final drive trade

[mwood7800]

I have a 06 fd 2.82 with 14000 miles, anyone want to trade me a rt 2.62?

[CoarsegoldKid]

I can't help ya but I am curious. Assuming you have a GS model. Why do you want a taller gear ratio?

[mwood7800]

i have an rt, the gs fd is my spare, i swap it now and again for something different. with the 2.82 on the rt the gear indicator doesnt work and no cranking in netural. there seems to be no one smart enough at bmw to tell me witch gear potoimeter to use. the lower gearing is fun but just looking for another 2.62 for a spare

[Huzband]

What does the final drive have to do with the gear indicator & neutral cranking?

 

I may be interested, I've been wanting a GS fd for some time.

[Glenn Reed]

What does the final drive have to do with the gear indicator & neutral cranking?

 

I may be interested, I've been wanting a GS fd for some time.

 

Oh no, Danny may be infected with the GS virus, it's just starting out slowly...

[OoPEZoO]

What does the final drive have to do with the gear indicator & neutral cranking?

 

I may be interested, I've been wanting a GS fd for some time.

 

Oh no, Danny may be infected with the GS virus, it's just starting out slowly...

 

Nah.....he already had one. I think I recall him riding through a creek with a perfectly good bridge right above him

[mwood7800]

took me a bit to figure, the gear poteniometer talks to the computer along with tach and speedo, between the three they decide what gear your in. bmw made 50 diff potenometers to match different tranny gearing and fd gearing and even wheel size, if all the crap dosen,t jive then no gear indicator, if the gear indicator dosent work then no cranking in netural without clutch in and kickstand retracted, i guess a gear indicator is hard to do, or bmw made it so

[mwood7800]

what gets me is bmw sells 3 diff gear ratios for the rt and gs but they cant tell me what gear poteniometer to buy to make the gear indicator work...

[Boffin]

Real OEM show the same part number for the potentiometer for both the 2006 R1200RT and the 2006 R1200GS.

 

I am moving this post to Hexheads, though the original request for a trade should have gone into classifieds, this has now moved into a discussion on a hexhead-specific wrenching topic.

 

Andy

[dirtrider]

Morning

 

Something more needs to be understood here.

 

The trans gear position potentiometer reports trans gear position to the BMS-K. The gear position is the same no matter what final drive gear ratio used. Trans 1st gear is 1st gear & neutral is neutral no matter what final drive ratio.

 

There are a lot of trans potentiometers available for the 1200 hexheads but according to my master parts book those are for different transmissions or years but no differentiation for final drive ratio.

 

There might be a different calibration as far as final drive ratio vs computer calibration but I see no direct link between the trans potentiometers & the final drive ratio.

 

 

[lkchris]

A bit on final drive nomenclature.

 

"Higher" and "lower" refer to the vehicle speed potential and not the size of the number.

 

That is, a bike with a 2.62 rear axle ratio ought to be able to go faster than one with a 2.82 ratio. It certainly will be going faster at the same engine rpm and same transmission gear.

 

Therefore 2.62 is higher (and taller) than 2.82.

 

Therefore the OP wants to switch to a lower ratio. This will reduce top speed (theoretically) but improve acceleration, as the engine will spin faster and produce more power to the ground at a given speed.

[w2ge]

A bit on final drive nomenclature.

 

"Higher" and "lower" refer to the vehicle speed potential and not the size of the number.

 

That is, a bike with a 2.62 rear axle ratio ought to be able to go faster than one with a 2.82 ratio. It certainly will be going faster at the same engine rpm and same transmission gear.

 

Therefore 2.62 is higher (and taller) than 2.82.

 

Therefore the OP wants to switch to a lower ratio. This will reduce top speed (theoretically) but improve acceleration, as the engine will spin faster and produce more power to the ground at a given speed.

 

Good one Kent... Thanks!

[mwood7800]

not sure how it all comes togeather but I do know that if I install the 2.82 my gear indicator works for about 5 miles then starts swowing 5 when in 6th and no other indicators, no crank unless sidestand retracted and clutch in. When I put the 2.62 fd on everything imeditatly starts working, after many calls to max and other places I still have no answer or computer update, I did talk to another gs guy who had bmw re do the computer but his worked only a week then blank..

[Huzband]

BTW, does your '06 2.82 have a drain plug in the bottom, or is it in the rear?