Gearing -1/+2 vs stock/+5

[BrianShaw]

Is there a benefit of one over the other for an increase in gearing. I know most say to go -1/+2 (14/42) but it seems like running a stock/+5 (15/45) would give the same/similar gearing with less stress on the chain.

This would be in conjuction with a 525 to 520 change at the same time along with a speedo healer.

[Wrider]

Um I would say to do the 1/2 personally. The reason to switch to the different gearing and smaller chain is for lighter weight and more acceleration right? If you do the stock/+5 it will require a longer chain, negating some of the gains...

[Zach929rr]

520 chain is completely unnecessary

[spideyrdr]

1) A +5 would more than likely require a longer chain, which might not be a concern if you're replacing anyway, but could find out that longer chain costs disproportionately more. And a +5 sprocket might also be harder to come by.

2) And now you're spending a little more HP spinning the extra links and larger sprocket, which is probably negligible but is still of consideration when debating the two.

3) Finally, a bike with a +5 rear sprocket might look like it's got a pizza pan on it - where aesthetically a -1/+2 is likely going to be less of a noticeable change.

All small considerations, but if you were to compare the two options, wherein you end up with the same gear ratio, I can't see why you wouldn't do the 14/42.

[madvlad]

520 chains will wear out rather quickly mainly given that the gearing you're looking at is more aggressive for acceleration. Also going down in the front is a lot cheaper and all you have to do is adjust your chain slack. Unless you need chain and sprockets all together and have to spend on them then well yea, also stay away from aluminum sprockets, they'll wear out quickly.

[BrianShaw]

I guess my logic is a little off then.

I figured that the 4-6 (just a guess) extra links of 520 compared to the standard 525 would still be a quit a bit lighter.

I figured I would still have to cut the 120 link chain even with 15/45 gearing.

There are a lot more options in 520 setups than 525 for my Ninja.

A stock 07-10 ZX6R runs a 16/43, 520 stock (compared to my 98's 15/40, 525) and they would go to a 15/45 for the same setup.

I was under impression that chain wear had more to do with the front sprocket size than the rear. Same reason you dont just go to a -2 in the front. Chain wear and theoretical loss in torque.

[Wrider]

No not really. It can bind the chain if you go down to 13 or (rarely) 14.

Honestly I'd stick with a 525 and -1/+2 if you can find it. Otherwise I'd go with a 520 in the -1/+2.

How many links are in the stock setup on your bike? If you do the -1/+2 you'll probably add a link, maybe two to stock, but if you do the +5, it will add quite a few.

[TFOGGuys]

Stock gearing on your bike should be 15/40. Chain wear is generally accelerated if you go smaller than 14 teeth on the front sprocket. You are correct that there are vastly more options in 520 than 525, but the 520 chain will usually last about 80% as long under similar conditions. Definitely go with a steel rear sprocket, as they will outlast aluminum by a factor of 3 or 4.

[BrianShaw]

I was actually looking at the "Driven", 520 Steel, front and rear sprockets.


Driven 520 Steel Sprockets
Every Driven USA sprocket is manufactured to a rigorous standard of quality which is unsurpassed in the industry
One of the lightest 520 steel sprockets available today
Designed using our proprietary EST Technology
Performance and longevity all in one sprocket
Attractive black zinc semi-gloss finish
Lowered surface to remove unnecessary weight

[Matty]

Stock gearing on your bike should be 15/40. Chain wear is generally accelerated if you go smaller than 14 teeth on the front sprocket. You are correct that there are vastly more options in 520 than 525, but the 520 chain will usually last about 80% as long under similar conditions. Definitely go with a steel rear sprocket, as they will outlast aluminum by a factor of 3 or 4.

Call this guy ^^^^ pick his brain, and order your chain and sprocket combo from him as well.

[vozproto]

If the chain is tensioned and maintained properly (clean and lube) the 520 will last you quite some time. Arguably longer than most people ride their bikes.

I have had numerous r6 race bikes as well as a street bike with the RK 520 -1/+2 conversion that hadn't had a single problem.

The street bike had 15k miles on the chain and it still looked brand new.
The key is the upkeep and the tension.

As for sprocket size, I'd say definitely go -1/+2 as that keeps it so you can go up or down a little bit on either end without issue whilst keeping the rotational mass to a minimum as that is what the 520 conversion is all about.

Oh and I personally didnt have any real issue with wearing out aluminum rear sprockets as far as street riding went.