Author Topic: Hardening Gears  (Read 2341 times)

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Offline kiwikx500

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Hardening Gears
« on: October 13, 2008, 08:22:50 AM »
Just seen this advert with the guy saying he has re-cut the gears and hardened.

Take it re-cutting is filing the gears into better shape to take up wear ? How do they harded the gears ?

http://www.trademe.co.nz/Trade-Me-Motors/Motorbikes/Motorbikes/Dirt-bikes/auction-181090411.htm



(That website is #1 in New Zealand and the young guy that set it up reckons he was cold in his flat and looked for a heater on-line but could not find one so set the site up, 9 years later he sold it for $700 million, looks like a straight copy of another site to me :-D )
1990 KX 500

Offline Mick

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Re: Hardening Gears
« Reply #1 on: October 13, 2008, 09:51:30 AM »
I'm not familiar with "cutting" gears?  I imagine maybe it's referring to filing down some jagged edes.  The gears in my '89 had burs on some edges so sharp they cut my fingers like a razor blade.  And the hardening I think may be the use of cryogenics.  From what vaque understanding of metalurgy I do have I believe freezing gears in sub zero temperatures for several hours will cure a component of atleast some manufacturer defects.
1989 KX500
2003 Service Honda CR500AF

Offline Platypus

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Re: Hardening Gears
« Reply #2 on: October 13, 2008, 01:03:23 PM »
If the gears were "cut" they would no longer have the same dimensions so the only possible thing I could come up with is hardfacing.  I worked at an iron foundry for a while and we had one part that we had to hardface for a street sweeper manufacturer.  Here is some info on hardfacing.

http://en.wikipedia.org/wiki/Hardfacing

Offline kiwikx500

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Re: Hardening Gears
« Reply #3 on: October 13, 2008, 08:28:07 PM »
Cheers

Sounds like could be a worthy investment, are the gears strong in a K5 ? Last long time ?
1990 KX 500

Offline Mick

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Re: Hardening Gears
« Reply #4 on: October 14, 2008, 01:19:29 AM »
My gears are 20 years old.  The motor has been modified a good deal for atleast ten of those.  Still work fine...
1989 KX500
2003 Service Honda CR500AF

stewart

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Re: Hardening Gears
« Reply #5 on: October 14, 2008, 05:06:33 AM »
the stock k5 gears are great parts   and dont ussaly fial unless ran with no lube or the wrong oil

Offline KXcam22

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Re: Hardening Gears
« Reply #6 on: October 14, 2008, 07:40:35 AM »
I used to harden the OEM shifter forks in my 1980 KX420 by heating them and then quenching them in oil to slowly cool them. It worked. Cam.

Offline hughes

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Re: Hardening Gears
« Reply #7 on: October 15, 2008, 09:41:43 AM »
Stock gear box is perfect for the the normal crowd who ride dirt bikes. Outdoor national pros or even supercross guy coudl benfit from gear box work, the key is to reduce friction and release hp.
Open Class 2-Stroke Kawasaki KX500
Yamaha 2005 YZ250
Richard Hughes
Dirt Hammers - Online Off-Road Journal
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http://www.dirthammers.com