Chain life

[fred_jb 10,265]

46 minutes ago, Xactly said:

It strikes me as somewhat ironic that BMW, whose bikes used to be synonymous with shaft drive, for some years now have made one of the most troublesome final drives of any manufacturer, except possibly Triumph with their Exploder and Atrophy 1200 models. Japanese shaft drives seem by comparison to be virtually trouble-free.

 

Yes, maybe it's the increased power outputs these days, but I don't recall the CX500 from 40 years ago having any shaft problems, and many of those did an awful lot of miles.  Mine certainly had no problems.

[MatBin 5,085]

My R80RT did about 150,000 miles, not fully sure as the odometer broke at about 140,000.  I don't ever recall it getting spline greased or disassembled, all it got was regular oil changes, so why have BMW shafts now got such a bad reputation. That bike was the most reliable thing I ever owned, bi-annual pushrod tube rubber replacement being the only non ordinary regular maintenance. As Fred says above maybe the 50 bhp was the reason, but it would still cruise at 85 all day even pushing that barn door through the air.

Edited April 5, 2022 by MatBin

[Xactly 5,419]

I believe they went downhill when paralever was introduced. Not sure about power output; I can think of a few Jap shafties that are powerful with no issues: Pan European, FJR etc. None seem to need paralever.

[davebike 943]

Quote

My R80RT did about 150,000 miles,

yes because the shaft ran in gear oil not dry !  Oil was suposed to be changed every service

 

Quote

I believe they went downhill when paralever was introduced.

Yes took a system that worked very well in an oil bath and ran it dry  Suprise it failed but lasted the garentee so that is OK

[jeremyr62 2,559]

My two FJRs were trouble free, they just came with with very little grease from the factory, so if you ignored them the splines and could corrode. Most owners were aware and used the Honda Moly60 grease on them.

[Andy m 23,543]

BMW motorcycles have been spreading the cost of too much weird **** over too few units. Honda buy an indicator switch and chain from the same suppliers as Triumph, Suzuki, Yamaha etc. BMW order a three thumb system and a selection of drive shafts. 

 

Not all shafts are equal. 

 

The BMW's with problems are/were mostly the GS's. When you make the shock longer you change the spline from an assembly joint to a sort of bevel gear because the change of angle is always there. Once teeth start to slide on each other you need lubrication. To keep whatever tiny advantage there is from palaver-lever on a GS you'd need different, probably heavier or harder to assembled bits. 

 

Guzzi's, Deauvilles etc. use what the Bavarians retrospectively called Mono-Lever. 

 

Andy 

[Rocker66 34,455]

As I have stated before I think that one of the reasons that BMW no longer have the reputation for quality that they once had is that the old airheads were marketed as premium bikes much of which were hand assembled and they were priced to match. My first R75/5 cost £1200 whilst at the same time a top of the range Honda or Suzuki cost circa £750. These days BMWs are mass produced and priced to be more competitive. I believe that this is why both quality and service has suffered.

[fat al 199]

1 hour ago, fred_jb said:

 

Yes, maybe it's the increased power outputs these days, but I don't recall the CX500 from 40 years ago having any shaft problems, and many of those did an awful lot of miles.  Mine certainly had no problems.

i had several failures shaft related on mine, cx500 and gl500, the problem was the connecton between the bevel drive and the rear wheel, hardened steel on the bevel drive and softer metal on the  splined bit that bolted to the rear wheel would get worn away resulting in no drive, after the first time it happened, which i bodged  with some 20pence pieces so i could carry on and get paid for my delivery in london, i carried a spare with me, as soon as i lost all drive i would whip the back wheel out, chage the worn out  part and be back on the road within 20 mins.

 

al

[Xactly 5,419]

53 minutes ago, Andy m said:

 

 

The BMW's with problems are/were mostly the GS's. When you make the shock longer you change the spline from an assembly joint to a sort of bevel gear because the change of angle is always there. Once teeth start to slide on each other you need lubrication. 

 

Andy 

Yes, the angle between the shaft and gearbox on my R850GS was a lot greater than that on my R1100RS, which was near parallel. Given the greater suspension movement on the GS and hence the greater movement at the final drive pivot bearings it’s hardly surprising that I had to replace them at a fairly low mileage. Although adjustable taper roller bearings they were too small IMHO and would have been better as plain bearings with grease nipples for lubrication. (A kit used to be available to do this). Then again the gearbox on my RS was pants and I had to replace it with a refurbished one. By contrast the final drives on my two K “bricks” never caused any bother and just needed the splines lubricating occasionally, an easy job. It’s basically the same system on my Moto Guzzi.
I’m not convinced that shaft drives need to run in oil; they don’t on rwd cars. A common issue with the airhead BMWs was oil migration from the gearbox into the shaft drive and/or final drive unit, caused by leaking oil seals. 

[MatBin 5,085]

3 hours ago, davebike said:

yes because the shaft ran in gear oil not dry !  Oil was suposed to be changed every service

 

Yes took a system that worked very well in an oil bath and ran it dry  Suprise it failed but lasted the garentee so that is OK

I knew mine was in an oil bath and it was changed as required, didn't know they swapped to a dry system. Although I was aware they fitted UJ's to solve a problem that didn't exist.

Edited April 5, 2022 by MatBin

[Steve Case 955]

BMW shafts work fine once taken apart and put together properly, unfortunately this seems to escape the fitters they use in the factory.

 

Certainly the bevel box bearing failures on the 1100 was due to incorrect torque settings at the factory, I would bet the problems seen on the later bevel boxes is the same.

 

 

[Steve Case 955]

The gearbox problems are because BMW gearboxes are the worstest ever.

And thats a mighty long time!

[Andy m 23,543]

What do they torque incorrectly? 

 

Andy 

[Steve Case 955]

The bearings sat on a kind of blind bolt arrangement with half by the bolt threaded and the half at the end furthest from the head ground for the bearing to sit on.

 

One had an allen key head with a flange and one had thread to the end with a lock nut.

 

Procedure was feed the bevel box on the spline shaft and then hand fit the 2 bolts flanged on outside of shaft housing, lock nutted on inside to support the bevel box.

 

Wind in both to finger tight then torque the inside (lock nut bolt) to 10nm and then torque the outside bolt (flanged) to iirc 160nm. Then finally the lock nut to 160nm.

 

From what I could work out the factory were fitting both bolts to the 160nm and side loading the bearings...

[Steve Case 955]

I have always believed (probably wrongly) that any BMW can be turned into a good bike by sorting and fettling until any issues are removed.

 

And they always look good even if they're complete junk.

[Xactly 5,419]

44 minutes ago, Steve Case said:

BMW shafts work fine once taken apart and put together properly, unfortunately this seems to escape the fitters they use in the factory.

 

Certainly the bevel box bearing failures on the 1100 was due to incorrect torque settings at the factory, I would bet the problems seen on the later bevel boxes is the same.

 

 

I used to carry a spare big bearing when I went touring. It was a relatively simple fix at a bike shop if you produced the bearing and oil seal. 

[Xactly 5,419]

43 minutes ago, Steve Case said:

The gearbox problems are because BMW gearboxes are the worstest ever.

And thats a mighty long time!

There is on the web a transcript of a conversation with Getrag, who used to make the gearboxes for BMW (and Porsche et al). When the oilheads were introduced BMW made stipulations to Getrag as to what they wanted in order to reduce the famous clunk on the airheads (yes, I know gear change technique - pre-loading - could eliminate a lot of it). So the first version in the 1100RS only (for that was the first to be launched) got one full size dog and one smaller dog on each pair of gears, the theory being that the smaller dog would ease the gear change and quieten it. It worked but unfortunately there was an unacceptably loud clatter in neutral that really upset the early adopters (fools). Apart from that the small dogs rounded off, causing skipping in second or third gear, which in turn wore the selector. BMW therefore asked Getrag to put o rings on the shafts, the theory being that this would slow down their movement and quite the neutral rattle. It did, but it didn't resolve the skipping and accelerated dog wear. It also didn't improve the gear change. The final iteration had full size dogs throughout and is the most reliable, though it was not without fault, the infamous wavy washer.

[embattle 332]

My chain maintenance is generally every 500 miles spray and every 1000 miles clean and then spray.

[Steve Case 955]

Yup they had some weird ideas, after I'd done work on the gearbox I could get an acceptable change out of it. Hoooever the action was not great and it had a fair amount of lash.

 

If I want the sweetest gearbox I'd buy a Suzuki, and if I want the paint not to fall off I'd buy a BMW. All swings and roundabouts really!

 

If I want the bike to survive WW3 I'd buy an NC.... Oh I've got one, lucky that!

[fred_jb 10,265]

52 minutes ago, Steve Case said:

 

If I want the sweetest gearbox I'd buy a Suzuki, and if I want the paint not to fall off I'd buy a BMW. All swings and roundabouts really!

 

 

I don't share your faith in BMW's paint quality.  It was peeling off the emgine on an F800ST I briefly owned, and when I was running a R1200 GS I read a lot of reports of people having engine swaps under warranty for similar problems, though my bike was fine.  There was a theory that the problems came about after the change to water based paints for environmental reasons, though car manufacturers didn't seem to have any such problems with this change.

[Steve Case 955]

I've seen the coating flake off a K5 GSXR swingarm cos its not bonded to the metal properly, BMW are generally better than that

 

Engine paint was always a problem with BMW as they used that stupid plastic coating and water gets trapped underneath, but if it had been dealt with quickly it would never have been an issue but its a BMW and people treat them like cars.

 

I wouldn't touch the 800/850. It was a collection of bits sourced from around the globe.

 

I'm starting to think the finish on the Triumphs is getting better, they used to be pretty industrial but they are getting better tho the Thunderbird I looked at wasn't that good.

[MatBin 5,085]

I loved my mid 80's monolever R80, the gearbox didn't klunk, it didn't have any paint issues anywhere, no torque reaction from the shaft, which BM 'cured' with the paralever apparently. It wasn't flash and it wasn't 'fast' but I would have taken bets on it getting me from A to B quicker than almost anything else and more often too, come rain, snow or sunshine.

[Xactly 5,419]

Yes, they fixed them ‘til they broke. I know of two R80G/S bikes that have gone round the clock twice and are still going. My Cali III used to twitch to the right if I blipped the throttle and the rear end rose on setting off I never found it to be an issue at all. Oddly my new V7 850 Special has the engine torque reaction but not the quirky raising of the rear end. Although essentially the same layout as the Cali (and similar to the non-paralever BMWs), I imagine this is because there are cush drive rubbers in the final drive (which I believe make rear wheel replacement a PITA, though it can’t be worse than an NTV700 Deauville, I hope).

 

[Steve Case 955]

Sorry should quantify that with silver engine paint on the 1100 and 1150, not sure what the 1200 engine paint was so cannot comment.

With the 1100 and 1150 you could guarantee the silver engine paint would have bubbled up or come off on any high miler.

 

Also the 1150s with the black engine finish cannot comment.

Oh and it may no difference to the engine or anything else, just looked untidy.

[Andy m 23,543]

BMW's problems include culture. The design engineers rule while production engineers and supply chain people are supposed to just make what was drawn. 

 

That torque dependent shaft bearing mount needs redesigning with a face to stop it at the right setting, You can't expect line monkeys to stop when it feels right and then torque two items, you need a design you can gun down. 

The water based paint needs a much better cleanliness and drying , hence you must get rid of traps where degreaser either won't reach or will hang about. 

 

The Japanese work as a team even if you must word the questions in a specific way when addressing some team members. 

 

BMW are also short of money. Its a private company, so when they are late or wrong someone doesn't get a new summer house in Berschesgarten. It's why they've been bailed out by the Bavarian state government a couple of times. Shareholders just put CEO's who cause the price to fall back on the merry-go-round of CEO's seeking new opportunities, just like managers of football clubs. When doing weird **** us your USP you actually need more development money/time a la Tesla. 

 

I've had two Guzzi's and a K100 with 50 to 100 HP and no anti-jacking on the shaft. I had two 80 HP R1100's with. I still can't tell you what palaver-lever in action feels like. You play traffic light GP, the bike digs and twists regardless. ASR activating and rubbish tyres I can describe. 

 

Andy