crank shaft weight difference

[dogmaboy]

I have a late 2013 gs ,But have been offered a good deal on a 2015 when I went in for a service.My question is do you notice any difference in performance with the heavier crankshaft.Also I read some where on this forum that owners of the 2015 bike thought they may seem a little lower,is this correct,thanks in advance ,Dogmaboy

 

[CPJS]

I have a heavy one and a mate the light one, we swapped bikes and neither of us noticed any difference, but in fairness it was not the reason why we were trying them. there was nothing that made us notice anything in particular.
We had our bikes hilltopped at the same time, mates was 1bhp and 2flbs more than mine but my dyno readings were more linear.
All pretty irrelevant really.
For less money than trading up get your bike set up properly it will make far more difference.
Don't spend your money for no good reason.

 

[roamer]

I had the light flywheel 2014 gs , and now 2015 heavy,
The earlier engine spins up quicker, slightly more responsive / urgent,
The heavier flywheel engine doesn't stall so easily and feels smoother low down,
As mentioned swapping a good bike with no issues that bother you wouldn't be a great benefit,
I had rejected the earlier bike after 2 weeks due to issues and ordered a new gs,
and as it was right on the change point I was unsure how the heavy crank would compare, as the earlier bike had a slick gearbox, and it does seem to be a lottery,
It had been sorted for other issues like heated grips for 2015
I came back from a year and a bit with a ducati multistrada 2013,
Missing the low down drive ability and complete package of the gs, ,
Roamer,

 

[batman1]

I have a 2015 RT (heavy crank) and 2014 GS (light crank).

The heavy crank does not show any noticeable difference in either speed or acceleration compared to the light crank.

However the heavier crank does seem to calm the bike down slightly and in particular it's a little bit smoother at low speed.

The light crank spins up quicker in neutral and revs quick like a racer when you blip the throttle.

I've often wondered if part of the reason that the heavy crank was fitted was to smooth out some of the lower speed poor running produced by poor fuelling issues caused by the very lean set-up required to get the bike through emission regulations, as it is an easier solution than trying to sort out the fueling for all bikes in all countries and all climates.

Perhaps CPJS's advice is the best, get the bike down top Geoff at Hilltop and sort out the fuelling before you do anything else.

From where I sit, the RT motor with the heavy crank is the nicer motor, but only because it's a little bit smoother and calmer.... but it's a subtle difference.

 

[ATG]

Prior to answering your question I've read through all the answers. I've also have read different comments on similar questions both here and at GSPOT. First of all I believe that not only the different rider's have different levels of sensitivity but also that within each rider we have different sensitivities levels for different things. For instance, one reider may be quite sensitivity to acceleration while not to vibration while another rider may be quite the opposite. Whatever opinions you may read, keep those differences in mind.

I presently own my 6th GS and 3rd WCGS and as far as my opinions go I find that my 2015 heavier crankshaft is smoother with quite less engine vibration, it is less prone to stalling al low revs, and it shifts better. On the negative side it has a slightly lower acceleration, less nervous, engine.

Consider that these differences are due to a the higher momentum that the heavier crankshaft provides.

To better understand the reasons for these changes, consider two wheels turning at any given low speed: one very light weighting for example 1 kilogram and another, weighting 100 kilograms. Imagimne both are stationary and you decide to spin them. It is easy to imagine two obvious effects: It is much easier to bring to speed the one kilogram wheel in relation to the 10 kilogram wheel; It is much easier to brake to a stop the lighter spinning wheel. These difference are due to the higher inertia and achieved momentum of each different weight wheel.

After thinking on the above example it become clear why the lighter crankshaft accelerates better while the heavier crankshaft one is more difficult to stall. It also explains why the heavier crankshaft model shifts better as its slower to drop rotational speed down allowing for less engine rev drop while the clutch lever is depressed for gear changing. The lower engine vibration is explained as result of higher mass and different resonant frequency.

Although these differences are all measurable each riders sensitivity to them is not; I believe that the different opinions people have are due to different sensitivity levels.

Hope this helps.

Andre

 

[roadrider]

I have a 2015 RT (heavy crank) and 2014 GS (light crank).

get the bike down top Geoff at Hilltop and sort out the fuelling before you do anything else.

There may be some transportation logistics to be resolved first.

 

[Engineer]

I have had both - not a lot in it really, 2013 bike a little bit more 'urgent', 2015 bike noticeably easier to ride at walking pace, less clutch slipping required.

 

[batman1]

I have had both - not a lot in it really, 2013 bike a little bit more 'urgent', 2015 bike noticeably easier to ride at walking pace, less clutch slipping required.

Which do you prefer?

 

[Bendy toy]

There may be some transportation logistics to be resolved first.

He could send the ECU for flashing with new maps. It wont have the last few % of rolling road fine tuning but Geoff is well versed in what these bikes need so a straight plug in should be fine.

 

[dogmaboy]

bought the 2015

Ended up buying the 2015,the dealers seem very keen in Oz at the moment to sell at very good prices.One more question please.There have been some advice about sending my chip to Hilltop,what would I miss out on ,on the final tune not having the bike in the UK.I can't seem to find an Australian version of Hilltop.Thanks again Dogmaboy