Any advice on performance & sprocket mods?

[gib422]

My 2001 FZ1 has about 30K miles on it. The rear sprocket has somewhat of an oval shape to it and needs to be replaced (aluminum - really???) So I've searched the forum, and read the two mods on Pat's Motorcycle Page for the 15 tooth front sprocket change and the 15/47 front/rear change.

It seems that most forum posts on the subject have the -1 tooth on the front (15T). I'm a very tame rider, I've never done (or want to do) a wheelie, and the bike has gone about 150mph twice in the almost 19 years I've owned it. This is my "really fun" commute-to-work bike, 50/50 neighborhood/highway use.

It's always kind of bothered me how little difference there is between 5th and 6th gear at legal highway speeds, but I don't want to get too far away from the OEM specs. I'm just looking for real world pros & cons advice from FZ1 riders who've done sprocket mods. Thanks, Tim

[treeguy]

Those mods will produce easy wheelies. IF you want to.
I run that combo. It makes for instant no downshift acceleration at highway speeds.
It also makes for easier slow traffic riding due to less clutch work.

[LiquidSilver]

The original rear sprocket is steel. Your first step should be to find out what you really have on it now first.

[Desmo]

An oval shape? Wtf?

There should be a number stamped on it that indicates how many teeth it has. As LS said, that’s not stock.

[iluvmyfz1]

I pull wheelies in 1st and 2nd, the bike accelerates very nicely even while 2-up, and I sure don't want more revs while on a highway run at 80-90. Stock gearing works for me, but the -1 on the front is common mod for some. Plus, the smaller sprocket gets more wear per mile, so, no thanks.

[fermic37]

Originally Posted by gib422

, I've never done (or want to do) a wheelie,

then put OEM size steel sprockets back on the bike.

[gib422]

Thanks for the replies! This helps me decide how to proceed. Also, please ignore my "aluminum" comment. That is what my cycle mechanic told me. This is the OEM 44T steel rear sprocket.

Also, the "oval" description is an exaggeration. What is happening is the chain will tighten and loosen as the wheel turns. I'm assuming a warped rear sprocket (hence the "oval"). My only workaround for right now is too have a little extra chain slack.

Smaller front sprocket and/or larger rear sprocket means more engine revs to go a certain distance. Which also means worse gas mileage, an inaccurate speedometer and more wear & tear on components. Make sense?

I'm leaning toward leaving it at the OEM specs: front sprocket at 16T and rear at 44T. I'll also do some of Pat's math to see what a 16T/46T does.

[oldjeep]

Tightening while turning indicates a chain that is stretched or links that are not pivoting smoothly . Highly doubtful it is a sprocket issue.

[grommet]

When you change the rear sprocket, ignore the torque specs in the manual for sprocket nuts. They are fairly soft metal and will strip or break if the specified torque is applied. I forget what the real recommended number is from users here, but it's quite a bit less than the spec.

[Desmo]

Originally Posted by gib422

Also, the "oval" description is an exaggeration. What is happening is the chain will tighten and loosen as the wheel turns. I'm assuming a warped rear sprocket (hence the "oval"). My only workaround for right now is too have a little extra chain slack.

Never seen a warped sprocked. Would suspect the chain is shot. Check for links that are not flexible.

[iluvmyfz1]

Originally Posted by grommet

When you change the rear sprocket, ignore the torque specs in the manual for sprocket nuts. They are fairly soft metal and will strip or break if the specified torque is applied. I forget what the real recommended number is from users here, but it's quite a bit less than the spec.

IIRC, the manual states in the high 30's lb/ft. I used Loctite 222, which is low strength, and 15 lb/ft. That was 33k miles ago.

Also, the service manual calls out over 100 lb/ft for the axle nut. I stop at at about 80 for that. I've also been thinking about drilling for a cotter pin, but 70k and several rear tires, no issues so far.

Also, it sounds like tight spots on the chain causing the tightening/loosening as the wheel is rotated. Usually once the chain develops tight spots, it is toast. With a 116 link chain you have 232 o-rings, which are there to keep the factory applied grease inside and prevent water/contaminants outside. All it takes is for one of those o-rings to become compromised, and chain destruction sets in.

Keep it (mostly) clean and rust free for many miles of trouble free operation.

[oldjeep]

Originally Posted by grommet

When you change the rear sprocket, ignore the torque specs in the manual for sprocket nuts. They are fairly soft metal and will strip or break if the specified torque is applied. I forget what the real recommended number is from users here, but it's quite a bit less than the spec.

Thought it was just me, or someone had replaced the factory nuts with some low grade stuff. Wound up replacing with some graded nylocks after I stripped 2 of them going to the factory spec.

[Desmo]

Originally Posted by iluvmyfz1

Keep it (mostly) clean and rust free for many miles of trouble free operation.

Could you recommend a good chain lube?

[grommet]

The chain is definitely done. Best to replace it before it breaks and puts a hole in your engine case.

I am unable to recommend any chain lube products.

[Fozzy1]

I use PJ1 Black Label chain lube every few rides. Just a quick spray before I ride and I'm good to go

[fermic37]

order from here when you do, that chain is shot

http://pjschurchofspeed.com/product-...sprockets-fz1/

[iluvmyfz1]

Originally Posted by Desmo

Could you recommend a good chain lube?

Nickel boron nitride.

[gib422]

Wow everyone, I'm so glad for all the discussion! Desmo and OldJeep are probably right, because as I introduced more slack into the chain, I see where the links are uneven and "sticking" now. And there is a little rust on it too. So I'll try cleaning and lubing the chain before doing any sprocket mods. Then a new chain first before anything else. Great forum! - Tim

[Desmo]

I see where the links are uneven and "sticking" now.

No amount of lubing and cleaning the chain will help. Those links are toast, and so is the entire chain.

[iluvmyfz1]

What he said.

Start with a fresh chain and sprockets, maintain, then .