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.

Hello?

OK: for a steel sprocket on a standard chain your options are going to be 42-45 teeth so you will have to go aluminum to get what your looking for: 38

Try these people: http://www.sprocketspecialists.com

[Cobrabiker]

Hi tatt2, thanks for the link, if I change the front to 18 teeth steel, can the old chain accomodate the bigger sprocket?

[tatt2dude]

Hi tatt2, thanks for the link, if I change the front to 18 teeth steel, can the old chain accomodate the bigger sprocket?

Yes it should. Just check the chain adjusters on the rear of the swinging arm to check there is plenty of movement, the wheel is going to move forward toward the engine so you will have to wind the adjusters in. From memory it should not be a problem on a nicely run in chain that has already stretched.

[neverdie]

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.

I'm not sure anyone here did some 'math' to try and tell the OP how his bike would accelerate in certain gears, I believe I was the only one that did some math and that was used to tell him how fast he would be going at a certain RPM.

The OP is entitled to speak with as many people as he likes about this, or was he just supposed to listen to what you have to say about it because of your 'god' status or something. Seems like you need a relaxed overdrive gear yourself .

Edited January 16, 2010 by neverdie

[tatt2dude]

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.

I don't post in that many threads, I tend not to unless I know what I am talking about. From what I have read of your posts it's an attitude you Neverdie could well adopt. Unless we were all meant to drop our jaws in awe at your ability to google gear ratios I have no idea why you posted, you CLEARLY don't know what your talking about with regard to this subject: But don't let that stop you.

Excuse me for trying to point the OP in the right direction.

Edited January 16, 2010 by tatt2dude

[tatt2dude]

Using a age old method, that I have used thousands of times I calculate the following. I can let you in on my secret later, after you asked me, "How the F did you do that neverdie" question.

God Like?

OR GOOGLE LIKE?

And it's not age old, my dad used to change sprockets on his bikes before the interweb. I think your time would be better spent trying to wind someone else up don't you?

[neverdie]

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.

I don't post in that many threads, I tend not to unless I know what I am talking about. From what I have read of your posts it's an attitude you Neverdie could well adopt. Unless we were all meant to drop our jaws in awe at your ability to google gear ratios I have no idea why you posted, you CLEARLY don't know what your talking about with regard to this subject: But don't let that stop you.

Excuse me for trying to point the OP in the right direction.

Well that would be an interesting thread, perhaps everybody could adopt the same principals as you and not post .

Unlike you though, I don't feel the need to qualify myself constantly and tell everyone how much I know & how much all the others are wrong .

Again, you might like to point me to the incorrect information I posted, as for my part was merely answering the OP's question as to what speed his motorcycle was travelling at a certain RPM based on a set of sprockets. All the other comments I made were strinkingly similar to what you have said (without the attitude). So does that make us both wrong now?

Another example of the old antage, "You don't need a long neck to be a goose".

[tatt2dude]

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.

I don't post in that many threads, I tend not to unless I know what I am talking about. From what I have read of your posts it's an attitude you Neverdie could well adopt. Unless we were all meant to drop our jaws in awe at your ability to google gear ratios I have no idea why you posted, you CLEARLY don't know what your talking about with regard to this subject: But don't let that stop you.

Excuse me for trying to point the OP in the right direction.

Well that would be an interesting thread, perhaps everybody could adopt the same principals as you and not post .

Unlike you though, I don't feel the need to qualify myself constantly and tell everyone how much I know & how much all the others are wrong .

Again, you might like to point me to the incorrect information I posted, as for my part was merely answering the OP's question as to what speed his motorcycle was travelling at a certain RPM based on a set of sprockets. All the other comments I made were strinkingly similar to what you have said (without the attitude). So does that make us both wrong now?

Another example of the old antage, "You don't need a long neck to be a goose".

Yeah as I said. Your time will be much better spent winding someone else up, or on google solving other peoples problems for them unless you really enjoy making yourself look this foolish:

I can let you in on my secret later, after you asked me, "How the F did you do that neverdie"

Great qoute, you mind if I use it in my signature? How do you deal with the cringe factor?

[neverdie]

I will ask you the question again (perhaps english isnt your first language).

What information did I provide that was technically wrong? Where is the incorrect information I provided?

Don't you feel slightly embarrassed that virtually everything I have said is the same as what you said, except I am so wrong and you are so right?

Of course you wont answer my questions, how could you.

[SeanMoran]

Eh Cobra'? Aren't you glad now you didn't ask any complex questions here?

[neverdie]

Eh Cobra'? Aren't you glad now you didn't ask any complex questions here?

Maybe he could get tatt2dude's advice for building a couple of spare gearboxes & use a real mans tool for addressing gearing issues.

I can just read the black ink on the pasty white skin now, "I am da man"

edit: by mistake

Edited January 16, 2010 by neverdie

[SeanMoran]

Eh Cobra'? Aren't you glad now you didn't ask any complex questions here?

Maybe he could get tatt2dude's advice for building a couple of spare gearboxes & use a real mans tool for addressing gearing issues.

I can just read the black ink on the pasty white skin now, "I am da man"

edit: by mistake

I just figured that swapping a 44 for a 40 would see a reduction in RPM at a constant velocity of the reverse of the 10% that moving from a 40 to a 44 would cause - around 9% reduction in revs. Acceleration is all in the right wrist and the left foot, but it sure has been an entertaining thread here.

I'm hoping that someone has the audacity to bring up the subject of carbies and mainjets or tuned-length extractors oneday soon, for if this is any indication, a thread like those would run for 100 pages!

[neverdie]

^ .

I wish I was one of the 'blessed' few that knew everything. Must be difficult to ride a bike with such a big ego.....maybe he has a sidecar

[tatt2dude]

I will ask you the question again (perhaps english isnt your first language).

What information did I provide that was technically wrong? Where is the incorrect information I provided?

I dont believe you supplied any information, you "borrowed" some to make yourself look "fascinating"

Don't you feel slightly embarrassed that virtually everything I have said is the same as what you said, except I am so wrong and you are so right?

Not even slightly. Without re-reading your posts (sorry I have a life outside of the internet) I seem to remember you getting into some sort of pissing competition with quite a large gentleman who I seem to remember you upset after he outed you for "borrowing" information to make you look "fascinating".

Of course you wont answer my questions, how could you.

Will that do? I am guessing not. I am getting the impression you are some sort of internet jedi who will hound me until you have the last word, well feel free, you can have it. BUT can I correct you on one matter: I did not say you dis-agreed with me, I just said you don't know what your talking about, subtle difference?

Instead of trying to own me with obscene gesturing emoticons you could of course prove me wrong!

Using a age old method, that I have used thousands of times I calculate the following.

So when did you last use this method and on what... do tell Crack on the last word is yours......

[SeanMoran]

^ .

I wish I was one of the 'blessed' few that knew everything. Must be difficult to ride a bike with such a big ego.....maybe he has a sidecar

I do consider myself lucky that this hotel has security-boxes so that I can leave my brain in safe-keeping before I get on the Honda, and the small ones on the top shelf fit my requirements quite well, but there are some double-sized lockers down the bottom that could look after egos like those without the rigmarole of a sidecar to steal away the enjoyment of the left-hand sweepers on the highway.

[VocalNeal]

2006 version when first introduced had distinct throttle snatch at 5000–6000 rpm, where rolling off the throttle and rolling back on caused a distinct surge in acceleration due to faster opening of the sub-throttle plates or secondary flies.

So now you know. Still no one can be expected to know everything. Seems mathematics or wed surfing is your strong point.

I know Cobra wants to reduce fuel consumption and reduce revs I was merely pointing out that he may suffer noticeable performance drop in 6th (cruising) gear and hence have to drop down a gear or more to get rapidly from his quoted 120 up to his quoted 200.

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.

Hello? OK: for a steel sprocket on a standard chain your options are going to be 42-45 teeth so you will have to go aluminum to get what your looking for: 38 Try these people: http://www.sprocketspecialists.com

I love it when all the experts get together. Seems the prosecution can rest.

Are you suggesting that I don't have a steel 40T sprocket?. You are welcome to come over and count them. 7/11 is only about 100m away if you give me 5mins notice I’ll get the beer in before you get here.

My hat,my coat I'm outa here.

If you lie down with dogs, you'll get up with fleas, and that's the fruits of travelling with a fool.

Edited January 16, 2010 by VocalNeal

[tatt2dude]

It was an entertaining thread to actually talk on a subject that I have some experience with and have made many mistakes with. Sorry if my passion was interpreted as "attitude" I am genuinely trying to help the OP not make the same mistakes.

Carbs, jetting and gearbox internals actually go over my head. I know a few very good engineers who I would pay to do that work as they are specialized and very highly skilled at what they do. However gearing is very much down to riders to determine. So if it's a gearing thread I can piss as high as all of you. But if we are going to get really technical, then that would be time for me to bow out.

I could I suppose get the information from google or one of the road race forums, or even phone my old mechanic in the UK between posts to make it appear that I know what I am talking about, but that's a bit weird really dontcha think?

But hey, thanks for pointing out what a cock I have been for speaking from experience. I now know my place.

[SeanMoran]

It was an entertaining thread to actually talk on a subject that I have some experience with and have made many mistakes with. Sorry if my passion was interpreted as "attitude" I am genuinely trying to help the OP not make the same mistakes.

Nothing personal mate. It's just been a most entertaining thread so see how together we've taken something so simple and complicated it to bejesusbelt and back. Sanuk maak maak!

[tatt2dude]

It was an entertaining thread to actually talk on a subject that I have some experience with and have made many mistakes with. Sorry if my passion was interpreted as "attitude" I am genuinely trying to help the OP not make the same mistakes.

Nothing personal mate. It's just been a most entertaining thread so see how together we've taken something so simple and complicated it to bejesusbelt and back. Sanuk maak maak!

some reaction, is there like a TV internet patch gang and you all pm each other if something "goes down" in the bikes in Thailand section.

[SeanMoran]

It was an entertaining thread to actually talk on a subject that I have some experience with and have made many mistakes with. Sorry if my passion was interpreted as "attitude" I am genuinely trying to help the OP not make the same mistakes.

Nothing personal mate. It's just been a most entertaining thread so see how together we've taken something so simple and complicated it to bejesusbelt and back. Sanuk maak maak!

some reaction, is there like a TV internet patch gang and you all pm each other if something "goes down" in the bikes in Thailand section.

Not for me. I wanted a CBR150 and I thought that was what I'd purchased sight-unseen until the next morning when I picked her up and discovered that she is a 125 two-stroke lookalike and they refused to let me join the owners' club, so I'm a loner here.

Riding a bike in Thailand though, is something that I have at least two very good reasons to be extremely superstitious about, and the most important thing I reckon about it is to smile as much as possible ... while we still have the face to do it.

[neverdie]

I dont need the final say tatty, but I will answer your question. After spending my life working with numbers I don't find it difficult to apply a mathematical formula.

You are partially right about the use of the internet for my calculations.....do you think I store the OP bikes final drive ratio inside my head? Ohh & I mentioned that before as well.

As for the calculations, the relationship between engine speed & road speed is determined by the characteristics of the drivetrain, from the crankshaft to the tires. I used information recorded by both Yamaha regarding gear ratio(s) and the final drive ratio and the rolling circumference of the tires to calculate the speed obtained.....hence you might recall my initial confusion with sprocket sizes. There is obviously room for error in my calculations because I also used the method of obtaining rolling circumference from the tire-size designation, which depending on manufacturer isnt always an accurate way of doing it, as it doesnt take into account the exact tyre fitted to the bike & its 'real' rolling circumfrence. Again I also 'assumed' that the rest of the bike was stock standard and of course this in hindsight obviously isnt the best thing to do.

Something else I mentioned in this thread earlier, prior to you opening your trap, I have used gearing charts and sights like gearingcommander & a few others before and found them to be reliable. I just ran past the quoted speeds I used and they were that different to the some of the gearing calculators online, so again, I can't see the problem you have with what I have said, except for the fact that you want to be seen as something like a biking guru and thats a label you can keep for yourself, because unlike you I believe its never possible to know everything. You may notice that I failed to make wild accusations about horsepower & torque & riderability of the bike after making such changes.

Anyway, no doubt you have an important gearing meeting to get to, it must be difficult with all those racing teams, world champions & motoring organisations on the phone all the time .

Have you ever thought about writing a book? Do you do autographs? Thankyou for educating us all, I don't know what I would of done without it. Also for your information, Ive never owned nor seen a motorcycle, I mean compared to you, I'm still a schoolboy dreaming of my first Pee Wee 50 or something.

[neverdie]

Carbs, jetting and gearbox internals actually go over my head.

Blast, thats a real shame because I'm having a Carb and jetting problem at the moment, perhaps you might be able to help me develop a fuel injection system for my scooter

[neverdie]

It was an entertaining thread to actually talk on a subject that I have some experience with and have made many mistakes with. Sorry if my passion was interpreted as "attitude" I am genuinely trying to help the OP not make the same mistakes.

Nothing personal mate. It's just been a most entertaining thread so see how together we've taken something so simple and complicated it to bejesusbelt and back. Sanuk maak maak!

some reaction, is there like a TV internet patch gang and you all pm each other if something "goes down" in the bikes in Thailand section.

Do you also feel as if someone is watching you or following you around all the time?

[neverdie]

It was an entertaining thread to actually talk on a subject that I have some experience with and have made many mistakes with. Sorry if my passion was interpreted as "attitude" I am genuinely trying to help the OP not make the same mistakes.

Nothing personal mate. It's just been a most entertaining thread so see how together we've taken something so simple and complicated it to bejesusbelt and back. Sanuk maak maak!

some reaction, is there like a TV internet patch gang and you all pm each other if something "goes down" in the bikes in Thailand section.

Not for me. I wanted a CBR150 and I thought that was what I'd purchased sight-unseen until the next morning when I picked her up and discovered that she is a 125 two-stroke lookalike and they refused to let me join the owners' club, so I'm a loner here.

Riding a bike in Thailand though, is something that I have at least two very good reasons to be extremely superstitious about, and the most important thing I reckon about it is to smile as much as possible ... while we still have the face to do it.

Sean, I'd much prefer one of those ones compared to the real cbr.......no doubt the Honda riders will be here shortly to take my head off.

[SeanMoran]

[quote

Not for me. I wanted a CBR150 and I thought that was what I'd purchased sight-unseen until the next morning when I picked her up and discovered that she is a 125 two-stroke lookalike and they refused to let me join the owners' club, so I'm a loner here.

Riding a bike in Thailand though, is something that I have at least two very good reasons to be extremely superstitious about, and the most important thing I reckon about it is to smile as much as possible ... while we still have the face to do it.

Sean, I'd much prefer one of those ones compared to the real cbr.......no doubt the Honda riders will be here shortly to take my head off.

She's certainly entertaining, especially now that I've made that change from a 44 tooth rear sprocket to the 36 she wears now, because the scenery passes by quite a bit faster than before by the sound of it.

ND though, although I admire your understanding of gear ratios and such, is it not just a matter of, (with a simple change of the sprocket that drives the back tyre after being rotated by the chain), the simple arithmetical calculation for that one adjustment?

Everything else being equal, apart from the rider's ability to change gears at the oportune moment, does not a change in rear sprocket size equate very closely to that simple mathematically derived percentage? I know that the engine will feel as though there is around 10% more mass to accelerate with the same force it had previously, but that's what the gearbox is for. It's just up to the rider to watch the tacho and realise that she'll take a little longer to reach 10,000 rpm through the gears, but the back tyre is traversing 10% more road throughout each change, and 10% more gently at that.

We're not racing 500s here, but just cruising, so if all the rest remains the same, it's not rocket science is it?

[neverdie]

Sean,

I agree completely with what you are saying & the mathematical equations are definately only 'part' of it all. I guess thats why you get different riders in race teams with different set ups, the rider being the key factor.

I have found in my humble experience (although it may not be as great or tall as some) that riders of 2 stroke road bikes have a greater feel or appreciation for aspects of riding such as gearing, theres definately an 'art' to keeping a 2 stroke on the boil but I have found as the grey hairs settle in that I appreciate a good standard set up, easy to ride. I recall one of the other guys on here talking about why he prefers litre sized bikes as opposed to the 600 class & I couldnt agree more. It was one of my disappointments with my current CBR600, I definately miss the torque of the bigger bike.

Anyway, I have enjoyed this thread, tis a little bit funny when Richard and his mates or alter egos get together and come gunning for you, isnt it?

Ohh & tatty, theres nothing like 'passion' and good on you for trying to stop the OP from wasting money and making mistakes, I don't think anyone here sets out maliciously to give the wrong advice or cause someone some grief.

[tatt2dude]

Anyway, I have enjoyed this thread, tis a little bit funny when Richard and his mates or alter egos get together and come gunning for you, isnt it?

Thanks for the multiple posts, I am still not in the slightest bit wound up, you really need to work on your internet warrior techniques, usually I bite pretty quickly but given your amateurish attempts I picture a 12 year old with a bit of a snotty nose. English skills way above your years though mate.... kudos!

I never said I was a motorcycle god/guru/ or anything of the sort, if that's how you want to view me? Well what can I say? I am flattered but slightly embarrassed you feel the need to look up to me in that way.

Just to clear up for you: I don't know Richard, or his mates and I am certainly no ones alter ego. And if you don't mind me saying so, trying to goad him back into the thread at this point is a bit trollish.

If ever you need any help with the CBR do get in touch, I raced CBR600fx's for two years, have you ever been fast on a motorbike or is it just speed with your mouth on the internet that you specialize in?

Now that you mention I do feel like I am being followed, could you stop it now?

[Cobrabiker]

Hi everybody, after so much info and research, I have decided to go for the 2 front teeth, 18 teeth, as I have checked out 17 teeth will get another 10km at the same rpm, not too much, so I hope the 18 will serve the purpose of high speed cruising, but can the old current chain take a bigger sprocket?

[SeanMoran]

Hi everybody, after so much info and research, I have decided to go for the 2 front teeth, 18 teeth, as I have checked out 17 teeth will get another 10km at the same rpm, not too much, so I hope the 18 will serve the purpose of high speed cruising, but can the old current chain take a bigger sprocket?

If you look at the tensioners on the end of the swing-arm, and there's some room to tighten the rear wheel back around the same length as one link in the chain (from the front pin on one link to the front pin on the next link behind it) then that will equate to two links to make up the extra two teeth in the front sprocket, so no worries ...

... except that a brand new sprocket would really appreciate a new chain to run itself in with and the cost is not exhorbitant. If you're going that far with this exercise, then be nice to your lovely young Yamaha, and buy her a new chain to go with her surgically-enhanced frontal sprocket.

[BSJ]

Woo there fellers, it maybe time to take a chill pill!

There's definitely a lot of friction in this thread....and it ain't coming from an under lubed chain 'n' sprockets!