sprocket ratios

[ATCWRENCH]

Ok I just bought an 85 tecate and it needs the good ol'fashioned maintenence check which is no big deal.

the guy who I bought from had the gearing stretched way out so there is no bottom end punch, actually you dont get a hit until about 30mph. I planned on going back to stock on the front sprocket and dropping two teeth in the rear.

well my all knowing brother(yea right) is trying to tell me that dropping 2 teeth in the rear is like going up six teeth on the front sprocket.

the motor has had the head shaved .60 and has a DG national pipe and silencer. new wiseco piston which is not a performance gain and I think a set of carbon fiber reeds, and 20x10x10 tires.

do you guys think going back to stock gearing on the front and dropping 2 in the rear will be to much for the motor to handle for trail riding.

[86200s]

well if you want to get more pull then going down on the back is not the way to go anyways how many teeth are on them and dropin 3 teeth on the back is a like gaining one on the front

[ATCWRENCH]

13 x 42 is stock gear ratio. it is now 16 x 42 ratio and I want to go 13 x 40 ratio

[TeamGeek6]

Heres a gear, sprocket and speed calculator for your machine :

http://home.earthlink.net/~gellett/tecate3.htm


Then figure the speeds with different sprocket combos compared to what it has now. The sprockets are a ratio of front : rear (mines a 14:36 = 0.388) That multiplies with the trans gear ratios to give vehicle speed once tire diameters are figured in.

2 teeth change in the rear makes small difference, 2 teeth in the front is a large difference:

14: 36 = 0.388
14: 38 = 0.368
16: 36 = 0.444

2 tooth change in rear makes a difference of 0.020
2 tooth in the front makes a diff. of 0.056

I dont think sprockets are the problem, those Tecates were fast machines. Im guessing from the build that it needs tuning and some of that low end will come back. Cheaper to try than $75 in sprockets.

id check compression before going much farther.

Granted its a different machine, but mines tuned to more than overpower a 14:36 sprocket combo and its a stock 8:1 compression.

[TimSr]

16T in the front? You must have to be doing 20mph before you can let your clutch all the way out! My only question is, why change two teeth in the back? Why drop gearing in the front, and then raise it on the rear? Why buy two sprockets instead of one? A front sprocket will run about $10-$15.

One tooth on the front is approximately the same as 3.5 teeth on the rear.

Will it help your trail raing? Slipping the clutch all day and not being able to hit high rev's until you are doing 30mph will both smoke clutches, fatigue the rider, and foul out plugs. Keep your rear sprocket, and drop to a 13 in the front, and be done with it. Personally, Id probably drop to a 12 in the front, because Ive never seen stock gearing low enough for true trail riding that keeps a two stroke cleaned out and revved up.

[firefirefire90]

Arent all wiseco permormance pistons because they are much lighter?