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Gear ratio

4K views 22 replies 5 participants last post by  Duc96cr 
#1 ·
My monster 750 game with a 15in tooth sprocket in the front and a 41 tooth sprocket in the past I learned to love 3-1 ratio 15 t front and 45t rear on my Kawasaki triples. Had great acceleration and felt it would help out ( Isabella ) my monster 750. But realize the lack of power was because it was missing a igniter box CDI . Felt stupid but never drove a Ducati before. So the question is when my pair of new upgraded igniters arrive is 45t rear going to give it great acceleration?🤩
 
#5 ·
Resist the temptation to change the front sprocket to a 14t. That will increase front sprocket and chain wear.
If you have sprockets and chain that are close to needing replacement, then it would be better to add 2 or 4 teeth to the rear. This will give better acceleration and allow the engine to get closer to the rev limiter, if not just engaging it. In reality, how often does one get to run those speeds and how long would you stay at those speeds? Clipping the top end a bit, if at all, will be more than made up for with the enjoyment of the acceleration gains.
An odd number of sprocket teeth is better for both sprocket and chain life.
My M1100 came with 15/39 and now has 15/43. That gives 138 mph at the limiter. And it just about reaches that due to aerodynamic resistance. But it's a lot more fun up to that. And that low end grunt is what makes a Monster so much fun.
Go to gearingcommander.com for more info and you can try different combinations and see the numbers.
 
#6 ·
In my younger, stupider years I knew exactly how fast my bike would go. I would re-gear my bike so that it would barely pull redline in top gear, which I felt was the best compromise between better acceleration and not losing top speed. These days I try to gear my bike so that I will spend most of the time in the “ happy zone “ on a Ducati, 4000rpm up. If a lot of your riding is at lower revs than that, a bigger (4-5t) rear sprocket is a nice change. If you ride high speed- high rpm a lot, maybe a couple of teeth bigger is enough . It is not permanent, it’s an experiment.
 
#7 ·
All was right I put the new 15 x45 sprockets and chain on Isabella before igniter box came. I also rebuild front forks. However when the igniter came and installed it I knew what the Ducati hype was all about. She accelerated so fast it spooked me. So I ordered a 15 x 40 set with chain and keeping the 15 x 45 setup for drag racing only... WOW did I say that? Must be getting old. 😆 lol
 
#8 ·
Yeah, you are getting old, but it’s better than the alternative. By Ducati standards, or for that matter 750 bikes in general, your bike is not fast. You will get your butt handed to you on the drag strip, gearing or not. This is just enthusiasm for your new toy. Don’t get carried away.
 
#9 ·
For a 750 it runs good I would think 10s but know bikes that do 8s. Man that 15x45 gets you to 100 as fast as you can shift. In 80s was doing 9s on Triple Kawasaki and that was fast then. But ya right enjoy it. For what it is. By the way much more driveable with 15x40 setup...perfect
 
#10 ·
You’re talking 1/8 mile ? No way is a 750 Ducati going to do 10’s in the 1/4 mile. Maybe with nitrous and a midget riding it, but probably not even then. I’d stake my professional reputation as a bullshitter on it.
 
#12 ·
Stock was 15/39. So 15/41 is already shorter gearing.

I would recommend avoiding even divisions like 15/45. That makes the gear teeth line up the same way every 3 revolutions, which contributes to uneven wear. If you really need shorter gearing than you've got, go with a rear of 43, 44, or 46.

I have been riding M900s for the last 26 years. At first, I actually geared it more the other way, going to a 15/37, because I was out West, and did a lot of highway miles. When I moved the NH, I went back to the stock 15/39.

The M900 could get into the 12's. with good gearing and a skilled rider. You're not going to get an M750 to honestly do anything in the 10's in the 1/4-mile without some serious mods.

PhilB
 
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#13 · (Edited)
That Kawasaki 750 triple must have had some very, serious performance mods. I had one back in the 70's, even had a go Drag racing it. Best 1/4 mile time was 12.45 seconds. Damn quick in it's day. Maybe a better rider could have got it closer to 12.00.s I do remember however, that the triple was credited in 1972, as being the first production bike to break the 12 second mark, 11.95 seconds.
You would have to more than double the horsepower and then some, to get it into the 9.00's
The Z900 Kawasaki four stroke that came out later was quicker, some even claim they got them into the low 11.00's.
Just my experience.
 
#20 ·
That Kawasaki 750 triple must have had some very, serious performance mods. I had one back in the 70's, even had a go Drag racing it. Best 1/4 mile time was 12.45 seconds. Damn quick in it's day. Maybe a better rider could have got it closer to 12.00.s I do remember however, that the triple was credited in 1972, as being the first production bike to break the 12 second mark, 11.95 seconds.
You would have to more than double the horsepower and then some, to get it into the 9.00's
The Z900 Kawasaki four stroke that came out later was quicker, some even claim they got them into the low 11.00's.
Just my experience.
My Kawasaki H2 had reported jugs deco killer expansion chambers air shift guillotine carbs raked front forks. Looking for pics my sister has. And it hauled the mail with a scream that would stampede cattle...
 
#14 ·
I had a ‘73 Z-1, first year, with 1000cc big bore, ported head, 4into1 header, gearing. I weighed 150#. It was a low 12 second bike in the quarter mile and was one of the fastest in my area. Many street races, never beat. I raced several 750 triples and it wasn’t a contest.
I think he’s talking 1/8 mile times. I never saw a triple that fast and raced against some heavily modified ones.
 
#16 ·
Interesting, here in Aus. never heard of 1/8 mile drag racing, all 1/4 mile.
"but know bikes that do 8s". That must be 1/8 mile then. I remember the first time I saw a bike pull 8 something seconds in the quarter, blew everyone away, a twin engine supercharged Triumph, (2x 750 Bonneville twins).. huge slick tyre and custom frame etc. even had a parachute to stop, No way could it be ridden on the street. Mid 70's though.

I bet you wish you had kept the 73 Z-1, My favorite Kawasaki, best looking bike they ever made. Worth a lot here these days.
 
#17 ·
I’ve never raced 1/8 mile , but I know there are quite a few around . It keeps the top speed down so maybe a bit safer. You still get the smoky launches so just as exciting for the fans.
Since all the time is wasted on the launch the ET isn’t that much less than 1/4 mile.
My brother has my Z-1 but refuses to sell it back to me. He also has my old Husqvarna 250cr and Eagle side car. He’s a hoarder who lives in the woods surrounded by his toys.
 
#18 ·
You may need to "talk', to your brother, A Z-1 in showroom condition sold here in Perth recently for AU 35 grand. But, back then I owned the original Ducati 900ss, bevel gear and silver and blue. Sold it for next to nothing, yes under 2 thousand dollars, to buy a Laverda 1200 Mirage. Today they are both worth a small fortune, but who knew.:cry:
 
#22 ·
By the way you educated me with the odd number front sprocket rule. I never did like 14 t front tried it out 40 yrs ago. But was not educated on the wear issue. That is what being around sophisticated Ducati riders can teach me. Here to learn, not stupid though 2 titles IDBA in 80s should not be. My manual shows 97 monster 750 came with 15x41 but now using 15x40 great for here on street. I love being around the smarter bike crowd... 👍
 
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