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Post by lc on Apr 28, 2010 14:29:39 GMT -5
I have exchanged several emails with Mike Lavine at PBI sprockets. PBI's online store website now includes a 520 option to the aluminum rear sprockets of KH250 (both 4 and 6 bolt) KH400, KH500, H2 750. The 520 option actually reduces the cost of the stock sprockets in most cases! shop.pbisprockets.com/category.sc?categoryId=31shop.pbisprockets.com/category.sc?categoryId=32I have also been in contact with Sandy at Rebel Sprockets who also will custom make 520 rear sprockets for the triples for little or no extra funds. www.rebelgears.com/catalog2010.htmlThe usual 520 countershaft alternates (listed at the resource site) will still have to be obtained. Both the above companies will ship international orders by US Postal Service. Sprocket Specialists identified they will only ship by UPS (HUGE international fees!). As a result, they were not considered for further contact or sales. J |
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Post by Walms on Jul 28, 2010 14:20:20 GMT -5
Hey LC, I thought I'd give you the heads up about my new aluminum sprocket.... Already pooched after 2000k  I have a wee bit of misalignment only because I can see slight wear on one side similar but to a lessor degree to my sprocket last year. But the big problem is the teeth are worn and bending over already! I'll take pics later to show you. I lubed my chain religiously on the Huron tour too. I'm curious if you end up with the same wear rate too... It might be heavier but I'm going steel the next time. |
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Post by zambia on Jul 28, 2010 14:33:26 GMT -5
Makes you wonder what they were thinking when they made plastic ones..  |
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Post by lc on Jul 28, 2010 14:59:01 GMT -5
Just checked mine. 1645 kms so far. Showing slight wear on driven teeth but no where a concern yet. I have not added any additional lube other than what was factory installed. My chain is a new DID 520 X ring. Running about 1 inch slack with bike unloaded and have only adjusted it once shortly after installation.
That being said I just looked at my previously installed steel 530 sprocket (considerably wider at 3/8in.) that has around 20,000 kms (also installed with a new DID X ring 530 chain) and it shows about the same wear.
I wonder if your issue could be a pitch conflict between your chain and your sprocket? You were talking of adding two additional links.
If you try a steel sprocket maybe keep the same chain and monitor the rate if its wear for a comparison?
J
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Post by lc on Jul 28, 2010 15:28:28 GMT -5
I just googled "pbi aluminum sprocket wear". Several threads are to be found (klrs/litre bikes etc.). Some say without a new chain the sprocket will be shot in short order. Other comments state aluminum will wear 3X faster than steel?
J
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Post by JA-Moo on Jul 28, 2010 19:03:09 GMT -5
The main thing, is if they are hardened and anodized.......
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Post by Walms on Jul 29, 2010 7:48:02 GMT -5
True enough about replacing all 3 components at the same time but my rule of thumb for checking a chain for stretch is to pull back on the chain about 1/2 way through the rear sprocket... Anything more then a 1/4 tooth exposed means the chain is on its way out. My chain probably had about 2000km on it before the new sprocket and the old sprocket shows no sign of tooth wear, it also passed my stretch test with flying colours...
It will be interesting to see if your sprocket looks similar to mine after 4000k LC.
Anodizing sounds good because it will add a HRc 65 case to the aluminum but it is probably only .0004-.001" thick and I'm not convinced the soft aluminum underneath would support it well enough to see it lasting very long.
I chaulk it up to the massive torque I'm getting out of this reeded motor of mine... ;D ;D ;D
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Post by lc on Jul 29, 2010 8:09:59 GMT -5
When I was corresponding with PBI I specifically asked about hard anodizing. The answer I got was to the effect they had tried it on their sprockets, but had seen no difference in the wear qualities as it was much too thin.
Walms,
When you find a supplier for steel rear sprockets (with lots of size options) be sure to post the supplier.
I think us people of average size might be behind the eight ball somewhat regarding sprocket wear. Leo states he gets excellent wear qualities from an aluminum sprocket. However, he also states he is able to pull past redline in fifth on a stock H1 running 16/42!
J
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Post by Walms on Jul 29, 2010 8:34:24 GMT -5
Walms, When you find a supplier for steel rear sprockets (with lots of size options) be sure to post the supplier. J Will do LC... I did find that guy that does the plate sprockets, of course if you are weight conscience, you'd have to send the sprocket out to someone with a waterjet to do a custom pattern... Like triples rule the world or something similar. |
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Post by Lou on Jul 29, 2010 8:42:03 GMT -5
Not many of us are still 90lbs soaking wet. ;D ;D ;D ;D
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Post by zambia on Jul 29, 2010 8:43:37 GMT -5
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Post by Walms on Jul 29, 2010 10:38:35 GMT -5
Not many of us are still 90lbs soaking wet. ;D ;D ;D ;D My head probably weighs that much...  |
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Post by Walms on Jul 30, 2010 7:16:37 GMT -5
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Post by lc on Jul 30, 2010 11:06:27 GMT -5
That's not all "hooked and bent over"!! LOL.. You should have seen the sprocket we had to flip (reverse) on the side of the hwy back in '74. I'm disappointed..... I was expecting something that looks like my B&D "Piranha" circular saw blade!
Yes. There is more wear on that sprocket than should be given its low mileage. The alignment issue has taken (added?) to the issue too. I see your chain alignment issue has now reversed itself. Looks like the countershaft sprocket has to be moved left this time.
Thanks for the "heads up" as I'll be keeping an eye on mine now.
J
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Post by tripletriplenut on Jul 30, 2010 13:28:16 GMT -5
that sprocket is not to bad just add weld were needed and bring out the chain saw file and touch it up good as new.  |
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