Low & Slow's Ninja 250 project

[renault_megane_dci]

pics please !

[low&slow]

as requested !
I ordered a 15 tooth front countershaft sprocket and hopw to receive it soon. I may go with a 39 tooth rear sprocket later. I also replace the seat with one I made for a lower seat height. I rode it yesterday and today and it seemed to dowell in the wind, better than the Vision.

[greenjoe]

l&s, send me an address some how, and I will send you a 33t rear spocket to try. My best results was with 14/33 and lowered the bike 2inchs{lowering link & clip-ons} no real aero mods. The 15/33 gearing was too steep for these Tennessee hills.

[low&slow]

Hi Greenjoe, Thank you for the offer, I'll send you a PM! I think Alan Smith may be running a 33T rear sprocket on his Ninja 250 so this will be a good test .
My bike is going great on the freeways with the modded fender and windscreen. It is just screaming for higher grearing. Currently with stock gearing and a larger rear tire ( 120/80-16") it running 8500 rpm at 70-75 mph. It will be interesting to see what kind of mileage I'm getting with these mods.
all the best L&S

[redyaris]

This may be stating the obviouse, but I suspect that until the aero is improved you will hit a limit on sprocket changes improving fuel economy.
I have a Yamaha WR250 that I have a 14T front sprocket for, but have not instaled because the bike can not maintain a reasonable highway speed [100km/h, 60mph] in 6th gear in head winds. So until I can make some aero improvements the 14T sprocket will sit on the shelf.
Keep up the good work, when do you expect to be installing your "Vetter" tail end?

[low&slow]

Hi RedYaris, The Ninja feels much improved with just the fender, windscreen ,seat lowering and temporary tail. I'll top it off and evaluate my progress in the next couple of days before I start raising the gearing. The 15t front/33 T rear combo may be too much at this point but we'll find out. Right now the bike pullls top gear down around 35 mph easily so I should have lots of room to bump it up. I probably will start on the Vetter tail right after playing the sprockets. I'm meeting with Alan on Thurs. or Fir. so he can critique my work so far. He and Craig are working on a new front end for his Ninja.
stay safe, L&S

[beatr911]

Vic, I'd consider just going straight to the 15/33 gearing. The only real limiting factor here is if first gear is too high. You don't need to be in 6th on the freeway, just use 5th. With a super long 6th you will also be able to evaluate the improvements in aerodynamic slipperyness as it will become easier to pull higher and higher air speeds.

[theycallmeebryan]

Check out my 101.5mpg Ninja 250 thread. Just gearing mods and riding technique got me there.

http://ecomodder.com/forum/showthrea...50-a-8686.html

I went with a 15/39 setup for a 2.60 final drive ratio. In my experience, anything lower would be detrimental. My bike already slows down considerably on minor upgrades in 6th gear. With a lower final drive you certainly can use 5th gear on the highway, and maybe leave the availability of having an extra low 6th gear to gauge future aero mods. However, i don't think all the aero mods in the world will allow a really low 6th gear to be functional. Hope you prove that wrong!

You can not fit larger than a 15 tooth front sprocket without both removing the sprocket cover and grinding away at the case.

I'd also advise away from attaching a fairing to the front wheel. You'd be much better off extending the stock fairing out over the front wheel.

[low&slow]

Hi Garth, My plan was to install the 15T countereshaft sprocket first note the change then install whatever rear sprocket I have handy which will probably be 33T rear that Greenjoe wants to send me. It may be too tall ( low numerical ratio ) or not. I'll find out.

TCMBrian, Great to hear from you! I have read your thread and commend your excellent efforts. Thanks for your input and advice about gearing taller. I'll see what happens with the 15/33 combo and post my results. I posted on your thread and was wondering how things are going this your Ninja. I hope to join you and Alan Smith in the Ninja 100mpg club soon.
all the best, L&S ( Vic )

[Green Myst]

Hack that Kawi!