I've had the chain snap 3 times on my KTM 690 in 15000 miles and I've had one replacement shaft on my R100GS in 50000 miles.

If I was setting off on a long trip on the airhead I would fit a new or refurbished shaft and thouroughly check the gearbox and final drive as part of the preparation. I would then be confident of at least 25000 miles trouble and maintenance free (and this is one of the less robust shaft drives). For me in normal use the unsprung weight and limited travel is not an issue. At travelling speeds (as opposed to racing speeds) the rear suspension performs well off road.

Chain drive does have a number of benefits and I would favour it for day to day off road riding as long as you carry all the stuff to get you home in the event of a failure.

hi I had a Yamaha tr1 fully enclosed chain case on my Yamaha sr500 ( I tried a peter furlong case too complicated lots of parts was a hassle in the front garden let alone at the road side) ,the tr1 case took a lot of hours to make it fit but what a difference ,I was using standard heavy duty chains ( before x-ring chains) which I would get about 12,000 miles with lots of oiling and adjusting ,I then put a new standard heavy duty chain in when I put the chain case on and got 36,000 miles with hardly any adjusting and just take the chain off clean and boil in chain oil maybe twice a year (I was doing around 12,000 miles a year then) the rear wheel would stay cleaner as well ,it always gets me how in the bike world we seem to treat the effects and not the cause, example in the car world cv joints ,open to the elements so clean and regrease or cover up with a boot to stop the grease being washed out and contaminated with dirt,treat cause and effect ,bike world cover up chain to keep it cleaner with less maintenance or keep adding new (special expensive )oil to replace the oil washed off, yes that sounds about right,treat effect not cause , it used to be the same with helmets linings getting dirty ,take out and wash ,so cant take out linings so buy special expensive cleaners to clean the linings again treating the effects and not the cause problem although this seems to be getting better? as some helmets the lining is removable , there I have had my rant steve

And there you have one more advantage of a chain drive, as opposed to a shaft drive: if you want, it´s very easy to carry a spare chain & sprockets (=all secondary drive parts) with you. That should make you pretty self-sufficient, no matter where you go, and you don´t need to be much of a mechanic to change them all in the bushes. And even if you don´t want to carry them all, finding replacement chains is also possible almost anywhere.

It comes down to how easy you can fix a problem if anything happens. Chains are easier to deal with.

I've had two R12GS's (normal and a GSA), the first one blew the output seal in the south of Spain.. and the other one blew the final drive bearing 2 weeks after I got (2nd hand). I dumped the R12GSA with 90k, as I got more and more concerned that the final drive would pack in....


Casper

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Shafts suck.... Beemer shafts REALLY suck.

And it's not just the shaft that is a headache, it's all the extra gubbins that goes with them..

Try changing your final drive bearing in a workshop in Mongolia or finding someone who can swap out your RWD oil seal in Mexico when it inevitably starts leaking..

They're great for long distance, non-maintenance riding but out in the wilds, simple is ALWAYS better.

Chain and sprockets are simple, easy, and everyone understands them...

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Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.

It's good to see that old 'black & white' view of the world in HU where no middle tone or even the slightest tolerance doesn't exist. What I'm amazed of is that comes from people who've presumably been travelling a bit.

I'll try to add my personal humble opinion:

I've replaced my FD bearing on Congo-Angola border with no special tools without any problems.

It looks to me the talk of shaft drive being too complicated and unrepairable is by those who know little or nothing about them or never worked on them on the field outside of the well-equipped garage. Posting catastrophe pictures doesn't say much since there are as many if even more horror stories with chains, whether its grinded output shafts (i.e. common on Africa Twins) or fractured engine casings or damaged swingarms and the list goes on till serious damages to the riders legs or hands or amputations of limbs or even fatal crashes of rear wheel locking up from a broken or poorly adjusted/aligned chain.

I've had chain drived bikes before and still have now. Like all competing systems there's no doubt chain is better in many fields, i.e. short-term extreme offroad rides etc, ultralight performance bikes, it has clear weight and function advantages for certain fields but for me nothing beats shaft drive for simple long distance combined on/offroad overland travel in terms of convenience. I never need to think or fiddle with gearing or carry spare sprockets with me since the factory setting suits me almost perfect. My bike's bottom, rear wheel, sumguard and swingarm are never oily, my pants and boots are always clean of oil drops, I don't have to carry oil or clean/oil the chain afer every long travelling day, I don't have to check the slack, or worry about additional complication of hydraulics when using an automatic chain oiler, my hands are always clean of oil, etc. With shaft drive I just ride. No worries in the weeks of rainy days, or extreme distances of muddy or sandy riding conditions or any other worries. Just ride till it wears the bearing out - just like with your normal wheel bearings. All I carry is spare FD bearing and seal on my travels. I've done a worn FD bearing replacement job 3X on my R1100GS (within 260 000km, some half of this offroad, mostly 2up full luggage covering 6-continents or 80 countries) and by now I can almost predict when it goes and it takes me some couple of hours to replace it with no special tools needed. The FD+seal set costs less, takes less room and weights less than a chain+sprocket set. So living with those pros/cons for me the shaft-drive's a no brainer for long distance overland travel. While I'd prefer chain for some other settings no chain setup replaces shaft-drive for serious long distance overlanding for me, especially now when I know how to field-repair mine when that very rare bad day comes.


IMHO the big downside of the shaft drive is that this fine system is mostly installed only on mammoth-sized bikes today. There're no limits putting this system on smaller bikes, i.e. there are already proven shaft-driven bicycles that can be ridden offroad and I know the people who've pedalled them rave about them. You could probably build an ultralight GasGas tricker bike with a shaft-drive if you really wanted to... It all comes down on how good they are designed and bult IMHO. It's just few or no manufacturers who would even dare to risk by taking such an engineering and marketing challange in todays poor economic climate.

Unsprung weight difference isn't as big as you'd think since shaft itself can be integrated as a supporting mechanism for the swingarm. If I remember someone once compared a R1200 shaft drive with similar chain drive swingarm weights and the difference was surprisingly small. There's also a lot of playroom with different materials and designs, similar like some chain driven competition bikes use to obtain their light weight (i.e. aluminium or even titanium bits, or even a complete carbon-fibre swinarm etc), so it'd be ignorant to stamp shaft drive as some excessivly heavy system with a lot of unsprung weight - when done right - it's not IMO. While it probably won't be good for high-end racing it'd deffo meet most of the demands an offroading enthusiast or an overlander would require.

Personally I think it would be fantastic to have 450-600cc class capable offroad-biased DS bike with a rock-solidly designed and built, field-repairable shaft-drive system that can be used for offroad oriented long distance overland. In fact it'd be a niche market. Understressed torquey long stroke with an air/oil cooled balanced single engine with big oil reserve giving it long engine service intervals - it'd be my dream solo-overlander bike. If 1200cc HP2 managed to get down to 175kg then a 450-600cc class bike would sure get down to 130-145kg range when using decent bits and components. Yes, it'd be fairly more expensive and maybe some 2-3kg heavier than a similar chain driven bike, but if the price is right I'd get it over similar chain driven bike any time of the day. While it isn't perfect, a proper shaft drive just feels, performs and does right for what I do. IMHO design-wise it's elegant in comparison with the usual "dirty-fiddly" multi-link chain drive system. But who knows, maybe I'm just another idiot who doesn't understand anything about adventure travelling.

Just my humble 2c,
Margus

If only the bearings were all that self destructed on shafts...

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Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.

hi I can remember back when bmw were hinting of bringing out a baby single cylinder gs ,I have always liked the first gs the bmw r80g/s from 1980 and the thoughts of a smaller more fuel efficient but still simple bike had me thinking of moving away from yamahas ,my dream of a 600ish cc single cylinder air cooled engine with shaft drive were dashed when they brought out the funduro they had the chance to do what no other bike maker were doing, just like they had done with the r80 g/s but instead offered just the same as all the rest, a liquid cooled single with chain drive, the rotax engine was a great engine but if bmw had designed their own im sure shaft drive could have been done, a wasted opportunity it seems to me you can only have shaft on big bikes or little scooters yamaha qt50 remember them thanks steve

Something is wrong with your KTM. Check the runout of both sprockets/output shaft/rear axle. Also check chain alignment throughout the range of rear suspension travel.

The only snapped chain I have ever seen in person was on a KTM. The dealer had changed it about 500 miles before, so maybe they are a PITA to fit correctly?

F650 chains fail very quickly once they start to go. It's because BMW or Aprillia took a chain meant for a 250 twin and used it on a 650 single.

The difference with the MZ enclosed chain and a lot of the others is that it was designed on, not bodged together afterwards. If you don't get the tubes in the engine case grooves it fails. Assemble correctly once, leave it alone and it'll work for years. I'm surprised no one has designed a bike specific add on though. Modern adhesives should make it possible at add something like the MZ grooves to the back of any case.

Andy

That's interesting as one of the guys I met in southern Germany on this year's Elephant rally was stranded with a snapped chain on his F650. One of the side plates had snapped, the chain had opened up, jumped the front sprocket and taken out a chunk of engine casing. We wondered whether battery acid vapour was responsible as there didn't seem to be any significant wear on the rest of the chain or the sprockets but the failed side plate had a kind of fault line break in it.

The chain looked to be the same size as those on my XR600 and CCM600 so I wouldn't have thought it underspecced. It certainly hadn't been ridden hard.

Broken chain = 50 dollar fix - chains everywhere around the glob. Minutes to oil and adjust.
Broken shaft or blow final drive bearing = Hours of labor only if you didn't pack along your own bearing and U joints. Beyond that depending on the country, you could be stuck for a couple weeks.

3 reasons:
1: because the Scottoiler was invented
2: because DID-X and DID-Z ring chains were too
3: because there is a tool which undoes and re-does them up if needed- 150 grams of deliciousness / size of a 12 guage shell.
But you already knew all that!

WoW...I have never seen one so clean. ether you spend a lot of time polishing your tool or your tool as never been used

Dazzer

Agreed. Although I am not sure about the sizing of the chain, those fitted as OEM on the F650GS single cyl were pretty much rubbish - mine was replaced with Renthal sprockets complete with a new chain.
It goes for lots of manufacturers of course; stuff fitted as OEM is often purchased by the accountants, not the engineers.

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Dave