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Hi All,
After reading other peoples comments on installing a new front sprocket, I decided to dive into a 14 tooth front sprocket replacement for '04 750 Katana. The following is my experience with this 'upgrade' and it's my hope this will make or break a decision to install a lower tooth count front sprocket. Unlike the K&N filter, installation was tough and took me 3 hours of fiddling around. I had to use muscles that haven't seen an honest days work in years. The end result is that I had to take off the fairing on the left side of the bike to get my impact gun into the right position to remove sprocket nut. However, I did managed to do it and get the chain back on. I want to thank Tim (a.k.a. Trinc) for supplying the instructions, which can be found here....
Note: If you plan to do the install yourself, use Loctite (or equivalent) when reinstalling the sprocket nut.
Now, I want to preface with this is that my expectations were tempered with scepticism about the difference the re-sprocketing would make. I felt that many of the comments made regarding the modification were hyperbole. After installing and trying it out the I must admit that my suspicions were correct but only in a very small sense. Like in previous reviews, I did not engage in any detailed analysis, hard number comparison or use any scientific methodology.
My full test compliment encompassed about 250km of riding on highway and street settings. The test day was a great day for a ride, with the temperature around 21 degrees Celsius (about 72 degrees Fahrenheit) and with lots of sun. I decided I would ride around for while to get use to the bike and warm it up to its operating temperature. I was careful not to apply much throttle as I was expecting a dramatically different bike. I did sense that the machine was itching to go but was still well behaved like all other Katanas.
The first series of test was to note the changes in acceleration. I eased into this test as I didn't want to get thrown off and find out how bad our Canadian medical system really is. Anyway, I felt an immediate difference on how the bike accelerated from a full stop. Prior to the install, the Kat always felt as little asthmatic when launching. However, with the new sprocket in place I felt the bike was more responsive to my throttle twisting and I launched with excellent results. It was crisper and assertive, with the front of my bike lifting up as I tached up the Kat. However, there seemed to be no risk for an undesired wheelie. I can say without much exaggeration that you will shave nearly a half second off your quarter mile, if such is your desire.
Top gear roll-on power was improved and I was able to hit the 130kph (80mph) mark faster than before the stock setup and K&N install. The bike was able to propel itself quickly and I found myself in the powerband faster. I was able to pull the bike up to 160kph (100mph) with less effort and there was better pull to 190kph (115mph). However, I was only able to take the bike to 215kph (135mph), which was at least 8kph (5mph) slower than my previous top speed. The tachometer was reading 11.3k at this point so I knew that I've reached my limit and that I've lost some top end. Nonetheless, this drop in speed was less than anticipated so I was satisfied with the outcome.
As for gas consumption, it actually improved according to my calculations. There is, however, an explanation for this. Firstly, I had my Speedohealer setup to compensate for the +7.14% over-reporting for the new sprocket. That means the odometer is now over-reporting by a significant amount as these meters are calibrated to be accurate in a stock setup. Secondly, I'm not gunning the throttle to pull the Kat to speed as I did before the upgrade, which helps keep the over throttling to a minimum. Based on my observations, people that do a lot of highway riding will see a drop in mileage but people that do in town riding will not see a noticeable difference.
Note: Once you compensate for the resprocketing (e.g. install a Speedohealer), your tachometer will be +7.14% higher at the same speed prior to the install (e.g. 5,000 RPM pre-install versus 5,350 RPM post install).
As an additional side benefit, the handling of my bike improved in the turns. Well, that's not precisely true but the fact is that I can now avoid gearing down to 1st gear when making turns. I can keep the bike in 2nd gear (or even 3rd gear) and still power out of a turn with ease. There is a need to struggle to get the bike in 1st gear and sometimes accidentally putting it in neutral. This made the bike more responsive in the twists and turns, which is a big plus in my book.
Verdict: Despite my initial scepticism, this upgrade is a must have (or must do). With better acceleration and in-town low-end performance (at a small cost in top-end speed) the 14 tooth front sprocket is probably the best upgrade for under $100. You avoid the more costlier and more temperamental tuning issues of a jet kit, without significant sacrifice. You'll also find you will be making your turns easier and more consistent as well.
PS: As usual, please excuse the bad grammer and syntax. It's been a long day and I'm usually too lazy to recheck my work anyway.
After reading other peoples comments on installing a new front sprocket, I decided to dive into a 14 tooth front sprocket replacement for '04 750 Katana. The following is my experience with this 'upgrade' and it's my hope this will make or break a decision to install a lower tooth count front sprocket. Unlike the K&N filter, installation was tough and took me 3 hours of fiddling around. I had to use muscles that haven't seen an honest days work in years. The end result is that I had to take off the fairing on the left side of the bike to get my impact gun into the right position to remove sprocket nut. However, I did managed to do it and get the chain back on. I want to thank Tim (a.k.a. Trinc) for supplying the instructions, which can be found here....
Note: If you plan to do the install yourself, use Loctite (or equivalent) when reinstalling the sprocket nut.
Now, I want to preface with this is that my expectations were tempered with scepticism about the difference the re-sprocketing would make. I felt that many of the comments made regarding the modification were hyperbole. After installing and trying it out the I must admit that my suspicions were correct but only in a very small sense. Like in previous reviews, I did not engage in any detailed analysis, hard number comparison or use any scientific methodology.
My full test compliment encompassed about 250km of riding on highway and street settings. The test day was a great day for a ride, with the temperature around 21 degrees Celsius (about 72 degrees Fahrenheit) and with lots of sun. I decided I would ride around for while to get use to the bike and warm it up to its operating temperature. I was careful not to apply much throttle as I was expecting a dramatically different bike. I did sense that the machine was itching to go but was still well behaved like all other Katanas.
The first series of test was to note the changes in acceleration. I eased into this test as I didn't want to get thrown off and find out how bad our Canadian medical system really is. Anyway, I felt an immediate difference on how the bike accelerated from a full stop. Prior to the install, the Kat always felt as little asthmatic when launching. However, with the new sprocket in place I felt the bike was more responsive to my throttle twisting and I launched with excellent results. It was crisper and assertive, with the front of my bike lifting up as I tached up the Kat. However, there seemed to be no risk for an undesired wheelie. I can say without much exaggeration that you will shave nearly a half second off your quarter mile, if such is your desire.
Top gear roll-on power was improved and I was able to hit the 130kph (80mph) mark faster than before the stock setup and K&N install. The bike was able to propel itself quickly and I found myself in the powerband faster. I was able to pull the bike up to 160kph (100mph) with less effort and there was better pull to 190kph (115mph). However, I was only able to take the bike to 215kph (135mph), which was at least 8kph (5mph) slower than my previous top speed. The tachometer was reading 11.3k at this point so I knew that I've reached my limit and that I've lost some top end. Nonetheless, this drop in speed was less than anticipated so I was satisfied with the outcome.
As for gas consumption, it actually improved according to my calculations. There is, however, an explanation for this. Firstly, I had my Speedohealer setup to compensate for the +7.14% over-reporting for the new sprocket. That means the odometer is now over-reporting by a significant amount as these meters are calibrated to be accurate in a stock setup. Secondly, I'm not gunning the throttle to pull the Kat to speed as I did before the upgrade, which helps keep the over throttling to a minimum. Based on my observations, people that do a lot of highway riding will see a drop in mileage but people that do in town riding will not see a noticeable difference.
Note: Once you compensate for the resprocketing (e.g. install a Speedohealer), your tachometer will be +7.14% higher at the same speed prior to the install (e.g. 5,000 RPM pre-install versus 5,350 RPM post install).
As an additional side benefit, the handling of my bike improved in the turns. Well, that's not precisely true but the fact is that I can now avoid gearing down to 1st gear when making turns. I can keep the bike in 2nd gear (or even 3rd gear) and still power out of a turn with ease. There is a need to struggle to get the bike in 1st gear and sometimes accidentally putting it in neutral. This made the bike more responsive in the twists and turns, which is a big plus in my book.
Verdict: Despite my initial scepticism, this upgrade is a must have (or must do). With better acceleration and in-town low-end performance (at a small cost in top-end speed) the 14 tooth front sprocket is probably the best upgrade for under $100. You avoid the more costlier and more temperamental tuning issues of a jet kit, without significant sacrifice. You'll also find you will be making your turns easier and more consistent as well.
PS: As usual, please excuse the bad grammer and syntax. It's been a long day and I'm usually too lazy to recheck my work anyway.
. 
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