Author Topic: Anyone Do a +1T at the Counter Sprocket?  (Read 6892 times)

Offline billincentraljersey

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Anyone Do a +1T at the Counter Sprocket?
« on: August 21, 2008, 03:25:26 PM »
Have any one here gone +1T on the front sprocket of their B1250.  I wanted to lower my LD cruising RPM and correct the speedo by going -3T at the rear sprocket.  If a +1T fits at the FRONT sprocket without chain clearance issues, it may be a better option.  No chain to replace.
Carpe diem quam minimum credula postero
Bragging Rights:  NJ to CA in 8 Days on my B1250ABS. Not quite ADV Rider.
07 B1250ABS, 90 Kawasaki Concours, 84 Moto Guzzi V65SP, 77 Yamaha XS360, xx-77 NYC Subway

Offline Dmaxhall

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Re: Anyone Do a +1T at the Counter Sprocket?
« Reply #1 on: November 01, 2008, 01:58:59 AM »
Did you have any luck with your +1 on the front?

I am considering going the same way and wanted to see if anyone here had done it yet.
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Offline Dmaxhall

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Re: Anyone Do a +1T at the Counter Sprocket?
« Reply #2 on: November 01, 2008, 08:53:34 PM »
I have been doing some checking with regards to gearing.

My GSF1250SA manual specifies the final drive ratio as 43/18 (2.388 ratio).

I have not yet counted the sprockets to see if this is what is fitted to the Australian bikes, but it sounds right as Holeshot goes a 17T front for better acceleration.

Vortex Racing sells Bandit Fr Sprockets in the 14-18 tooth range and Rear Sprockets in the 38-53 tooth range. (Listing for GSF1200. Probably the same fit. Anyone confirm this?)

Removed the cover from the front sprocket. Clearance between the gear teeth and the rear cover bolt spigot(?) is pretty close (approx 1/8 inch, by eye... :trustme:), the clutch pushrod is also pretty close. So fitting a 19 tooth sprocket, if you can locate one, may end up being tricky.

Looks like -3T on the rear and shortening the chain may be the way to go.
« Last Edit: November 01, 2008, 09:00:18 PM by Dmaxhall »
"It is dangerous to be right
 in matters on which the
 established authorities are wrong"
                                                       Voltaire

Offline Red01

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Re: Anyone Do a +1T at the Counter Sprocket?
« Reply #3 on: November 02, 2008, 02:37:52 PM »
FWIW the OE gearing on the B12 is 15/45 (3.00:1 ratio) and AFAIK, the biggest front you can use is a 16 - and that may require light clearancing to make work, so there's no real comparison here with the 1250.
Paul
2001 GSF1200S
(04/2001-03/2012)
2010 Concours 14ABS
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Offline CWO4GUNNER

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Re: Anyone Do a +1T at the Counter Sprocket?
« Reply #4 on: November 05, 2008, 10:11:05 PM »
I sometimes have to remind myself to shift up to 6th gear on the interstate with my B1250, compared to my B1200 with only 5 speeds I would occasionally be looking for a taller 6th gear. If anything I have considered a 1 tooth smaller drive sprocket like most have installed to gear it down and add more wheelie popping ability and closer ratio. Not that I like popping wheelies or feel that it needs more in the low end, just that the ratio spread seems tall if anything. No one has had any issues dropping 1 tooth on the drive sprocket along with no chain adjustment issues. If however its too tight to add a tooth to the drive sprocket  your safest and necessary action will be to drop three at the rear sprocket and possibly not have enough adjustment room and need to brake 3 links off the chain. Not my idea of fun, as I get older now 51, stock seems to look better and better in my book.
« Last Edit: November 05, 2008, 10:14:42 PM by CWO4GUNNER »

Offline Dmaxhall

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Re: Anyone Do a +1T at the Counter Sprocket?
« Reply #5 on: November 06, 2008, 02:13:23 AM »
Too be honest, I also prefer something close to stock.

The main reason I am looking into the overdrive options is that I am sick and tired of getting only 200 kms to reserve.

However, it would seem that there is a GP sensor issue with some of the Australian spec bikes that causes enging hunting and excessive fuel consumption. Fixing this gets the engine right and puts fuel use from 7 or 8 litres/100km to about 5.5 ltr/km. Quite a difference.

If I do end up doing big touring distances, a -3T on the rear could be good anyway for relaxed travel.
We shall see.
"It is dangerous to be right
 in matters on which the
 established authorities are wrong"
                                                       Voltaire

Offline billincentraljersey

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Re: Anyone Do a +1T at the Counter Sprocket?
« Reply #6 on: November 10, 2008, 03:16:41 PM »

If I do end up doing big touring distances, a -3T on the rear could be good anyway for relaxed travel.


Having done the cross country thing (USA), I definitely can say I can use a slightly taller gear while flying 85-90 mph across the wide country for hours and hours. 

If I need more wheelie popping torque, I can still down shift to 5th.  I don't think I need to do wheelies from the 6th gear.
Carpe diem quam minimum credula postero
Bragging Rights:  NJ to CA in 8 Days on my B1250ABS. Not quite ADV Rider.
07 B1250ABS, 90 Kawasaki Concours, 84 Moto Guzzi V65SP, 77 Yamaha XS360, xx-77 NYC Subway

Offline pondingie

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Re: Anyone Do a +1T at the Counter Sprocket?
« Reply #7 on: November 16, 2008, 02:27:58 PM »
Just got back from a 100 mi.- 80 to 100 mph breakfast putt.  It can be done out here in Bumscrew, NM.  I am totally satisfied with the gearing on the B12.5.  I have never had a bike that is more stable at 100 mph, and I've had a lot of scooters.

Offline Dmaxhall

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Re: Anyone Do a +1T at the Counter Sprocket?
« Reply #8 on: November 16, 2008, 06:19:43 PM »
Back from a weekend 900km jaunt in the countryside around Sydney.

Mainly backroads with a combination of twisties, sweepers and long straights.

On country roads, I find myself going for another gear and finding that I am already in top.  :duh:

I am thinking, that when the time cones for a chain/sprocket replacement, that I will give a -3T rear a try.
"It is dangerous to be right
 in matters on which the
 established authorities are wrong"
                                                       Voltaire

Offline billincentraljersey

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Re: Anyone Do a +1T at the Counter Sprocket?
« Reply #9 on: January 19, 2009, 02:49:12 PM »
Back from a weekend 900km jaunt in the countryside around Sydney.

Mainly backroads with a combination of twisties, sweepers and long straights.

On country roads, I find myself going for another gear and finding that I am already in top.  :duh:

I am thinking, that when the time cones for a chain/sprocket replacement, that I will give a -3T rear a try.

The B1250 is fantastic for coast to coast.  I could use another higher top gear.  +1 at front would be nice.  It is also good for back roads that keeps you at 40 to 50 mph.  I am OK in this range.  However, when you're down to 15 to 35 mph in very narrow back roads, where the speed varies often, you are stuck with 1st and 2nd gear, too low.  3rd is too high.  A +1 in the front or -3 at the rear would be better.
Carpe diem quam minimum credula postero
Bragging Rights:  NJ to CA in 8 Days on my B1250ABS. Not quite ADV Rider.
07 B1250ABS, 90 Kawasaki Concours, 84 Moto Guzzi V65SP, 77 Yamaha XS360, xx-77 NYC Subway