<div class="FTQUOTE"><begin quote>Originally posted by: mywifesquad

I wonder if you could just preload the bearings correctly and not use a tube inside? I havnt seen this rear end, mine is the old style with ball bearings. I would think it would be like the front wheel bearings on a car. Tighten to seat the bearings and then back off about 1/8 to 1/4 turn. Is there a grease zerk on the rear end anywhere to fill the cavity with grease?</end quote></div>

Mind you I am not a motorcycle frame engineer but going off basic physics the spacer is needed in this application given the way it is designed. It could be modified with the addition of load bearing washers to take the load off the bearing centers.

The whole 150 axle is designed with the load coming from the nut on the wheel onto a n outer sleeve that then presses against the inner bearing race. This occurs on both sides except one side has a splined brake rotor and the other a sprocket. Both just pass the load through on the sleeves. There is only one set of axle nuts on one side that keep the load locked into all these moving parts. There can be not slop or movement in any of these for obvious reasons and as you can expect there can be quite a load on these components.

Since the load carries all the way through, it seems there needs to be support between these bearings. If it is not there then over time, the lateral load from the other components will incrementally keep pressing inward on the inner bearing race and then cause the bearing to fail. A proper length and diameter spacer sleeve allows the full load to be passed through the bearings without placing any extra lateral load on them, thus keeping the inner and outer race and bearing cage and bearing properly aligned.

If a large washer was used to spread the load from the outer spacer sleeves onto the full face of the bearing face (cover inner and outer race), this might work as well; although, I've not analyzed it fully.

The reason it works differently here than in a typical single bearing design is the single bearing is pressed into some housing that provides even load bearing on the back side of the full bearing and races. The outer bearing side is usually covered with a large washer or some other part that is wide enough to cover both inner and outer bearing races. This eliminates any possibility of uneven lateral loading of the bearing.

 

<div class="FTQUOTE"><begin quote>Originally posted by: windtrader

Mind you I am not a motorcycle frame engineer but going off basic physics the spacer is needed in this application given the way it is designed. It could be modified with the addition of load bearing washers to take the load off the bearing centers.

The whole 150 axle is designed with the load coming from the nut on the wheel onto a n outer sleeve that then presses against the inner bearing race. This occurs on both sides except one side has a splined brake rotor and the other a sprocket. Both just pass the load through on the sleeves. There is only one set of axle nuts on one side that keep the load locked into all these moving parts. There can be not slop or movement in any of these for obvious reasons and as you can expect there can be quite a load on these components.

Since the load carries all the way through, it seems there needs to be support between these bearings. If it is not there then over time, the lateral load from the other components will incrementally keep pressing inward on the inner bearing race and then cause the bearing to fail. A proper length and diameter spacer sleeve allows the full load to be passed through the bearings without placing any extra lateral load on them, thus keeping the inner and outer race and bearing cage and bearing properly aligned.

If a large washer was used to spread the load from the outer spacer sleeves onto the full face of the bearing face (cover inner and outer race), this might work as well; although, I've not analyzed it fully.

The reason it works differently here than in a typical single bearing design is the single bearing is pressed into some housing that provides even load bearing on the back side of the full bearing and races. The outer bearing side is usually covered with a large washer or some other part that is wide enough to cover both inner and outer bearing races. This eliminates any possibility of uneven lateral loading of the bearing.</end quote></div>

Im guessing you have never repacked front wheel bearings on a car? There are tapered bearings and no spacer. I understand what you are saying but its been working on cars for decades.

 

Ive been thinking about the tapered bearings and a spacer some more. I have never seen a spacer used on tapered bearings. The only places I have seen spacers in between bearings is when ball bearings are used. I have seen them used on every motorcycle hub wheel that uses ball bearings.

I think if this was just put together and torqued correctly it would be fine. If the spacer isnt the perfect length it will either be too tight or too lose. Neither one will be good for bearing life.

 

Am I wrong but the inner race is not backed up against the axle anywhere (like a car bearing would be backed up against the spindle) and this is where the spacer is playing a part. I have not looked inside mine just guessing!

 

<div class="FTQUOTE"><begin quote>Originally posted by: outofline

Am I wrong but the inner race is not backed up against the axle anywhere (like a car bearing would be backed up against the spindle) and this is where the spacer is playing a part. I have not looked inside mine just guessing!</end quote></div>

Now Im confused. Is the spacer to keep the races apart? Or to control the preload on the tapered bearings?

 

Where they are talking about ID is the important size it seems this must be the case as it will ride right on the axle! and against the inner race!?

 

<div class="FTQUOTE"><begin quote>Where they are talking about ID is the important size it seems this must be the case as it will ride right on the axle! and against the inner race!? </end quote></div>

You are correct sir!

Update: I received the bearings from John within 3 days and had everything back together in about an hour. Everything went pretty smooth. I ended up using electrical conduit for the sleeve which was pretty close to what was in there to begin with. It all seems to be working out pretty good. No noise. Also the bearings that John sent me seem to be of better quality than what was in there to begin with.[img]i/expressions/face-icon-small-happy.gif[/img]

Unfortunately I have another problem. [img]i/expressions/face-icon-small-frown.gif[/img] Last night my daughter had the 150 out and now it seems to stutter when you give it some gas. Here's what it does. As you give it some gas, it rolls along for about 3 seconds and then it stutters / jerks (almost feels like it dies) for a second. Rolls along for another 3 seconds or so and stutters again. This is the pattern; continually. Any ideas? When it's idling it sounds fine. You can give it gas in neutral and it sounds normal. It doesn't seem to be an engine problem. Maybe tranny?

I'm starting to get pretty discouraged. I've been working on this more than the kids have been using it. [img]i/expressions/face-icon-small-disgusted.gif[/img]

 

I'm starting to get pretty discouraged. I've been working on this more than the kids have been using it.


isn't this what you expected from a chinese quad?

 

Wings did it do this before or is this a new problem. Several of us had to lower the C Clip on the Carb slider needle. If you listen to my 150 outing video you can hear the gap in response I had on both 150's before I made the adjustment.
Or this may be it:
Last week I rode our blue 150 around the neighborhood and it started running quite bad and would die upon acceleration, looking into it I found the stock fuel filter has plugged. I had replaced one of my 250's now I need to buy 3 more filters.

 

<div class="FTQUOTE"><begin quote>Originally posted by: billl2099

I'm starting to get pretty discouraged. I've been working on this more than the kids have been using it.





isn't this what you expected from a chinese quad?</end quote></div>

Even Ive got to admit its getting pretty discouraging.......



wings36, are you using the stock spark plug?