the book. 32 front 36 rear. It started cupping right away. Then I read all I could about tire pressure on a bunch of websites. The best thing I found is set the pressure and ride for 20 minutes. The pressure should increase by 10% from the heat. More than that and you need more air for less heat. I ended up at 38 in the front and the cupping went away.

 

More heat = better traction and faster tire wear.

 

YMMV....

 

I feel my tires when I stop. Not all the time, but its a good indicator.

David

[DunRTer]

I also run Z6 tyres, and am quite a big lump, at 100kgs (220lbs) plus luggage. When the tyres are reasonably new, I can get away with pressures as low as 36psi front; however, once they are worn at least halfway, I really need 41psi front and 43 rear to retain good handling. I also keep my suspension quite firm, so you can see I prefer good handling to maybe a little better comfort.

[upflying]

Tire cupping?

I think it is caused by engine pulses and vibrations which send harmonics through the bike and into the front forks. The vibrations cause the tire to ever so slightly skip and hop over the pavement. Hence the cupping wear.

How is that for an unscientific opinion?

[Polo]

Thanks Andy.

[pjw73nh]

Boatzo and Andy S,

 

I have been following this thread. I have a thread HERE that details my left side wear issue. I want to correct it before I buy a new tire.

 

I am somewhat confused. I have the manual and have reviewed the page/proc several times, and I am not sure I understand the procedure. The page cautions to perform the procedure EXACTLY as written. The next line says: "The front suspension strut is removed". I don't understand this. Are they saying to remove it? Are the saying that they are assuming it IS or HAS BEEN removed prior?

 

Neither my slider tube bridge nor my front suspension strut nor my fork bridge has been messed with (that I know of).

 

How much of this procedure do I actually have to do in order to align the forks so that my tire life will be extended? I am at a loss for an explanation of the tire wear as I have never had the front end apart, and this (worn) tire is the 3rd one the bike has had. The first two tires (Metzeler 880's) DID NOT have the left side wear. Each of those went about 13k miles with perfectly centered wear. Did the dealer do something different when installing this tire on the front that the other dealer (previous two tires) didn't do?

 

I am hoping that someone can explain the correct procedure to me.

 

Thanks.

 

Paul.../NH

[boatzo]

Hi Paul,

 

I did not follow the book, but it was interesting to see the clip that Andy posted. I am going to guess that the book is assuming the strut had been removed.

 

Lets assume here that the only thing that was done was the dealer replaced the front tire. This is what happened to me. After the replacement, the tire developed a distinctive ridge one one side of center.(I honestly can't remember if it was left or right side) I replaced the tire at 4500 miles, actually replaced both tires as the rear had not been replaced when the front was done. This time I ordered a set of Pilot Roads and had both tires changed at a local tire warehouse. Removing the wheels myself and taking them there. In removing and replacing the wheels I noticed that the front axle was very difficult to remove and also to reinstall especially when trying to get it to align with the left fork. I muscled it into position and tried out my new tires.

 

BTW, I also had what I considered to be excessive PTTR.

 

In a short time I started getting that old familiar ridge on the front tire again. I previously posted that the dealer said "TADT". I was not satisfied and was concerned. So, one day I stopped in to a Super Bike shop that had been recommended to me and the owner there did a lot of set up work for racing bikes. He also previously had been a BMW trained mechanic. He came out to the parking lot and looked at it and said that he suspected the front axle was not aligned properly.

 

He went on to tell me to remove the wheel, loosen the bridge bolts and slightly move the forks until the axle would slide freely from one side to the other and align and insert easily with the left fork. Then snug up the bridge bolts and retract the axle and re-insert it. If it was still smooth, then torque the bridge bolts and try the axle again. I did this and was amazed at how easily the axle aligned afterwards.

 

Also in reinstalling the front wheel, it is recommended to give the bike a good couple of bounces prior to torquing the axle clamp bolts. I get on the bike and push the front wheel against a wall a couple of times and then do the clamp bolts.

 

The results were great, the bike did not pull to the left any more and the ridge eventually evened out. I have since worn out those PRs @ 9500 miles and am now on a set of 880s and am seeing even wear, no ridges.

 

Sorry to be so long winded, but I hope this helps you solve your problem.

[pjw73nh]

Boatzo,

 

No apology needed. Thank you for such a great reply. Clarified a lot of it for me. Two questions for you. 1. The axle (mine anyway) has a hex on one side (left) and hollow on the right. Why the hex? Does it thread into something? Your post indicates it "slides". 2. Prior to the "bounce", how tight should I make the axle pinch bolts?

 

Thanks again for the clarification. I'm going to try it today (hopefully).

 

Please tell me I don't have to take the tupperware off for this? I am so tired of the "tupperware dance". It looks like I can get to the bridge bolts with it on.

 

Thanks again.

 

Paul.../NH

[boatzo]

Boatzo,

 

No apology needed. Thank you for such a great reply. Clarified a lot of it for me. Two questions for you. 1. The axle (mine anyway) has a hex on one side (left) and hollow on the right. Why the hex? Does it thread into something? Your post indicates it "slides". 2. Prior to the "bounce", how tight should I make the axle pinch bolts?

 

Thanks again for the clarification. I'm going to try it today (hopefully).

 

Please tell me I don't have to take the tupperware off for this? I am so tired of the "tupperware dance". It looks like I can get to the bridge bolts with it on.

 

Thanks again.

 

Paul.../NH

 

Paul,

 

The only tupperware that you have to remove is the front fender.

 

The axle is a tube, it slides in through the right side clamp to the left side clamp. If my memory serves me, The hex is a bolt that is installed after the axle is in place, it helps to put the axle in the correct place. Of course, this hex head bolt must be removed prior to removing the axle.

 

Also if my memory is correct, there was a plug cover for the hole in the end of the tube on the right side. It was cosmetic only and I guess helped to keep dirt out. Mine has been missing for years.

 

As for how tight to make the pinch bolts prior to the bounce, I would say, just snug, giving the ability for things to seat when you bounce. Then torque to spec, sorry I don't have the book in the house and it is 100 deg. in the shade outside so you will have to look up the torque on those bolts and the bridge bolts.

 

Let us know how it goes. Of course you won't know about the tire wear for some time.

 

I hope that you have a Haynes or Clymer manual as there are some other things like speedometer drive and ABS stuff that has to come off and be replaced if you are removing the wheel (recommended).

[pjw73nh]

Thanks.

 

Yes I have both the Clymers and the CD based shop manual. I have been going over them a lot.

 

One thing I MAY notice right away (I hope) is the squirrely ride on uneven surfaces improves. If you look at my other post, I get some very "squirrely" riding when I am on sandy pavement, or on the black "semi-liquid" tar patches they use to repair asphalt cracks. It feels as "kind of" like I am on ice. Very un-nerving. I hope it solves this too, but I am not holding my breath. I'll take whatever improvements I can get.

 

Thanks again.

 

Paul.../NH

[AndyS]

Thanks.

 

...I get some very "squirrely" riding when I am on sandy pavement, or on the black "semi-liquid" tar patches they use to repair asphalt cracks. It feels as "kind of" like I am on ice. Very un-nerving. I hope it solves this too, but I am not holding my breath. I'll take whatever improvements I can get.

 

Thanks again.

 

Paul.../NH

 

Your feeling of looseness is not uncommon on sandy surfaces and overbanding. We call it 'white lining' and the bike tends to follow the surface rather than track over it. This experiece is very tyre dependant and also changes dramatically with wear and tyre pressures.

[dsl]

We have heard it is from the crown of the road, If this infact is correct does the front tires tend to wear on the right side of center line in places like England where they ride on the opposite side of the road then we do?

Hmmmm, very interesting that of three people responding from left-hand side drive countries, one still wears the left side first and two didn't respond to the question.

 

I always wear the left sides of my tires by a good margin Clicky - doesn't matter what bike/suspension/driveline. For the most part, I think I know why:

 

Inherent Reasons:

 

- Left turns, always being on the outside, have a greater radius, and therefore result more miles traveled.

- (as mentioned) Road crown makes lefts off-camber and rights on-camber or slightly banked resulting iess side wear.

 

There is something innate (Or is it inane?) in the human psyche that encourages us to go faster turning left than right.

Yes! For many riders these are subconscious reasons, but for me they are very conscious reasons as I ride in a lot of heavily wooded, tight technical twisties:

 

- Right-handers are always (ie, 100% of the time) blinder and always sharper, then the same corner taken as a left-hander.

- You are much more likely (eg, 90%) to encounter a cage crossing the double yellow on a right-hander.

- You are more likely (eg, 70%) to encounter sand/gravel in a right hander.

- In case of error (ie, you go down), there is the possibility of sliding into on-coming traffic on a right hander.

 

Of course... YMMV

[pjw73nh]

Followup:

 

Ok So I went through the proc this weekend. I did a combination of the service manual and the proc documented in this thread. It was time consuming and tedious. I am still not sure I got it right.

 

Yes, the axle was VERY tight in the fork holes. I had to use a brass drift and tap it with a hammer to remove it. Not wail on it, but a few light to medium hits.

 

Once out, I cleaned it up with some brakes parts cleaner and re-lubed it with a very light coat of oil.

 

It was hard to get back in (even without the wheel), so I knew I was on to something. As per the instructions here, I loosened the 4 fork bridge-to-slider tube bolts slightly. Now (of course) the axle slid in very easily. As I tightened the bolts up, I would try the axle again. After each bolt it was tighter and tighter until I couldn't easily twist it by hand. I repeated this many many times. I finally got it to a point where I could at least twist it by hand (with effort) with the bridge bolts tightened to torque spec. (25 Nm). In the end, it was looser than it was when I started, but I wouldn't characterize the axle as "sliding easily" in to the holes...

 

I buttoned it up, took it for a short ride (Couldn't really feel any difference). I guess time will tell if my tire starts wearing in the center the way it should.

 

Thoughts, Comments, Suggestions?

 

Thanks.

 

Paul.../NH

[boatzo]

Paul,

 

What you found is exactly what I found on mine. The center of my front tire now wears evenly (2nd set of tires) since I first encountered the problem. Let us know how the wear goes and good luck.

[dirtrider]

Hi Paul

 

The procedure in the manual is basically to make the forks stroke smoothly. It really can’t do much for the front wheel lean as the axle to fork attachment is machined at a precise right angle to the forks and the axle is solidly bolted through those precision machined attachment holes.

To believe the wheel can lean when bolted up tight between the forks must mean you believe that solid front axle is bending. Is it?

 

[breyfogle]

Followup:

 

Thoughts, Comments, Suggestions?

 

If it wasn't nearly impossible, it would sound like a bent fork tube. Has the bike ever been in an accident ???

[BrianM]

IF the forks were removed from the bike, there is enough play in the bolts/brace over the front wheel that the axle can be a poor fit. You may try loosening the bolts, slide in the axle and then reloctite and tighten the bolts so the axle slides smoothly.

[AndyS]

[quote=dsl.....

Inherent Reasons:

 

- Left turns, always being on the outside, have a greater radius, and therefore result more miles traveled.

- (as mentioned) Road crown makes lefts off-camber and rights on-camber or slightly banked resulting iess side wear.

 

There is something innate (Or is it inane?) in the human psyche that encourages us to go faster turning left than right.

Yes! For many riders these are subconscious reasons, but for me they are very conscious reasons as I ride in a lot of heavily wooded, tight technical twisties:

 

- Right-handers are always (ie, 100% of the time) blinder and always sharper, then the same corner taken as a left-hander.

- You are much more likely (eg, 90%) to encounter a cage crossing the double yellow on a right-hander.

- You are more likely (eg, 70%) to encounter sand/gravel in a right hander.

- In case of error (ie, you go down), there is the possibility of sliding into on-coming traffic on a right hander.

 

Of course... YMMV

 

 

Unless you live in the UK or other countries which use the correct side of the road to travel on, where your proposals don't work.

Lefthanders are tighter, more debris on left handers etc etc.

 

Andy

[pjw73nh]

Ok, Well I think I may have messed something up when I did the fork alignment. I did the alignment a while ago, and I took the bike for a short test ride immediately after and it seemed ok though I really didn't know what I was looking for. In the mean time I injured my back and have been unable to ride until last Monday. After a week of riding (about 150 commuting miles) I have made this determination.

 

The bike handles well when turning to the right. But has issues when turning to the left. By "turning" I mean a sweeping type of turn that you might find in twisties or an on or off ramp to a major highway. I am not talking about the sharp, slow, 90 degree turn of a basic intersection.

 

I am hoping that I didn't mess something up too bad.. I *suppose* and am hoping that it is a function of the already worn out left side of the tire that is causing the issue, but I need some more guidance.

 

I'll preface my findings by saying that I am familiar with the term counter-steering and how it applies to motorcycles.

 

Here is what is happening as best I can describe it:

 

1. Turning to the right, the bike feels very normal, no under/over steer. Good lean angle, no "odd" forces to deal with. The steering feels "neutral" no effort required to keep the bike stable at any angle.

 

2.. When turning to the left in the same type of turns, the bike *feels like* it wants to fall over on the left side. I have to apply a fair amount of pushing pressure on the right handlegrip to keep it from leaning over/turning too far to the left.

 

If it was a bicycle, this is what I would liken it to. While holding a bicycle by the seat while standing still. Leaning the bicycle over to the right slightly causes the front wheel to turn commensurately with the amount of seat lean. When leaning the bicycle to the left, the front wheel will want to turn (using gravity) all the way to the left.

 

I hope these descriptions are enough to go on. It's a very difficult feeling/sensation to describe.

 

Added info: The MC still has a very slight PTTR, but less than I had before the alignment. I have not had the opportunity to test the PTTR with a locked throttle at a steady speed. I have always done it while decelerating, and I think the engine compression is responsible for the pull I feel.

 

As usual, any thoughts comments suggestions welcome.

 

Thanks...

 

Paul.../NH

 

 

 

[AndyS]

What mileage do you have on those tyres.

Do you get the same sensation when the tyres are up to temperature?

 

Andy

[pjw73nh]

Andy, 7k on the tires. Same sensation hot or cold.

 

I do have to retract a typo from my last post. It is the *LEFT* handle bar I have to push on to keep the bike from feeling like it wants to fall left during the left turns. Not the right handlebar.

 

Also I tested the PTTR with locked throttle on the way home tonight. It is MUCH better than before the alignment. At 40 mph on flat straight road, I let go of the bars, and it has just an ever so slight PTTR. I can easily counter it by moving my butt slightly to the left.

 

Thanks again.

 

 

 

[boatzo]

Paul,

 

Glad to know the alignment helped some. My experience was similar and when I put a new tire on the front, things got really good.

[AndyS]

......Andy, 7k on the tires. Same sensation hot or cold.

 

......

 

 

 

Do you think your problem is the fact that the tyres are now worn.

Most of us are well onto our second rear and have just replaced the front at that sort of mileage.

 

Andy

[David R]

I think you will be happy with a fresh set of tires. You fixed the problem but still have the odly worn tires on.

 

 

I took the shim out from the rear wheel. It still pulled to the right with Z6 on. now with pilot roads it does not pull. They DO howl and vibrate. They also seem to be wearing even with no cupping.

 

David

 

 

[pjw73nh]

Thanks for the replies folks. Boatzo, so far, all the way through this, your experience has mimicked mine with good results. That's encouraging. Though I am reluctant to spring for a new tire right away, I guess that's the only way I am going to find out if it is remedied or not. Seems like an expensive "diagnostic" though.

 

I have what I believe to be a full history of the bike from the original owner (with receipts). The tire history is as follows Originals replaced with first set (F&R) replaced about 13k. No unusual wear. Flat topped rear. Second full set replaced at 26k, by my dealer. Flat topped rear, no unusual wear. Now at 32k, rear is fine (not flat topped, hardly any wear on it. Very good, uniform tread depth. The front is as described in all these posts.

 

Assuming from previous tire change history, if in fact, it was the alignment that was the issue (now hopefully resolved), what did my dealer do during the last tire change that "upset the apple cart". The previous two sets of the same tires did not wear oddly. I can't imagine that they tweaked/adjusted the fork at all during a tire change. Remove calipers, remove axle. Done..... Or is this an incorrect assumption? I would feel much better if I had a logical explanation.

 

Further, if I bring it to them again to have the front tire replaced, how do I know they will not repeat the same thing and I will be in for a new tire yet AGAIN at 6-7k miles? Should I tell them what I found, what I did etc ???. Or should I just "hope" they get it right.... Or should I ask them to be very careful when they replace it because "this is what I have experienced from them in the past"? Not being an expert, I very much dislike instructing someone on how to do their job. Probably even more than they dislike hearing it.....

 

Thanks.

 

Paul.../NH

 

 

[AndyS]

.....I have what I believe to be a full history of the bike from the original owner (with receipts). The tire history is as follows Originals replaced with first set (F&R) replaced about 13k. No unusual wear. Flat topped rear. Second full set replaced at 26k, by my dealer. Flat topped rear, no unusual wear. Now at 32k, rear is fine (not flat topped, hardly any wear on it. Very good, uniform tread depth. The front is as described in all these posts.

 

........

 

Hi Paul.

The tyre history, is that while you have owned the bike?

Also, have you always lived/ridden in the same area, or have you moved recently?

Your tyre life is unusually good (although far from unheard of). I was wondering if you have moved and maybe you are now on more abrasive roads like so many of us, and your tyre life is starting to reflect this?

 

Andy

[pjw73nh]

Hi Andy,

 

History is from new. Bike was purchased new from Hap's Motorcycles in Sarasota, Florida in 2002. I bought it from the original owner. He had driven it two-up from FL to New Mexico and back. Then to Boston, then to New Mexico and back to Boston. The rest was just general riding in Mass. I received it in Oct 04 with about 20k on it. He was very diligent about maintenance. All work was done on schedule and by the selling dealer.

 

I ride in southern NH typically from March to early December though less time at either end of those times. 85 percent of my mileage is commuting, with an occasional 200-600 trip here and there... I am a very "easy" driver. I drive like an old man. Rarely do I "get on the throttle", more commonly is a heavy brake foot (I still haven't gotten used to the sensitivity of the power/abs/linked brakes.) Even after 6 years.

 

Tnx

[boatzo]

Paul,

 

I have found that unfortunately, dealers do not always do what should be done, that is why I try to do everything my self as much as possible.

 

Try to ask your dealer if you could watch as they change the tire (for your own edification). Don't be afraid to ask pertinent questions so as not to appear to be telling them what to do, but rather learn the process. After all you are paying for the work to be done.

 

I just had a horrible experience with a Kawa dealer. I needed to have a rear tire changed on my LT. Bought the tire on ebay. We do not have many cycle shops in this area so I called this Xtreme Powersport joint about 15 miles away. They said they would change the tire and balance it for $45.00. I thought that was high, but needed to get it done. A local HD chop shop does it for $25.00 but he was out of pocket. I explained to the service writer that I wanted the weights removed and then balance and add weights as necessary. When I went to pick up the wheel, the service guy brought it out along with the old tire. I said I didn't want the old tire and he said that would be $12.00 disposal fee. I was extremely pissed after having just paid $45.00 so I said I would dispose of the tire. Then he said, oh by the way, I checked you balance and it was way off, I didn't want to remove the weights and leave a gooey mess on you rim so I broke the tire loose and rotated it to get a better balance. By this time I was so livid, I left the shop before I got myself into real trouble. I had road rage all the way home and couldn't stop myself from throwing the single finger salute constantly!

 

I installed the rear wheel and noticed vibration at 65 mph and worse at higher speeds. I ordered a Marc Parnes tire balancer for around $105.00 and built a nice oak stand for it. Pulled the rear wheel and tried out my new toy and sure enough it was way out of balance. Stripped the weights, cleaned the rim and rebalanced the wheel & tire. Took it out for a run up to 100mph and it ran smooth as can be. (almost met a LEO in the process, but got slowed down soon enough).

 

We have a local tire warehouse that does everything including farm tractors and wheel barrows. They do not sell motorcycle tires but will gladly change them for $16.00 for 2 tires. They cannot balance, but I can now. So in the future, they will change my tires and I will balance them.

 

Sorry for the long rant, but I am just trying to point out that dealers are not always the answer. If you do it your self you will know what you have done. Best of luck going forward