Triumph Rat Motorcycle Forums banner

Gear ratio

12K views 14 replies 11 participants last post by  BonnieRider 
#1 ·
Hey All!

Guys chime in what gear ratios (sprockets) you have or currently run.
I'm thinking to go +2 front -1/2 rear to lower hi way RPM.
Thanks in advance.
 
#4 ·
Biscuit is correct. Reducing the tooth count on the countershaft sprocket increases the numerical ratio (increasing the engine RPM for a given road speed), while reducing the tooth count on the drive sprocket reduces that ratio with a corresponding drop in RPM for a given speed.
 
#6 ·
Guys we're going off track here.

DRIVEN(rear sprocket)
----------------------------- = FINAL RATIO
DRIVE(front sprocket)

Apply final ratio numerical figure to transmission ratio(s), you'll have individual gear final ratio.

The higher, numerically, tooth count on a DRIVEN gear, the higher the RPM at any given speed. The lower, numerically, tooth count on DRIVE gear, the higher RPM at any given speed.

But this is all irrelevant...All I was asking about the real experiences of having numerically different sprockets front/back...

Any real cases of "gear change" and how it affected your riding experience?


Cheers ...
 
#8 ·
I use 1200Trophy gearing on my 900 it works out to 4500rpm at 70mph which suits me really well it improved the fuel economy a little but for me because I was doing a fair amount of motorway riding, the drop in revs stopped the bike feeling buzzy.
It's a 19 tooth on the front. Can't remember the rear but it was whatever was stock for the 1200.

Sent from my GT-I9100P using Motorcycle.com Free App
 
#9 ·
Its been a bit of a toss up for me,I like the gearing Ive got on the bike on backroads,but then its revving 4 grand at 70 mph,it seems like a 1200 should be able to loaf along at 2500 rpm on the hiway.
But really,to pass quick the thing should be revving at 3500 or 4 grand to whoosh past cars,its a 4 cylinder and seems real smooth at 4 grand and still gets over 40 mpg doing so. Im not so sure gearing it way taller would help with mileage that much.
I do like the acceleration as the gearing is.

Guys who have geared it taller,does it get much better mileage?
 
#10 ·
I think the stock gearing is the best over all for most conditions, at least where I live. Most of my riding is pretty curvy badly surfaced secondary roads with a lot of elevation changes. There is a lot of slowing down and speeding up. On some of these roads 50 to 60 mph is a good pace and with the stock ratios there is a minimum of back and forth shifting. The few times on a highway I think sure the revs could drop a lot and the bike could easily mantain speed, but the compromise would be less than ideal on the roads I usually ride. If most of my riding was out west with long sweeping 70,80,90mph roads I probably would add a tooth or two to my countershaft sprocket. But give your riding area and road type a serious look and don't change gearing just for change sake.
 
#11 ·
If I lived in the hills with lots of twisty bits I'd be less concerned about gearing it for the highway. But I live in Iowa, lots of open 4 lane roads(i.e. boring) and I usually ride at 65-75mp all the time. If I'm running 4 lanes it's frequently a bit faster yet.

I've also not achieved 40mpg so far. I bought it with a "stage 1" jet kit, averaging about 80mph I returned about 23mpg.......
 
#12 ·
Exactly what I was getting at. The type of riding you have would have me looking at taller gearing too. Starting out in first would be an only limiting factor. Too much clutch slippage just to get moving is not good. Even with the higher speeds you run at though 23 mpg doesn't sound right even with stock gearing. What actually does a "stage 1" jet kit entail? I've not had the "pleasure" of having to inspect my carbs so I don't know what's in there for jets or the needle position but I have no drivability issues and am returning just about 40 mpg.
 
#13 · (Edited)
19/40 is the tallest gearing you can get for the Trophy. I don't think a 20 tooth sprocket will fit in the housing, and I haven't found anything smaller than 40 that will fit the rear. For the 1200, this is probably the best overall gearing unless you're an acceleration freak. This may be a little to tall for the 900 unless you ride solo and lightly loaded. Maybe 18/40 or 19/43 would probably be as tall as I would go with the 900.

Travis, don't know who trashed your carbs, but you should be getting much better mpg's than that. Is this a 900 or 1200? If no other mods have been done, I would return to stock jetting. 2-up, loaded heavy and pushing hard I get 36mpg out of my 1200.
Happy trails,
Erv
 
#15 ·
My 96 900 came with 17/43. Currently I have 19/40, but I am going to go back to (US) stock with my next chain. I find that I am always riding in a lower gear.

The 19/40 was stock for certain markets, but I feel it has changed the ridability of the bike too much. Probably fine if all you do is open highway riding.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top