Front wheel & brake rotor weight!

[Wolfman]

Did you know that an FZ6 wheel with Tyre...(Dunlop Qualifier) weigh's just on 10kg's? maybe you did, but i bet you didnt know that the same wheel, that has been stripped and polished, with the same type of Dunlop Tyre, weigh's in at 9.7kg's....surely polishing cant reduce weight by 300grams....

Neither wheel had brake discs on them, or any bolts, or spacers, etc, in them...that was just wheel and trye.

Did you also know that a standard FZ6 front brake rotor weigh's just on 2kg's, whereas a Braking brand Wave Disc, weigh's in at 1.4kg....a 600gram difference!!!! that's 1.2kg total saving in weight!

just thought i would share, whilst i had wheels laying around in the shed!

:thumbup:

 

[RJ2112]

Did you know that an FZ6 wheel with Tyre...(Dunlop Qualifier) weigh's just on 10kg's? maybe you did, but i bet you didnt know that the same wheel, that has been stripped and polished, with the same type of Dunlop Tyre, weigh's in at 9.7kg's....surely polishing cant reduce weight by 300grams....

Neither wheel had brake discs on them, or any bolts, or spacers, etc, in them...that was just wheel and trye.

Did you also know that a standard FZ6 front brake rotor weigh's just on 2kg's, whereas a Braking brand Wave Disc, weigh's in at 1.4kg....a 600gram difference!!!! that's 1.2kg total saving in weight!

just thought i would share, whilst i had wheels laying around in the shed!

:thumbup:

I wonder what the difference in air pressure in the tires was. It wouldn't be too difficult to stuff in an extra 300 grams of air.

Did you have a chance to repeat the measurements, to see what sort of accuracy your scales have?

 

[Wolfman]

I wonder what the difference in air pressure in the tires was. It wouldn't be too difficult to stuff in an extra 300 grams of air.

Did you have a chance to repeat the measurements, to see what sort of accuracy your scales have?

I forgot to mention that I checked tyre pressures after...one was 29, the other 31 psi.

I will weigh them both again tomorrow with 10psi more in one of them

 

[OZXJR]

I wonder what the difference in air pressure in the tires was. It wouldn't be too difficult to stuff in an extra 300 grams of air.

You can weigh air

 

[RJ2112]

You can weigh air

Air has mass.... when you compress it, the weight goes with it. (Just had to google that, to make sure of the number.) Seems an expert claims it's 0.08 pounds per cubic foot, for generic air.

What is the weight of 1 cubic foot of air?

Another google converts 0.08 lbs to 36 grams

Pounds to Grams (lb to g) conversion calculator

Try lifting up an air compressor tank when it's completely empty, and then try that fete again, when it's charged up to 30 psi or so.

 

[RJ2112]

I forgot to mention that I checked tyre pressures after...one was 29, the other 31 psi.

I will weigh them both again tomorrow with 10psi more in one of them

It'll be an interesting exercise, Wolfman.

For the record, I have no doubt that removing the paint and polishing the rim did reduce the weight. I'd have to think the reduction was pretty small, though.

One of the problems with using digital scales, and pressure gauges is they tend to make us think they are more accurate than they really are. It's always best to ignore the furthest digit to the right in any measurement, if you are trying to be accurate.

 

[RJ2112]

I forgot to mention that I checked tyre pressures after...one was 29, the other 31 psi.

I will weigh them both again tomorrow with 10psi more in one of them

I'd also suggest repeating each measurement 5-10 times, and taking the average value for what you think the wheel weight is. Your scale is almost certainly going to give you different numbers, based on how the wheel sits on it (if you are using a bathroom type scale). Is the wheel standing on edge, or laying across the platform, is it tilted one way or the other, etc., etc.

If you have a hanging scale, like a fish scale that is able to record 10 Kg weights near the middle of it's range and you can hang the wheels so all the weight is applied the same way each time, that's going to be more consistent.

 

[Wolfman]

I'd also suggest repeating each measurement 5-10 times, and taking the average value for what you think the wheel weight is. Your scale is almost certainly going to give you different numbers, based on how the wheel sits on it (if you are using a bathroom type scale). Is the wheel standing on edge, or laying across the platform, is it tilted one way or the other, etc., etc.

If you have a hanging scale, like a fish scale that is able to record 10 Kg weights near the middle of it's range and you can hang the wheels so all the weight is applied the same way each time, that's going to be more consistent.

I am using a hanging scale...rest assured I will be thorough, now that there is interest.

 

[Razer]

Air has mass.... when you compress it, the weight goes with it. (Just had to google that, to make sure of the number.) Seems an expert claims it's 0.08 pounds per cubic foot, for generic air.

What is the weight of 1 cubic foot of air?

Another google converts 0.08 lbs to 36 grams

Pounds to Grams (lb to g) conversion calculator

Try lifting up an air compressor tank when it's completely empty, and then try that fete again, when it's charged up to 30 psi or so.

Generic air...I love it...I want some After market air

 

[PVFZ6]

I just air up my tires with helium, and I also starve myself two days before I ride. :thumbup:

We are the heaviest thing on our bikes and the easiest thing to reduce weight on. Eat right and hit the gym is the trick.

 

[RJ2112]

I just air up my tires with helium, and I also starve myself two days before I ride. :thumbup:

We are the heaviest thing on our bikes and the easiest thing to reduce weight on. Eat right and hit the gym is the trick.

Before I put new springs in the fork, I could tell a difference in steering any time I had less than a half a tank. It changed the weight on the front wheel that much. (I actually think it changed what part of the spring I was 'on', with the lighter fuel load, I was using the softer part of the spring.... had a lot more vague feel then.)

 

[shuckle]

I just air up my tires with helium, and I also starve myself two days before I ride. :thumbup:

We are the heaviest thing on our bikes and the easiest thing to reduce weight on. Eat right and hit the gym is the trick.

I suspect they're thinking about rotational weight.