| Author | Message | ||
     Rpm4x4 |
I took my wheels off my City X to take them in to get balanced before I go on my trip in one month. It doesnt shake but I figured with that many miles being put on Id just do it anyway. It will be roughly 2500miles. The bike has 13500 miles on it now. With my fingers in the bearing and spinning the wheel I can feel a little click as I rotate it. I checked the front and it is the same as the rear. Is that normal? So I got to wondering, what is the average life span of wheel bearings on a Buell? Im wondering if I am being paranoid. | ||
| Moosestang |
Mine felt the same. 7500 miles on mine. | ||
| Etennuly |
I had a '05 City-X, 13,500 miles no problems at all. I have an '06 Uly that made 33,000 miles on the rear bearings. I now have 34,000 on it and expect a lot more miles out of the front bearings. Every time I change tires I pick the outside seals out to check and re-grease the bearings. The fronts have always turned easily and smoothly. The rears always turned hard and notchy, even from new. When the rear failed it was a real noticeable screeching-squalling noise. I stopped to check it when it first did it, unsure I continued on. A few more miles it did it again where I was able to feel a small amount of slop in pushing the wheel from side to side. I pulled off immediately and arranged to truck it home as to not do damage to the rear axle, spacer, and rim. | ||
| Froggy |
You are not being paranoid. It is good to check the bearings while you got the wheel off. | ||
| Bombardier |
Here's a tip - If your Stealer balances the the front wheel and puts the weights on the wrong side(the non rotor side) your wheel bearings last about 30000 km. | ||
| Nillaice |
why is the non-rotor side the wrong side? my weights have been on that side since i got the bike | ||
| Zoedogg1 |
I understand that you really should NOT be able to turn them to easy with your fingers. They are pressure bearings that need the pressure of load to make them turn correct. I would think that if they were really going bad you would hear them when you push your bike from the garage..etc. It wouldnt be a bad idea to change them every 25k to 30k though. I dont have any weights on my wheels. I use DynaBeads inside my tires. They are balanced PERFECT. I only have 13k on my bike an 04 XB12R. | ||
| Thetable |
Here's a tip - If your Stealer balances the the front wheel and puts the weights on the wrong side(the non rotor side) your wheel bearings last about 30000 km. I'd love to hear an explanation of that, because from a theoretical standpoint, that makes absolutely no sense why it would make any difference. | ||
| Jlnance |
Rpm - I wouldn't expect to see any problems with your bearings. You'll have 16k miles on them when you get back, which isn't really a lot. Bearings are one of those things that are reasonably cheap to replace. When you get about 25k miles I'd pop a new set in just so you don't have to worry. | ||
| Nillaice |
i know on cager rims that there are 2 types of balancing a tire; static (2 dimensional => weights on one side) and dynamic (3 dimensional => weights on both/either sides).  from a theoretical standpoint, that makes  however if i put this theory to practice; i would think that a motorcycle tire is so narrow (especially the front) that it would not make a difference what side of the rim it is on. and to contradict my self 'BUELL: DIFFERENT IN EVERY SENSE' so let's give Bombardier a chance to explain himself before too much is said against him. | ||
| Thetable |
It was not intended as an attack or a challenge, I just don't get it, so please help me out. | ||
| Cityxslicker |
8500 miles if you ride off pavement. Every other tire change, I preemptively change the bearings.... A bit of insurance, because I DONT want to be stranded on the side of a trail again with down bearings. | ||
| Rpm4x4 |
Every time I change tires I pick the outside seals out to check and re-grease the bearings. After I saw this post I tried that, it worked great. when you get the seal out you can clearly see the bearings. The bearings looked good. I greased them and they are smooth as silk. Great tip! Thanks  I'd love to hear an explanation of that, because from a theoretical standpoint, that makes absolutely no sense why it would make any difference. That actually does make sense because your getting a static balance with a motorcycle wheel and the rotor side is the heavier side. It would be more accurate. | ||
| Moosestang |
Is it necessary to add grease to the bearings? Standard wheel bearing grease? | ||
| Xoptimizedrsx |
do what we have done for years if they are just a little click and stiff. go slow. take the seals off the bearings. they pop out. dont damage them. there are a few sights on repacking bearings that have rubber seals online. wash out all grease. repack will a high temp grease with at least 20% moley do this till they are 80% full. dont over pack them you want a little space not a lot but a little. then repress the seals on the bearing and ride ride ride. when you recheck them they will spin like glass. its a old racers trick. when we replace my tires i got home and just took the outer seals off and dripped some fresh 100% MOLOY liquid on mine. they spin free as heck now compared to stock new. easy and cheap fix. if it spins free it rolls fast. mike | ||
| Iamarchangel |
It's not really up to Bombardier to defend the statement. He is quoting from the Buell service manual. | ||
| Bombardier |
Correct on the manual quote Iamarchangel, however I do have a theory as to why this is so. Firstly you have to ask why Buell would define which side the weights must go on. This is the most difficult side of the wheel with the rotor in place. I believe that the answer lies in what is called gyroscopic presession. Not really sure how to describe it but the gist of it is that gyroscopic forces prefer to act in a linear plane. When a force that does not lie in that plane acts on the gyroscope the result is a 'wobbling effect' similar to a wheel imbalance. This imbalance would not be apparent in a statically balanced wheel which is the common way of balancing motorcycle wheels. It is this desire of the wheel to attempt to follow two different planes of rotation that reduces the lifespan of the bearings. This situation arises because of the difference in gyroscopic forces from one side of this wheel to the other due to the mass of the disc rotor which is fixed to the outside of the rotational mass - it is there where it has the most affect. My 2 cents. | ||
| Nillaice |
hmmm, i stand corrected | ||
| Swordsman |
Huh... my rear wheel has 2 weights, one on each side of the spokes. ~SM | ||
| Rpm4x4 |
Huh... my rear wheel has 2 weights, one on each side of the spokes The rear is not the same as the front. Buell having the front rotor on one side makes a large difference. There is more mass on one side. The rear has a sprocket on one side and a rotor on the other. | ||
| Thetable |
This situation arises because of the difference in gyroscopic forces from one side of this wheel to the other due to the mass of the disc rotor which is fixed to the outside of the rotational mass - it is there where it has the most affect. But I am still not understanding why you would want to put the weights on the already heavy side of the wheel, as opposed to the lighter side of the wheel in an attempt to somewhat balance the wheel laterally. | ||
| Petebueller |
But I am still not understanding why you would want to put the weights on the already heavy side of the wheel, as opposed to the lighter side of the wheel in an attempt to somewhat balance the wheel laterally. If you think of the rotor as part of the rim maybe. The ZTL brake is mounted inside the line of the rim of the wheel. It is inside the line of the tyre (even though it is not at the centre) so it contributes to the gyro effect of the wheel. (It would not be controllable if it were outside of the line of the rim and tyre - like most centre mounted disks or double disks). You cannot dyno balance this without adding the weight of the rotor to the other side of the rim. Putting a weight outside the line of the rotor when balancing on the opposite side to the rotor would be fine if you had a thin flat weight that went evenly around the whole rim. What is being done instead is putting a lump to simulate this. The distribution of the weight is imperfect. A bit like swinging a string with a washer tied to it. I can see why Bomba thinks that this would set up a harmonic wobble. The rear wheel has a rotor on one side, and the belt pulley on the other, and these add rotating mass to the centre of the wheel and not to the rim. The tyre and the rim are the most significant gyroscopic influence. 3D balancing around the rim of the rear wheel would reduce rather than contribute to wobble. | ||
| Bcool83 |
Petebueller - that still doesn't make it clear (to me) why the weight on the front wheel should be placed on the rotor side vs. the non-rotor side. | ||
| Petebueller |
Hi Bcool83 It is possibly easiest to look at dyno balancing a drum. I had to put dots in the drum because spaces get optimised away. -------------------------+ |........................................| |........................................| -------------------------- In the picture above the plus is the heavy part. If you can you want to reduce this weight to get the best balance, otherwise you add weight to balance. Weight shown as o characters. Wrong ~~~~~~ -------------------------+ |........................................| |........................................| o------------------------- If you add weight diagonally opposite you will create a harmonic imbalance. Right ~~~~~~ -------------------------+ |........................................| |........................................| -------------------------o The objective is to keep the centripetal forces on the one plane. The radius of gyration is radius at which the entire mass of the wheel can be seen to be concentrated. The XB wheel is a complex shape with the spokes concentrated in the left part of the wheel. My guess (only a guess) is that if you cut the wheel in half through rim spokes and axle, the mass of the left side would be less than the mass of the right (with the rotor attached). The radius of gyration on each side is different, because of the influence of the distribution of weight from the rotor. If they managed to work it so that the weight x radius of gyration were the same on both sides of the wheel then I have to worry about my wave rotor which is lighter and narrower than stock. Centripetal force is related to weight, radius and RPM power 2. If radius of gyration x weight is not identical on each side of the wheel then the difference in force will change with speed. In the example above of the drum, the weights needed to be placed on the plane to balance the centripetal forces of the heaviest part of the drum, and I think that the heaviest side is the RH side on the rim under the rotor. | ||
| Bcool83 |
While I don't fully understand the tech. terms used, I believe I do get the general gist of it. Thanks! | ||
| Petebueller |
I think I haven't got it quite right still. But the gist is that a significant centripetal force will come from the rotor, as well as from the tyre. If you put a lump of metal on the other side to the rotor it will not be dynamically balancing the wheel with the rotor. |
