Changing Rear Sprocket 4 Teeth Lesser

[tatt2dude]

I changed from a 42 to a 40 on my bike to take advantage of extra power and primarily to improve mid range 'cruising" during a commute. It works fine for that. But it is a little slower off the line but only for the first 10m.

I do notice however that at my level of riding when I am in Khao Yai that in some slow corners I am in between gears. Too slow for 2nd too fast for 1st. But then I still get passed on the straights.

Is Khao Yai a track? Excuse my ignorance.

[VocalNeal]

I changed from a 42 to a 40 on my bike to take advantage of extra power and primarily to improve mid range 'cruising" during a commute. It works fine for that. But it is a little slower off the line but only for the first 10m.

I do notice however that at my level of riding when I am in Khao Yai that in some slow corners I am in between gears. Too slow for 2nd too fast for 1st. But then I still get passed on the straights.

Is Khao Yai a track? Excuse my ignorance.

It's the national park north East of Bangkok. It's a favourite short ride for many riders in BKK. The southern part of the park has a few twsties.

Bira in Pattaya and Keang Kachang (spelling again. Not my day today) are the tracks . Also a shorter, twisty one near Nakom Pathom.

Edited January 13, 2010 by VocalNeal

[neverdie]

I would agree with what tatt2 is saying about dropping too many teeth, it has alot more to do than what the gearing commander is showing you.

Theres absolutely no point in having a bike geared to do 650km/h if you need a 500km straight to get it up to 100.

As I said, I would only drop it 2 at a time, you will notice it changes everything, not just the speed ur doing at a certain rev.

I only recommended changing chain and sprockets together, as if ur chain is 3 parts pharked and you put a new one on and it goes on bad sprockets you will phark ur new chain. If ur current chain is good, just go with a sprocket change.

Everytime I replace worn sprockets I go for a fresh chain, but im an old cranky baaastard and im set in my ways.

let us know how you go and again as the tatty dude says, dont drop 8 teeth or even 6, you will regret it.

Is that okay Richard?

[Cobrabiker]

Hi vocalneal, 2 teeth down you can feel a lack of power for pickup, will it be a mistake for me down size 6 teeth, 44 to 38 ?

[neverdie]

Hi vocalneal, 2 teeth down you can feel a lack of power for pickup, will it be a mistake for me down size 6 teeth, 44 to 38 ?

Different horses for different courses.....as its not that great of an expense, why dont you shout urself two teeth down and test the theory out....you will notice a difference and im not talking about speed at a certain RPM but other things such as corner gearing and acceleration will change.

I have a few spare sprockets for my little pocket rocket, I also have 3 carbies, soon 2 cdi's, a pile of pipes, cables, brake bits, carby jets, bibs and bobs, its part of livin the dream, i've even got odd bits for bikes i dont own anymore, im some weird kinda freak

[Richard-BKK]

If you just go down two teeth on your sprocket, it's possible that you not need to change the chain... But the thumb of rule is to change them both as one will have effect on wear on the other...

[neverdie]

If you just go down two teeth on your sprocket, it's possible that you not need to change the chain... But the thumb of rule is to change them both as one will have effect on wear on the other...

whilst i agree with what you are saying Mr Richie, are you offering any 'guarantee's' with what you are saying

[neverdie]

Heres a good article which talks about the pro's and con's of changing sprocket sizes. Its a good read OP and may help you along a little, as i said before theres a little more too it than meets the eye, but subtle changes are best to experiment with.

http://www.sportrider.com/tech/146_0008_gearing/index.html

[neverdie]

More Info:

http://www.webbikeworld.com/t2/motorcycle-chain-sprocket/

[Richard-BKK]

Dear Mr. Neverdie,

As you can read I say YOU CAN us the same chain, BUT THE THUMBS OF RULES is to change both chain and sprocket at the same time... I know some Australians cannot get away with common English understanding...

[neverdie]

Dear Mr. Neverdie,

As you can read I say YOU CAN us the same chain, BUT THE THUMBS OF RULES is to change both chain and sprocket at the same time... I know some Australians cannot get away with common English understanding...

Theres no reason to bring about your rascist remarks Richard, as I said previously I agree with you, but was trying to stir you after you badgering me last night.

You really need to relax a bit and try and understand what humour is, have you had a massage lately? (Ohh and this isnt an offer for one, they're only a few hundred baht anywhere in Thailand).

[Richard-BKK]

RACISTS REMARKS???? Do you know the meaning of this word?

Anyway, what your meaning you just get me over the edge... I will surely tell you in personal what RACISTS REMARKS are...

Edited January 13, 2010 by Richard-BKK

[neverdie]

Anyway, what your meaning you just get me over the edge... I will surely tell you in personal what RACISTS REMARKS are...

Okay, deep breath Richie, I never mentioned the word 'edge' or getting you over one.

So, what am I waiting for now, are you about to send me a personal message or should I look out my office window?

[Richard-BKK]

Anyway, what your meaning you just get me over the edge... I will surely tell you in personal what RACISTS REMARKS are...

Okay, deep breath Richie, I never mentioned the word 'edge' or getting you over one.

So, what am I waiting for now, are you about to send me a personal message or should I look out my office window?

No, you will know when you in trouble when somebody near 2 meters tail and near 100 kilo knocks you on the shoulder...

[BSJ]

As an aside to the ongoing pi$$ing contest.....

Changing the gearing can have an adverse effect on the extra top speed your looking for. I remember my first sprocket change back a few decades when I was looking for more out of my Honda. I was disappointed when I actually went slower! What your always doing is attacking the wind. And the faster you go the higher the wind pressure. The higher the revs the less torque you have and the higher the engine speed the lower the volumetric efficiency. Everything is conspiring against you in your quest to go faster.

So before you change that gearing boys and girl's my advice is to fit a turbocharger, big port heads and a humungus exhaust!

[tatt2dude]

I would agree with what tatt2 is saying about dropping too many teeth, it has alot more to do than what the gearing commander is showing you.

Gearing Commander?

[tatt2dude]

It's the national park north East of Bangkok. It's a favourite short ride for many riders in BKK. The southern part of the park has a few twsties.

Bira in Pattaya and Keang Kachang (spelling again. Not my day today) are the tracks . Also a shorter, twisty one near Nakom Pathom.

Ok.

I know Bira been round it a few times.

Well for anything like a track you are going to be at a disadvantage because you have raised the gearing. By dropping two teeth you have raised the top speed at the cost of acceleration. So basically you will be losing drive and getting passed half way down the straights more than likely by someone who is on a bike with a top speed lesser than yours.

For cruising or on the road you have more than likely gone the right way. By raising your gearing: third gear for example will be a much longer gear so you can more than likely stick the bike in a very usable gear for long periods of time.

Gearing is a real dark art, I know a bit through experience but would not throw my hat in the ring as an expert simply because my results never justified it. People like Rossi, Haga etc... gearing experts!!!

[tatt2dude]

There's is no need to change chain and sprockets unless the sprocket is worn. The shape between the teeth should be a perfect U, as the sprocket wears one side of the U will wear away, on a worn sprocket the space between the teeth takes on the shape of a worn tick.

What mileage is on the original chain and sprockets?

If you go 8 teeth on the FZR this is what will happen: You will have to break harder as your engine will not slow you as much going into corners. Off the line the bike will be much slower if not a slug, first gear and all your other gears will be much longer so it will take you longer to reach top speed. Power delivery will change, and the hit that you start to get at 3500 will not come until 5000. Forget Wheelies, unless you clutch it and please don't do first gear wheelies with a first gear that long, not going to end well!

If you don't get your chain and sprocket combination right: You will lengthen or shorten the wheelbase, this will change the way the bike steers. Given in a previous thread you are possibly thinking about speeding up the steering I would take baby steps with regard to radical gearing change.

You go one tooth up at the front: I doubt very much you will need new chain and you will not be making dramatic changes to wheelbase, the wheelbase will be a smidge shorter. You will experience all of the above effects/changes but to a much lessor degree. It will be noticeable!!

OK HERE IS THE MILLION DOLLAR QUESTION!

How do you like to ride?

If sitting on Motorways watching the world go by at a steady 80mph never having to change gear again is your thing, then go the direction your going and stick it in third. If you like wheelies, track days, track style ridding then go no where on the front and two on the back that will give you the thrills and you can pick it up on the back wheel in second off the throttle. It will be very usable on a track day. And if you like that direction then drop one off the front for a stunt bike.

[Cobrabiker]

Hi Neverdie, thanks for the articles, interesting read. I am willing to sacrifice pick up and wheelie for lower rpm at top gear, I will be cruising a lot at the speed of 120 to 200, so I guess changing down to 38 teeth may suit my driving style.

Tatt2dude, I am not a track fello, but a highway cruiser, so I guess it is ok for slightly slower acceleration, but I don't have a clue of how much slower, do you think downsize 6 teeth will be at about 10% loss on acceleration at standstill? If it is 10%, then will be ok for me. Maybe Neverdie can do a indepth research on this, and I know there is no free lunch on this planet, so I have reserved a masseur for him, she is definitely a heavy weight class in this industry.

And also, I am using 530 chain with 16/44 teeth, if I change to 16/38, what chain should I use? 520 or 525?

[katabeachbum]

Hi Neverdie, thanks for the articles, interesting read. I am willing to sacrifice pick up and wheelie for lower rpm at top gear, I will be cruising a lot at the speed of 120 to 200, so I guess changing down to 38 teeth may suit my driving style.

Tatt2dude, I am not a track fello, but a highway cruiser, so I guess it is ok for slightly slower acceleration, but I don't have a clue of how much slower, do you think downsize 6 teeth will be at about 10% loss on acceleration at standstill? If it is 10%, then will be ok for me. Maybe Neverdie can do a indepth research on this, and I know there is no free lunch on this planet, so I have reserved a masseur for him, she is definitely a heavy weight class in this industry.

And also, I am using 530 chain with 16/44 teeth, if I change to 16/38, what chain should I use? 520 or 525?

only done it once, Suzuki GT 100 in 1978. From 51 to 46 rear sprocket, changed from 90 to 110 top speed. at 11000 rpm as I recall

[tatt2dude]

Hi Neverdie, thanks for the articles, interesting read. I am willing to sacrifice pick up and wheelie for lower rpm at top gear, I will be cruising a lot at the speed of 120 to 200, so I guess changing down to 38 teeth may suit my driving style.

Tatt2dude, I am not a track fello, but a highway cruiser, so I guess it is ok for slightly slower acceleration, but I don't have a clue of how much slower, do you think downsize 6 teeth will be at about 10% loss on acceleration at standstill? If it is 10%, then will be ok for me. Maybe Neverdie can do a indepth research on this, and I know there is no free lunch on this planet, so I have reserved a masseur for him, she is definitely a heavy weight class in this industry.

And also, I am using 530 chain with 16/44 teeth, if I change to 16/38, what chain should I use? 520 or 525?

In that case you are going in the right direction.

6 teeth is a huge leap. Many of the posters in this thread are referring to two strokes, you can make radical changes on a two stroke. We used to race 125's (I was racing from 12 years old to 40 years old so been around!) and we once got a maximum (4 wins) from a sixth place qualification simply by throwing the biggest rear sprocket we had in the box on the bike.

4 stroke Thousands are a different beast altogether. A slight change will make a noticeable difference. The manufacturer has already geared your bike for your riding style (in their opinion), they believe most of their customers want to cruise, so really you just need to fine tune.

I don't know how else to say what I am trying to say! So lets try this:

YOUR CHEAPEST ROUTE TO SUCCESS!!!!!

Get a standard front sprocket one tooth more than you have already. Dont worry about chain rear etc, just fit it and then ride the bike for 50 klicks. You will know instantly if it is right, wrong or in the right direction but you need more!

From there you can spend your money in the right direction. Big bikes are all about feel and your riding style. Giving you an exact answer as to a 10% loss of power is not possible, nor is it possible to research it on a website, everything will go on manufacturers stated power output. If anyone has ever raced or modified a big four they will tell you those figures are a complete nonsense. So again it depends on your bike, it could be a Friday night pig that is already down on power or it could be a golden nugget engine producing R1 power, in which case gearing it down will work better for you. You wont find that answer on a forum but you will on a dyno.

Given your riding style suggests mileage I would actually use standard chains and sprockets, they are heavier but they are harder wearing, as soon as you go the performance/race route then you are saving weight and looking cool but be prepared to replace chains and sprockets regularity in comparison with standard.

Where are you based? If it's in Pattaya and you need a hand give me a holla. Once you have done a front sprocket it is easy, first time from factory can be a bitch as they torque the nut to extremes.

[neverdie]

Anyway, what your meaning you just get me over the edge... I will surely tell you in personal what RACISTS REMARKS are...

Okay, deep breath Richie, I never mentioned the word 'edge' or getting you over one.

So, what am I waiting for now, are you about to send me a personal message or should I look out my office window?

No, you will know when you in trouble when somebody near 2 meters tail and near 100 kilo knocks you on the shoulder...

I'm laughing but probably shouldnt be, how on earth did you end up with a tail that is 2 metres long. Must be hard to ride your Ducati with that thing wound up on the pillion seat.

Of course it probably wouldn't surprise you Richie, but Im really not intimidated by someone on the internet proclaiming to be this or that & I managed to survive 2 decades of street policing without having my backside kicked, so I'm not really feeling too threatened right now .

Anyway, thanks for all your help here, I'm sure the OP has really benifited from the dribble you have contributed.

[Cobrabiker]

Hi Vocalneal, I like to ride at high speed on the highway from 120 up to 200 and up when the road is cleared, and it is not just a burst, but it is rather as long as the traffic would allow so dropping the rpm by 1000 with a 6 teeth lesser sprocket will help on fuel economy and also lesser stress to the engine.

From your personal experience with a 8 teeth smaller sprocket, how much loss in power in acceleration from total standstill? can you give a rough estimate?

I am very tempted to drop another 2 teeth if the 6 teeth drop is still enough to power the 1st gear acceleration, so your experience is very valuable if you can give more details on standstill acceleration.

[Cobrabiker]

Hi tatt2, Yamaha realises the gearing problem and have made the 2nd generation a taller 5th and 6th gear, for 1st generation high speed tourer, it is gonna be DIY. Where in Pattaya can I get it done? Where can I find 38 teeth rear or a 18 front sprocket for my bike? The mechanic couldn't find and I may have to order from the internet.

The mechanic told me it is hard to change the front, if you know someone can do it, I may consider changing up to 18 teeth front, is about 5.5 teeth rear.

[tatt2dude]

Hi tatt2, Yamaha realises the gearing problem and have made the 2nd generation a taller 5th and 6th gear, for 1st generation high speed tourer, it is gonna be DIY. Where in Pattaya can I get it done? Where can I find 38 teeth rear or a 18 front sprocket for my bike? The mechanic couldn't find and I may have to order from the internet.

The mechanic told me it is hard to change the front, if you know someone can do it, I may consider changing up to 18 teeth front, is about 5.5 teeth rear.

From what I just read Yamaha went up one tooth on the rear on later models. You have a 2004 Fazer right 141bhp?

If you need to go one tooth up on the front to try it, have a socket for the nut, a paddock stand, either a torque wrench or strong ratchet with a scaffold pole then call by my place in Pattaya and I will help/show you how to do it. It is not hard to do at all, it requires effort, there is a difference. And seriously if changing a front sprocket is beyond your mechanic (Or for that matter is anymore than 30 min labor) stop referring to him as a "mechanic".

Going 6 down on the back your on your own unless you buy new chain and sprockets, you will need open ended spanners for the adjusters as well. I always used Talons in the UK for all my chains and sprockets search Talons sprockets in google.

However: before you do anything check 16/44 is standard gearing, I had a quick look on the web but could not find the standard set up.

[VocalNeal]

If my math is correct your choice of 38 is to get new 5th gear to equal current 6th and therefore new 6th would be like an overdrive.

This seems OK as long as you realize that 1st gear also rises. As you say, if it pulls OK, off the line and you realize that you won't just be able to sit at 120 and simply twist the throttle and zoom up to 200 like you can now. You will have to drop down a gear to get the same performance. For "relaxed" cruising I would think that 6th gear roll on - roll off performance, if that is the correct expression, would be more important than actual RPM.

Changing the front in theory maybe easier but going to 17 of course has more effect than your 38 choice.

You'll just have to try it and see. I found the FZ1 forum have you searched there or asked the same question?

Edited January 14, 2010 by VocalNeal

[tatt2dude]

For "relaxed" cruising I would think that 6th gear roll on - roll off performance, if that is the correct expression, would be more important than actual RPM.

If it is an expression then it's one I have never heard. However I tip my hat to you.... for mathematically answering the question in theory. All I can say is wow . I am sold, drop it 6 teeth and let us know how it goes

[Cobrabiker]

Yap, I want the 6th gear to be a overdrive, but how much power loss you experience on your 1st gear after the change from a standstill, I would like to know before I go ahead.

[tatt2dude]

Yap, I want the 6th gear to be a overdrive, but how much power loss you experience on your 1st gear after the change from a standstill, I would like to know before I go ahead.

Dude no one can give you that answer. Anyone who claims they can from a website or through doing some "math" is bs'ing you to look good on a forum.... the only person who can tell you that is someone who has done it. So unless anyone on TV has dropped 6/8 teeth on the rear of an FZR you are asking the wrong question on the wrong forum.

I have some experience with gearing. I have made several genuine post to help you, all with the same message "do it step by step", it is genuine well meant advice but I cant make you listen to it can I as it's not what you want to hear.

If you want overdrive buy a dolomite sprint.

[Cobrabiker]

Hi tatt2, be cool, I have read every post and I appreciate your advice, as well as everbody's, but since vocal has done the change, he should be able to feel the difference, before and after, I am not asking for a detail dyno graph, but a simple personal feel should be able to judge how much approximately the acceleration has lost power, compare to before the change. Just like now if I change to a K & N filter, I should be able to tell how much better the bike rides, it is a personal feel, not a review, so no need to worry about getting a lawsuit or taking responsibility. Hope you understand.