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View Full Version : 83 big red gear ratio in low range?



1badatc
03-28-2011, 10:05 PM
exactly how low is the low range on the old big red chain drive 200?i have a 200m and im getting a bigger custom rear sprocket made by sidewinder but i dont want to over do it because im wanting to swap a big red 200 motor in it so i can turn 29.5 outlaws,anybody know the exact ratio or have an idea of how low low really is??thanks in advance!

MNATC
03-29-2011, 03:44 PM
If you can get a hold of a shop manual for an '83 it should have it in there. I'm not sure if there is a difference in tranny's as far as gear ratios from '83 to '84, but it has it listed in my '84 shop manual. I don't know if they are the same, if they are, I can get you the numbers for the '84 BR.

oscarmayer
03-29-2011, 03:51 PM
83 and 84 are the same for the ES (electric start/shaft drive/reverse) and 82-83 for the E (electric start only) are the same. hope that helps.

MNATC
03-29-2011, 04:56 PM
These are the gear ratios from the shop manual, maybe this will help:
Primary Reduction: 3.333
Gear Ratio
(Posi Torque Gear Ratio)
1 2.841 (4.339)
2 1.767 (2.698)
3 1.306 (1.995)
4 1.026 (1.567)
5 .836 (1.277)
Rev: 4.616
Final Reduction: 4.255

Low Drive Gear I counted 30 teeth
Low Driven Gear I counted 47 Teeth
If I did it right (went by the photo in the shop manual, at work so can't check my spare gear set), it would put it around 1.566:1 gear ratio for the low gear.
*edited: The gear ratios above are for a '84 BR, not sure if it covers the '83 BR

Edited again.....ha ha ha
Ok, so I have a little free time today, and downloaded a manual for the '83 BR. Has H/L no reverse, so not that many gears to see what's what. Anyway, the low gear has 18 teeth, idler gear it mates to has 19. If I'm correct, you'd be looking at a 1.055:1 Ratio for low gear. All the tranny ratios are different between the two years, '83 and '84.

1badatc
03-29-2011, 09:06 PM
thanks mnatc but how do you figure out the final ratio in low?and with a 60 tooth rear sprocket and a ten tooth front i will have a 6to1 ratio correct?do you think that is low enough to turn 29.5 wides in gumbo?or do i need it lower???

MNATC
03-30-2011, 09:33 AM
For low gear ratio, I did it by the low gear in the subtranny. For sprockets, I'm not much help. Even on the motorcycles I've owned I've never swapped out from stock front or rear sprockets sizes. Ask some of the guys with the race trikes, or maybe someone with a better understanding of sprockets. I know add a couple teeth (rear) gain accel lose top speed. That's about the extent that I have. Sorry it's not much help.

11/47 is stock sprocket size. You could try just adding a couple teeth on the rear, I don't know a lot of people on here, but I'm sure someone would have great insight on this with going to 29's and sprocket sizes. I would think in low gear alone you'd have enough up to crank those over in the thick stuff, but I'm not 100% sure on it either.

ebecme01
04-01-2011, 04:56 PM
I'd say a 60t rear would be fine. Dropping 2 teeth in the front would make about the same amount of difference I think. The low range is very low. I haven't looked in a book, but I own one. It seems to be twice as tall in low. I think I would change the front first if I were you so you can keep the clearance and save you from buying a chain.