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-   -   Chain or shaft drive? (https://www.horizonsunlimited.com/hubb/which-bike/chain-or-shaft-drive-32357)

maxwell123455 18 Jan 2008 00:50

I understand that if thinking on the round the world trip sense or to South africa sense, ok its not a big pro or con, but for some people who use there bike for commuting every day or just for the sunday blast, looks are everything.

Me i like the look of shaftys they are different then most bikes, they stand out instead ohh its a chain again, you can image the gears in there with all the oil, metal and all flying around. I am studying to be an engineer and thing that this is a great idea that bikes have shaft drive. Others just dont like them its down to personall opinions

Walkabout 18 Jan 2008 00:57

Quote:

Originally Posted by maxwell123455 (Post 169135)
. I am studying to be an engineer


Take a look at the F800S/ST swinging arm and belt drive in that case!
Best looking swinging arm on the road today, including the Ducs!!
Just a personal opinion of course.

oldbmw 18 Jan 2008 01:41

Quote:

Originally Posted by Margus (Post 168951)
Hmmm...

The pro for BMW engine+gearbox system is all the shafts rotate parallel, which, at least in theory, should give the best mechanical efficiency and longevity -

No, the problem with the BMW gearbox is it outputs top gear via gears. so it loses power by sending it across two shafts and through gears. Most gearboxes do not do this. they transfer power direct because the input shaft IS the output shaft. so no gears or layshafts carry power, therefore no power loss at all when in top gear. This is why a typical BMW engine lasts three times longer than a typical BMW gearbox.

Margus 18 Jan 2008 07:05

input/output shafts on different gearboxes
 
Quote:

Originally Posted by oldbmw (Post 169139)
No, the problem with the BMW gearbox is it outputs top gear via gears. so it loses power by sending it across two shafts and through gears. Most gearboxes do not do this. they transfer power direct because the input shaft IS the output shaft. so no gears or layshafts carry power, therefore no power loss at all when in top gear. This is why a typical BMW engine lasts three times longer than a typical BMW gearbox.

Can you explain how a single 1:1-rotating-shaft-to-engine-speed-on-both-ends can be input and output shaft at the same time in the conventional (not on automatic or semi-automatic or variator type of) gearbox? Only possiblity is if the final drive somehow "switches" between secondary and input shaft (that rotates 1:1 to engine speed) if switching between final gear and all other gears.

My mind says they may be parallel and at the same reflected co-ordinates on both sides of the gearbox (one shaft rotates "over" second), but input and output shaft have to be separated with gears anyway to change gear ratios.


Honda gearbox has a separate input and output shafts:
http://www.offwidth.co.uk/bike/crm_rebuild/gears.jpg



Yamaha gearbox, separate input and output shats:
http://i5.ebayimg.com/07/i/000/bb/6e/302e_1.JPG



Suzuki gearbox, separate input and output shafts.
http://www.mwbbikewreckers.com.au/us...%20Gearbox.JPG



BMW R-series bike gearbox, separate input and output shaft (same as all others):
http://www.bmbikes.co.uk/photos/mech...%20Cutaway.jpg


Or a modern car gearbox:
http://www.f1-blog.co.uk/wp-content/...sg1%5B1%5D.jpg
This illustrates even if the input shaft is the output shaft with separated rotation - the power will go through the gears (they'll not just "stop" to completely isolate any friction) even if it runs 1:1 with crank ratio in the end.


Surfing in the Google I can't find a manual gearbox that nearly 100% transfers 1:1 rotation power (by "stopping" all the secondary shaft(s) rotations) into output shaft w/o touching the secondary shaft(s) that changes the gear ratios...? I may stand corrected here.


The "bulky" gearboxes maybe didn't last long on old airhead BMWs (i.e. like some had bearings failures at around constant 50Kkms etc reports, needed modification to last longer), but on the newer oilheads there are doing some serious mileages on stock gearboxes. I.e. Hank Hits 400,000 Miles on His BMW R1100GS - Lone Star BMW / Triumph Motorcycle Dealership - Austin, Texas,

After 640 000 kilometres and he's still on original gearbox (even pistons and rings aren't changed, no major repairs aren't done on the bike).

AliBaba 18 Jan 2008 07:58

Quote:

Originally Posted by Walkabout (Post 169122)
Hi Alibaba,
I would "imagine", again I don't have weighing scales to hand, that the current crop of BMW shafties are heavier than the earlier models - they just look bigger and, therefore, heavier.

Swingarm weight (without shaft and beveldrive):
R80G/S – 2950 gram
R80/100GS – 2140 gram
R1100GS – 3120 gram
R1150GS – 2973 gram
R1200GS – Supposed to be lighter the R1150GS but I don’t have the weight


Quote:

Originally Posted by Walkabout (Post 169122)
So, is it a useful comparison to take an old bike alongside a current production model (including the next generation of F650GS)?. I quite understand that you are riding one, so you have a personal interest!

I’m talking about the “old” 650 GS Paris Dakar and the. Paralever BMW (production ended 1996). Both bikes are out of production but I don’t think that means much for the weight.
Sadly I don’t have the numbers to compare the 1200GS and the new 800GS.

Quote:

Originally Posted by Walkabout (Post 169122)
Apart from this, I would just like to remind the original questioner that the chain drive bike can have it's gear ratios changed pretty easily - I don't hear or read of shaft drive owners fiddling with their gear ratios.

Most shaft driven bikes are powerful with a straight torque-curve. As long as the bike runs “slow enough” (for offroad conditions) there is not much to gain to change the gear ratios. (Eg: My bike runs slower then a KTM 640 ADV in first and faster in fifth gear)

It is possible to change the final drive ratios on the R80/100/R1100GS (don’t know about the 1150 and 1200) and some people do this. But it’s not “common” and it’s more work then changing a sprocket.
Ural has the same option (sidecar rigs have lower gearing), don’t know about the others.

You can also get lower/higher first and top gear for most models.
Remember that most of these bikes also are used by the police and army and they want to drive real slowly.

But again it’s not a common job and with a powerful engine with a straight torque-curve it’s no need – for most people.




Quote:

Originally Posted by Walkabout (Post 169122)
That's why the "racers" will always have a whole pile of sprockets and gearboxes for the various circuits - lets see how BMW are going to deal with this when they go racing!!

BMW has raced for more then 75 years and they still do.
The HP2 wins everything in it’s class. The factory team uses HPN for touring and they use two different gearboxes. As far as I know the “fast” box has only been used in Pikes Peak (and once at Erzberg because the “slow “failed). With the “slow” (standard) box they still have the speed-record at Erzberg (183 km/h).
The racing with HP2 sport might bring more solutions for altering the gearing.

Quote:

Originally Posted by Walkabout (Post 169125)
Ah!
Maybe difficult to separate out the functions for a shafty, but I may look around for a single-sided swing arm/chain drive and weigh it!
A Duc or a Triumph perhaps??! :rolleyes2:

Yes that can be done (I don’t have the numbers), but I don’t see the point. The point must be to compare swingarms on two comparable bikes, one with shaft and one with chain. Maybe a 1200GS and a KTM990…

Margus 18 Jan 2008 08:06

Quote:

Originally Posted by Walkabout (Post 169137)
Take a look at the F800S/ST swinging arm and belt drive in that case!
Best looking swinging arm on the road today, including the Ducs!!
Just a personal opinion of course.

They do look nice.

I really like the "organic" looks of the new 3-rd generation paralevers with that particular "hole" inside:

http://www.r1200gs.info/misc/images/R1200GS-rearhub.jpg

http://pds.exblog.jp/pds/1/200611/27...9_23145047.jpg


http://www.motorcyclespecs.co.za/Gal...008%20%201.jpg


http://donald.hypermart.net/MCPix/BMW_HP2_SPORT/5.jpg


Most of the single sided shaft drives look aesthetically good.

MotoGuzzi CARC system:
http://blog.crazymoto.net/wp-content...bellagio05.jpg
Looks more "massive", but very nice in its own way.

http://www.motorcyclespecs.co.za/Gal...007%20%203.jpg



Honda:
http://www.f6rider.com/Rune/Rune_large_01.jpg

http://moto.by/articles/image/honda_...rie_rune_3.jpg


Kawasaki system (two sided swing, but still very nice if it's exposed, IMHO):
http://www.rubbermag.com/news/0609/i...3_gtr1400c.jpg


http://www.seastarsuperbikes.co.uk/K...styling_lb.jpg

So there's enough competition from shaft-drives side into chains&belts beauty-contest :)

Margus 18 Jan 2008 08:34

Quote:

Originally Posted by AliBaba (Post 169167)
Swingarm weight (without shaft and beveldrive):
R80G/S – 2950 gram
R80/100GS – 2140 gram
R1100GS – 3120 gram
R1150GS – 2973 gram
R1200GS – Supposed to be lighter the R1150GS but I don’t have the weight

Good info!

I'm relatively sure the third generation paralever (K1200 and R1200) are lighter looking how light they've got the HP2s.

But it's also strange, while it's the most hevay of them, HPN seems to prefer the 1100 swingarm???

http://micapeak.com/bmw/gs/images/hpnsport.jpg

Or if you have more money to pay them, then you get their own welded version of swing arm:
http://micapeak.com/bmw/gs/images/hpnp.jpg

AliBaba 18 Jan 2008 09:15

Quote:

Originally Posted by Margus (Post 169172)
I'm relatively sure the third generation paralever (K1200 and R1200) are lighter looking how light they've got the HP2s.

I think so, but I'm not sure.

Quote:

Originally Posted by Margus (Post 169172)
But it's also strange, while it's the most hevay of them, HPN seems to prefer the 1100 swingarm???

The reason why HPN use the 1100 swingarm is that is the longest one. You want the long one to increase wheel-travel.
HPN use the 1100 swingarm as the cheap (haha) solution. They make their own swingarm which has the same length as the one on the 1100.
The HPN swingarm is way more robust then the 1100 swingarm and it gives better room for a wide 18” tire but it is pricey!

If you look on your second photo you will se that it is not an 1100 swingarm, it’s a HPN swingarm.

No I’m not going to remove my HPN-swingarm to weigh it!!! Maybe I will overhaul my gearbox this year and I can weigh it then (the box has never been opened and it’s close to 200kkm)

HPN has the following variations:
-Standard R80/100 swingarm
-1100 swingarm
-1150 swingarm
-Extended monolever
-Standard monolever
-Double sided (?) extended monolever
-Double sided (?) standard monolever

But I guess the 1100 swingarm is the most common solution today.
If you use the 1100/1150/HPN swingarm you can choose between the airhead or oilhead final drives (drum/disk brake)

Note;
The swingarm for the 1200 might be longer, I don’t know.

Caminando 18 Jan 2008 11:55

Quote:

Originally Posted by pauldelft (Post 168556)
Hi people,
new to the site and absolutely love it!
I'm planning to make a RTW trip or Amsterdam-Cape town within two years from now, depending a bit on budget, time etc.

The big question everyone faces is of course which bike to choose? Lots of info and pro's and con's on weight vs power vs reliability, but no one seems to talk about shaft drive vs chain driven bikes (at least, i can't find it, might just be me).

Here in Holland I drive a bashed up cx500 (due to budget and living in inner city), which is shaft driven and i love it. It has never let me down (nearing 90,000km) and the shaft is totally care free. This experience tilts me towards shaft driven bikes, but the only enduro bikes seem to be BMW's, which are not my type of bike (too expensive and too high tech) for a RTW.

What are the options on shaft driven enduro's? Or can someone convince me chain is just as good/better?

cheers
Paul

Hi Paul

I suggest that with a good chainoiler there is no longer a need for shaft drive. I've had fantastic kilometrage out of my chains (Africa Twin) since fitting a Scottoiler.

I think that this allows a much wider choice of bikes for you. Get a chain drive and fit that oiler.

Shaft drive is of course, still an excellent choice, but the oiler opens up possibilities.

Martynbiker 18 Jan 2008 16:48

Cammys Old Bike......
 
Quote:

Originally Posted by Caminando (Post 169197)
Hi Paul

I suggest that with a good chainoiler there is no longer a need for shaft drive. I've had fantastic kilometrage out of my chains (Africa Twin) since fitting a Scottoiler.

I think that this allows a much wider choice of bikes for you. Get a chain drive and fit that oiler.

Shaft drive is of course, still an excellent choice, but the oiler opens up possibilities.

Are you keeping the same theme with your AT then Cammy?

http://i235.photobucket.com/albums/e...uff/biker1.jpg

pauldelft 18 Jan 2008 17:33

Never intended to get a discussion going on looks, but there you have it! Thanks for returning back to subject caminando, I had figured the same; either a shaft (limited choice of bikes) or a chain with oiler will do fine for most trips. Cheers for all the input!
Go ahead and have fun talking about looks, gear ratios and the weight of swing arms, i've got the info i need!

Paul

AliBaba 18 Jan 2008 18:00

Quote:

Originally Posted by pauldelft (Post 169261)
Go ahead and have fun talking about looks, gear ratios and the weight of swing arms, i've got the info i need!

Paul

Hey! Don't run away we have more obscure details :rofl:

Walkabout 18 Jan 2008 18:11

[quote=pauldelft;169261]Never intended to get a discussion going on looks,
Paul[/quote

But it is all part of the heady equation. So, as Alibaba says, don't stop reading this one!

Good stuff there AliB and Magnus; I do like your pics and the research that you guys have put into your preferred steeds.

Sime66 18 Jan 2008 18:15

me too
 
Quote:

Originally Posted by Martynbiker (Post 168600)
That is just GORGEOUS! I want one...... I Do...really, really, really.... Sod my XT......... ive fallen in love with an inanimate object......:eek3:

Martyn

Oh my god - I'm off to Bike Trader

oldbmw 18 Jan 2008 21:07

Quote:

Originally Posted by Margus (Post 169161)
Can you explain how a single 1:1-rotating-shaft-to-engine-speed-on-both-ends can be input and output shaft at the same time in the conventional (not on automatic or semi-automatic or variator type of) gearbox? Only possiblity is if the final drive somehow "switches" between secondary and input shaft (that rotates 1:1 to engine speed) if switching between final gear and all other gears. .

Hey guys, be kind. some of us still have to use dialup.

Margus

If you look at any old Brit bike, or the new Enfield gearbox you will note that the drive train is arranged like this := The engine output sprocket drives the primary chain to a the clutch hub.
There is usually about a 2:1 reduction here. The clutch hub is free to rotate when the clutch is used, but locked to a shaft when the clutch is closed. This shaft goes from the primary chaincase into the gearbox and is the gearbox input shaft. In the space between the back of the primary chaincase and the input side of teh gearbox sits the gear sprocket which drives the rear chain. The gearbox sproket is mounted on splines on a bearing mounted collar that is free to rotate over the input shaft. The collar extends a little way into the gearbox. There is a gear here that takes power from a layshaft driven gear in all the lower gears. In top gear however, instead of driving via a gear onto the layshaft and back out, the output collar is locked to the input shaft via dogs on a gear which is in the input shaft and splined to it. This locks the output gearbox sprocket to the input shaft. It is possible that some gears may be meshed and rotating, but they are idling and not carrying any power. This is one reason these geaboxes whine (straight cut gears) in all gears except top. It may also account for the higher speeds attained with less power than is needed with some newer designs with offset output shafts. After all, a Tiger cub produced only 10hp so energy conservation was important. Or put it another way, a 650 cc triumph Tr6R with 40hp is about 5 mph faster than a BMW 800cc bike producing 50hp. I am not trying to criticise anyones design, They all were (and still are) compromises based on what the conditions were expected at the time of design and marketing fashion. Nowadays bikes have so much power losing the odd 20hp is of no consequence (except to range/mpg) In the case of the BMW, having a centrally mounted input shaft forced them into having an off set output shaft, in order to clear the rear wheel. When they made the K series.. I expect that the reason for lying the engine on its side was to put the centreline of the engine crankshaft inline with the output shaft, thereby making it easier to construct a longer lived gearbox. But I do not know, never having owned a K series bike, but that is what I would have tried to do.


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