Gearing conundrum: Stay stock or Not--520 or 525

[kam1996]

Hey guys,

Due to a recent cush drive issue, I am contemplating buying a whole new chain/sprocket kit. I am currently stock, hence the cush drive failure.
While I am getting a brand new chain, front sprocket, rear sprocket and cus drives, I figured why not look into getting a "high maintanence" 520 chain and may be drop/add a tooth for "quicker" acceleration.
If staying stock, both in chain weight and gearing is your suggestion, please take a minute to explain why.

I need to order the "set" my late monday so I woudl greatly appreciate any help.

Thank you

[916duc]

10 years ago I went down one tooth in the front, 15 to 14, ('95-916) which is equal to 2-1/2 up on the rear and never looked back. One of the best mods I did. Much more street-able gearing, and eliminates hunting for the best gear in most speed controlled areas. YMMV.......

[jheurte]

On my 996 I ran 15/40 with a 520 chain. Made a huge difference!

[Ben710]

A good 520 chain is likely to last as long as a 525 chain. I wouldn´t bother about buying one again if I had a 525 setup bike for the street. I equipped my ZX10R with a 525 instead of a 520 chain, because I feel it might be a little stronger than the 520 in the end.

But then I have used 520 chains on my 999R, 916 SPS and now on my 955 SPR. Can´t complain about anything.

I´d just suggest you get a good quality chain, DID (ZVM or ERV3 maybe), RK or Enuma.

On my SPS race bike I ran 15/40, the 999R was setup at 14/38. I was running 15/38 on my 955 SPR, now went for a 14t front sprocket which made it 14/38. I really like it and it´s going to stay as it is.

[socal]

The new sprocket may result in an inaccurate speedo. A speedo healer will correct this. Aftermarket sprockets generally do not last as long as OEM. The advantages to switching, however, are huge- I would do it.

[brad black]

the speedo drive is on the front wheel.

the 996 has the wide ratio gearbox and 1.84 primary drive ratio, and 15/43 works very well on them as an all round ratio. similar to 14/36 on a 916.

[rjjablo]

I went to the 520 on my 748. It allowed me to do the Dept of Suspension mods and lenghten my wheelbase as far as I could. Of course the 748 does not have enough HP to hurt a 520.

Quick Change Sprockets are typicaly proprietary so price out which one you want before you buy. I shortened my ratio and it realy woke up my 748. Of course highway cruising at 80 is a little more frentic

[998R]

I've got an AFAM quick change fitted with 15/40 and a 520.

Awesome combination, and I can assure you it has been thrashed to within an inch of my life with no problems what-so-ever!

[kam1996]

Originally Posted by 998R

I've got an AFAM quick change fitted with 15/40 and a 520.

Awesome combination, and I can assure you it has been thrashed to within an inch of my life with no problems what-so-ever!

Most people have suggested 15/39 but you are the 2nd to be running 15/40.
Have you ever run 15/39, how big a difference from 15/40?

[Ben710]

Not big, you´re going to lose a bit of top speed. But 1 tooth is not going to make a huge difference.

[Desmo Demon]

Originally Posted by rjjablo

I went to the 520 on my 748.

My '02 748 came with the 520 from the factory...and it was absolute toast in under 12k miles and trashed both sprockets. The 520 chain on my wife's Monster was trash in 13k miles.

I have grown to dislike the 520 chains for their seemingly short life and have since changed my 748 to a 525. 525 and 530 size chains tend to last in the 18k-24k range for me, so I can almost double the life of my chains by bumping up from the 520 to the 525. I just wish I could find a front sprocket for the '01 M900ie in a 525. Seems I can only get a 520 for it.

For gearing, I don't have a 996, but I have dropped the front sprocket down to a 14 (from a 15) on both ST2 bikes and the M900ie. The 748 originally had a 14 tooth front, so I went up from a 38 to a 40 on the rear. I have a brand new (freebie) 43 tooth I'm playing around with the idea of slapping on the 748, soon, just to see what it may be like in the mountains.

[john S.]

I've grown cautious with the idea of going down a tooth in the front. When my chain is ready to be replaced on my 999R, I'll be going up in the back while leaving the front alone.

It might be rumor, but there are folks that claim going down a tooth on the front can mess with your transmission gears.

I found a nice looking black Vortex 38 tooth rear sprocket I picked up at Cycle Gear. It was in a clearance bin for $24, I couldn't resist it. I'm not going to do anything with the front then maybe I should get a 40 for the back, not a 38 tooth. Oh well, I figure 2 up is better than nothing and I don't like the sound or sensation of loosing top end. I think 2 up will give me just a little added punch. I'll be going with a strong 520 chain too.

[duc572]

I've run 15/39 thru 15/41 and like the 15/40 the best for the tracks here and when it used to be street ridden. Afam QC and quality 520 chains with proper maint. were great.

[kam1996]

I ended up going with a 15/40 AFAM QC set up.
Now if I can only find some cush drives so I can actually ride this thing

[kam1996]

Thank you all for your help.

I got my bike back on saturday, all I can say is WAO.

The 15/40 520 combo has the bike transformed. First gear is all but usless (for serious acceleration anyways) power wheelies all day in 2nd. All gears pull much harder (almost like getting on a twin for the first time).

Due to my crazy work hours, I never got a chance to weigh t he old 525/Stock chain-sprocket combo, but its safe to say there is significant weight advantage as well.

I did have a moment at teh end of the ride when my "usual" downshift blip wasnt enough for the now shorter gearing and the rear locked up.

All in all, a great investment

[Ben710]

Good to hear you´re enjoying it.

Seems like we´re not that useless after all

[G8RDuc]

Know I'm late to this party, but I went from a 14T front to a 15/42 and loved it. Definitely a different beast.