My quest to lighten the 884 has now become some what obsessive; however... Can I be expected to be able to lighten the rear disc myself by either just popping in more holes; or putting a larger drill bit through the current ones? I never use the rear; but might compensate the lack of surface area by using a better compound pad. Keen for advice on how much I could get away with. I know there is not much point in doing it; but in conjunction with going to a 520 chain and putting an alloy rear sprocket; it all helps. And it may only cost me an hour or two??? Thoughts?? Cheers, Bob
Even if I were to take my rear disc off and throw it away, I doubt that I would feel any difference in the bike. You could come and look in my garage, there are loads of aircraft titanium bolts laying around, these things are about a third of the weight of steel and some of the small 8mm ones would have cost £60 a time a few years ago.
As I said; every little bit here and there... I saved three pounds last weekend taking off the fans, horn and locking petrol cap. Not a great deal, but I'd rather not have it... Bike must be 40-50 lbs lighter now than it was standard road trim... A lot of it in small bits... No offence intended; but I'm more after the technical opinion really; it is just as easy as drilling / milling some of the disc baulk away?
I once heard about some TT boys who put on BMX rear discs; they needed one for scrutineering but nothing else !
my mate doesnt run a back brake at all on his track bike but hes nuts!! tbh ive still got mine plumbed in even though i know it aint going to save me but i still like to know its there, false hope i suppose.
Not a good idea. The reasoning is that you will weaken the compound of the steel as you drill out the holes to make them bigger because you are effecting removal of the case hardening of the steel when it was heat treated, this could lead to fractures than can emanate from the hole itself after you re-drilled them. If you want a lighter disc then get one made for you from scratch.
I need something there for scrutineering... But I agree, would gladly junk the lot. Over the years we've gone from cable driven brake hubs and shoes; to twin hydraulic discs, but still need a rear apparently... Reminds me of when they stopped enduro bikes putting the rear brake disc on the front sprocket. Awesome idea, but ACU / AMCA wouldn't agree
Thanks; just what I was after... So If I drilled it, then got it re-hardened?? Above my pay scale; but my mates a pretty good engineer.../?
I hear the weight saving plan and am all for new ideas. You could just mill the disc down to its minimum thickness, and a bit beyond if you're brave and don't think your mot guy will notice. As the surface wears anyway I wouldn't have thought this would affect the structure of it. FWIW my 996sps dry weight is something like 198kg, as a track only bike I've got it down to a kerb weight of 157kg. Yes with battery, fuel, oil, water and still with starter motor, and I've shed a bit more since it's last weigh in. The only magnesium is the wheels and it's not had every titanium bolt thrown at it either so still room to improve. Keep it up, you WILL notice the difference if it becomes obsessive.
mag swing arm,carbon body work, mag/carbon wheels,carbon fuel tank, can get rather expensive trying to save those few kgs.
Good effort... A much heavier beast that mine to start with... Agree that it can get expensive as we strive to loose more pounds... At some point it would be cheaper to buy a newer lighter bike; such as lovely 1299; but that's cheating ! I'll look to weigh the ole' girl soon. Is it as simple as doing one wheel at a time with the bathroom scales??
I agree; she's 12 lbs lighter than last year right now; and i notice the difference; even just loading it onto the van
I've been weighing some bits as I take them off / put them on with the kitchen scales... but it would be nice to get a real world all up weight...
Take a good effort on the John before you go out... Bet you never put that reduction to a scale...? Not trying to be a wise ass, but what will the disk work save...? I bet a good pile of your damping discharge will weight the same as the whole damn disk.... My idea (and so i did) Ti all the way, go bonkers at your local Ti bolt suplier!! Carbon bodywork, LiPo battery, Forged Magnesium wheels, and stop eating... (Stop eating is actually a joke, don't take it seriously, it'll get you hospitalised or even death may occur... Not worth it!!!)
If you want a rough idea of the bikes weight, use a pair of bathroom scales under the wheels, or measure each end seperatly and add them up. Just don't do it on the stand or putting any body weight on it. Balance it upright with as little contact/effort as possible.
well if its like the front it can be a couple of kilos Surely if you domt use it anyway, onlu risk is it overheating somehow and binding the pads on...just put really low pads in
