43 Tooth rear Sprocket

[VTRDark]

if your bike only makes power at 7000, i would take it back

Peak power that would be! Funningly enough I was coming through Blackwall tunnel the other day, in slow moving traffic, doing around 20mph. I found myself caught between two gears so decided to slip into the lower gear, revs up higher than normal, 7000ish Then rolled on and off the throttle from time to time and used engine braking. My cans where screaming!!! but the bike had the power right there and then. It's not often I use high revs in slow moving traffic as I like the exhaust sound (exhaust gives a deeper tone low down) but higher revs in slow moving traffic was a little eye opener. I usually keep that range for more open roads.

(:-})

[koko]

Mmm. Ive been commuting to work this week. Standard gearing on mine 70mph is 3750 revs! Reserve light has just come on at128.7 miles. 16 litre tank.average speed 70-80mph

[VTRDark]

Standard gearing on mine 70mph is 3750 revs! Reserve light has just come on at128.7 miles.

That might explain my bad mileage. Drop it down a gear and your revs will go up, you can still go the same speed.

(:-})

[koko]

Is it better to go -1 on the front or up to a 43 on the rear?

[cheekykev]

I'm one down at the front and two up at rear, it's great fun

[7moore7]

Bloody hell you must be some rider if you can feel about 5mm longer on the wheelbase!!! and if your bike only makes power at 7000, i would take it back, lighening the flywheel will lose engine braking, which twins are meant to have. Are you sure you have not got a V Twin with 4 cylinders?

regards Paul.

Actually, lightening the flywheel increases engine braking. The flywheel is just rotational weight. So it will want to retain it's momentum more as it gets heavier. What this means is that if it is spinning at high speeds, it takes more energy to slow it down the heavier it gets. Similar trying to start or stop an empty merry-go-round versus one full of kids.

Engine braking comes from cylinder compression resistance (not flywheel weight). When this doesn't have to fight the momentum of the flywheel, it is even more noticeable.

[Furrybiker]

Doesnt the different sprocket size affect the speedo reading though? Probably not by much but if you are living on the ragged edge of legality it may be enough!

I find that the tank range is better in 4th or 5th on the motorway. I have a 43t sprocket on the rear, the front is standard, I also find it makes the bike easier to ride in town, before it felt as though neither 1st or 2nd was quite right at low speeds.

[bigtwinthing]

Bloody hell you must be some rider if you can feel about 5mm longer on the wheelbase!!! and if your bike only makes power at 7000, i would take it back, lighening the flywheel will lose engine braking, which twins are meant to have. Are you sure you have not got a V Twin with 4 cylinders?

regards Paul.

Actually, lightening the flywheel increases engine braking. The flywheel is just rotational weight. So it will want to retain it's momentum more as it gets heavier. What this means is that if it is spinning at high speeds, it takes more energy to slow it down the heavier it gets. Similar trying to start or stop an empty merry-go-round versus one full of kids.

Engine braking comes from cylinder compression resistance (not flywheel weight). When this doesn't have to fight the momentum of the flywheel, it is even more noticeable.

hmmm i dont agree about the engine braking sorry, lighening the flywheel spins it up easier, but the normal weight then slows it down quicker, yes compression,big pistons does effect it massively. I have ridden me mates with a lightened flywheel and it does spin up quicker but it doesnt slow so good rolling off the throttle. Regarding the speedo being out in normal standard gearing at 4000 revs it was doing 70mph and at 5000 it was doing 90 mph, with the 43 tooth sprocket it was doing 75 at 4000 and 96 at 5000 revs, so about 5/6 mph out, i can live with that to be homest as i feel the bikes simply blasts out of the bends a lot better, my mates GSXR 750 was left for dead exiting bends together, he was doing about 13000 revs to get by
me on thursday. he did have me on the flat though!!

[Tweety]

Actually, lightening the flywheel increases engine braking. The flywheel is just rotational weight. So it will want to retain it's momentum more as it gets heavier. What this means is that if it is spinning at high speeds, it takes more energy to slow it down the heavier it gets. Similar trying to start or stop an empty merry-go-round versus one full of kids.

Engine braking comes from cylinder compression resistance (not flywheel weight). When this doesn't have to fight the momentum of the flywheel, it is even more noticeable.

hmmm i dont agree about the engine braking sorry, lighening the flywheel spins it up easier, but the normal weight then slows it down quicker, yes compression,big pistons does effect it massively. I have ridden me mates with a lightened flywheel and it does spin up quicker but it doesnt slow so good rolling off the throttle. Regarding the speedo being out in normal standard gearing at 4000 revs it was doing 70mph and at 5000 it was doing 90 mph, with the 43 tooth sprocket it was doing 75 at 4000 and 96 at 5000 revs, so about 5/6 mph out, i can live with that to be homest as i feel the bikes simply blasts out of the bends a lot better, my mates GSXR 750 was left for dead exiting bends together, he was doing about 13000 revs to get by
me on thursday. he did have me on the flat though!!

Well... You can argue that point all day... It makes no difference to the laws of physics, really... You really can't both eat the cake and still have it... Either the lessened rotational mass applies to the engine the same way both on acceleration and retardation, or it doesn't apply at all... Can't have one effect at one time, and another in another instance... Simply doesn't happen...

Either less mass makes the engine spin up quicker, and loose revs faster period... Then you have more engine braking... Or it doesn't...

[sirch345]

wow i am inconsiderate, 2 up on a storm!!! thats the reason i bought it, i told my other half they dont have a seat for a pillion and quickly took the foot rests off!!! 2 teeth up on the back has worked a treat for my blast out of bends riding etc, and i can happily lose 10mph of the top end, The handle bar mod (all be it £90 has made a real difference too) the bike now for me is an absolute keeper and providing i never loose the "buzz" it offers i wont sell it. and thats whats owning a bike is all about.

It sounds like you are a very happy man with the gearing change

Chris.

[8541Hawk]

Bloody hell you must be some rider if you can feel about 5mm longer on the wheelbase!!! and if your bike only makes power at 7000, i would take it back, lighening the flywheel will lose engine braking, which twins are meant to have. Are you sure you have not got a V Twin with 4 cylinders?

regards Paul.

Well Paul I am not really sure how to take your response so I will answer your questions and statements even though I do find your attitude a bit crusty.....

Yes I can feel the difference with the wheel base change. The front end "feels" more planted to me.
Now I do have to ask about people saying the have better "turn in" when shortening the wheel base with a 43T rear sprocket.
Isn't that "feeling" the 5mm difference in wheelbase? or are they just special also??

Can you please show me where I said my bike only makes power above 7K RPM?
I said maybe you should try running the bike there sometime if you believe you are low on power....... not because it has 4 cylinders but because you would at least be close to he HP & Torque peaks.
In case you don't have the numbers or a dyno sheet the peak torque is in the 7,800 RPM range and peak HP is around 8,700 RPM so it is quite simple....if you want max performance these are the speeds you need to spin the engine.
Many people I have encountered don't know what kind of power these bikes really make as they never rev the engine.
So go ahead and ride the poor thing like a tractor if you like but to really get performance from this engine you need to keep it between 7-9K as that is where the real power lives on just about any VTR.

As for engine braking, you are dead wrong. As stated in an earlier post, a lightened flywheel will give you increased engine braking as just as it is easier to spin up it is also easier for it to slow down.....simple physics.

[Jamoi]

I like the sound of having a snappier motor with increased engine braking

Will look into this mod

cheers

[VTRDark]

The Pros and Cons of Lightening the flywheel.
http://cbr250.com/forums/general-techni ... -cons.html

(:-})

[sirch345]

You really can't both eat the cake and still have it...

I have found that to be very true

Chris.

[bigtwinthing]

Bloody hell you must be some rider if you can feel about 5mm longer on the wheelbase!!! and if your bike only makes power at 7000, i would take it back, lighening the flywheel will lose engine braking, which twins are meant to have. Are you sure you have not got a V Twin with 4 cylinders?

regards Paul.

Well Paul I am not really sure how to take your response so I will answer your questions and statements even though I do find your attitude a bit crusty.....

Yes I can feel the difference with the wheel base change. The front end "feels" more planted to me.
Now I do have to ask about people saying the have better "turn in" when shortening the wheel base with a 43T rear sprocket.
Isn't that "feeling" the 5mm difference in wheelbase? or are they just special also??

Can you please show me where I said my bike only makes power above 7K RPM?
I said maybe you should try running the bike there sometime if you believe you are low on power....... not because it has 4 cylinders but because you would at least be close to he HP & Torque peaks.
In case you don't have the numbers or a dyno sheet the peak torque is in the 7,800 RPM range and peak HP is around 8,700 RPM so it is quite simple....if you want max performance these are the speeds you need to spin the engine.
Many people I have encountered don't know what kind of power these bikes really make as they never rev the engine.
So go ahead and ride the poor thing like a tractor if you like but to really get performance from this engine you need to keep it between 7-9K as that is where the real power lives on just about any VTR.

As for engine braking, you are dead wrong. As stated in an earlier post, a lightened flywheel will give you increased engine braking as just as it is easier to spin up it is also easier for it to slow down.....simple physics.

sorry no arsy attitude intended, buy quite simply, i feel a 43 tooth sporockets does pick up better, and like i said i can happily loose 10mph off the top end. To be honest, if i did ride always at 7000 revs and needed that power i would buy an SP2 (133 ish bhp) i just think its a simple mod for £30 odd quid and noticed the difference straight away. i did get to the redline today on my trip to Silverstone (400 mile round trip)today and i was havong great fun, but in the New Forest where i live i have to cope with just blasting out of the corners most of the time. My R1 with the crossplane crank filled the (feel like a twin but still had top end poke quite happily when i had it).But still loving the storm. Apologies if i pissed you off.