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Discussion Starter · #1 ·
So some of you may recall that I replaced the transmission on my buddy's 2002 LT a few months back. I sourced the transmission from @saddleman who lives about an hour from me. Saddleman (Dave) is a great source for all things LT and has a few around his (immaculate) shop as well. His own 99 (I think) LT is pristine, of course. Anyway as he is 'the' guy for all things Final Drive we got to talking about them. I recalled meeting a fella up in Blowing Rock NC the previous year who had come up to me as my wife and we dismounted the LT. We chatted for a bit and I lamented that my biggest gripe about the bike was its tendency to want to stall when taking off, causing me to slip the (dry) clutch WAY too much. Turns out he's @Lee510 here on the forum and he told me about getting to use another final drive from Dave while his FD was being rebuilt. He said he thought it was a 3.0:1 ratio and it made a huge difference in how the bike behaved. The biggest thing was how much easier it was taking off with the shorter gearing.

Dave has several FDs with differing ratios and decides he'll sell me the 3:1 FD because it's a little too short for him as he actually prefers the 2.91:1 ratio. I buy the FD and it sits on my workbench for a few months but I never seem to get around to swapping it over. Then on a ride with my wife up to Blowing Rock again Google takes me down Globe Rd, against my better judgment and a series of events occur that forced my hand. Long story short, the bike stalled and we are dumped unceremoniously onto the tarmac as we tried to get back onto the main road from the very steeply inclined Globe Rd. I decide before we ride together again I will have installed the new FD, and did so last week. After I ride it around a little bit to ensure it's put together correctly as I have a trip in a couple of days.

We leave Saturday morning and head southwest towards Hiawassee GA, as it will get us into sunshine quicker than heading northwest. Initially, I notice the higher RPMs, as you'd expect. This was easy for me to get used to as I would often leave the bike in 4th gear to keep the revs up and more into the power band. In 5th gear at 60 mph indicated I'm at 3400 RPM, at 70 mph indicated it's at 4000 rpm. All good numbers IMO. I am wondering about gas mileage though, and I had reset the computer before we left on Saturday. So last night (Monday) I checked it once we'd gotten back and it read 41mpg. BTW, this was with some rather spirited riding. I think my average gas mileage with the stock ratios, according to the computer, was 42mpg so pretty much the same.

So, what's my overall impression? Taking off from a stop is no problem at all now. None of that just-on-the-verge of stalling or having to slip the clutch too much to get moving. This is huge to me. Second, take-off, in general, is much better. Now redline in 1st gear is mid-40's (still high IMO) not the 62mph I heard others quote (that's insane to me). There were a few times I just decided to 'get on it' and wound it up to redline all the way through 4th gear and it felt so much better to me. I didn't redline 5th, but I suspect I would run out of HP before I did anyway. Triple digits come at the end of 4th gear now, if that information is relevant to you. Pulling out of corners is better in the mountains, 3rd gear is much more useable, no more downshifts to 1st on those uber tight switchbacks, 2nd had enough torque to keep you going. And the list goes on.

So, what's the downside? If there is a downside it's that you lose one of the lug bolts. As this FD was on various other bikes, those other bikes didn't have a center lug like the LT. In fact, I think only one other bike they made had a center lug? However, I am not concerned about these 4 lug bolts being able to handle the weight of the bike. I've seen these older GS's and RT's loaded to the gills and have never heard of a single time where a lug failed in these scenarios, and I've seen the GS's rode hard and put up wet. But I have a bolt in there to ensure the cavity is not going to fill with dirt or water, I just have a nut on the backside with a little spacer to keep it in place.

Anyway, I wanted to share my experience with the new FD ratio and recommend it to those out there to give it a try. In talking with Dave all you really need to do is source the FD and swap over the backing plate from the LT and it will work. It's probably worth getting it rebuilt to be sure it's healthy, then you can keep the old FD as a backup in case of emergency. Box it up ready to ship (for example) in case you are out there and the FD gives up the ghost, probably keep the special socket and giant Allen wrench in there too. So you can just have someone grab the box and head to a UPS store...is my line of thinking.

I'm actually going to go out and get a 2.91:1 FD now and have it or the 3.0:1 as the backup so I don't have to revert to the 2.6:1.

Be safe and enjoy! :)
 

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Hi Shifthead , thank you for the write up on your final drive. I have been thinking of changing the final drive on our K1200lt/ Hannagan rig. I do not use 5 gear as it doesn't let the motor spin up where I would like it. But for now, we don't go on the interstate so 60 mph in 4th is is as fast as we go.

I had made a chart of all the different ratio's that BMW has. I measured the rear tire on our bike ( 165-15 -70 ) , and had some the the final drive ratios worked out to the speed it would go in all the gears at ..I think 3800rpm Trying to find the ratio that would put us at a good rpm for the different speed limits . If I get the right we could go on the interstate, but I really don't want to go over 70 - 75, but I need a good gear and rpm for 25 , 35 , 45 , 55..

That was just before my wife said we are moving from Michigan to Florida a few years ago.. We have been in Florida for 2 years.. and I have been remodeling the house . But , I am starting to see the light at the end of the tunnel ,so maybe I can get back to finding a ratio that will do it all...
 
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Thats good information SHIfTHEAD thanks. I do not like the stock f.d. ratio either. Which machine had this ratio you speak of? I have been riding many years and just don't like slipping the clutch as I just replaced it. After doing the clutch one of the test runs included top end run. I know the speedo could be up to 10 mph slow but it went to 130 plus and was still pulling, does any one have a top speed report? Was your speedo closer to correct or even worse?
 

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Enjoy The Ride
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Thats good information SHIfTHEAD thanks. I do not like the stock f.d. ratio either. Which machine had this ratio you speak of? I have been riding many years and just don't like slipping the clutch as I just replaced it. After doing the clutch one of the test runs included top end run. I know the speedo could be up to 10 mph slow but it went to 130 plus and was still pulling, does any one have a top speed report? Was your speedo closer to correct or even worse?
Your speedometer is off about 10% on your year LT. Changing the gear ratio has no effect on the speedometer.
 

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Discussion Starter · #5 ·
Thats good information SHIfTHEAD thanks. I do not like the stock f.d. ratio either. Which machine had this ratio you speak of? I have been riding many years and just don't like slipping the clutch as I just replaced it. After doing the clutch one of the test runs included top end run. I know the speedo could be up to 10 mph slow but it went to 130 plus and was still pulling, does any one have a top speed report? Was your speedo closer to correct or even worse?
Yeah, like @saddleman said, it's still going to be off. That's why I stated the speeds as indicated. I used them more for measuring the increase in RPMs throughout the range. I generally am using the GPS speedo as the real speedo.
 

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Discussion Starter · #6 ·
Thats good information SHIfTHEAD thanks. I do not like the stock f.d. ratio either. Which machine had this ratio you speak of? I have been riding many years and just don't like slipping the clutch as I just replaced it. After doing the clutch one of the test runs included top end run. I know the speedo could be up to 10 mph slow but it went to 130 plus and was still pulling, does any one have a top speed report? Was your speedo closer to correct or even worse?
I found this list of ratios when searching a while back and it's a good starting point to look at on eBay. However, it does not mean that every FD from that model will have that ratio. I've seen that many of the FD will have the ratio stamped into the housing, and many sellers will show that. Here's the list I mentioned:

37/11 = 3.364 - 850R ; 850GS
34/11 = 3.091 - 1100RS b.93
33/11 = 3.000 - 1100GS ; 1100R
32/11 = 2.910 - 1100RT ; 1150RT
31/11 = 2.818 - 1100RS a.94 ; 1150GS ; 1150R ; 1150GS/A
33/12 = 2.750 - 1100S

Here's one of the pics from the FD I just bought on eBay that should have the 2.91 ratio I want
Bicycle part Rim Close-up Auto part Metal


However, I'm not sure that all FDs will have this marking. I see that some sellers will list the ratio in the title or description, but I also noticed that most of those that do charge a premium. Good luck!
 

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Some times it is stamped on the tip of the pinion shaft. I am running a 2.82 Dave made for me and love it. I just can't get to 62 in first any more, I hit redline at 58 now.
 
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