better top end with 15 tooth...

[mister]

The Charts that were posted here Prove the smaller front only benefits from first movement.

Did find Another chart however which also Proves the smaller front only benefits first movement - and this was even reference by you Safe-T in your post here. Read about how it only benefits first here http://www.fz6r-forum.com/forum/f89/effects-changing-sprockets-23986/

And found a couple GS500 charts which show dyno comparison between smaller front (1st image) and stock (2nd image)...





Don't know if these were the ones I was lokoing for cause I found them out of context. But they still show the point - smaller front only benefits first movement and loses top.

Michael

[mahemmjr]

Has anyone compared trap Times with both?

[mahemmjr]

I'll try tonight. Have yet to top her out yet I've been curious anyways. I must say coming from an 08 ninja 250 its a nice jump

[SAFE-T]

The numbers are neat, and they certainly seem to show that altering gearing has less of an effect than one might expect. I was intrigued by the charts comparing 'relative driving force' between bikes of different gearing, though ~ the bike with the smaller front sprocket shows higher numbers in every gear ~ wouldn't it also be accelerating faster in every gear as well ?

Also, if we add in the effect of aerodynamic drag, isn't it possible that the bike in the 2nd chart with the stock gearing wouldn't actually be able to get to the same top speed it did on the dyno ? 

[Paulcet]

Look closely at the two charts again, at 80mph.  Driving force is the same, but the next higher gear is engaged.

Nonetheless, we are drag limited to about 110 mph.  Only two things you can do: more power or less drag.

[adidasguy]

I'll finally have an opinion next week. When putting Junior back together, we found a new 15t sprocket. We put on Junior to make him different. I'll see if I notice anything in my around town driving.

[jestercinti]

I remembered something today. I had an older gs450 once. Replaced rear with +3 teeth than stock. It did take off faster off the line, and revved higher on highway. I do agree with the others. It was like I was down a gear on the interstate. I did it mainly to accelerate quicker, but noticed on the top end it didn't help as much as I thought. Later realized that the sprocket change took me out of the powerband at higher speeds. Sold it soon after that.

[adidasguy]

Now that Junior has a 15t front, I have an opinion.
Better for slower city riding and twisties. More responsive at lower speeds. Can keep engine above 3k RPM at slow speeds.

For highway, I'd say no. RPM needs to get too high for sustained highway speeds.

For city and twisties: I think I like it better than a 16t.

[bombsquad83]

I have a 15t and I would agree.  You have to be up around 6-6.5k to maintain good speed on the interstate with the 15t.  I would rather be able to be lower in the RPMs.  It's worth it for me though seeing as most of my riding is in town or on country blacktop.

[speedfreek]

It gives the engine a better mechanical "leverage" advantage, but also decreases fuel economy as you will be at higher RPM for the same speed.
It also can throw your speedo off on some bikes.

For instance, on the blackbird, the increased leverage shows improved HP on a dyno chart even though the top speed is reduced.
I've seen it make a pretty substantial difference on some bikes -- others not so much.

Most twins are geared for torque as opposed to HP anyway, since two cylinders (whether in-line or V) really isn't the best configuration
for HP

TJ

[adidasguy]

Speedo is fine. It is mechanically connected to the front wheel and generally reads 10% fast.

[dougdoberman]

It gives the engine a better mechanical "leverage" advantage, but also decreases fuel economy as you will be at higher RPM for the same speed.
It also can throw your speedo off on some bikes.

For instance, on the blackbird, the increased leverage shows improved HP on a dyno chart even though the top speed is reduced.
I've seen it make a pretty substantial difference on some bikes -- others not so much.

Most twins are geared for torque as opposed to HP anyway, since two cylinders (whether in-line or V) really isn't the best configuration
for HP

TJ

I've yet to see a dyno chart show a measurable (outside the margin of error) HP improvement with back to back runs where the only change was a sprocket.    Can you point me to one?

[speedfreek]

Not online.  One of my blackbird friends went from 140 to 144 on a third gear run.  I was there at the time (the 144) and saw it. (Dynojet dyno)

TJ

It gives the engine a better mechanical "leverage" advantage, but also decreases fuel economy as you will be at higher RPM for the same speed.
It also can throw your speedo off on some bikes.

For instance, on the blackbird, the increased leverage shows improved HP on a dyno chart even though the top speed is reduced.
I've seen it make a pretty substantial difference on some bikes -- others not so much.

Most twins are geared for torque as opposed to HP anyway, since two cylinders (whether in-line or V) really isn't the best configuration
for HP

TJ

I've yet to see a dyno chart show a measurable (outside the margin of error) HP improvement with back to back runs where the only change was a sprocket.    Can you point me to one?

[dougdoberman]

Not online.  One of my blackbird friends went from 140 to 144 on a third gear run.  I was there at the time (the 144) and saw it. (Dynojet dyno)

Since that doesn't correlate to the way that engines & gearing actually works, I'm gonna remain skeptical.