Is this normal !

[DING-DONG]

But I do miss that lighter crank engine.

This is the conversation i had in great detail today with BMW UK, the heavy flywheel makes the power delivery very flat and effects the inertia, the difference is very adamant if you like to trap on, if your a plodder than you'll not be bothered. After having the light flywheel engine i personally would not buy a 15 bike now due to this upgrade its lost that edge now .

Throughout the summer i did some roll on tests against my mates 950sm my 14 light flywheel engine bike would just pull away quite easily leaving a big gap, I'd like to do the same with the 15 engine i doubt I'd get the same results tho.

 

[tecman]

so I measured my bike clutch drag using method ( luggage electronic scale http://www.ebay.co.uk/itm/50kg-Portable-Hanging-Electronic-Digital-Travel-Suitcase-Luggage-Weighing-Scales-/161454185635?pt=UK_TravelTickets_Accessories_RL&hash=item25976b5ca3 ) provided in this thread while ago. Here are results:

engine hot:

Neutral: wheel started to move at 1.60 - 1.70kg
1st gear with clutch in: 3.80 - 4.00 kg (measured when I stopped wheel from spinning)

That means that clutch drag equates to aprox 2.2kg, which is 21.5N (2.2*9.8) of force

I'll check cold engine drag tomorrow morning...

 

[Titto]

Wow, nice one tecman good stuff!

 

[tecman]

this test was done on running engine obviously. My clutch started playing up which made me to run this test after recent gearbox and clutch replacement. It was not doing this right after the swap. I'd like to compare that with DING-DONG's bike. It costs only 4 quid...

 

[Neil W]

Mine is so bad now that I start it in first gear with the clutch in so that it doesn't go into first with a bang.

At tickover it is the only bike or vehicle that I have owned or driven in the last 35 years that will not physically engage second gear at standstill , it will baulk and crash on and just not go into gear . .

 

[stevemersey]

Mine is so bad now that I start it in first gear with the clutch in so that it doesn't go into first with a bang.

At tickover it is the only bike or vehicle that I have owned or driven in the last 35 years that will not physically engage second gear at standstill , it will baulk and crash on and just not go into gear . .

Neil, did anything happen before it got worse. An oil change or service for example?

 

[Wrinkly]

Neil, did anything happen before it got worse. An oil change or service for example?

Mine was absolutely spot on until it's first service.

 

[pistole]

is this thing still on ?

hasn't ding sold his bike back to the dealer ?

hasn't ding bought a 1190 ?

isn't this over ?

how many bikes and how many engines/gearboxes are we talking about again ?

 

[Neil W]

Poor before the first service , even worse since the service

Neil, did anything happen before it got worse. An oil change or service for example?

 

[DING-DONG]

is this thing still on ?

hasn't ding sold his bike back to the dealer ?

hasn't ding bought a 1190 ?

isn't this over ?

how many bikes and how many engines/gearboxes are we talking about again ?

Pistole very strange you seem to no certain things only BMW Uk no ! and Ding hasn't brought a 1190 you should no that if you WORK FOR BMW.

 

[stevemersey]

Poor before the first service , even worse since the service

Neil,
in another thread, someone said that oil level was critical and that by reducing his overfilled engine to the correct level, the gear change improved considerably. I wondering if this is the case for anyone else?
There are a few other reports of things getting worse after a service oil change.

 

[pistole]

Pistole very strange you seem to no certain things only BMW Uk no ! and Ding hasn't brought a 1190 you should no that if you WORK FOR BMW.

har har ... Ding , take off the foil - hat man .. we're not stalking you !!

 

[Nutty]

har har ... Ding , take off the foil - hat man .. we're not stalking you !!

So you do work for BMW?

 

[Magnon]

Mine was absolutely spot on until it's first service.

So was mine. I rang dealer when I got home and asked about oil used (it was castrol correct stuff). When next in the dealers I had a word with mech and specifically ask him what the original oil was like when drained and he said seems thinner and tends to splash more. So my take is they use a running in oil on first fill at the factory and the clutch like this!

 

[tecman]

So here are results.

Little bit of comment. When engine reached temperature above 70 degrees, measuring wheel drag in 1st gear became bit unpredictable. I could definitely feel that wheel was "catching" occasionally and then force required to move it from stationary position was significantly higher. I recorded range of 4.0 kg all up to 6.20ish. That would explain why some gear changes are smooth (small clutch drag) and some go with grinding noise or clunk.

In my case, when engine was hot already and it was in 1st gear, I was able to put wheel in motion by pushing it forward and then it caught and started spinning until I stopped it by boot. This is exactly same behaviour as Dave's and my bike prior to gearbox and clutch replacement. I'll be calling dealer today to report this problem resurfacing after 700 miles from repair.

 

[Engineer]

So here are results.

Little bit of comment. When engine reached temperature above 70 degrees, measuring wheel drag in 1st gear became bit unpredictable. I could definitely feel that wheel was "catching" occasionally and then force required to move it from stationary position was significantly higher. I recorded range of 4.0 kg all up to 6.20ish. That would explain why some gear changes are smooth (small clutch drag) and some go with grinding noise or clunk.

In my case, when engine was hot already and it was in 1st gear, I was able to put wheel in motion by pushing it forward and then it caught and started spinning until I stopped it by boot. This is exactly same behaviour as Dave's and my bike prior to gearbox and clutch replacement. I'll be calling dealer today to report this problem resurfacing after 700 miles from repair.

On the centre stand - with the clutch in and engine then started my real wheel does not spin - if I release the clutch lever a little to start the wheel spinning, then pull it back in to the bar I struggle to stop the rear wheel spinning with my boot (i.e. loads more drag once the clutch has engaged for the very first time) BUT apart from the clonk into 1st gear, changing is fine as long as I blip on downshifts. This test was done from almost cold.

I think this slipper clutch thingy (back torque limiter) is more complex than one imagines.

P.S. your torque figures have to be divided by the gear ration to get the actual torque at the clutch.

 

[tecman]

Engineer,

They are Force figures (F=m*g), Torque is F x r ( displacement vector) as per

http://en.wikipedia.org/wiki/Torque

 

[pistole]

I think this slipper clutch thingy (back torque limiter) is more complex than one imagines.

me thinks you are correct. BMW calls it a "self energizing clutch" , which in other words is a self-locking clutch. This probably accounts for the very light clutch lever pull on this bike and also (maybe) the strange engagement points in some cases

 

[Engineer]

Engineer,

They are Force figures (F=m*g), Torque is F x r ( displacement vector) as per

http://en.wikipedia.org/wiki/Torque

Sorry should not have said torque.

Yes but you are measuring the force at the rear wheel this is force at the crank multiplied by the gear ratio is it not?

 

[Engineer]

me thinks you are correct. BMW calls it a "self energizing clutch" , which in other words is a self-locking clutch. This probably accounts for the very light clutch lever pull on this bike and also (maybe) the strange engagement points in some cases

Yes I think you are correct - it seems to behave differently to a normal, simple wet or dry clutch.