Monster 900Sie 50000mile refresh.

[Dukedesmo]

Regarding lighter wheels, I too was surprised, indeed shocked at the difference felt.

I replaced the wheels on my 916 with Marchesini forged 10-spokes and whilst not carbon light they are significantly lighter than the original 3-spoke wheels.

Fitting them improved every aspect of riding: acceleration, braking and cornering with no downside (other than the cost). The thing that hit me the most was how much more agile the bike felt, especially tipping into a corner, it was like riding a different bike.

Of course you get used to it after a few hours and it all becomes the new normal but of the many upgrades I have made to that bike (and there are many) - more power, less weight, better brakes & suspension etc., lighter wheels were by far the best, most noticeable of all.

It is definitely something I'd like to do to the Monster one day

My advice to anyone considering any modifications - lighter wheels are the best 'bang for your buck' by far.

[350TSS]

I read somewhere that Michelin tyres because of their softer tyre wall construction are significantly lighter than other brands (from memory about 10%).
Manufacturers do not appear to quote tyre weights in their blurb. If it is true then the combination of lighter wheels and lighter tyres should lead to faster acceleration (the wheel and tyre are effectively another flywheel) improved traction because the lighter wheel/tyre combination is better able to follow the profile of the road surface and better/faster directional change due to reduced gyroscopic forces.

[Mr Gazza]

Just checked the Ti disc bolts against standard ones.
The Ti are 4g a piece lighter than the standard ones so 4 x 12 = 48g. I've got my 49g deficit back.
Also had Ti caliper bolts for a while so that put's me slightly ahead of standard, but not dramatically. I'm staying fairly level weight wise but gaining upgraded brakes.

Hoping for the phone to ring tomorrow, so I can pick up the centre stand for the weekend.

[utopia]

Originally Posted by Mr Gazza

I'm going to contend the gyroscopic effect that you mention in a playful way, as I don't fully understand the details of the principle.
Does the weight of the gyro have an influence or is it the speed of rotation?
Motorcycle steering is initiated by interference to the gyro's procession and if the effect was reduced by weight then I think you would have noticed more effort required to initiate a turn and overcome the bike's mass? Whereas I think you have said the reverse in the past?

I would also posit that the effect has been increased, (or remains the same?) if the major weight is now at the periphery (the tyre) relatively speaking, The central part, (the wheel.) having a lesser effect? That brings diameter into the equation too come to think of it.

There's a nice think for you if you fancied a think and couldn't think of a think..

Ha !
Back down the rabbit hole we go.
I've never yet found my way out.
Anyway, let's have another go.
And joke on you, mate, cos I'm now going to clutter your thread with goodness knows how much ramble.
But first, I might say (and here I quote Jefferson Airplane in paraphrase) ...
Well I thunk and thunk.
Couldn't think of anything better.
I tried so hard.
But thinking ain.t doing me no good, people.
Thinking ain't doing me no good.
https://www.youtube.com/watch?v=JRNRVe0kgC0
Though maybe I'm wrong ... it probably helps keep the Alzheimer's at bay.

I have some notes in the attic from my days as an engineering student in the mid 1970's ... but I'm going to leave them there and instead try and reason my own way through the warren .. cos that's more fun.
I'll get stuff wrong, probably, but it won't be the first time.

So...
Lets say that gyroscopic forces arise from the angular momentum of a rotating mass.
The two variables here are 1) the mass and 2) the radius of rotation .. and 3) the speed of rotation (nobody expects the spanish inquisition) ... but lets rule the latter out by assuming a constant speed.
The mass is distributed over the whole radius, from wheel spindle to tyre periphery (and across the width of the wheel too, but ...)
Lets resolve that mass distribution to a single centre of mass ... imagine a rotating wire hoop of infinite density and thinness (although I use the word infinite loosely here otherwise it would disappear up its own black arsehole, but I digress).
So we now have a single hoop of infinitely thin mass rotating at a single "effective radius".
And here I can say "yes", it seems obvious that lighter wheels would not only reduce the magnitude of the mass but also its distribution and hence the effective radius, both of which contribute to reduced angular momentum.
Since gyroscopic forces arise from angular momentum then those gyroscopic forces must be reduced if the wheels are lighter.

Here is where words start to play tricks ... well on me at least (if they haven't done so already).
But in for a penny .....

So ...
Less angular momentum (from lighter wheels) should mean less force necessary to overcome said angular momentum (Newton's laws of motion). Hence easier steering.
But at the same time I can see your argument, Gary, that if there are more gyroscopic forces acting (from heavier wheels) then there are grounds for saying that there would be a greater tendency for the bike countersteer. Hence easier countersteering ???

I remain somewhat baffled and perplexed by all this.
And there I'm going to leave it, for now.
Capo would have said that only calculations will provide the answer, but that would mean a good rummage in the attic for my 50 year old notes.
I might just go out for a nice relaxing ride on my old Raleigh bicycle instead.
Trouble is, I think there's something wrong with it.
Every time I steer left the bloody thing turns to the right.
Which isn't great on the canal towpath.

By the way, no substances other than tea were used in the production of this rambling.

[utopia]

Also,
Dukedesmo sums up the advantages of lightweight wheels perfectly.

With respect to the improved acceleration, I would say that it felt like the carbon wheels had given the bike at least an extra 10bhp if not more ... and remember the 750 only produces 60 odd bhp in the first place so we're talking over 15% increase.

Another advantage of the tune-up that comes from lighter wheels is that the improved performance (unlike engine tuning) puts no extra load whatsoever on any component part .. in fact it reduces overall stress in more than one area.
Its like magical free performance (apart from financially of course).

[Mr Gazza]

Originally Posted by utopia

Though maybe I'm wrong ... it probably helps keep the Alzheimer's at bay?

Oh dear! I don't think so..
I do like the Jefferson Airplane association though, as I'm a big fan and of Grace Slick in particular, but hadn't come across that track before. I instantly though of her when you mentioned the rabbit hole, but actually had Spike Milligan in mind with the think of a think thing.

Glad it gave you a think though and also a bit sorry really! I do realise of course that light wheels are a good thing.
Pondering, after writing the comments I also realised that bicycle wheels are considerably lighter than you could possibly get a motorcycle wheel and yet the gyroscopic forces still work to initiate a turn even at very low speeds.
It is probably not possible to make a rotating mass light enough to negate the gyroscopic force? Certainly not on a motorcycle where a tyre will always be required.

Thanks for the think and careful with that tea (Eugene.)

[Darren69]

Keep your eyes peeled for some S4/ST4 5 spokes! I read that they are 500g lighter ea than the standard ones, which may not sound much. 1kg static is something then you have less gyro aswell. May not be carbon but in the right direction, cheaper too!

[Mr Gazza]

Time marches on and I haven't been updating this thread!
Work has been on going though, in fits and starts.
The front end is pretty much sorted now apart from re-lacquering the wheel and fitting the new discs and tyre.
The callipers now have new Ti pinch bolts saving a whopping 50 grams on just 6 bolts. Also they have Stainless pad pins, new pads, Ti banjo bolts and nipples.
I blew each piston out and thoroughly cleaned them fitting them back with a smear of rubber grease.
I gave the calliper bodies a good scrub with a toothbrush and Mr Muscle foaming drain cleaner.. Works a treat. Great on engines too.
It's a two part liquid and gel. I pour a little into a takeaway tub and it foams almost instantly, then dip the toothbrush in and scrub away. Rinse off with water.



Brake lines are new too and yet to be heat-shrunk and filled with fluid.

After a long debarkle trying to find a longer speedo cable, I finally did the obvious and called in at Tinklers, a local Yamaha dealer of long standing. Luckily a mate of over 40 years was behind the counter and he kindly disappeared into the stores with a tape measure and emerged very quickly brandishing a cable of correct length and fitting type, under £20 too.
I now have a speedo cable of equivalent OEM quality.



One slightly impetuous thing I did was replace the Ti mudguard bolts with alloy ones.
They weigh a mere 1 gram each and will take a torque of 5Nm. The recommended torque for mudguard bolts is 4Nm, so they are in spec by the skin of their teeth.
I will be keeping an eye out for fractured bolts!
Saving there was 28g on 4 tiny bolts over the originals. The now spare Ti bolts were re-used to replace the very rusty ones holding the seat plastic undertray, the crankcase breather catch tank and the petrol tank hinge.
Total unsprung weight saving on the front end is 191 grams. and I'm pretty sure the Arashi discs are a little lighter than Brembo too.

[Darren69]

Those calipers have come up nice Mr G

[Mr Gazza]

Yes, thanks for the callipers Darren. I'm hoping it won't be too long before I can try them out.

Continuing with the catch up. I had been wanting to do something with the remote reservoirs on the handlebars for some time, as the rather complicated brackets, pipes and clips had been getting scruffy and also on my nerves.
Following what Nasher had done with his I had designed some pots that fit directly to the masters and also pick up on the mounting bolt hole for the remote pots.
But then I happened upon a pair of Multistrada reservoirs going very cheap on eBay, complete with lids gaskets and bolts. For sale by a certain "Buzzer" as it happens.
I've sanded the lettering flat on the lids and polished them up, replaced the rubber grommets in the masters and fitted them.. easy as that.





This is much cleaner than the remotes and I quite like the look.
The ones I have designed will eventually be 3D printed by my nephew, but he is a rather busy lad at the moment, getting his career off the ground after getting a degree.
We've done some experiments with printed PETG and it seems to hold brake fluid indefinitely with no leaks. Polypropylene seems to be a little more problematic to print at the moment pending further experimentation when time permits.

Another little detail that had been annoying me was the rear light lens screws.
I had painted them silver a couple of times before, but this doesn't last and the heads are in poor shape.
I took a sample to my stainless screw man at UKStainless and we matched the thread rate on the self tappers with round-head wood screws. A little rub on the buffing wheel puts a sparkle on them and they fit a treat. I had to buy 100 so they were a rather expensive pair of screws, but I will offer these in twos by post when I work out the price. I think they'll come out at a quid posted if anyone's interested?



They did make the old lens look decidedly scruffy, so I bit the bullet and bought a new (pattern) one. The light body is rough too, but I'll probably blow a bit of Gold on it and magic it back to new..