| Author | Message | ||
     Smac |
First off...I have a '08 XT with just over 30K miles. I bought the bike brand new & at about 10K miles, I noticed the FRONT wheel bearings were notchy at a tire change. I took it to the dealer where they agreed the bearings were shot & replaced them under warranty with the black KBC bearings. I've heard of the rear bearings going bad, but those checked fine. I doubt the dealer replaced the spacer which I heard could be the culprit of premature bearing failures. Fast forward to the present, again putting on new tires...dropped the front off at the local shop & was told that my bearings were bad. Seriously?!?! Another FRONT wheel bearing failure?!?! I didn't believe them, so I went back to the shop & witnessed it myself on the balancing stand! The shop quoted me new NTN bearings for $80/pair which I thought was high, so I checked Al's page & found the OEM replacements for $45/pair. But then I thought of the old definition of insanity...performing the same task over & over with the same unwanted results. Are the more expensive, NTN bearings going to last any longer than the Korean-made KBC's?!?!? I'm not sure, but I have to try something or my actions would fit the exact meaning of insanity!!!! Anyone else out there feel my pain with FRONT wheel bearings?!?!?! | ||
| Nobuell |
I never had any issues with front bearings failing. I replaced the fronts on my XT at about 40K miles because they felt a bit dry but were not notchy feeling. I replaced mine with Nachi bearings from the local bearing supplier. They cost $23.00 for the set and are Japanese made. I wonder if the dealer is correctly installing the bearings? | ||
| Tootal |
They need to check the spacer between the bearings for damage. If it's good then they need to measure it's length. Then measure the distance between the inner bearing surfaces. The spacer should be longer than the bearing surfaces. In other words, the bearings should never seat on both surfaces, just one. The spacer will keep it from hitting both. I know on the rear wheel they even specify which side to seat first. Then you install the spacer and the second bearing. I don't remember if the front matters or not but a manual will specify. | ||
| Poppinsexz |
Manual says brake side first lettering out | ||
| Hughlysses |
Per a previous post by Al Lighton of American Sport Bike, the front spacer tube should measure as follows: Front Spacer Tube: 107.9 +/- 0.05mm, 4.248 +/- 0.002 inch If it's outside of those dimensions, get a new one. Here's a link to Al's complete post: http://www.badweatherbikers.com/cgibin/discus/show .cgi?tpc=142838&post=1505281#POST1505281 This post was focusing on rear wheel bearings, but all the recommendations about mounting the bearings also apply to the front. | ||
| Smac |
Thanks for all of the replies! I will discuss further with the shop & ask them to check the condition of the spacer & check the length. BTW, I'm not working with an HD shop...the shop is a small, privately-owned establishment that's local & has a good reputation. I only went there to have the tires mounted & balanced, not expecting any other issues. I will have a discussion with the owner/shop manager this morning before he performs the bearing change. Thanks again! | ||
| Smac |
So I just talked to the shop. They measured the OAL of the spacer using (2) different mics (metric & english)...107.948mm & 4.249"...both on the high side but in spec. The spacer visually looked in good condition. He also said that he never heard of having to install the brake-side bearing 1st & appreciated the info. Still at a loss as to why the early failures have occurred to the FRONT. I'm now assuming I'm gonna have to replace the original rear wheel bearings when I pull that wheel off this week. Again, thanks to everyone for chiming in! | ||
| Tootal |
Ok, so they measured the spacer but now they need to measure the wheel. If the wheels not in spec then you have a problem. The wheel should be less than 4.249". I'd prefer .005" or more. | ||
| Uly_man |
"Anyone else out there feel my pain with FRONT wheel bearings?!?!?!" Not really. My 06 bikes front bearings were done at 13K and the 10 bikes were done on the 5K service. First thing to know is that all bearings are made to a Quality Assurance grade IE Tested as fit for the application they are intended for. You can buy many grades of bearing for these wheels right up to the top grade (very expensive) made with ceramic balls and metal seals. All are machine made so there is little chance of getting a "rouge set" if ever these days no matter which country they come from. I use SKF myself. I have no idea why (maybe it is about un-sprung weight) they used an alloy spacer on these bikes but I am convinced it is the reason people have problems. It is an over precise system for the "road going" public. So what to do about it? Well that is a little hard to specify but if I had just taken a wheel off and found the spacer loose then I would say it had been over crushed and replace it. If the spacer was still hard to move about then I would re fit it but only torque the axle until it was "snug" IE It felt safe. The axle thread direction will not allow it to come out as will the pinch bolts. It is not a very scientific way of doing it more an engineering way. Or at least it is my way. The torque settings on this bike, but not the engine, are VERY high in my opinion and the axles are no exception. | ||
| Nobuell |
The dealership may have pressed the bearings into place without supporting the outer and inner race. I have seen bearings pressed in using only the outer race. Both races must be pressed concurrently and within the same plane. If only the outer race is pressed, it will put a side load on the inner race after it contacts the spacer and cause premature failure. All this is contingent on the hub stop measurement as discussed above. | ||
| Uly_man |
The wheels are made in China but I do not know who machined the hub for the bearings. Given the VERY PRECISE dimensions required for this system I am skeptical that all are perfect which they would NEED TO BE. | ||
| Motorbike |
Nobuell is exactly right. You have to understand what he means in his reply and if you don't, you will continue to have bearing failures. Your shop also needs to understand the theory of all of this. I'm sure a lot of shops press or pound the bearings in and try to seat the outer race on both bearings. That will cause them to fail... | ||
| Desert_bird |
Not sure what's with all this pressing business. Stick the bearings in a freezer for half-hour. Put a hair dryer to the hub for 5 minutes (knock whatever is in there out) then drop the new bearings in, smooth as butta. Have a beer. | ||
| Hughlysses |
The wheels are made in China but I do not know who machined the hub for the bearings. Given the VERY PRECISE dimensions required for this system I am skeptical that all are perfect which they would NEED TO BE. No, they don't. The minimum acceptable length of the spacer is longer than the maximum acceptable dimension between the bearing recesses in the wheel. If the factory recommendations are followed for pressing in the bearings (press in the brake side bearing until it is fully seated, then press in the other side until the inner bearing race seats lightly on the spacer), the bearings are correctly installed and shouldn't fail prematurely. The spacer in combination with the installation procedure allows for tolerances in manufacture of the wheel. | ||
| Nobuell |
Hughlysses - That is assuming the wheel stops are not to far separated. If so the outer race would seat against the wheel outer race stop but not allow the inner race to sufficiently to contact the spacer. Once the axle is tightened, the center race would be loaded causing premature failure. Each issue would cause inner race loads from the opposite direction. The directions in the manual will work great if the wheel in machined properly. | ||
| Hughlysses |
Obviously it's possible for a wheel to be machined so badly that it wouldn't work with a properly machined spacer, but the wheel doesn't have to be "perfect"; the bearing arrangement allows for a significant amount of slop. The simplest check would be to make sure that the length of the spacer is =/> the distance between the bearing shoulders in the wheel. | ||
| Zac4mac |
IMO the whole bearing failure issue is caused by "torquing" the axle. There is no reason to put more torque on the axle/bearings than snug, both axles have pinch bolts. By all means, torque the pinch bolts to spec. Go 40-50% light on torque if using grease or Neverseize. Z | ||
| Smac |
All, unfortunately by the time I got back to the shop to ask about measuring the bearing recesses in the wheel, he already had the assembly completed. He did, however, follow my instruction about seating the bearing on the brake-side first. Everything appears good to me...the spacer is lightly loaded with the bearing on the opposite side of the brake slightly proud, so I'm assuming it's not fully seated. I'm going to install the front wheel tonight & pay special attention (as always) to the instructions in the shop manual. I might take pics of the bearings in the wheel beforehand and share on this thread...if it would be helpful. | ||
| Nobuell |
It sounds like it is assembled correctly if the spacer is lightly loaded against the bearing races. I agree with Zac4mac, the axle torque is way to high. I typically use no more than half of the recommended torque. Once the bearing components are in contact with some preload, that is as good as it will get for the mechanical connection. The resistance to side loads are the bearings and cages within the grooves themselves. No amount of additional axle load will change this. Quite frankly, a single row ball bearing such as what is being used in not designed for axial loads. They are designed primarily for normal to the axis loads. The correct bearing would be a tapered roller. This set up would be much more expensive from a manufacturers stand point thus the single row ball bearing being used. My old BMW R100S had tapered bearings in the front wheel with very nice external grease seals. They were a pain to adjust the preload using shims, but the original bearings had over 150K miles with no signs of wear. Only required a grease repack on occasion. (Message edited by Nobuell on May 06, 2015) | ||
| Smac |
I'm glad you guys mentioned axle torque...I usually set my torque wrench to the nominal value (best chance of ending up in spec with my non-certified wrench!). For the wheel install, I will shoot for about 75% of the LSL & make sure the pinch bolts are torqued to proper spec. Maybe that will improve the bearing life this go-around. | ||
| Uly_man |
"No, they don't. The minimum acceptable length of the spacer is longer than the maximum acceptable dimension between the bearing recesses in the wheel. If the factory recommendations are followed for pressing in the bearings (press in the brake side bearing until it is fully seated, then press in the other side until the inner bearing race seats lightly on the spacer), the bearings are correctly installed and shouldn't fail prematurely. The spacer in combination with the installation procedure allows for tolerances in manufacture of the wheel". Ah, I see your point Hugh. Yes that would work fine and makes sense. I still think it is an over complicated system for a road going bike and see no reason why they did not use the old fashioned method of a steel spacer and fully seated wheel bearings. If anyone can enlighten me as to why they used the system they did then I would be interested to know. | ||
| Arcticktm |
Nobuell, at the risk of being picky, I have to disagree that single row ball bearings are "not designed for axial loads". More accurate is that they are not intended for LARGE axial loads, where a tapered would handle it much better. In my field, switching from plain hydrodynamic bearings to a ball bearing actually allows us to remove our normal axial bearing, as the ball bearing can handle the amount of loads we typically need. Of course plain/journal bearings truly cannot accept axial load. I just was envisioning someone running around saying "those guys at Buell were idiots for using ball bearings in the wheels", when that is the normal practice in the vast majority of motorcycle applications. Up front at the steering head is a different story. I really do wish Buell had used tapered bearings there, as it would have saved me the trouble of replacing them. | ||
| Tootal |
The bearings in the steering head are called angular contact bearings and they must be installed correctly, (back to back), in order for them to work. They act like Timken, (cup and cone), bearings as they each have one side that's taller and traps the balls giving it axial strength. When mounted in opposite directions it gives axial strength in both directions just like a Timken. I usually replace Timkens with angular contacts in higher rpm situations as the balls run smoother than tapered rollers. In a steering head, that is obviously not the case. My whole point is just that they are not roller bearings like what's in your wheel hub. | ||
| Nobuell |
Arcticktm - I agree, single row balls are designed for minimal side loads. I do disagree regarding the application. Using self sealed Ball bearings are just adequate given the conditions they must operate in. The combination of the side loads and not having properly designed external seals are not an application that I would design into the equipment that my company builds. It is an inexpensive application that many bike manufacturers use. | ||
| Djohnk |
I changed my front bearings once just for preventive maintenance (they looked kind of suspect as far as condition). I also carry a spare set of both front and rear bearings when I travel away from home overnight on the bike. They are cheap, small and a known likely failure on the rear of older Ulys. I figure if I had to I could change them at a hotel and use a hair dryer to heat the rim etc. Last week I had to change my rear bearings (the one by the disk brake failed this time) for the second time ... presently I am at about 66K miles on my '07 Uly. I was actually glad that was all it was, because I was hearing a really bad noise and thought it was a magnet from the stator or something. If you balk at spending the $$'s at the dealership you can get a blind bearing puller at Harbor freight for less than $70 that works just fine. I think there might be some "how tos" here on swapping them out. | ||
| Djohnk |
The All-ball bearings are much cheaper, and work fine. http://www.ebay.com/itm/BMW-Ulysses-XB12X-FX-2008- 2009-All-Balls-Front-Wheel-Bearing-Kit-/1814604045 01 | ||
| Uly_man |
"I figure if I had to I could change them at a hotel and use a hair dryer to heat the rim etc". Worth a try but you would need a VERY GOOD blind puller to do it as these things can be a nightmare to remove as they have a habit of seizing in the hub. A good idea to carry a set as most motor garages would be able to change them out with little problems. I would advise anyone who buys one of these bikes to replace, correctly, the spacers and bearings as soon as they can as a precaution against future problems. It is cheap enough to do anyway. Also use anti-seize in the hub/ bearing seating and axle. Something they should have done at the factory build stage. Otherwise check them at every tire change or at about 10k miles which ever comes first. I would change them at 20 to 30k anyway, as they WOULD have wear on them, just as routine maintenance. Just me though. | ||
| Smac |
Well, returned to the local, private shop with my rear tire off of the bike...the original ORANGE NTN bearings are in worse shape than the front bearings I had replaced. I guess I kind of expected this since they are the originals with ~33K miles. Very notchy and catchy as you spin the wheel on a balancing stand. Told him to replace the bearings in addition to mounting the new tire & provided him with the correct install method from the shop manual. He's also going to inspect/measure the spacer tube before re-installing. Oh well...better to have the bearings replaced front & back now instead of being stranded on the side of the road with perhaps more damage to the bike & myself! Thanks everyone for all of the responses/advice...this forum is always helpful! -Sean | ||
| Hughlysses |
Worth a try but you would need a VERY GOOD blind puller to do it as these things can be a nightmare to remove as they have a habit of seizing in the hub. IIRC Etennuly has removed his more than once with a steel rod with a good "sharp"/flat end on it. You can "catch" the edge of the bearing and drive it out from the opposite side without damaging the wheel or the spacer if you're careful. That's an item you could pack in your tool kit. Another point worth bringing up in this thread: you should never try to re-use bearings you've removed even if they seemed good before removal. The only way to get them out is by pounding against the inner bearing race which likely dimples the inner and outer races AND the balls. The bearing is junk once it's been removed. | ||
| Tootal |
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