HI I have just purchased a final drive/bevel box from an 1989 k100rt ratio 32/11 and want to know what difference it would make to my 89 k100 rs not sure what ratio but it is the standard one
also will I have to make any changes to speedo etc (only really needed disc but had to buy the full box to get it so just wondering what difference it will make

Thanks Cliff

cliff the speedo will not be affected at all ...it counts a number of pulses for each revolution of the rear wheel ....and if your using the same one ...its all good

to check your ratio current ratio look om the top side of the bevel box , near the union of the swing arm ....just there you shoukl see stamped into the housing the numbers for the ratio.

history tells us that the rs versions had the taller ratios ...meaning slightly higher speed per engine rev .

forgive me that i cant remember the numbers right at this moment (just woke up ) im a night type person ..,night owl in fact . but the overall conclusion is ....not too much difference

the disc should bolt off the drive in any case ...there should be 2 countersunk retaining screws in the disk face ....carefull as they are made of fairly soft type metal ...and are specified as one use only ...but many of us have been sucessfull at using them again...they arent dear to buy ...so get some in any case

good luck

Hi Biker92 The final drive ratio for the K100RS is 33/11

Lazyboy wrote:Hi Biker92 The final drive ratio for the K100RS is 33/11

No 31/11, 2.81 - 1 and the RT & LT are 32/11, 2.91 The 33/11 was only in the early K100 naked and the 32/10 is for the K75

got it in one rick ....cheers

Oops at my age I should not try and do something from memory, the brain cells dont always fall into place ! Please see a attched copy of relevent Owners Handbook page.

I'm asking this question on behalf of my friend Phil. I've also hankered after lower revs on my K100 and there may well be others too. Or maybe someone who's done it.

Has anyone ever changed the bevel drive ratio on their K100RS ? The R1200C has a bevel ratio of 2,54 ; I think 28 + 11 teeth. This would make the bike a ( hopefully ) much nicer tourer, dropping revs by about 9% ( 2,82 standard ratio ). I think the 2,82 ratio is 31 + 11 teeth.

The problem is : are the bevel gears interchangeable? Obviously the housings aren't but the innards may be interchangeable.

Kafflut wrote:I'm asking this question on behalf of my friend Phil. I've also hankered after lower revs on my K100 and there may well be others too. Or maybe someone who's done it.

Has anyone ever changed the bevel drive ratio on their K100RS ? The R1200C has a bevel ratio of 2,54 ; I think 28 + 11 teeth. This would make the bike a ( hopefully ) much nicer tourer, dropping revs by about 9% ( 2,82 standard ratio ). I think the 2,82 ratio is 31 + 11 teeth.

The problem is : are the bevel gears interchangeable? Obviously the housings aren't but the innards may be interchangeable.

There's a bloke in Oz who's swapped R1200C guts into his K100/K1100 final drive for a relaxed cruise. It can be done, and requires careful shimming.

Kafflut wrote:I'm asking this question on behalf of my friend Phil. I've also hankered after lower revs on my K100 and there may well be others too. Or maybe someone who's done it.

Has anyone ever changed the bevel drive ratio on their K100RS ? The R1200C has a bevel ratio of 2,54 ; I think 28 + 11 teeth. This would make the bike a ( hopefully ) much nicer tourer, dropping revs by about 9% ( 2,82 standard ratio ). I think the 2,82 ratio is 31 + 11 teeth.

The problem is : are the bevel gears interchangeable? Obviously the housings aren't but the innards may be interchangeable.

The inners are interchangable, just not sure the exact ones. I do have a file someplace setting out suitable ones but I think you are on it. You need a matched pair. The big bearings are the same in a lot of final drives too.

Thanks Olaf .. I will forward the message to Phil

Kafflut wrote:Thanks Olaf .. I will forward the message to Phil

Unfortunately the man that as going to do it passed last November. A local ex BMw man and the go to man for rebuilding final drives.He said it only required shimming and 'why on earth would you want to do that'!!!.