| Author | Message | ||
     Mark_weiss |
No, it does not. Last time I had the rear shock off I forgot to check, this time I remembered. I built a simple spring loaded device that allowed me to apply a repeatable amount of pressure to the belt and checked multiple times. With the swingarm down equivalent to full suspension extension, my spring device deflected the belt a repeatable 6 mm. With the rear wheel raised the full spec suspension travel, the belt tension was a repeatable 5.5 to 6 mm. Belt tension changes during suspension travel were not causing rear-wheel bearing failure. | ||
| Smorris |
interesting research. the 3 bearing setup certainly resolved the problem. still curious what the root cause is for the bearing failure | ||
| Mark_weiss |
My 2005 Yamaha R6 has three bearings at the rear axle. Two bearings are in the wheel and support the weight of the motorcycle and me. Bearing #3 is in the sprocket carrier. Its only job is to carry driveline load. The Ulysses's bearings do not seem to be terribly heavy duty. The distance between the inner and outer diameter of the bearings leads me to belive that the races and balls are not very beefy. They are probably not very impact resistant and probably operate closer to their load limit than in most other motorcycles. Lightweight for high performance, but lifespan is shorter. | ||
| Smorris |
good analysis | ||
| Pushr0d |
I think the design of the two-bearing wheel is faulty. The right side bearing has not only the weight of the bike and 'cargo' to deal with, but also the tension of the belt. The '2010' 3-bearing wheel has three bigger bearings, two on the right side. I had the bearing failure, and looked into modifying the wheel for a bigger/beefier bearing. There's neither room nor 'meat' in the hub to do it. I ended up buying a new 3B wheel from Newcastle HD. | ||
| Dr_greg |
As a (retired) Mechanical Engineer, I'm the last person to dispute experimental results. Nevertheless, the only broken belt in 100K miles (two '06 Ulys) occurred when I tipped over and swingarm fully extended. Perhaps SLIGHTLY more belt tension upon full swingarm extension? I was always gonna try and work out the geometry analytically to check belt length vs swingarm travel, but it's darned complicated! --Doc | ||
| Tootal |
Interesting analysis Mark.That's how we set belt tension on v-belts. I think we used 60 lbs. of pressure at 3/4" deflection. We had a pressure gauge on top of a 3/4" piece of key stock. As far as the bearings I always wondered since the center spacer was aluminum if it didn't get crushed from too much axle torque or maybe some were a little short creating side pressure on the bearing. I never had a problem with the 2 bearing wheel but got the 3 bearing one anyway. | ||
| Ratbuell |
I, also, suspect load (rating vs. actual). Same wheels survive fine on the 1125 (MASSIVE amounts of power and torque); the XB-s (and Ss long-swingarm), and the XB-R. Only the XB-X - with its vastly increased load capacity - experiences these failures with any regularity. The 3B wheel and axle are beefier in all dimensions - outer race diameter, inner race diameter, and axle diameter at the races (I think - the axle may only have a wider thick section to accommodate the extra race, and may be the same overall diameter due to the hole size in the swingarm). The race thickness itself is also, I believe, greater than on the 2B wheel setup - i.e. a thicker/stronger race itself, along with beefier "balls". | ||
| Whisperstealth |
My bearing failures always occurred soon after a belt change. | ||
| Firemanjim |
Interesting as I have never had a bearing failure on any bike I have owned--all had 3 bearing wheels, including my S-2's.Including the high HP ones-- | ||
| Ratbuell |
I have yet to have a bearing failure, and I ran the 2B wheel on my '06 for quite a while. Including fully-loaded, 2-up trips to FL and East Troy; fully-loaded solo trips to FL, TWO, ET, WVBR... I do run a 3B wheel now, but still have a fully-functional 2B in the shop if needed. | ||
| Tempest766 |
my take on rear bearing failure poor application. too much torque. higher quality bearings solved my issue with it. | ||
| Ratbuell |
So how do you explain the same setup surviving in the 1125 bikes? | ||
| Mark_weiss |
I did test to maximum movement, as well as maximum normal travel. Even with the swingarm low enough that the rear tire was against the muffler the belt tension did not change. | ||
| Mnrider |
Some of the problem may have also been water in the rear hub. I drilled holes in my hub and installed good bearings and had no problems. My orange seal bearing were not smooth so I think some of those were bad also. |
