Best sprocket combo for Model 99?

[viclioce]

OK. This Red Toad has a 14 tooth countershaft sprocket & and a big 62 tooth rear sprocket.

When I road it down the road, I got about only 38-40 mph as a top speed, based on the original speedo, which hasn't been reworked or checked for accuracy. Now, the 62 is probably going to give it a better, aggressive gearing for the dirt, but I believe my nephew is going to want to also ride the bike to school, as well as ride it in the street to get to areas where he can ride it off road.

I've never worked the math for gearing, and don't know how to calculate the effects of changing final gear ratios. Who can tell me,

1. What was the OEM front/rear sprocket configuration? Was it 14/56 or something different?
2. A good middle of the road rear sprocket to go with the 14 tooth front, which will keep the bike from riding down the road in 5th gear without being at near full throttle, and,
3. Will still provide decent power to the rear wheel for moderate trail riding.

If we go all the way down to a 50/52 tooth rear sprocket, will it not have enough low end torque to pull well through a turn in dirt?
Thanks in advance for whatever info & insight you can provide!
I'm almost ready to buff out the tank and add the graphics! I'll also need to pull the Triple tree off and do some screw extraction because there are broken off screws in the bottom tree which is proventing me form securely mounting the front fender. Shouldn't be more than an hour's work, but I put it off trying to get this motor running. No excuses now! Victor

[taber hodaka]

Victor if you just got this thing running, you should not be testing for top speed especially when it is so low geared.------------Clarence

[viclioce]

Clarence. It's already been through 2 idle heat ups with full cold cool downs & it's had about 1/2 to 3/4 hour of riding time in 3 increments.

Not pushing it to 100% full throttle top end in 5th gear yet, but I can tell that maybe 45 mph is going to be the best it's going to do with that 62 tooth rear.

I believe the 56 tooth was the OEM size rear sprocket? That's which one shows up first on the parts list, which is usually what they do. List the OEM first, followed by over available sizes. Isn't that usually the case? Don't they do the same thing with other interchangeable parts like jets & countershaft sprockets?

Dropping from 62 to 56 seems reasonable and should keep the bike from rev'ing high too quickly and allowing for a more moderate throttle engagement in 4th & 5th gear, so as NOT to over rev the motor going down the road. Just seems like a smart move to me. Victor

[rlkarren]

This might be helpful:
viewtopic.php?f=1&t=1864&p=12569#p12569

This was a post from Doug that calculated theoretical speed based on gear ratios. There's more information that can be gleaned from it and it also does not take into account wind drag, etc. But it is useful as a general reference for other bikes. I don't think the numbers would be too far off in regards to maximum speed possible, for other bikes.

$0.02

Roger

[viclioce]

Very good, Roger! I remember that thread but couldn't find it. I'm going to go with a 14/56 combo and it should be good enough for around town and still be functional for moderate off road riding. After all, I think that's the OEM configuration for this Model 99!

He only has about 2-3 miles to school in the morning. And will likely put the bike in his truck to take it to off road riding locations. He's on the South side of town & the off road stuff is either 5-8 miles west of his house or about 13 miles north. And then there's the track if he decides to try that as well! Victor

[Hydraulic Jack]

Stock gears were 14/56 as shown in the supplement:

https://www.strictlyhodaka.com/v/vspfil ... /SH_99.jpg

Having ridden only one model 99, I can't say what they all,do, but the one I road in the UCTT last year would cruise at 55 no problem.

Frankly, 2 heat cycles doesn't break in a two stroke, any more than two heat cycles would break in a new car. Run a full tank of fuel through it before attempting a new land speed record.

[viclioce]

Jack. Really not trying to reach physical top end of the bike yet. We've burned through almost a gallon of gas so far. But I acknowledge some of that was leak loss.

Still taking it easy. Still riding smoothly & slowly. She has about 2 hours on her now with 4, 10 minute heat cycles at idle, and a couple of slow 1 mile rides around our closed subdivision. Not done with the bike yet but it should be closer to beak in point by the time I finish tapping out the broken fender bolts in the bottom of the trees & mounting the fender.

I'll just keep warming her up and cooling her down, with a few more easy rides around the subdivision.

Still have the other Toad to finish as well & waiting to hear back from Bruce about a possible trade for the correct pipe for the Green Toad. Victor