My 2000 ZR-7 has 15 tooth front sprocket. Can a 17 tooth go in its place? Thanks

Hey ATV... I moved your post from the Daily Ride... I thought you might get a bit more feedback here. I hope you found it alright.

As for your question... You CAN go to a 17 tooth front sprocket. Many folks on the board have done that. It WILL require a little modification of the sprocket cover. Nothing major. I will try to find a thread to point you to...

A quick search found the following... (Thanks Martin!)

In case you haven't seen this, http://www.zr-7.com/fsprocket.htm , it shows all the details.

Thanks Gump!
Next question. How much does this drop the RPM at highway speeds and how much does it hurt take off. I am not a hot rodder. Just want to lower RPM (HAVE A SIXTH GEAR) when running highway speed.

try useing this...quite usefull for considering mods to sprockets

Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator

The people here that have gone to a 17t front sprocket have not complained about power issues. The ZR makes decent torque. IIRC the stock front is a 16t so someone must have changed yours. Going from a 15 to a 17 is a huge difference. You may notice it on acceleration. Stock rear is 38t.

Thanks, and how do i get to the performance mods page? cant find it. NEVER MIND!!!!!!!!!

Will the ZR7 hold a 18t front sprocket?

Originally Posted by rustysterling

Will the ZR7 hold a 18t front sprocket?

i highly doubt it..you need to mod a bit just to keep the 17 from carving out the case and cover....an 18......umm i would guess you would likely have to perminantly lose the cover and remove its mounting holes ...really going bigger just means removing more meat off the case

18T won't fit and it is really too much of a drop. Figure roughly about 300 rpm drop in fith gear for every tooth you add in front. Loss of accel is not very noticeable unless your are racing your neighbor at every stop light. Hopefully you are not one of those.

I rode the ZR7 to work this morning. First time since a 17t and new rear tire (Pirelli Diablo).
Wow, what a difference! I do lots of highway miles, and the new ratio works so much better.
Thanks for the forum and help, guys.

Just wondering if the 17t front sprocket changes the hiway buzz. My vibration seems to lessen at higher rpm.. thanks

I think it is quite common in most 4-cylinder bikes. There is vibration at a certain point in the rpm range.
My zr-7s has the vibration at around 5000 rpm (70 mph). Once you past that point (or below that point), the bike is relatively smooth.

Sort of counter intuitive--you'd think that as the rpm rises, so would the vibration. Not in this case.

Has anyone figured out how to stop the windshield vibration? Mine rattles pretty hard when slowing down. I am a new zr7s owner, please be patient...

Originally Posted by OldBiker

Has anyone figured out how to stop the windshield vibration? Mine rattles pretty hard when slowing down. I am a new zr7s owner, please be patient...

remove it?....some well placed bits of rubber washers have workd..som ppl have braced it with aluminum

Originally Posted by zr7_interloper

I think it is quite common in most 4-cylinder bikes. There is vibration at a certain point in the rpm range.
My zr-7s has the vibration at around 5000 rpm (70 mph). Once you past that point (or below that point), the bike is relatively smooth.

Sort of counter intuitive--you'd think that as the rpm rises, so would the vibration. Not in this case.

That's true for something that's out of balance but here we're talking about harmonics.