2nd Chain Sprocket Replacement

[StratTuner]

Last time I did this was the first time, so it was a learning experience.

Things I think I know....

- chains sprockets last 16 to 18 thousand miles. (D.I.D. VX2, OEM sprockets)
- removing the rear sprocket is best done BEFORE removing the rear wheel from the NC700 as you get more leverage agingst the bolts with the wheel still in place.
- a chain breaker tool is required ($40 from Cycle Gear)
- a wrench extender is a good idea since some of the bolts resist easy removal.

Forgive me if I'm repeating observations or request for recommendations.

Am I forgetting anything that will make this go more smoothly?

 

[treybrad]

chains sprockets last 16 to 18 thousand miles. (D.I.D. VX2, OEM sprockets)

Eh, you should be able to get quite a bit more than that out of it with decent care where you live. I got 50k out of the OEM chain on my Bandit here in dry Texas with good, but not obsessive care. The OEM chain on the NC was garbage, but I certainly expect to get more out of my VX2 set.... only time will tell though.

Am I forgetting anything that will make this go more smoothly?

If you're replacing the front sprocket, break the countershaft nut loose before you break the chain so you can use the rear brake to keep the sprocket stationary (vs. having it in gear).

trey

 

[Spaceteach]

- removing the rear sprocket is best done BEFORE removing the rear wheel from the NC700 as you get more leverage agingst the bolts with the wheel still in place.

Am I forgetting anything that will make this go more smoothly?

Strat,
Did you mean to say removing the FRONT sprocket is best done before removing the rear wheel, or are you just talking about removing the rear sprocket bolts?

Bob

 

[Old Can Ride]

If you do not remove the front sprocket bolt first while everything is still in place, you ain't going to get that bolt off the front sprocket. Also follow the manual's recommendations on the torqueing of the rear sprocket bolts. Spaceteach is correct !

 

[StratTuner]

Strat,
Did you mean to say removing the FRONT sprocket is best done before removing the rear wheel, or are you just talking about removing the rear sprocket bolts?

Bob

I actually did mean the rear sprocket. I remember that waiting to go after the rear sprocket AFTER the wheel was off the bike made it difficult. I just thought it might be easier to take the REAR (not the front) sprocket off while the rear wheel was still mounted.

 

[StratTuner]

If you do not remove the front sprocket bolt first while everything is still in place, you ain't going to get that bolt off the front sprocket. Also follow the manual's recommendations on the torqueing of the rear sprocket bolts. Spaceteach is correct !

I do use a torque wrench that measures torque and get the reading as close to the manual as possible.

 

[StratTuner]

Eh, you should be able to get quite a bit more than that out of it with decent care where you live. I got 50k out of the OEM chain on my Bandit here in dry Texas with good, but not obsessive care. The OEM chain on the NC was garbage, but I certainly expect to get more out of my VX2 set.... only time will tell though.

If you're replacing the front sprocket, break the countershaft nut loose before you break the chain so you can use the rear brake to keep the sprocket stationary (vs. having it in gear).

trey

I'm just guessing that it's time to replace the chain. The first (stock) lasted 16K, so I'm guessing the VX2 is similar. There are one or two kinked links I observe on it now, but nothing like the number of the first chain at the same mileage.
OCR mentioned once that he got 18K out of his VX2... so I figure I'm close to time.
Honestly, I don't know how to tell when to replace the chain. I suppose one answer is "when it breaks"... but I'd kinda like to get to it before that happens.

you also wrote:
"If you're replacing the front sprocket, break the countershaft nut loose before you break the chain so you can use the rear brake to keep the sprocket stationary (vs. having it in gear)."

use the rear brake to keep the sprocket staionary? How does one hold the rear brake down while loosening the countershaft nut? I suppose I could put a brick on the rear brake pedal, but that doesn't seem like it would apply enough force to engage the rear brake sufficiently.... hmmm...

(honestly, I'm being analytical not difficult. All advice is welcome since I barely know how...having done it only once.)

 

[showkey]

Honestly, I don't know how to tell when to replace the chain.[/B] I suppose one answer is "when it breaks"...

(

You actually measure the chain and determine wear and stretch:

REGINA CHAIN - Inspecting the chain

Trouble shooting chain problems :

REGINA CHAIN - Potential chain drive problems and causes

All chain manufactures have info available specific to their product.

It is not an accident that many chain problems are related back to chain tension........especially noise, kinked links, vibration to mention a few. Second on the list cleaning and lube

 

[StratTuner]

ChOKE..... Always, it comes down to a loss of confidence.
Two things are stopping me now:

1) I can'f find what the torque value is for the front drive sprocket
2) the rear sprocket nuts get torqued to 80 lbs/ft (what ever that means!)... but my smaller torque wrench shows lbs/inches (???)

now, those of you who can balance a check book will laugh at those of us who can not.
I am one of these. I should be able to convert lbs/ft to lbs/inches....
but I confess I can't. I make all sorts of calculations...many look right, but only one is.

(that mathematical disability has cost me dearly over my life time, I assure you.)

 

[StratTuner]

It's a good thing I have a car to take to work tomorrow. The sun light fades, and here I sit...trying to find the torque value for the front sprocket in the service manual.....
I know! Let's look in the index under torque! NOPE. Refers you to 1-15 which lists some torque values but not the one for the front drive sprocket.

 

[StratTuner]

OK... just turning pages and looking for a picture of the front drive sprocket took me to page 16-23. 2nd photo from the top shows the torque to be 40lbs/ft.

 

[dduelin]

No worries. 40 ft/lbs is 480 in/lbs and 80 ft/lbs is 960 in/lbs. I have a torque wrench that shows in/lb like yours.

 

[StratTuner]

I've had to put everything on hold, not because I'm inept, but because I don't have a Rivet-style master link. The local Cycle Gear store will help me with that tomorrow.

Examining the sprockets and chains, I have to say that the chain links show wear. There is a worn place on every link on the side of the pins that contact the sprockets. The sprockets show almost no wear at all. The teeth are all the same size and squared off as if they just came out of the box.
I'm considering changing the sprockets every other chain change...or HALF as often as I change the chain.

I miss my family. They are away, and I'm living on corn dogs for dinner and cereal for breakfast.
sigh....

 

[Spaceteach]

Strat,
Page 1-6 of service manual under maintenance is a listing for "Drive Sprocket Bolt". which is the front sprocket. The torque is listed as 40 lb-ft. To convert inch pounds to foot pounds divide the inch pounds by 12 (12 inches in a foot). Going the other way, lb-ft times 12 equals lb-in. Unfortunately I doubt that that a torque wrench calibrated in inch pounds will go up to the torque value for the bolts you're going to be working on since You will need 480 lb-in for the front and 960 lb-in for the rear.

Hope this helps,
Bob

 

[dduelin]

I've had to put everything on hold, not because I'm inept, but because I don't have a Rivet-style master link. The local Cycle Gear store will help me with that tomorrow.

Examining the sprockets and chains, I have to say that the chain links show wear. There is a worn place on every link on the side of the pins that contact the sprockets. The sprockets show almost no wear at all. The teeth are all the same size and squared off as if they just came out of the box.
I'm considering changing the sprockets every other chain change...or HALF as often as I change the chain.

I miss my family. They are away, and I'm living on corn dogs for dinner and cereal for breakfast.
sigh....

Don,

I tried this with my first chain replacement. The new chain on the old sprockets (even though I could not see any wear) wore out the new chain and in 8,000 miles IIRC I was buying new sprockets and another new chain. I thought I was saving a good bit of money at the time but I really wasn't.

 

[Old Can Ride]

I agree with Dave Duelin about changing the old sprockets. You will get a lot longer wear life on the chain with new sprockets.

 

[StratTuner]

OK... experienced riders I trust... I will accept that as REAL data. Thank you, Gentleman.
Two sprockets are only $55, so it's not a cost thing, and it really isn't that hard to get to them, and replace them.
(Seems like it it when you're doing it....but things look better after you're done!)

 

[StratTuner]

Strat,
Page 1-6 of service manual under maintenance is a listing for "Drive Sprocket Bolt". which is the front sprocket. The torque is listed as 40 lb-ft. To convert inch pounds to foot pounds divide the inch pounds by 12 (12 inches in a foot). Going the other way, lb-ft times 12 equals lb-in. Unfortunately I doubt that that a torque wrench calibrated in inch pounds will go up to the torque value for the bolts you're going to be working on since You will need 480 lb-in for the front and 960 lb-in for the rear.

Hope this helps,
Bob

Thanks for the help with the math. I came up with those answers, but amongst the other answers, I couldn't pick them out of the line up!

I did have the very experience you described.
I have two torque measuring socket wrenches:
1) shorter that measures in ft/inches
2) one much bigger that measures in ft/lbs

After I got the correct torque values, I tried setting the smaller wrench for 960. I couldn't bend that wrench enough to get it to click the way they do, so I used the big one! That worked.

I was sure I had a revet master link, but when I took it out, it was clip. I drove to "Cycle Gear" and found them closed, so now I have something to do when I get home today.

The rear wheel is back on. The rear brake caliper (I know that word now) threads over the axel, and then is secured by.... nothing...
That always surprises me. It rests against the swing arm, and that arm stops it from rotating with the disc brake.
It's a simple design, and it works. I like that!

I'm almost done. All that remains is to thread the new chain over sprockets and guides and then add the rivet-clip. That went well last time, and I hope to duplicate that success.

Someone gave a link to "how to determine chain wear", and I need to read that. I don't own a set of calipers for measuring stuff like that, so I'll be looking to get one. I was hoping for a sign (possibly from heaven) that was obvious and direct and said "now is the time to change the chain". I can see myself measuring carefully with calipers, and then scratching my head and going "huh?".... but that's the learning experience.

 

[bamamate]

Generally torque wrenches are most accurate in the middle of their range. I try to stay away from the bottom and top 10-20% of the range if possible. Also clicky type wrenches don’t click very well in the bottom range. I’ve snapped a bolt because of that.

When I changed my chain and sprockets the sprockets looked good but I could feel the saw tooth with my finger especially on the front sprocket. Having a definite wear pattern and the relatively low cost prompted me to change it all as a set.

 

[SergeantChuck]

Also clicky type wrenches don’t click very well in the bottom range. I’ve snapped a bolt because of that.

Caterpillar is almost strickly clicker type torque wreches. We measure by newton metre though. Anyway, we have clickers that torque from 3 Nm (2.2 ft. lb) to 800 Nm (590 ft. lb). The torque required will change the size of the wrench. You won't have a three foot long clicker wrench torguing to 6Nm bolt and vise versa. Clicker type are very convenient, and accurate enough for general usage but the accuracy of these is best in the mid torque range for the given wrench. They tend to skew a little towards the high/low ends. This is why our clicker wrenches are set to a specific toruque and tested regularly to ensure they have stayed within thier range. That is typically +/- 5 Mn from the required torque. I know we can't all afford one wrench per operation. It was just a long explanation to say I agree with Bamamate.