Sprocket replacement

bultaco4ever · Post by **bultaco4ever** » 04:09 pm Jan 28 2016

So, I'm doing some service to my rear caliper and looked at my rear sprocket at the same time. First about the caliper...the brake pad hanger pins were frozen in really good. The allen head hex shape got rounded out right off the bat. So, I took it to a real mechanic who had to cut a slot in the head and was able to fit a impact wrench 'blade' bit in and then whack it with a hammer. He got them out. I'll put Tusk replacement pins in that have the bolt head instead of the recessed allen head for next time.

But the rear sprocket looks a bit worn. It says JT 460-47 on it. (47 tooth). It has 6 bolts that hold it to the hub. The front sprocket looks good. Suntap 12 tooth.

So, if I want to replace the rear sprocket...should I go aluminum OR stay with steel? Should I re-use the 6 bolts for the hub? By the way, I just got a new chain for it. I didn't realize when I ordered it but I got an 'O' ring chain.

Anyone have an opinion?

canamfan · Post by **canamfan** » 05:06 pm Jan 28 2016

I think 47 is stock. I just put a 49 on mine and a 13 front which is stock. I would use steel on both sprockets as it wears better and the weight difference isn't much. I would recommend replacing all three items at once. I also had frozen brake pins in mine I tried to use a small sharp edged punch to turn them out but just messed them up, ended up drilling out the threaded part and used a tap to clean up the threads.

ohgood · Post by **ohgood** » 07:56 am Jan 29 2016

bultaco4ever wrote:So, I'm doing some service to my rear caliper and looked at my rear sprocket at the same time. First about the caliper...the brake pad hanger pins were frozen in really good. The allen head hex shape got rounded out right off the bat. So, I took it to a real mechanic who had to cut a slot in the head and was able to fit a impact wrench 'blade' bit in and then whack it with a hammer. He got them out. I'll put Tusk replacement pins in that have the bolt head instead of the recessed allen head for next time.

But the rear sprocket looks a bit worn. It says JT 460-47 on it. (47 tooth). It has 6 bolts that hold it to the hub. The front sprocket looks good. Suntap 12 tooth.

So, if I want to replace the rear sprocket...should I go aluminum OR stay with steel? Should I re-use the 6 bolts for the hub? By the way, I just got a new chain for it. I didn't realize when I ordered it but I got an 'O' ring chain.

Anyone have an opinion?

aluminum wears out very very fast, like three rides fast. go for steel, 13 / 47 is stock, i run 15 / 47 because I run roads to connect trails a bunch. 13 is the "ok i'm in trials mode now!" gearing, for me.

the brake pins are allen / recessed so that when you drop the bike the hex head won't be smeared /broken by rocks and stuff. i prefer the allen pins because of this, and pack the end of the bolt with grease or rtv to prevent corrosion and dirt. make sure you coat the ends of the pins and the threads with anti-seize, and they will turn out easily next time.

if you get in a bind and one of the pins is frozen (one of mine is) you can use a round file to shave a little off the steel portion of the brake pad, and slip the pads in, then insert the remaining pin. i've done this for the last year or two, need to drill it out and replace it one day ;-)

Chilly · Post by **Chilly** » 08:24 am Jan 29 2016

Replace it all at once. I bought renthal sprockets 13 48. The place I ordered from didn't have the 47 tooth. I can't tell much of a difference. O ring chain is all I use.

Sullyfam · Post by **Sullyfam** » 10:13 am Jan 29 2016

I use supersprox and buy all at once because when you do their rear sprocket (which is a steel outer with alum inner) comes with a lifetime guarantee. Kewl.

http://www.supersproxusa.com

All in its no more spendy then the renthal alternatives so the guarantee is a plus.

However, if your want to limit cost get an all steel sprocket. Sure it's a bit heavier, but I seriously doubt it's slowing anyone (including me) on this forum down. [emoji12]

O-ring chains are good, so no worries there.

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Friedom · Post by **Friedom** » 05:05 pm Feb 01 2016

Lifetime guarantee on a wear item. Nice!
I just stated running non o ring chains. Word is that the grit in the desert south west destroys the o rings. I lube with ATF. It has detergents that sling off dirt instead of sticking to it. Chain stays pretty clean, haven't been through one to see how long it lasts, but the price is right too.
I've heard of guys that run o ring chains and don't bother lubing them too. Just replace when worn enough, which takes quite awhile. I think that's outside of heavy grit use areas, though, like adventure riding.
I'm still deciding whether to replace rear sprocket though. Both are in decent shape, though I have a 15t ready for longer hauls.
Thoughts on reusing sprocket bolts? If you can get them out in one piece, that is.

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ohgood · Post by **ohgood** » 07:19 am Feb 02 2016

Friedom wrote:Lifetime guarantee on a wear item. Nice!
I just stated running non o ring chains. Word is that the grit in the desert south west destroys the o rings. I lube with ATF. It has detergents that sling off dirt instead of sticking to it. Chain stays pretty clean, haven't been through one to see how long it lasts, but the price is right too.
I've heard of guys that run o ring chains and don't bother lubing them too. Just replace when worn enough, which takes quite awhile. I think that's outside of heavy grit use areas, though, like adventure riding.
I'm still deciding whether to replace rear sprocket though. Both are in decent shape, though I have a 15t ready for longer hauls.
Thoughts on reusing sprocket bolts? If you can get them out in one piece, that is.

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atf is the stuff. don't make a big deal about it, just knock the dirt off with soap/water, ride to dry, lube.

you can reuse the bolts and nuts easily for the rear sprocket. the key is to turn the NUT and torque the NUT, NOT the bolts ! the bolts normally snap when people try to turn them either installing or removal. you can always mark the bolt and nut heads with a paint pen if you're paranoid (me) about things working loose over time. same goes for fork bolts, axles, rotor bolts, etc - it makes inspection fast and easy.

bultaco4ever · Post by **bultaco4ever** » 08:32 am Feb 02 2016

Cool idea. I never did that. Do you mark a dot at 12 o'clock position, or something like that?

david · Post by **david** » 01:29 pm Feb 02 2016

You mark the nut and the bolt together. That way you can tell if the nut starts to loosen up. Doesn't matter the orientation.

Post by **SS109** » 06:31 pm Feb 02 2016

Friedom wrote:Lifetime guarantee on a wear item. Nice!
I just stated running non o ring chains. Word is that the grit in the desert south west destroys the o rings. I lube with ATF. It has detergents that sling off dirt instead of sticking to it. Chain stays pretty clean, haven't been through one to see how long it lasts, but the price is right too.
I've heard of guys that run o ring chains and don't bother lubing them too. Just replace when worn enough, which takes quite awhile. I think that's outside of heavy grit use areas, though, like adventure riding.
I'm still deciding whether to replace rear sprocket though. Both are in decent shape, though I have a 15t ready for longer hauls.
Thoughts on reusing sprocket bolts? If you can get them out in one piece, that is.

Sent from my SM-G900V using Tapatalk

I run nothing but X-ring chains and they last longer than non-ringed chains here in the dez. I only lube my chain after I wash the bike to keep it from rusting.

I run 13/48 gearing. I only use Renthal CS sprockets as they fit the KDX output shaft the best out of the various brands I have used. On the rear I use any cheap steel sprocket and would never use aluminum in the dez. Sprocket bolts can be reused with no problem. Just use some medium (blue) thread locker and torque to spec and you can also do like David's pics shows. I mark all my linkage bolts/nuts like that.

Friedom · Post by **Friedom** » 06:36 pm Feb 02 2016

I guess it's time to learn what an x ring chain is.
How close is 13/48 gearing to stock on your H model 220?

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Post by **SS109** » 07:29 pm Feb 02 2016

Friedom wrote:I guess it's time to learn what an x ring chain is.
How close is 13/48 gearing to stock on your H model 220?

Below is a pic showing the difference. Rings are in red. X-rings have two sealing surfaces instead of the one of a standard O-ring. The X also has less drag (ie;friction) than an O style as the O style has to have more pressure on the O to last the life of the chain. Lastly, ringed chains last longer because they keep dirt and grit out of the rollers and pins which wears them out.

As for gearing, stock on KDX's is 13/47. I would still be running that except they were out of the 47 last time I replaced it so I went 48. It works well riding hike-a bike technical stuff to blasting down washes.

Friedom · Post by **Friedom** » 07:41 pm Feb 02 2016

Wow that makes really good sense!
You really don't need to lube a ring chain then, huh? Either the lube is sealed in, or the seal is broken and grime is getting in.

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Post by **SS109** » 08:17 pm Feb 02 2016

Friedom wrote:Wow that makes really good sense!
You really don't need to lube a ring chain then, huh? Either the lube is sealed in, or the seal is broken and grime is getting in.

Yup! You only lube them to prevent rust not to actually lube the pins and rollers.

Friedom · Post by **Friedom** » 08:19 pm Feb 02 2016

I'll see how long my no-ring chains last, but I expect I'll try x ring next.

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Jaguar · Post by **Jaguar** » 10:34 pm Feb 02 2016

One big reason to use o-ring chains is that they are better for sprocket life if we don't lube the chain. When you lube a chain the oily rollers hold on to dirt particles which then are abrasive on the sprocket and wear it down.

Friedom · Post by **Friedom** » 10:41 pm Feb 02 2016

Thus the ATF mentioned above. Not as sticky.

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Friedom · Post by **Friedom** » 11:55 pm Feb 07 2016

Ok I heard from a guy recently that you oil a ring chain periodically to keep the o rings from drying out. Makes sense, sort of.

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