2006 R/T Gearing too tall - especially first gear

I am commencing a run at being a bicycle race moto ref and at the first road race its clear my 1st gear way to tall to putt-putt behind bicycles uphill when they are going less than 10 mph.

It looks like the best way to resolve this is to either buy a 1200 police bike or the gearbox and final drive from one.

I would rather retrofit my regular RT as it has all the touring goodies on it for two up touring as well as other bits.

Anyone have any experience with this? I guess if I got a much shorter final drive I could swap back and forth but the police setup looks like a good compromise.

Anyone have a police bike they want to trade drive lines with me with?

A question here also is whether a gearbox from a 2009 RT will fit a 2006 RT as there's a 2009 RTP gearbox on ebay right now.

Well, the part numbers for a 2006 and 2009 are different. On this page, RealOEM says that the '06 transmission was used up to 1/2008. But there's another version that was used up to 8/2009.

https://www.realoem.com/bmw/enUS/sh...26-BMW-R_1200_RT_05_0368,0388_&diagId=23_0963

However, the part number ending in -743 does seem to appear in 2009 as well...so maybe???

Thanks for digging, I have a 20 spline driveline in my '06. I am thinking if a gearbox from an '09 has 20 splines its likely going to work?

You'll need to hear from the other Hexheads. Seems to me that transmissions are more complicated than just the number of splines. What about the electrical connections??

20774 said:

You'll need to hear from the other Hexheads. Seems to me that transmissions are more complicated than just the number of splines. What about the electrical connections??

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yeah these things can be tricky

Blerg... this is a tough topic that I went through a while back, as not all major parts fiches align.

As I understood it (which may not be right):

All final drives have the same number of splines. The number of splines on the transmission has changed - (A&S states "To 1/2008" and "To 8/2009" depending on color and type, Ted Porter states "To 12/2007"). IIRC the transmission potentiameter (sp) also has a different type, but the connections are the same (double check). Then you have the "enduro" transmission, which was optional for the RT (which may be actually be a "police" or a GS transmission). Therefore, I found that yes, you can change to a different transmission from a different year, but you may have to change the driveshaft to compensate for the mismatch from your original spline layout.

A fair word of warning - most eBay sellers have no idea what they actually have. I bet I looked at 30 different transmissions with varying levels of incorrect info. I thought about posting all my findings, but I couldn't find a decent enough consensus to be confident in directing people.

Buying a retired police bike would probably be more financially viable then replacing your tranny/driveshaft (and since you're already in so far, you may as well replace your clutch $$).

I really appreciate the input, folks.

I am still leaning to the enduro gearbox for the 06 I have as I really want to do the clutch anyway. I have had a vibration at 4K which I have not been able to eliminate even with a new Ted Porter drive shaft and replacing the left rear pivot assembly. All I can think of now is that the clutch was replaced at some point and it was not done correctly. Different story there.

I did some research a few days ago and I don't think the GS gearboxes are "enduro" gearboxes which I believe have a very short 1st gear even when compared to the GS boxes. I could be wrong but too lazy to go looking again.

too tall

Curious what the solution is as my RT is miserable in city traffic

Might want to see or check on what the other Road Marshals are riding and how it works out for them.
OM

Would GS final drive lower the gear ratio enough? From my limited search the trannies appear to be the same with only difference being final drive ratio on GS Vs RT.

Hi Roy, anything would help. Lots of marshals use the GS or even other adventure bikes like Truimph Tigers etc. and I think its probably the gearing they are after.

I have begun looking for used GS boxes and am just not sure about compatibility and some of those boxes might actually be non-enduro boxes like my RT

roy said:

Would GS final drive lower the gear ratio enough? From my limited search the trannies appear to be the same with only difference being final drive ratio on GS Vs RT.

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Depends on who you ask about the transmission...

(and these may not be right, as Webbike world lists different ones)
'05 R1200GS ratio: 1st 1.583 / 2nd 1.259 / 3rd 1.033 / 4th 0.903 / 5th 0.903 /6th 0.805:1

'05 R1200RT ratio: 1st 2.28 / 2nd 1.58 / 3rd 1.26 / 4th 1.03 / 5th 0.90 / 6th 0.81:1

Look into installing an AF-XiED. There's a very complete discussion on the ADV Forum. Basically it enriches the fuel mixture to give you better power/torque, especially at lower RPM's. I installed this on a 2006 R1200RT with sidecar due to a concern similar to yours and it made a world of difference.

Mark
Chicago

chrisinsc said:

I am commencing a run at being a bicycle race moto ref and at the first road race its clear my 1st gear way to tall to putt-putt behind bicycles uphill when they are going less than 10 mph.

It looks like the best way to resolve this is to either buy a 1200 police bike or the gearbox and final drive from one.

I would rather retrofit my regular RT as it has all the touring goodies on it for two up touring as well as other bits.

Anyone have any experience with this? I guess if I got a much shorter final drive I could swap back and forth but the police setup looks like a good compromise.

Anyone have a police bike they want to trade drive lines with me with?

Click to expand...

masegraves said:

Look into installing an AF-XiED. There's a very complete discussion on the ADV Forum. Basically it enriches the fuel mixture to give you better power/torque, especially at lower RPM's. I installed this on a 2006 R1200RT with sidecar due to a concern similar to yours and it made a world of difference.

Mark
Chicago

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Had not thought about that. Thanks Mark.

chrisinsc said:

Had not thought about that. Thanks Mark.

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Using the Tag Cloud and entering af-xied will reveal a lot of information.
OM

Omega Man said:

Using the Tag Cloud and entering af-xied will reveal a lot of information.
OM

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thanks!

I just ordered the af-xied from beemer boneyeard, looks like that might have use even if it doesn't totally solve the problem.

I did run into a product called Rocket Sprockets which replace the cogs on the cam for the cam chain. I guess since the bikes don't have variable cam timing that this product clocks the cams to move the torque curve lower in the RPM range. This might also be another way to improve lower RPM performance. My riding style is in general lower in the rev range so I might do this as well.

chrisinsc said:

I just ordered the af-xied from beemer boneyeard, looks like that might have use even if it doesn't totally solve the problem.

I did run into a product called Rocket Sprockets which replace the cogs on the cam for the cam chain. I guess since the bikes don't have variable cam timing that this product clocks the cams to move the torque curve lower in the RPM range. This might also be another way to improve lower RPM performance. My riding style is in general lower in the rev range so I might do this as well.

Click to expand...

The af-xied has definitely smoothed out the bike considerably and helped the low speed performance. Really curious about the rocket sprockets now

Changing out an RT transmission or rear drive is not trivial nor likely to be inexpensive. To contemplate doing it to be able to ride alongside bicycles at less than 10mph uphill shows true dedication to an activity. I’ve seen videos of motorcycles at bicycle events carrying camerapersons and such, but if low speed capability is a requirement, why aren’t maxiscooters used by the referees? They would seem a better choice but I’m probably missing something.

Just curious.