Disk weights - a comparison!
 

I've been a bit bored today, so decided to weigh some disks!!!!

I'm trying to get the best wheel/disk combination and had a few disks "lying" around, so I though a comparison may be interesting, as the lighter you can get unsprung weight, the better!!!

I compared a single front disk off of a 916 (I think) a single disk off of a 996R and a single Braking "Wavey" disk.

The Brembo 916 disk is circa 1999 I think and weighed 1.85kg.

The standard, alloy centred, disk off my 996R weighed in at 1.3kg.

With the Wavey disk weighing in at 1.375kg.

You can work out all of the differences / percentages etc if you want.

So although there's only 75 grammes difference (x2 for both sides), I'll probably stick with the waveys as they do perform better and look better than the standard 996R disks.

If you've got the standard Brembos - you're giving up a lot of weight advantage if you've not got the later "alloy" ones or Waveys fitted.

The weight differences may not sound alot, but its all about gyroscopic forces and the heavier the front wheel / tyre / disk setup the slower the bike will turn.

If you can get the bike to turn quicker, you can go faster and turn later into a bend and also pick the bike up faster to get on the gas earlier! This can save seconds a lap!!

The 996R and Wavey disks aren't cheap though, with a pair of either costing around the £330 mark.

Worth it? If it can reduce your lap times its gotta be good.

I can post some pics of the different ones, if anyones anal enough (as I am) to want to see them.

Tim:frog:

you are bored aren't you !! - I mean, I am at work bored, but your at home and could be out riding/boozing etc, etc, but what do you do - weigh disks ! :lol: !!!! :P :D

Would be interesting to see how the cast-iron floating brembo's weigh up to those.
Been thinking of swapping the ones on mine to waveys for a while now.

I wouldn't have thought that it was a good "scientific" measurement in terms of gyroscopic effect... don't forget that a weight further from the centre would cause more gyroscopic effect than the same weight closer to the centre...

The design of the wavey disks may mean that although they weigh slightly more, they actually produce less gyroscopic force on the wheel...

...or something :frog:

Yep........
 

Dave........If only the kids would look after themselves eh!!!!

Anthony - Fair point, but it was the comparison between the older and newer type brembos that is the greatest difference!!

Tim:frog:

Chris,
The Brembo ductile iron full-floating rotors weigh 1.71Kg each.

Tim, give them one of your bikes to play with that should keep the quiet for a while - especially if you give them the keys as well !! :lol:

Unsrung weight is important though. The disks, wheels etc are not supported by the suspension so any weight you can loose here gives the suspension an easier time.

Tim !:)

Jon!!!!
 

.........I know, I know!!!!

These are your disks, I promise.

Just show me the money!!!!

;)

Tim:frog:

Tim,

Did you get an anorak for xmas ....????

:sing:

Bog off skinny!!!
 

I'll try to add to this soon. i'm going to take a selection of discs into work and weigh them, I know the Spondon ones are my lightest but not there actual weight, will also weigh EBC pro-lites and a few others.

This anorak fits well and its keeping me warm and dry in this weather.

Skids........
 

.........that'll be good.

Just a comment that I did measure these very scientifically - I used some cheap kitchen scales!!

I wasn't too concerned about the accuracy, more on the difference between the disks.

Tim:frog:

As already pointed out, it's not the static weight alone that makes the difference. For instance, I have narrow track race Brembo discs in both 290 and 320 mm sizes. As it's the disc itself, not the carrier that accounts for the majority of the weight, a narrow track disc reduces the weight where it counts most. The discs themselves weigh about the same as what you've measured, but they can now carry a thicker disc which last longer and dissipates heat better. Remember, brake systems are a science and very difficult to understand, well, certainly for me.

Felix......
 

.......I'm not quite sure I followed your point. Whay are narrow track lighter?

The waveys are thicker than the R brembos, but weigh virtually the same.

Perhaps the centres weigh less.

They also have the wavey edge that in theory provides a greater edge surface to aid cooling!

How do you accomodate the smaller disks (290mm) with your calipers?

Tim:frog:

They weigh virtually the same as the standard ones but are thicker at the same time. Were they the same thickness they would be lighter due to the narrower track using less steel.

Proper Ohlins race fork have two sets of mounting holes for the calipers.