I kind of figured that, so is nylon a good alternative to a metal cage? I am going to order a bearing, but want the best easiest alternative, thanks for the info Jim.

yes, I should have rephrased that before hitting post. Is nylon a good alternative would have been more direct?

I wouldn't get too hung up on avoiding the shims...I would think it important to check the end play of the shaft regardless of the bearing that is chosen and the shimming process is simple.

EDIT...just discovered the above comment is redundant. Good to know I agree with somebody who knows what they are talking about.

rvich wrote:I wouldn't get too hung up on avoiding the shims...I would think it important to check the end play of the shaft regardless of the bearing that is chosen and the shimming process is simple.

EDIT...just discovered the above comment is redundant. Good to know I agree with somebody who knows what they are talking about.

Good to know somebody else agrees. It was common practice to shim the countershaft long before roller bearings ever came into use there. Jim

So what was the outcome of this bearing fiasco?

britbike220 wrote:So what was the outcome of this bearing fiasco?

1. replace you layshaft bearing before it fails.
2. use a roller or a ball, your choice, roller lasts longer, ball is cheaper.
3. shim the kicker shaft as per Old Britt's site to prevent trans from popping out of first gear, ball or roller. Jim

No, I was wondering if the dude that started the thread actually tore into it and how this turned out for him.

britbike220 wrote:No, I was wondering if the dude that started the thread actually tore into it and how this turned out for him.

Good question.

By the way, I did a 850 Mk3 today that was brought to me with the complaint of pops out of 1st gear and see if it needs a layshaft bearing. He had only owned the bike for a short while. It has 17,000 miles on the odo. but I don't know how accurate that is. I pulled it apart and found the case was scarred from a failed layshaft bearing and it had a replacement ball bearing that had been installed sometime back. One of the tangs that held the steel cage together in the new bearing was broken off. I found it in the bottom of the case.
I installed a roller and .040 shim on the kicker shaft. Jim

Correction for the last post. After I cleaned the bearing I see it is missing two tangs and the two halves are loose. 2nd failure was on the way. It is a ND bearing , made in USA. Jim

So balls with steel cages are OUT as replacements.

[quote="comnoz"]Correction for the last post. After I cleaned the bearing I see it is missing two tangs and the two halves are loose. 2nd failure was on the way. It is a ND bearing , made in USA. Jim

What size gearbag sprocket has the bike been running?

I'm kind of sceptical about this bearing failure issue overall. I'm am by no means saying there aren't bearing failures at low mileage, but as I've mentioned I have a gearbox with 30K miles on it and have not had a beariung failure. Is it because I take it easy on my old bike all of the time therefore not stressing the bearing? I don't know, but I do know my bike is obviously different than many others for a reason and I doubt I have a special one off bearing. I'm not saying it isn't going to happen today or the next, but why are so many bearings failing on others bikes and I'd be more curious as to how many riders out there have the same longevity as I have? I do know when I do decide to change the bearing, I am going to replace it with what ever is in there now regarless of type because 30K miles seems like a lot better average than what I'm hearing on here. So I'd like to hear from those that are riding happily into 20-30 + thousand miles w/o layshaft bearing failure.

I would not use a ball bearing with a steel cage there after seeing that one. The bike presently has a 20 tooth sprocket on it , it also has a performance motor.
I have not doubt a ball bearing is good for more than 30,000 miles. I have seen the brass or plastic caged ball bearings with more than that. If you have an 850 MK3 with 30,000 miles on the original bearing, I would find that hard to believe. Jim