200 miles with old rear sprocket - damage done?

Norway · July 10th, 2017, 07:22 AM

About 10 days ago i showed up at Ride in Trondheim, Norway, to have the 250 serviced. I was told that the mechanic had become ill, and that they could unfortunately not do the service on the bike that had been agreed upon earlier.
I should use it for a trip to Østersund, Sweden, a few days later, so instead I made an agreement with a workshop there, CJ Motorteknik. I had bought a new chain and the front and rear sprockets from a 3rd company in Norway.

After a couple of hours they called from CJ Motorteknik and told that the rear sprocket did not fit, so it was decided to change the front sprocket (smallest diameter) and the chain, but keep the old rear sprocket. I have always heard that both sprockets as well as the chain should be changed at the same time, not for old parts to damage new ones.

Since there was no chance in getting the right rear sprocket during my few days in Sweden, I drove approximately 300 kilometers (180 miles) with the combination of the old rear sprocket and a new chain and front sprocket.

The old chain and front sprocket were in bad shape. Should I change the old rear sprocket ASAP, or is it likely that the damage is done, anyway?

There is little, if any, visible wear on the rear sprocket. Should I rather just run the bike with the present mix of new chain and front sprocket and the old rear sprocket, or not..?

Thanks for any advice, and sorry if similar cases have already been debated here..

Brother Michigan · July 10th, 2017, 08:34 AM

It's probably not a big deal to run the old rear sprocket if (and I stress if) it's truly in good shape, but I would go ahead and replace it for peace of mind, especially if you were already going to have it done.

Triple Jim · July 10th, 2017, 09:16 AM

You didn't hurt anything in that distance. I've changed a worn chain and kept the old rear sprocket many times, if it had little or no visible wear. Some sprockets can be turned over so the backs of the teeth become the drive surfaces, and it's essentially new again.

JohnnyBravo · July 11th, 2017, 09:09 AM

Should be fine

Norway · August 2nd, 2019, 12:02 AM

Quote:

Originally Posted by Norway

About 10 days ago i showed up at Ride in Trondheim, Norway, to have the 250 serviced. I was told that the mechanic had become ill, and that they could unfortunately not do the service on the bike that had been agreed upon earlier.
I should use it for a trip to Østersund, Sweden, a few days later, so instead I made an agreement with a workshop there, CJ Motorteknik. I had bought a new chain and the front and rear sprockets from a 3rd company in Norway.

After a couple of hours they called from CJ Motorteknik and told that the rear sprocket did not fit, so it was decided to change the front sprocket (smallest diameter) and the chain, but keep the old rear sprocket. I have always heard that both sprockets as well as the chain should be changed at the same time, not for old parts to damage new ones.

Since there was no chance in getting the right rear sprocket during my few days in Sweden, I drove approximately 300 kilometers (180 miles) with the combination of the old rear sprocket and a new chain and front sprocket.

The old chain and front sprocket were in bad shape. Should I change the old rear sprocket ASAP, or is it likely that the damage is done, anyway?

There is little, if any, visible wear on the rear sprocket. Should I rather just run the bike with the present mix of new chain and front sprocket and the old rear sprocket, or not..?

Thanks for any advice, and sorry if similar cases have already been debated here..

Haven't been logged in for quite some time. I continued using the bike without doing anything, and found that the new chain (and sprockets) were worn out in just about 5000 miles.
So, I'll not combine a new chain with old parts another time..

DannoXYZ · August 2nd, 2019, 12:47 AM

Yes, couple hundred KM is fine, but riding for years with worn rear-sprocket accelerated wear on your new chain and front-sprocket.

One trick that could have been done when CJ Motorteknik called about new rear-sprocket not fitting is to flip old sprocket inside-out. This places chain-load on other unworn side of teeth. Effectively doubling sprocket life.

Triple Jim · August 2nd, 2019, 05:53 AM

Quote:

Originally Posted by DannoXYZ

One trick that could have been done when CJ Motorteknik called about new rear-sprocket not fitting is to flip old sprocket inside-out. This places chain-load on other unworn side of teeth. Effectively doubling sprocket life.

As I posted above.

Hexadecimus · August 29th, 2019, 02:31 PM

Quote:

Originally Posted by Triple Jim

... so the backs of the teeth become the drive surfaces, and it's essentially new again.

Yeah......... it doesn't really work that way though

DannoXYZ · August 29th, 2019, 04:34 PM

Quote:

Originally Posted by Hexadecimus

Yeah......... it doesn't really work that way though

Oh, why not?

We're talking about using new chain with flipped sprocket, not re-using old chain with spaced-out pins.

Hexadecimus · August 29th, 2019, 05:18 PM

Same reason. Accelerated wear and premature failure. They don't wear on just one side.

July 10th, 2017, 07:22 AM	#1
Norway ninjette.org member Name: S n 0 r r £ Location: Stjoerdal, Norway (San Diego, CA, USA, 2015-2016 , Bielefeld, Nordrhein Westfalen,Germany 2021-'22) Join Date: Sep 2012 Motorcycle(s): TMZ 5.952 "Tula" 200, Ninja 250 -Special ed. '11, ZZR 1400 (ZX14), Honda CB 1100 F Super Bol D'or Posts: 143	200 miles with old rear sprocket - damage done? About 10 days ago i showed up at Ride in Trondheim, Norway, to have the 250 serviced. I was told that the mechanic had become ill, and that they could unfortunately not do the service on the bike that had been agreed upon earlier. I should use it for a trip to Østersund, Sweden, a few days later, so instead I made an agreement with a workshop there, CJ Motorteknik. I had bought a new chain and the front and rear sprockets from a 3rd company in Norway. After a couple of hours they called from CJ Motorteknik and told that the rear sprocket did not fit, so it was decided to change the front sprocket (smallest diameter) and the chain, but keep the old rear sprocket. I have always heard that both sprockets as well as the chain should be changed at the same time, not for old parts to damage new ones. Since there was no chance in getting the right rear sprocket during my few days in Sweden, I drove approximately 300 kilometers (180 miles) with the combination of the old rear sprocket and a new chain and front sprocket. The old chain and front sprocket were in bad shape. Should I change the old rear sprocket ASAP, or is it likely that the damage is done, anyway? There is little, if any, visible wear on the rear sprocket. Should I rather just run the bike with the present mix of new chain and front sprocket and the old rear sprocket, or not..? Thanks for any advice, and sorry if similar cases have already been debated here..

July 10th, 2017, 08:34 AM	#2
Brother Michigan ninjette.org sage Name: Aaron Location: Winder, GA Join Date: Jun 2012 Motorcycle(s): 2013 Ninja 300 Posts: 718	It's probably not a big deal to run the old rear sprocket if (and I stress if) it's truly in good shape, but I would go ahead and replace it for peace of mind, especially if you were already going to have it done. __________________________________________________ DISCLAIMER: I generally have no idea what I'm talking about.

July 10th, 2017, 09:16 AM	#3
Triple Jim Guy Who Enjoys Riding Name: Jim Location: North Carolina Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot. MOTM - Oct '18, Aug '17, Aug '16	You didn't hurt anything in that distance. I've changed a worn chain and kept the old rear sprocket many times, if it had little or no visible wear. Some sprockets can be turned over so the backs of the teeth become the drive surfaces, and it's essentially new again.
	2 out of 2 members found this post helpful.

July 11th, 2017, 09:09 AM	#4
JohnnyBravo Certifiable nontundrum Name: Harper Location: NC Milkshake stand Join Date: Mar 2013 Motorcycle(s): 2013 SE NINJA 300 Posts: Too much. MOTM - Sep '13, Sep '16	Should be fine __________________________________________________

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August 2nd, 2019, 12:47 AM	#6
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