Rear sprocket change

[red]

I changed out the front sprocket to a 15T and it is indeed better. I have read the diy, but I am debating on the best on what/if to do the rear.

44? 43? even 41??

This is a stock engine and I am concerned that I don't make it more difficult for a new rider with the non-existent low torque. Ninjette riding seems to teach that you can't be lazy and find yourself in the wrong gear when you need some go in a hurry.

Suggestions on "just right" 15/4?T gearing suggestions would be greatly appreciated.

Thanks for any experiences.

[JMcDonald]

It's completely subjective. I went all the way to 16/41 on a stock bike and loved it. As I mod it for performance, it only gets better. Having just barely played with the low-speed mixture needles, now if I am just putting with with traffic or going through neighborhoods with many stopsigns, I will often leave it in second gear and just pull off from stops like that. That is just to say with a little tuning you can basically haul around on a stock bike from 3rd gear.

But, if you have already done 15/45 and want more, I'd say go to 15/41, or 15/43 at least. A lot of people seem to like those combos, but I like my long gears .

[randomwalk101]

42

[JMcDonald]

Oooh, the meaning of life?
http://en.wikipedia.org/wiki/42_(number)

It would be nice of you to elaborate with supporting information, rather than provide unnecessarily truncated, unfortunately unhelpful responses.


Red, what kind of riding do you like to do?

Do you find yourself consistently trying to romp from stops?
Do you like to drag race?
Do you wish to have a longer 6th gear?
Do you like rolling on the throttle from various cruising speeds?
Do you care about shifting less / each subsequent gear being longer?

For me, the answers would be something like No, No, Yes, Yes, and Hell Yes.

I have yet to launch the bike from a stop, stock or otherwise. I very rarely even wrap 1st and 2nd together, from a stop or low speed. I did want a lower 6th gear, and love cruising at 80mph (actual) at 7900rpm. Most of the "going" I do is rolling on the throttle from the midrange to the top end, often to get around "slow" traffic. I could have easily done that in a higher gear on a stock bike, but the answer to the last question meant I wanted to be able to do this with fewer shifts to get there.

Beyond the universal "15t is better," it is largely up to the individual rider what you prefer. Play with the gearing calculator (www.gearingcommander.com) and compare ratios as far as cruising speeds, shift speeds, etc, and see if you can't find some numbers that appeal to you. Then weigh those numbers with how willing you are to sacrifice a bit more pep off the line to achieve them. I was happy to sacrifice a pretty good amount to meet the above personal desires, but you might not want to lose that off-the-line pep (which isn't a significant part of the riding experience, IMO).


BTW, my beginner GF has had no more trouble with this setup than with the original setup. She even still finds first too low for parking-lot speeds because of the choppy throttle (and hasn't learned much about how to really feather the clutch).

[red]

Originally Posted by JMcDonald

Oooh, the meaning of life?
http://en.wikipedia.org/wiki/42_(number)

For me, the answers would be something like No, No, Yes, Yes, and Hell Yes.

For me pretty much the same. This is actually my daughters primary bike, I ride it probably more than she does in total when I can get it away from her, but I find the gearing unusably low.

I am trying to strike a balance between talling-it-up a bit so as to not make 1&2 just, well, annoying and not unnecessarily bogging the little lump and making it difficult to drive for her off the line.

All this at the same time I am changing my bike (not a K) that is impossibly tall and gearing it down to be usable at legal speeds instead of 80mph at 4k.

[JMcDonald]

If that is the case--if you still think 15/45 is annoying too low--then I'd go with the 41t rear at the largest, if not going down even further.


However, I would recommend at least playing with the idle mixtures (it is free and not difficult). I have loosely played with mine, and found a notable improvement. Whereas before it wouldn't start "pulling" til about 15mph, it now starts going at around 10mph, obviously requiring less clutchwork for faster takeoffs.

[kashun84]

I think it's 100% personal preference. I have a 15/38 setup and I am doing 99.99% highway riding (7-80mph). My rpm is staying at 7-8K. I think this setup suit me perfect since the torque start picking up around 7-7.5k and the engine runs really really smooth in that range and 8% MPG improvement compare to the mfg. spec. Try the gearingcommander.com, play around with different combinations and find out one which fit your riding style the best.

[JMcDonald]

Ah, hey, another "extremist!" 15/38 is actually another 1% lower than my 16/41! Good to know I'm not just crazy in liking the bike like this, haha.

[red]

Originally Posted by JMcDonald

if you still think 15/45 is annoying too low--then I'd go with the 41t rear

I guess I am most interested in any experiences from riders as to any negative aspects of this or similar gearing (i.e. 41-43T) with the base engine, which does not do much below 4k.

Since this is really not my primary bike, I am not wanting to toil over diddling to extract a percent or two out of the power band, but just making it as ridable as possible around town, stop and go, and highway speeds too. A usable 1st (i.e. not requiring unnatural acts and massive throttle/clutch slip, to get it rolling) and a usable 6th.

Now I always keep trying to shift into 7th and maybe it is a training problem that it is what it is.

[Alex]

Just to provide the other side of the coin, we did switch our earlier ninjette out to a 15-tooth front, ending up at 15/45. It was a significant enough hit at off-the-line response, and starting on an uphill, that on our new ninjette we were more than happy with the 14/45 ratio and have no plans to change it. Once the bike is up and running, no matter what the gearing is it just becomes about keeping the bike in the right gear. YMMV... (and yes, I do try and shift to 7th from time to time... )

[JMcDonald]

Exactly! Personal preferences vary about as much as bikes themselves, heh.

But it seems pretty logical that if he finds his current gearing "[annoyingly]" short, then he should go longer. Just as since you found the reduction in off-the-line pep "significant" rather than some other less-powerful adjective, it made sense for you to go back to 14/41 :P .

So does that help you, red?
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[CZroe]

15:41 took some getting used to but I started spooling it up at stop lights and now I'd never go back.

[red]

Originally Posted by JMcDonald

Personal preferences vary.

So does that help you, red?
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Yes, clear as mud. I may have to ride it a bit and mull it over. Having to "spool it up at lights" is not really where I wanted to end up leaving it for the kid, but I may split the diff and try a 43T if I find one less than full price. Choices, choices.

[JMcDonald]

Like I said, my GF had no problems taking off with the 16/41 setup on a stock bike, and she hasn't ridden it since I messed with the needles. To reiterate, for in-traffic riding, that really made the difference between having the clutch out by 5mph and smoothly accelerating, and having to wait til 10+mph before the engine can efficiently pull without feathering. For more aggressive riding those numbers are more like 10mph and 15mph, respectively (as I mentioned above).

But yeah, the 16/41 and 15/38 setups are on the extreme end for this bike, and definitely not for everyone.

[slolane]

Good reading, thank you all for the input. I'm thinking about trying 15/42 now... good thing is sprockets are cheap enough to try out and ditch if I don't like.

Thanks again!

[JMcDonald]

Sweet! Yeah tht definitely is nice heh. This is also one morr thing i love about bikes compared to cars: the ability to change final drive ratios easily and cheaply. With most cars, all you can do is fudge tire size a bit, and even if you are lucky you still have to spend the day pulling the rear end / transaxle apart to install a several-hundred-dollar gearset.
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[slolane]

Originally Posted by JMcDonald

Sweet! Yeah tht definitely is nice heh. This is also one morr thing i love about bikes compared to cars: the ability to change final drive ratios easily and cheaply. With most cars, all you can do is fudge tire size a bit, and even if you are lucky you still have to spend the day pulling the rear end / transaxle apart to install a several-hundred-dollar gearset.
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Agreed. It's not too bad when I replace gearing in some Mustangs I had (rwd only) but when I did it in some Jeeps where you do the front and rear (4wd) that really adds up.