pinging noise

[mustangman]

  Humm, let's see now, 60 -65  lbs. for the bike w/motor, batteries 20-25 lbs. and one rider 250 lbs (like me) = 330 to 340 lbs(plus any cargo) on just two axles (4 bearings). That means each bearing is taking a true beating!  

[myelectricbike]

Maybe the stock bicycle axle bearings but most likely not the 6202's.

[mustangman]

Ahh, then it comes down to the grade of the bearing. I would not want grade ones on the front wheels of my car or bike!(grade 5 or better please)

[myelectricbike]

A link to bearing sources such as VXB that list grades 6202-8 might be a good thing.

[Draggin]

OK so I got the sucker knocked apart again.  I hated cutting the power cord, but I had to to get it in the lathe.  When I measured the shoulders on the axle at the bearing it had a woble(for failure of a better word) of .018.  I decided that the only way to true it up was to make a bushing and cut the shoulder down on the inner race saddle.  The other thing that this would address would be the shoulder to shoulder length could be increased by 1mm. or .039".  Thus putting the bearing further into the end cover. The first cut went excellent, used three jaw chuck on one end and a live center on the other.  The power cord end was a different story.  It appears that when they pressed in the axle not only did they mushroom over the bearing shoulder, but also bent the shaft.  The run out on the one end of the shaft looked like 1/4" although was probably half that.  To top it off once the shaft was bent the saddle was machined for the bearing.  My buddy then says so now what you going to do?  I thought, "yea the guy on the press made 350 canadian dollars worth of garbage."  I grabbed the thing out of the lathe and chucked it on the machined surface on the other end and said,"turn this one the same".  So the shoulders are now parallel but I have an excentricity of 8-10 thou on one end!     

[Draggin]

I started thinking about all I have been through with this motor and every step of the way wondering if it is worth it.  I feel sorry for Phillip and Golden motor.  I'll bet half of the units out there have the same problem as this and will prematurely fail..This is the new improved version.  What were the old ones like?  I assembled the mkII this morning just to check the fit.  I thought that there might be excessive Preload on the end cover.  This turned out to be false..It actually spins better.  I'm thinking that the .008" over 2.5" between bearings may actually be acceptable, as the actual bearing shimmy would be somewhat less.  Especially with cheap bearings with lots of freeplay.  Its too bad that they couldnt push the axle in from the solid end instead of the hollow end.  It probably doesn't matter mild steel will bend anyway.  If this bearing fails I don't know if there is a fix.  My buddy says that the pressed on shaft is a one shot deal and pressing it appart would probably destroy the hub.  I was thinking about starting to jog to work anyway.

[Dalecv]

Draggin, a few questions to make sure I understand your post.

The axle shoulders that the inner portion of the bearing seat up against are not parallel with each other?

The axle shaft itself is not straight?

Thank you for taking the time with good equipment to figure these things out.

[Draggin]

dalecv Yes and yes.  The non wire end was ok.  It is machined smooth up to the hub.  Im thinking it is the end that gets pressed into the hub, as the other end is rough steel sticking out of the hub.  It looked to me like it was maybe not in the press quite straight.  When the press came down the axle bent and mushed the bearing shoulder.  It didn't seem to be bent anywhere else.  I would give this repair an 8 out of 10 chance of working.  At least when I tighten the heck out of the wheel nuts the bearing will be forced straight instead of crooked.  I'll let you know if the fix pans out.   

[Draggin]

and by the way my twenty minute repair ended up being 3 and a half hours in the machine shop!

[mustangman]

   I hope they did not charge by the hour!!!

[myelectricbike]

How come you did not drill the axle out and use a keyed sleeve to separate the inner races? This is how I plane to do the stub axle for my etadpole with a bolt through the sleeve as the stub axle and a grove in the sleeve and bolt for the wiring. If I'm not aware of a good reason why I should not drill out the pressed axle, please let me know. 

[Draggin]

myelectricbike, I was just thinking that.  I mean what if this doesn't work?  I think that is a great idea.  Especially if you can get one a little harder.  maybe even stainless.  As for me I got the mkII put back together last night and had it out for a test ride.  it seems to coast much better and no noise.  when you pick up the wheel and spin it there is a slight noise that souns like one of the magnets just touching the stator.  I know it is not.  it is the missalignment of the bearing-eccentricity-.  If this gets worse I think I will sell the bike and take the loss.  Replacement is not really an option anymore here in Canada, as the price almost doubled with no battery in the kit.  That puts them in direct competition with Wilderness and Crystalyte.  I think the one comes with Nimh batteries.  Ive noticed that Bionx is comming down in price a bit too.  It's too bad cause these are nice units.  But the axle issue is a fatal flaw.  The guy on the line has to be a little more carefull pushing things together and that aint gonna happen, and he probably needs a new die every 10000 units or so, and that aint gonna happen.  so if and when I go to replace this thing that aint gonna happen either.  Ive only had it for 6 months do you think the warrantee is still good?   

[myelectricbike]

Yeah, Draggin. Sorry I did not say something before. I was convinced your purpose was to tinker as much as to have a working bike. Write Philip Yao, tell him the problem briefly from start to end, site this topic and request a replacement from him. Philip is extremely sympathetic with owners who have a problem that is obviously Golden's fault and especially with owners who have gone to as much trouble and effort as you have to fix it on their own. Tell him I support your request and if you feel it is necessary ask other owners for their support as well. I do not think you will have any problem getting a replacement from Philip.

[Draggin]

Thanks that makes me feel better.  But there may be no problem now.  I will write him and let him know of the problem.  Just incase this project goes south.  You weren't exactly wrong on the purpose.  I don't know if I would have the nerve to try the warrantee angle.   

[myelectricbike]

Even so Philip is very understanding and wants to make good. If the problem originated with Golden then it is simply not your fault and Philip will agree. Never hurts to ask.