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[acacia1731]

Quick report related to chain life...

I have about 1,500 miles on the stock chain kit, with 90% road use, 10% muddy trails.  The sprockets both look pretty good.  I tried to tension the chain tonight, but found out that I'm out of space - the axle can't move any further back in the swingarm.  Time to either shorten the chain (plan A) or swap everything out (plan B, hopefully not until next year).

When confirming that the wheel can move forward enough to shorten the chain I noticed that the tire had been rubbing on the crosstube protector where there is a flange for the tightening bolts.  That protector definitely fits poorly, as Ray mentioned.  It wants to slide toward the center of the bike, which puts it too close to the tire.  The poor fit also prevented the chain from riding on the protector's vertical rib as intended, which allowed the chain to wear through the thinner material next to the rib and then start eating into the cross tube.  Glad the cross tube protector is cheap, but it definitely needs to be mounted differently to be effective. 

As the length of this thread indicates, there sure is a lot to dislike about this chain setup (odd motor shaft, odd sprocket sizes, poor fitting guides, have to remove swingarm to change sprockets, high cost, etc.)

[odedmaz]

That's interesting. I followed Ray's suggestion and just used few zip ties next to each other, instead of the crosstube protector.

By the way, my chain is adjusted to 109 links. It provide forward and backward rear wheel movement for tension alignment. Do you remember the number of links?

Sent from my XT1585 using Tapatalk

[42Cliffside]

but found out that I'm out of space - the axle can't move any further back in the swingarm.  Time to either shorten the chain (plan A)

Um, Bing? I think it's time to shorten the chain.

[rayivers]

the tire had been rubbing on the crosstube protector... fits poorly... poor fit also prevented the chain from riding on the protector's vertical rib as intended... needs to be mounted differently

+4    I'd forgotten about the tire hitting the mounting flanges, which was the main reason I ended up chopping them off.  I also failed to mention I removed the rear locating tab that fits into the space between the top & bottom LH arms behind the crosstube, leaving only the front tab that fits into the triangular forward space (which prevents protector rotation & orients the rib correctly to the chain run).

If the screw flanges and rear side tab were removed and the protector supplied with several wide tie-wraps, it would go right on and fit fine, presenting a non-snagging profile to the chain, tire, and anything tall you might ride over.

Ray

[acacia1731]

Shortened the chain from 109 to 107 today - no problems there.

As for the cross-tube protector, as usual, Ray is two steps ahead!  I also cut the rear flange off (before reading his post), and used zip ties to secure it better.  I also cut a 45 degree chamfer around the entire circumference of the protector (with a knife), allowing it to sit more flush against the swingarm.  It looks as if the designer forgot about the generous weld where the crosstube meets the swingarm, which was pushing the protector out almost 1/4 inch.  The chamfer helped line up the vertical ribs with the center of the chain.

On the bright side, the chain noise has subsided quite a bit now that everything fits better.

[rayivers]

I replaced the 10T front sprocket last week, with the hardened version (Martin 50BS10HT). It had less than 1,500 miles on it, and 5 teeth left.   The new one was a nightmare to machine; I was told six lathe points were destroyed in the process.

Removal/installation was much the same as before. 30 seconds of torch heat and the M10 shaft screw came right out.  The setscrews were not very tight at all (these use .125" hey keys, do NOT use 3mm !).  The sprocket came right off with the bearing puller. The new sprocket was slightly longer than the old one, so I added a .020"/.5mm shim washer to the existing .044"/1.1mm washer under the retaining dome washer.  I used blue LocTite on the shaft screw & 40 ft/lb of torque, and I would've used 7 ft/lbs on the setscrews if I had a .125" key socket (I just LocTited it & tightened as much as I could with a key, probably 5 ft/lbs or less).  There was .043"/1.1mm clearance from the shaft screw head to the swingarm pivot.

I hope to get at least 2K miles out of this hardened sprocket, we'll see.

On a side note... the eBay stainless swingarm bearings I put in last time (not the ceramic/stainless precision hybrids) were completely shot again - I couldn't get the RH one to turn at all without the swingarm attached.  I'll post on this in my bearing thread at some point.  This is a truly serious design problem that Zero needs to rectify before hard-locked bearings start reaming out frame pockets. I looked into roller bearings like the NJ204, but they're unsealed and would be a real challenge to make work in this application (I found 28x40x5mm outer seals on eBay that are currently en route and should work, but inner seals remain a problem).  There's a reason why the industry standard is multiple swingarm-mounted sealed needle bearings - they survive for extended periods, and won't damage the frame when they fail - but custom double-sealed NJ204's would be a huge improvement in the meantime.

Ray