Sprocket vs Shaft final drive

A lot of discussion on Smoak's post about belt/sprocket vs shaft as the final drive. I think that discussion deserves its own thread.

All drive trains that I can think of that use a shaft as the final drive have the engine mounted such that only one direction change is needed: the engine rotates parallel to the vehicle axis. Think Ryker, Honda Goldwing, BMW and Motoguzzi MCs, cars and pickups. That amounts to half of the power loss in the system if it were a simple conversion on the existing 1330 engine-transmission drive train.

Drive shafts require regular maintenance, far more than a typical belt drive but less than a chain/sprocket design. Lube on the splines and angle gear ("differential") box. To me, it's a much more complicated system overall, but wouldn't need belt tensioning and alignment. Plus the additional manufacturing cost. I'd rather deal with the belt: the sprocket spline issues will be solved or changed to a regular maintenance item.

"...just boost HP..." to make up the difference in power loss of the shaft drive: more power = more fuel to turn the wheels. Fuel mileage will suffer proportionally. And performance will suffer, too, due to higher inertial resistance in both acceleration and braking.

There has been a lot of "woe is me" complaining about the existing belt/drive sprocket design: some deserved, but most is whining or trying to be the loud voice in the crowd. Longevity and outright failure are issues: how much could have been avoided via preventive maintenance will never be known. Arguably, one of the best quality manufacturers of MC, BMW, has had its share of drive shaft failures.

not a dang thing wrong with belts. drive shafts on bikes require lots more maintenance plus a repair on a drive shaft on a bike can cost 2-3 times as much as replacing a belt.
i wonder how many motorcycle dealers have a driveshaft in stock.

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HAPPY enough with the belt system on the :spyder2:. My poor, old, slow V-Max is shafty. I change the differential oil every other year, it's easy. Splines get cleaned and lubed at tire changes as they are exposed in the process, that's easy too.

Lew L

I think you have an up-hill position/argument. If belt/chain drives are so good, why aren't they used in vehicles that DEPEND upon efficiency and longevity????? IE: long haul trucks, NASCAR, Formula, and virtually all commercially manufactured automobiles..... ???

As a BMW owner of 4 different models since 1977 I assure you that motorcycle shaft drive systems are not the mostly trouble free units we enjoy in cars and trucks. They require regular spline lubes at the transmission and rear drive. It you do not have the mechanical talent to do it yourself, you will be paying about 10 hours labor to have it done. I have always loved my BMW's and one gold wing. But check out any forum for bikes that have shaft drive and you will be much happier with your belt. My wife and I both have high mileage spyders that have both suffered red dust at about 50,000 miles. I changed them myself, which is a very easy job. Now with 70,000 or so miles on them, that has been the only maintenance required. My BMW k75 just hit 40,000 miles and is starting to be notchy when shifting which means next spring I will be spending hours pulling the transmission to clean and lube the input splines. I sure wish it was belt drive.

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Originally Posted by pauly1

A lot of discussion on Smoak's post about belt/sprocket vs shaft as the final drive. I think that discussion deserves its own thread.

All drive trains that I can think of that use a shaft as the final drive have the engine mounted such that only one direction change is needed: the engine rotates parallel to the vehicle axis. Think Ryker, Honda Goldwing, BMW and Motoguzzi MCs, cars and pickups. That amounts to half of the power loss in the system if it were a simple conversion on the existing 1330 engine-transmission drive train.

Drive shafts require regular maintenance, far more than a typical belt drive but less than a chain/sprocket design. Lube on the splines and angle gear ("differential") box. To me, it's a much more complicated system overall, but wouldn't need belt tensioning and alignment. Plus the additional manufacturing cost. I'd rather deal with the belt: the sprocket spline issues will be solved or changed to a regular maintenance item.

"...just boost HP..." to make up the difference in power loss of the shaft drive: more power = more fuel to turn the wheels. Fuel mileage will suffer proportionally. And performance will suffer, too, due to higher inertial resistance in both acceleration and braking.

There has been a lot of "woe is me" complaining about the existing belt/drive sprocket design: some deserved, but most is whining or trying to be the loud voice in the crowd. Longevity and outright failure are issues: how much could have been avoided via preventive maintenance will never be known. Arguably, one of the best quality manufacturers of MC, BMW, has had its share of drive shaft failures.

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Another thing to take into account on a Spyder is the length of a driveshaft that would be required. You're looking at a shaft length nearing three feet long. A shaft that long would have to be solid metal or large in diameter for strength and to keep it from oscillating. You think your belt vibrates? Get a shaft that long and heavy out of balance or oscillating after a big bump. The weight of that shaft would be unacceptable for our Spyders. Those things aren't an issue on cars, trucks, etc. where weight isn't such an issue and where there are carrier bearings along the shaft to control unwanted oscillation. Where are you going to put a carrier bearing on the Spyder? Motorcycle drive shafts are in the neighborhood of a foot long. Big difference than what the Spyder would need. No comparison. Talk about a horsepower loss? TWO right angle changes and a heavy metal shaft. No thank you.
Belts are the way to go on many bikes including our Spyders.

I have owned belt, drive shaft, and chain drive. Don't know where you get a 50% lost in power. Chain is 3%, belt is 9% and drive shaft is 25% maybe add 9 % more for the belt system so maybe 34% maybe on the Ryker , but that could be already included with the transmission. I have owned more drive shaft bikes and have only changed out 1 drive shaft and a couple u joints. With the Ryker they show the splines as non service. I don't buy that. I'm a retired chief mechanic and do all my own work. Servicing a drive shaft isn't bad once you know how to do it. I haven't serviced my Ryker rear end yet, but I will be pulling the driveshaft and inspect the splines and lube them. The only issue I have is the failure of the Spyder sprockets and also on some of the earlier models running the belt too tight making the drive shaft bearing fail. All of these has pros and cons. As far as the Rykers go will see how they hold up. Some has some seals and bearing issues. More seals than bearing. I could be wrong but I have looked all over the rear end of the Rykers and haven't found a venting system on it. If not that is a main cause of seal failure. Pressure builds up and pressure has to go somewhere. I like the driveshaft, but will see how it holds up on the Ryker. I think the belt drive on them is a good product being they have been on Snow mobiles for a long time. But running a belt drive is not bad either. Maintenance is the key to all bikes. Without proper attention they will fail.
JMO David

I have owned all 3, Chain drive (1978 KZ 1000), Shaft Drive (2004 VMax,2008 FJR1300) and now a belt drive (2022 Spyder RT L). In my opinion, the shaft was the easiest to maintain (between the two I have owned, I just purchased the Spyder). Chain drive you are constantly having to adjust the chain and oil it (which can be a mess if you over oil it). Shaft drive I change my final drive every other oil change (about once a year). And servicing the Splines is not the difficult and not need to be done that often. Gives you something to do in the winter when Its cold out. The Spyder is my first belt Drive. But Harley and other Manufactures have been using them for years. They are all 3 good in there own way. Chain gives you more HP to the rear wheel. Shaft is only about a 5% drop in HP (I had my FJR Dyno tuned when I put my aftermarket exhaust and power commander on it and it has 125HP at the rear wheel). I was surprised that the Spyder was a belt drive. But I can see why they went that direction. Less hardware and lighter weight. She is already a hefty girl.

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Originally Posted by canamjhb

I think you have an up-hill position/argument. If belt/chain drives are so good, why aren't they used in vehicles that DEPEND upon efficiency and longevity????? IE: long haul trucks, NASCAR, Formula, and virtually all commercially manufactured automobiles..... ???

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Please re-read my original post. I stated engine rotation alignment and the need for one less direction change. The vehicles you cited also require a differential at the drive axles: the nearly coaxial alignment of the the engine, transmission and drive shaft support the system. With the current 1330 engine/transmission monolith, I don't believe it would be feasible to reorient the engine/transmission to get drive shaft alignment.

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Originally Posted by Warlock

...Don't know where you get a 50% lost in power. Chain is 3%, belt is 9% and drive shaft is 25% maybe add 9 % more for the belt system so maybe 34% maybe on the Ryker , but that could be already included with the transmission. ...
JMO David

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Good points. However, I didn't stated "...50% lost in power...": the original post stated 2X the loss for directional change as 2 would be need for a retrofit of any sort.

Keep the discussion rolling!

I had 5 Goldwings and the ‘83 required greasing the zirk fittings. The 1500 & 1800 didn’t require a thing other that change the hypoid oil. No real pewter loss as Goldwings can do wheelies. Would love a shaft drive in the Spyder but it would require. Different engine for a more direct line to the rear.

Does the little Ryker have a shaft drive?

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Originally Posted by 2dogs

Does the little Ryker have a shaft drive?

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:2thumbs:

https://can-am.brp.com/on-road/us/en...les/ryker.html

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Originally Posted by canamjhb

I think you have an up-hill position/argument. If belt/chain drives are so good, why aren't they used in vehicles that DEPEND upon efficiency and longevity????? IE: long haul trucks, NASCAR, Formula, and virtually all commercially manufactured automobiles..... ???

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Every system has it's +'s & -'s. A good engineer will survey all the options and apply the best one (in their opinion) to the task. If tracks are so good, why don't they run them on cross country trucks? Well, obviously, tracks are great for tanks, dozers, track-hoes, etc. But that doesn't mean they are universally the best way to go. So it is with the Chain, Belt, Driveshaft debate. In other words. Nothing works best for everything.

Power loss industry standards for Motorcycles (Also extrapolates into Fuel Mileage, Top Speed & Acceleration)
Chain drive system 1-4%
Belt drive system 9-15%
Drive shaft system 20-25%

Taking the mid amount for each drive option and applying it to the 115 crankshaft HP of the 1330 (ignoring transmission loss)
Chain = 2.3 hp loss
Belt = 13.8 hp loss
Shaft = 25.9 hp loss
(Do we really want to expend 25hp just to turn a drive shaft?)

Weight Difference
Chain drive - Lightest
Belt drive - Heavier
Shaft drive - Much Heavier

Cost
Chain drive - Least Expensive
Belt drive - More Expensive
Shaft drive - Much More Expensive

Maintenance
Chain drive - Most maintenance
Belt drive - Least maintenance
Shaft drive - More than belt. Much less than chain

Cost to replace/repair
Chain - Least expensive
Belt - More expensive
Shaft - Most expensive

Reliability (All are very reliable. So, more head-to-head than specific issue based)
Chain - Least Reliable
Belt - More reliable
Shaft - Most reliable

Cars/trucks put a much heavier load on their drive systems than do motorcycles. The added weight of a drive shaft on a car/truck is a very small percentage of overall weight. It makes a bigger difference on a motorcycle. True, a number of motorcycles are using drive shafts. Including the Ryker. But the Ryker is touted as an 'Off Pavement' machine. You don't want a belt drive if you're going to be doing a lot of gravel or unpaved roads.

My take is that the problem is not the drive system selected for the Spyder. I think it is the best of the bunch given all the parameters. The problem is that this excellent option has some engineering issues. Fix the components and you're going to have a very good drive system. In other words, if it weren't for the 'Red Dust of Death' issue. I don't think we'd be talking about this nearly as much. This is not a drive system issue. It is a design issue.

And more than the dust is the loong time BRP has taken to address/fix the issue. If they had done so sooner rather then later,we also woulg be having very little discussion about this .

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Originally Posted by Isopedella

:2thumbs:

https://can-am.brp.com/on-road/us/en...les/ryker.html

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Well good.........because for me I think I would put reliability at the top of my list. I'm just say'n. I've never dropped a shaft (on a motorcycle) but I've thrown one belt. That was on a HD.

Haha. Its a Harley. What do you expect? Somethings going to fail aint it. :roflblack:

Had chains and sprockets on most of my rides, I just deal with it. No Problemo.

Thats except but my 2009 GL1800 Wing which needs a smidgen of new rear drive oil now and again. No problems at all with an Annual Works-Burger service no matter what the mileage was. Sadly sold a few months ago after I trialed my F3. No where the effortless smooth ride but it will do the job. Buggered up smashed body dosnt help. Now a pensioner but lived life to the max and had some exciting moments but lived to reflect on the memories, lost some mates.. and did some good along the way. Gotta be good overall I guess.

Anyhow. I have some sort of 1/2 cover on my F3 LTD for belt protection. I will put my hand up and say I do ride country gravel roads here in New Zealand from time to time. Yeah I know. Its the River Fords that turn me around unless they are very shallow and have concrete to ride across. So far so good. :thumbup:

I damaged one belt on my Spyder from going over freshly laid blacktop, but it was covered by the construction company. $350. The flagman put traffic over the area before it had been packed properly. Later I installed a lower belt guard I bought from Inspector Gadget. Very easy to install and well worth the protection.

FWIW: I currently have put just shy of 450K miles on BMWs and have had only one final drive problem. I noticed oil spots on the back of the right saddlebag as I approached one of the bikes from behind. Closer inspection revealed some oil on the rear rim with that distinct smell of transmission/final drive fluid. I immediately eased it up to the shop bout 80 yards away and a few days later had parts in hand to replace the main bearing which had begun to come apart at around the 113K mark on that bike. Other than lubing splines on an 1100RT when upgrading the final drive to a higher ratio, I have never lube splines either. That said the bike ('00 R1200C) with the rebuilt FD now has 145K miles on it and the mileage of the others are as follows from high to low;

120K on a '98 R1100RT
71K on a '99 R1200C
68K on a '00 R1100RT
61K on a '00 R1100S
50K on a '76 R75/6
36K on a '79 R80S
30K on a '00 R1200C

That totals 581K because all but one of those bikes were purchased used.

That's a pretty good record for drive shaft bikes with little to no maintenance efforts on my part other than fluid change every 20K or 4 engine oil changes. I guess I'm just lucky OR maybe others over-maintain their machines based on the myth that they require more maintenance per the dealers who want your $$ in their pockets rather than yours.