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-   -   Gearbox Guru wanted in England or Germany (https://www.horizonsunlimited.com/hubb/bmw-tech/gearbox-guru-wanted-england-germany-22685)

colebatch 10 Aug 2006 11:56

Gearbox Guru wanted in England or Germany
 
Recently bought a R1200GS Adventure and am pretty happy so far with the exception of the gearbox ... which is clearly a road gearbox rather than a 'go anywhere' gearbox ... as you can determine from looking at the gear box ratios of the R1200GS, R1200GSA, R1200R, R1200RT, R1200S, and R1200ST .... all identical set of 6 ratios. Why spend money developing a purpose built gearbox when you can just drop in the bog stock gearbox eh?

There is only one other gearbox that BMW make for the R1200 series that has any different gear ratio, and its on the R1200RT-P and R900RT-P Authorities bikes. It has a very low first gear (to allow clutch free riding at walking pace during escort duty).

Can anyone recommend a BMW gearbox specialist who might be able to get me these alternate cogs and install them?

BMW UK themselves have been about as much help as a jacuzzi full of jellyfish.

smitty 10 Aug 2006 15:57

Gearboxes same same?
 
The gearboxes are probably all the same because BMW knew that 90 something % of the purchasers of the R1200GS and Adventure would never leave the pavement(not intentionally that is). Other than marketing strategy, to BMW, it's a road machine(the gearbox thing speaks for itself). Those that do venture off the pavement represent a fewer % of their market. The reality is that you "can" ride it off the road but let's face it, it's not an off the road bike. You could say it's a "sheep in wolfs clothing". Best......Smitty

colebatch 22 Aug 2006 13:05

Anyone ?
 
OK I have a guy who will happily fit it for me, but I need to find a dealer in Germany who will supply me with the R1200 RT-P first gear. Can anyone advise me of a co-operative flexible BMW dealer in Germany?

Margus 23 Aug 2006 09:08

It looks to me that only the non-experienced offroad riders complan about the gb ratios.

The HP2 has the same gearbox ratio spec as far as i'm concerned, and the bike was ridden into 2nd place on German Cross Country race series final in the same track where 125-650cc single cylinder enduros-crossers race with the top riders :). The race is extremely difficult and varying, mostly slow speed action! But sometimes a near flatouts too. So it quite says how well the ratios are choosed.

The very-very-very slow "standing" speed offroad is more trial and stunt riding speciality, over the size of three heights-of-human rocks jump from one to another etc, you can't go into such places with a big pig like a big trailie bike anyway.

Experienced offroad riders go through/over the obstacles usually with the accelerated speed when the bike is stable and the front end is light, very rarely with the very low speeds where the bike turns highly unstable and the front end nailed. Thus the very short first gear looks rather like a "academical" option for the newbie offroad riders to me.

Anyways, that's my 2-cents about it...

colebatch 23 Aug 2006 10:13

Not that it addresses my actual question ...
 
but Margus while I appreciate the info on the performance of the HP2, I cant see that it is relevant. The intentions of a HP and GSA are completely different. The GSA is meant to be a load carrying 2 wheel land rover, while a HP is a lightweight, stripped down, 2 wheel dune buggy. The HP is designed for racing. The GSA is designed for touring. The HP carries no load and will rarely be too far from a support crew if you happen to bend it. The 12GSA (which has a much taller first gear than your 11) is not going to be raced full throttle over unknown roads through the backblocks of Kazakhstan or Mongolia without a support crew, is it? You are effectively suggesting a Land Rover and a racing dune buggy should share the same gearbox ratios.

With racing in mind, and ridden by enduro wizards, it makes sense for the HP to have a narrow gearbox. But I cant see where that relates to the GSA and a mere mortal rider touring around the middle of nowhere laden with 20kgs of panniers, 30kgs of fuel, 30 kgs of luggage and a spare tyre. I, personally, want the widest possible dynamic range from my gearbox on a touring bike, not a narrow racing one. You might want to race your 11GSA across the Gobi - I dont.

Guest2 23 Aug 2006 10:59

Quote:

Originally Posted by colebatch
OK I have a guy who will happily fit it for me, but I need to find a dealer in Germany who will supply me with the R1200 RT-P first gear. Can anyone advise me of a co-operative flexible BMW dealer in Germany?

You should not need to go to Germany for this. A UK dealer should be able to find the part number and order it for you.

colebatch 23 Aug 2006 11:24

Thanks Steve
 
I have tried that route ... apparently the parts are not on the dealers "ETK", parts microfiche yet. Whether that is because no police force in the UK has ordered them yet (i.e. is the ETK country specific) or whether it is because the RT-P is very new, i dont know. One way to find out be to check with a german dealer as I understand some police forces in Germany have ordered the bike.

I am still learning my way around how the tightly controlled BMW network operates. Any help / advice you can give is much appreciated.

Guest2 23 Aug 2006 18:16

I looked on my 1200 GS manual and only one first gear ratio is listed (also checked the 1200RT) I would have thought all you need to order a part is the part number and it should arrive through the system. I realise getting the part number is the hardest part, have you tried the German GS forum.
How sure are you that these gears exist? Pre 1200 (11**) I think the way to lower the gearing was by fitting different final drive, I not saying this is the way to go as you lower the overall gearing.
I might just suggest you take a moment to consider what you’re trying to achieve. I have ridden the 1200 GS in muddy and sandy conditions and a lower first gear would be handy, in such conditions I advocate the slow and steady approach on such a heavy bike. I have witnessed ( and tried) the fast and furious approach and it often goes wrong, and while amusing to watch the consequences for the bike and rider and often disastrous. However, how much will you need the lower first, it's going to cost estimated £500 plus.
I had a KTM 640 adventurer and that has a low first gear and it did not make it a joy to ride in tight fast corners on the road, first was too low and second too high. But it did make a good bike in the worse off road conditions. I also carried a larger front sprocket for faster road work. 15 minutes to change over the front sprocket.
If you are going to be riding a lot in the conditions that need a low first gear maybe you need to consider if the 1200 is the right bike.

Only trying to play devils advocate here:)

I have listed the ratios for the 1200 below incase you have'nt seen them.

Steve

Primary transmission ratio
1.824 - 31 / 17 teeth

Gear ratio, 1st gear
2.277 - 41 / 18 teeth

Gear ratio, 2nd gear
1.583 - 38 / 24 teeth

Gear ratio, 3rd gear
1.259 - 34 / 27 teeth

Gear ratio, 4th gear
1.033 - 31 / 30 teeth

Gear ratio, 5th gear
0.903 - 28 / 31 teeth

Gear ratio, 6th gear
0.805 - 29 / 36 teeth

colebatch 24 Aug 2006 06:20

Quote:

Originally Posted by SteveAttwood
How sure are you that these gears exist? ...

I have ridden the 1200 GS in muddy and sandy conditions and a lower first gear would be handy, in such conditions I advocate the slow and steady approach on such a heavy bike. I have witnessed ( and tried) the fast and furious approach and it often goes wrong...

If you are going to be riding a lot in the conditions that need a low first gear maybe you need to consider if the 1200 is the right bike.

Thanks Steve

Yep the bits exist, but BMW dont sell them yet to civilians. They exist on the new Police RT... which is differet to the regular garden variety RT ... here is BMW's blurb from March this year:

"The new R 1200 RT has significant advantages over its predecessor. For example, a large 27-litre fuel tank allows a greater range before refuelling. There's also a shorter first gear ratio, which offers better low speed stability and allows the motorcycle to be easily ridden at walking pace speeds for sustained periods (for example, when performing escort duties). The rear suspension strut has also been strengthened to cope with the extra stresses put on it during operational riding. "

The Police RT website is: http://www.bmw-motorrad-authorities..../en/index.html

I agree that a lower first gear alone is a crap compromise, what is really needed is a more widely spaced out gearbox across all the 6 ratios. Those ratios you mentioned are identical for all 6 R1200 bikes, be they GS, RS, RT, R, S, or GSA. As mentioned above even the HP has the same innards and ratios. I am just really annoyed that having spent the best part of 12 Quid on a bike, I have a bike without gearbox ratios designed specifically for it.

And yes, the end result is reluctantly having to consider whether it is the right bike after all. Might have to get a Dakar or wait and see how the F800GS pans out.... or even go back to the ever-reliable TransAlp

colebatch 24 Aug 2006 10:06

Steve, check your PMs

beddhist 7 Sep 2006 16:24

Try writing to motorrad at bmw.de


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