Reducing unsprung weight/mass

[qldzxr250a]

they use nitrogen in tyres because it is far more stable then just air and far lees chance of combustion/exploding when the tyres are hot.

as everyone know when air gets hot molecules expand inside the tyre increasing the pressure in the tyre in relation to road/tyre temps.

nitrogen is more stable and less prone to blowouts (has more room for inaccurate tyre pressures)

thats what the tyre shop told me.

[Warren]

I don't think helium will make any difference, as a helium baloon will only hold up at max 1 miniture G.I.Joe. If you really want to reduce the unsprung weight you have to attach a few thousand baloons to the front forks and rear swingarm.

[FROSTY:Me]

beyeebers reeves--just eat one less mack attack and youll be heaps faster

[Motoracer]

But... but... what if the bike slips away from you and flys away, into the sky?

[cowpoos]

Did I hear that Helium will leak out of a rubber tyre wall due it being smaller in particle dimenisions (compared to air that is)?

yes yes yes yes.....bling dispatched.... permiates I think is the word....

[skelstar]

But does the helium aid in the gyroscopic effect poos?

[SixPackBack]

But does the helium aid in the gyroscopic effect poos?

Reduction in unsprung weight will reduce gyroscopic effect.

[sAsLEX]

for all those people still confused over sprun and unsprung weight heres how you tell, sit on yur bike and everthing that moves cloeser to the ground like the muffler, engine you are sprung weight and the things that dont move closer to the ground like the wheels, brakes, forks lowers are unsprung weight.

[jonbuoy]

Would have more of an effect than helium in your tyres - only on your sprung weight though!

[ManDownUnder]

Each helium molecule is considerably smaller than anything in the air, and WILL leak from a rubber tire and or rubber tube. It won't be a fast leak - but it'll be consistant.

I'd expect the weight saved to be less than that of adding the tube to contain it too - so there's a negative gain too.

I understand the reason Nitrogen is used it either because it has less moisture in it, and/or because it expands less with heat. Either way it gives a lot more stable tire pressure when they're hot and cold...

Unsprung weight reducton would be best achieved by looking at the densest unsprung parts of the beast. Tires, rims, lower shock and possibly fork oil (although I'd be inclined to stay away from that). Britten did a good job addressing this issue by putting everything in Carbon Fibre.

Strong as hell, and light light light.

If you can come up with a new solution to the problem - go for it, let us know how you get on!
MDU

[sAsLEX]

this issue by putting everything in Carbon Fibre.

Strong as hell, and light light light.

Wont mention how carconogenic most of the stuff he worked with by hand was......

[ManDownUnder]

Wont mention how carconogenic most of the stuff he worked with by hand was......

I hear ya - but then there's a lot of things out there that'll kill ya. Besides, it wasn't the material that killed him, it was the lack of safety gear while handling/working it.

There's a lot of people out there working with it, but they have the gear.

[svs]

Apart from the leakage issue, I reckon by some really rough calculations that you'd save around 50g per tyre.

So is it worth it for 100g reduction in weight - I doubt you'd notice the difference. Start saving for the carbon dymags.

[HDTboy]

Could do burnouts and save more weight huh?

[ManDownUnder]

Apart from the leakage issue, I reckon by some really rough calculations that you'd save around 50g per tyre.

So is it worth it for 100g reduction in weight - I doubt you'd notice the difference. Start saving for the carbon dymags.

And has been suggested... take a dump before the race. In fact - down a 1/2 bottle of castor oil... hang around the loos till you're ok to put your clothes back on (let's face it - it IS the decent thing to do), cut down on the maccas and you'll be good.

Unsprung weight - svs has it sussed.
MDU