Time to Replace Sprockets?

[arronjackson]

Hey forum,

Wondering if anyone can speak to the life left in these sprockets. Bike has 50,000km [31,000 miles].

Also wondering if anyone has had success ordering chains from a machine shop to save cost.

Thank you,

 

[trepetti]

Definitely looks like sprocket time to me. Front teeth looks really thin......

 

[Gary in NJ]

The front teeth are thin, and I see some cupping on the rear sprocket. There's some life left, so I'd wait until the winter to make the change. Congratulations on taking such great care of the chain - it looks new.

I would get an o-ring or x-ring chain from one of the reputable manufacturers (Renthal, DID...). An industrial chain may work, but a broken chain can be expensive if it smacks the engine case, or worse, put you in the hospital with missing skin and a broken bone. It's not a good place to try to save money.

 

[bigborer]

I'd say the front is 90% done, and the rear about 75%. The chain is definitely at least equally worn.

The life left depends on how hard you ride it and the condition of the chain- are the links binding (first picture suggests so)?, and does it have too much stretch (tension the chain as per the manual, pull a link away from the rear sprocket and take a pic while holding)? If it's not that bad and if you ride it very easily you might get 5000km more. The rubber cush drive from inside the rear wheel are also important- the more worn out (or shrunken by age) they are the more the chain will get jerked and stretched, accelerating the wear. If they have slack (they shouldn't) a ghetto "fix" would be to take away the slack by jamming some bike tube cut to size.

As Gary said, if a chain breaks it could likely hit and break the engine case, or at worst lock the rear wheel and make you crash/die.

If you do decide to ride this chain kit for longer, at least remember to ride it as easily as possible, and to check the tension very frequently. IME the last 20% of the chain wore out 10x faster than the first 20%.

 

[TownsendsFJR1300]

Agreed with all the above, the fronts pretty worn, the rear not as bad.

A new OEM has no master-link but you have to slide back the swingarm some to slide the chain in.
I see "DID" on that chain so I'm not sure that's the original chain...
.

As BB saw and noted, you DO have some links binding up (shown by the front sprocket).

That alone, I'd change them all out. It's way cheaper and safer than throwing the chain thru the case/crashing..

.

 

[arronjackson]

Thank you for all the info.

Is there any downside to going to a 520 chain conversion?

I'm also thinking about going down a tooth in the front or up two teeth in the rear (probably up two in the rear to prevent excessive wear). Does anyone know how many km/h I will lose at top speed or in 5th gear? I sometimes do 140-160km/h highway trips and I don't want the get up and go to be compromised at those speeds.

 

[bigborer]

A tooth down the front will accelerate the wear.

I actually do have a 520 with -1 front and +1 or +2 (can't remember now). It wears faster than a 530.
The speedometer and odometer show about 7-8% more, but there's also 7-8% quicker acceleration. Combined with the leo vince exhaust it feel at least 20% faster than a stock FZ6. You'd certainly go 140-160kmh.

 

[Gary in NJ]

With the stock gearing, 150 kph (93 mph) will result in 7,679 rpm. Changing the sprockets as you suggest raises the rpm to 8,547 at the same speed. The FDR goes from 6.0876 to 6.7758.

 

[arronjackson]

Without sacrificing too much fuel economy I'm leaning towards going 16:48 teeth. As you've said in the past Gary:

15:46 produces an FDR of 6.4934, a change of 6%
16:48 produces an FDR of 6.3523, a change of 4%
16:49 produces an FDR of 6.4846, a change of 6%

 

[trepetti]

Thank you for all the info.

Is there any downside to going to a 520 chain conversion?

I'm also thinking about going down a tooth in the front or up two teeth in the rear (probably up two in the rear to prevent excessive wear). Does anyone know how many km/h I will lose at top speed or in 5th gear? I sometimes do 140-160km/h highway trips and I don't want the get up and go to be compromised at those speeds.

There are lots of arguments about a 520 conversion. As was mentioned, a 520 chain will wear faster. If the only reason to do so is performance, I don't think a street bike will benefit much from the performance increase. I do not know the difference in chain cost, so there might be some value there is the 520 is measurably cheaper.