Tri-Z rear sprocket?

[puggerton03]

I plan to use 20" tires on it and I already have a new Sunstar 13T front. I need to know what size rear sprocket to get, to get me back to stock final drive ratio with the 20" tires. Stock is 13/44 with 21" tires. I was thinking a 41T? Its an 86.

[puggerton03]

Anyone have any gearing experience with 20s on Tri-Zs?

[Bryan Raffa]

yes.. I run 15t/ 44t six speed ,, so if you run with a 41t it would be like haveing a 14t on the front.. one tooth on the front is 3 on the back.

[puggerton03]

So if I went with a 13/41 with the 20s would that be good? Or would it still rev out too fast. The problem I have now with 12/44 and 22s is that it revs out waay too fast.

[Bryan Raffa]

front sprockets are cheeper....get a 13 and a 14.. it will be still cheeper than a rear..lol

[puggerton03]

I already have a new 13T, just need to decide on a rear so I can order. Stock is 13/44 with 21" tires, so, how many rear teeth equals 1" in tire diameter is what I need to know.

[WilliamJ]

If its any help, I have a gearing and speeds spreadsheet in Excel that I could email. I can't work out how to post an image of it but maybe someone else can.

It's set up with Tri Z 85 gearing but you can put any figures into it - as long as you know the basic numbers - I imagine the box ratios and primary drives stay as the factory made them.

If you want to have a look let me know and I'll email you the sheet.

Bill

[WilliamJ]

AHA! I may have discovered how to ad the Excel sheet......let's try it out (I am such a moron)

[puggerton03]

Call me an idiot but I have no idea how to use that.

[WilliamJ]

Okay, I 'll run through it........There were some comments but they didn't transfer into the upload. If you have an 85 Tri Z step One and Two will almost certainly have the same numbers. Otherwise they will definitely be different.

Step One - do you know your Primary gear ratio or the tooth numbers? Someone is bound to know or they may be listed in the manual. If the tooth numbers are know put them in the blue boxes. Or put the ratio number into the yellow box. Big number is the teeth on the clutch - small number is the teeth on the end of the crank. EITHER PUT NUMBERS IN BLUE BOXES, OR YELLOW BOXES - NOT BOTH

Step Two - Same thing but with the individual box ratios - should also be in the manual. Same deal with inputting the figures...teeth= blue; ratio=yellow

Step Three - Sprockets - just count your teeth and put in the numbers as before.

The results of the ratios will appear inthe box with the bright green header.

Put in the tyre diameter (blue box below 'Speeds In Each Gear') and the speed at 1000 rpm in each gear will appear below the mauve box. If you want to know what speed you get at max rpm just put 10,000 (or whatever you rev to before you change gear in the mauve box).

If the numbers aren't listed in the manual then you can either count teeth - which is tricky when they are concealed inside the transmission - or you can count the number of revolutions of the engine for every revolution of the rear wheels. These numbers go below the bright green header 'Overall ratio Results'

E.G. The Tri Z engine turns 18.6 times for every rev of the rear wheel - in first gear - 15.2 times in second etc. etc.

Hope that helps, let me know if not.

Bill

[Bryan Raffa]

I already have a new 13T, just need to decide on a rear so I can order. Stock is 13/44 with 21" tires, so, how many rear teeth equals 1" in tire diameter is what I need to know.

how is your motor built?

[puggerton03]

Carb off of an 86 250R, Boyesen reeds, Phase Five silencer, UNI filter. Have 13T front already and Im putting 20x11x9 rear on it soon. Need to know what rear sprocket to get to have it not rev out too fast. Thanks for all the help.

[Bryan Raffa]

Git a 40..;) and if you dont like it ,, throw a 14 tooth front on..

[puggerton03]

Just ordered a Sunstar steel 40T sprocket and an x-ring 98L chain. Cant wait to try it out.

[puggerton03]

Well I got the new sprockets and chain on today. 13/40 sprockets. Big differance from 12/44. I like it alot better. Anybody have any advice on how to make the carrier/axle straight across and even using the chain adjusters? That was the hardest part of the job.

[volfan537240]

i just bought a banshee rear sprocket hub and it came with a 39t rear. i will also be running 20" tires. so tri-z's have a 13t on front stock? i didnt know that. im use to the 14/41 on a banshee.

[Mosh]

A mild or stock Z engine is a low end torque monster compared to a 250R.
The stock gearing is very steep on a Z and I actually prefer it for trails, but the front end yanks up super easy on stock gearing.

My bigbore is not a hi RPM revving machine. Most power is focused right in the low and mid, so it runs better as a short shift motor.

I was running 14-44 with 20's on it, and in 300 ft it was topped out at the finish line.

I have gone to 14-41 with 20's and it really legs out alot more, but to ride it in tight trails with that gearing requires a little more clutch work.

Volfan..DO they make a 39 tooth banshee rear, for the 6 bolt hub? I thought 40 was the lowest you could go on the 6 bolt hub.
Think I remember Ronnie saying you can run a 87-88 banshee 4 bolt rear hub and get down to a 38 tooth also.

[volfan537240]

yes i have a 39t on a banshee 6 bolt hub. it doesnt look like the chain will interfere with the hub but i havent tried it yet so im not 100% sure. i have heard of 4 bolt hubs that can go lower on the sprocket as well. seems like lonestar makes a honda style 4 bolt for the banshee/ tri-z.

[Mosh]

yes i have a 39t on a banshee 6 bolt hub. it doesnt look like the chain will interfere with the hub but i havent tried it yet so im not 100% sure. i have heard of 4 bolt hubs that can go lower on the sprocket as well. seems like lonestar makes a honda style 4 bolt for the banshee/ tri-z.
That is good info there.Thanks.

[Bryan Raffa]

I got a 38... the chain just touches the hub


Well I got the new sprockets and chain on today. 13/40 sprockets. Big differance from 12/44. I like it alot better. Anybody have any advice on how to make the carrier/axle straight across and even using the chain adjusters? That was the hardest part of the job.

tape measure off the chain adjuster,, where the bolt goes through,, to the end of the bolt.... the marks on the swinger is a PITA