Also if I did the -2 +4 could I still use the 520 chain? Also what would my top speed be?

 

Ryuu600 has it spot on, you will pull a wheelie at 60 as it is now with stock settings but you'll have to downshift to get the revs up not a good idea as this really stresses the drive line components,
go for -2 front & +4 rear

 

with -2 +4 how easy will my front end come up @60?

 

First off - what you really need to do is find out where peak torque is. Then pick the speed you want to wheelie at. Then pick a set of sprockets that puts the peak torque at about that speed...

I used metric but you can convert after.

Find the circumference of the rear wheel:
17" wheel * 0.0254 + (tire width * tire profile/100 / 1000) * pi = circumference in metres


speed = ((PEAK Torque RPM) * 60minutes) / (Primary reduction * 2nd Gear Ratio * Final Ratio (ie. 45/15 for F4)) / 1000

Put in the speed and solve for final ratio...

I'm going to make a webpage up to do this... keep it simple.

 

My speed does not have to be 60mph, thats just a ballpark. What speed is -2 +4 good for? Does anyone know my top speed also?

 

New Top Speed = (OLD TOP Speed * New Final Ratio) / Old Final ratio

Going -1,+2 on the F4 is a 14% change... so my top speed dropped from ~268 to ~244 (from memory)

If you get the primary reduction ratio, the gear ratios and the stock sprocket size... and the tire size I'll put it in my speadsheet and make it available...

I made the spreadsheet for picking gears for my F4... it has the F4's torque and hp curves matched to rpm... I've been using it to pick the next sprocket set I buy. I'm kind of partial to -1,+2 as it doesn't change top speed much, cruising rpm isn't too much higher but I get a definate punch in the lower speed turns. Stock was 16-45 and I'm now 15-47 fwiw.

 

If you knew your peak torque rpm it would also help... I can add that in and highlight it... that'll give you the speed in each gear where you are when you hit peak torque.

 

I believe stock for us F2ers is 15 front 43 rear. I don't remember for sure. I know the rear is 43 stock. I don't have my Veypor with me or I could tell you the final drive ratio. I'll check when I get home tomorrow night.

hmm... I want to say it is like 2.85

 

I've got a 93 f2. Went -1/+2 and a 520 chain. Front wheel comes up like mad in first and second. Top speed dropped about 15 mph (from about 150-155 down to 135mph) Cruising @ 80mph bike runs 7500rpm. Not really sure if I like running that kind of rpm's on a consistant basis but it is a blast through town and on shorter trips. Just finished a 350 mile ride and the fuel economy dropped (hit reserve @ 140 miles). Think about what kind of riding your going to do and how long you want keep that cbr alive. Are Wheelies that important? -2/+4 and I'd keep it in town and parking lot side shows.

 

Brian97, What is your speed in 2nd when you reach your powerband? How fast are you comin up in 2nd? Thanks