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Re: Wombat gearing
Posted: Fri Mar 17, 2017 5:22 pm
by matt glascock
Victor, try jacking up the bike to get the rear wheel off the ground with the bike in neutral so that the rear wheel spins freely. Now mark a countershaft sprocket tooth with a bright grease pencil. Starting with that tooth as "one", spin the rear wheel and count the teeth as they go by until you get back to one tooth before the marked one. Presto, CS sprocket tooth count without removing the shifter cover.
Re: Wombat gearing
Posted: Fri Mar 17, 2017 6:13 pm
by Bill2001
If nothing else this thread may make folks here more aware if their final drive ratios. With the availability of c'shaft and rear wheel sprockets anything might be possible on a used bike.
One thing that helps is a tach. Engine hour/tachs, self-contained and -powered, and triggered by a sensor wire wrapped around the spark plug wire, are available. I use one made by Moose Racing, a Resonator advertiser. You can see it on my Speedo in the Kill Switch pic in "The Current Resonator comments" thread.
Re: Wombat gearing
Posted: Fri Mar 17, 2017 6:44 pm
by matt glascock
Good call, Bill. I'd like to try one of those. I currently use the saddle tach method. Another bit of food for thought on gearing. I typically alter my gearing, often at track side after practice, by swapping out the CS sprocket. This is the simplest unless you have the resources to have extra rear wheels with alternate drive sprockets. Dropping a tooth on the CS sprocket is roughly the equivalent of adding 3-4 teeth on the drive sprocket. There are some drawbacks though. The smaller the CS sprocket, the harsher the angle the chain takes around it increasing wear on the chain, CS and sprocket. A 13T sprocket seems to be the smallest without this effect although I have run a 12T CS sprocket on an insanely hilly hare scrambles course I hit every spring and fall. It is really helpful, at least to me, to keep the bike on the pipe by changing out the CS sprocket as track conditions suggest. Bill, I would be interested to know if it is easy to swap the hour meter/tach from bike to bike.
Re: Wombat gearing
Posted: Sat Mar 18, 2017 1:33 am
by Bill2001
There seem to be a couple of different designs. Some have an attached, fixed wire that can't be replaced. One other, used by Moose, uses a replaceable wire that fits into a cavity in the meter. This way, you can attach the meter to the bike with Velcro and have a signal pickup wire permanently attached to each bike. Easily swappable. Meter is epoxy sealed, has a nonreplacable battery with a 5 year life, and cumulative non-resettable engine hour meter. Record the beginning reading and end rdg and you can monitor the running time for each bike. Good deal for $40.
I addef mine because I didn't have a feel for engine speed (redline and "lugging") and had an inop speedometer. I calculated the road speed vs rpm in top gear so I wouldn't get busted for speeding in town or guilty of poking along like a geezer. And it's a nifty bling and farkle, so the Inner Child is happy.
Re: Wombat gearing
Posted: Sat Mar 18, 2017 5:34 am
by matt glascock
Bill, my inner child thanks your inner child. Sounds like the Moose Racing is the way to go. Added bonus - they support The Resonator Revisited. Everybody wins. Thanks so much, Bill. I'm on it.
Re: Wombat gearing
Posted: Sat Mar 18, 2017 9:04 am
by viclioce
So, what are folks opinions on which final drive ratio is a best bet for both street riding and off road riding combined? I'm inclined to believe that 62 tooth rear needs a 15 tooth countershaft. Is as close as you can get to a 4:1 final drive ideal? Do you agree or disagree?
Victor
Re: Wombat gearing
Posted: Sat Mar 18, 2017 10:30 am
by viclioce
Note to my last post. The Red Toad with the 62 tooth rear sprocket also has an 18" rear wheel instead of a 17" rear wheel!
Victor
Re: Wombat gearing
Posted: Sat Mar 18, 2017 2:20 pm
by viclioce
BTW Matt, the motor isn't in the bike yet, so counting teeth will be easy while it's still on the workbench!
Victor
Re: Wombat gearing
Posted: Sat Mar 18, 2017 2:32 pm
by taber hodaka
Victor there is no perfect answer. How experienced is the rider. How you like to ride , the terrains where you like to ride, How much do you weigh. Sandy, loose gravel, mud, steep hills. ----------Clarence
Re: Wombat gearing
Posted: Sat Mar 18, 2017 2:45 pm
by viclioce
Mixed terrain, 160 lb rider (guesstimating) back & forth to school on the street, and maybe an occasional MX track. It's my nephew. I'm guessing his weight and not an experienced rider, yet. Do I guess I'm looking for a round starting off point.
Victor
Re: Wombat gearing
Posted: Sat Mar 18, 2017 3:43 pm
by taber hodaka
I would keep a 14 tooth handy. Also how tuned is the engine? -----------Clarence
Re: Wombat gearing
Posted: Sun Mar 19, 2017 12:15 am
by Bill2001
Also depends on how Hodaka designed the geartrain. Your Toad may have different primary ratio, ratio for each gear and consequently a different final drive ratio. Comparing a 'Toad to a 'Bat may be like apples and oranges. Check your specs and see what the factory suggests for the final drive.
Also going from a 17" wheel to an 18" wheel is s game changer. Effectively increasing the wheel size is like decreasing the size of the rear sprocket. So the 65 tooth rear may be equivalent to a 59 tooth rear, all else being equal.
It's hard to say. Check your specs.
Re: Wombat gearing
Posted: Sun Mar 19, 2017 5:01 am
by MTrat
What is the largest CS sprocket that will fit without modifying or removing the sheet metal shield?
Re: Wombat gearing
Posted: Sun Mar 19, 2017 5:26 am
by hodakamax
Good question and I'm trying to remember. It seems as though the 16T worked but was close on an Ace 90/100. I second that question!
Max