Wheel Mods

alienator said:

Has anyone ever tried trimming off the excess thread on the presta valve stem cores on their tubes so that the MOI of their wheels will be less? There has to be a time advantage, here, because less weight on the wheels means you go faster.

I only pump my tires full of warm, humid air. And I only eat rice cakes - they're full of light, light air.

John Swanson
www.bikephysics.com

alienator said:

Has anyone ever tried trimming off the excess thread on the presta valve stem cores on their tubes so that the MOI of their wheels will be less? There has to be a time advantage, here, because less weight on the wheels means you go faster.

The scary thing is someone probably has🙂

I do that. I also leave off the cap and file away some of the threads.

I like to remove every fourth spoke with cable cutters. Taking out a few hub bearings also saves weight. Riding without the skewers takes a lot of practice, but pays dividends, as long as you don't pedal too hard or bunnyhop.

I leave the valved unscrewed, because doing it up puts the weight of the tip 2mm closer to the outside of the wheel

I used to balance my wheels by ripping a valve off an old tube and taping in to a spoke on the opposite side of the 'real' valve, but this added too much weight

My next wheel build is to be with DT RR1.1s, out of which I'll be drilling much of the useless aluminium between the spoke holes, then I'll build the wheels using only 12 DT Revolutions to reduce weight

alienator said:

Has anyone ever tried trimming off the excess thread on the presta valve stem cores on their tubes so that the MOI of their wheels will be less? There has to be a time advantage, here, because less weight on the wheels means you go faster.

It's better to just get rid of the stem completely. Once you pump it up to pressure, it's a terrible waste. Just crimp it off and weld it shut with some solvent. Really helps with the aerodynamic drag as well.😉

ScienceIsCool said:

I only pump my tires full of warm, humid air. And I only eat rice cakes - they're full of light, light air.

John Swanson
www.bikephysics.com

I would have thought that helium filled tires would be better. Helium being light n all. Hydrogen maybe?

I also take all the stickers off the wheels too. Find I can spin those wheels up a whole lot easier.

I friend of mine has been buying low density, highly oxygenated water for the last 2 years from a chemist in Mexico. A full 750ml bottle weighs only 410g, which is approx 55% the weight of regular water.

The same guy puts small helium-filled balloons under his helmet and in his jersey pockets, but only for races. He nearly got busted last year

531Aussie said:

The same guy puts small helium-filled balloons under his helmet and in his jersey pockets, but only for races. He nearly got busted last year

That's so amateur! A friend actually insert these sausage shaped "balloons" filled with helium into his streerer, top tube, down tube, seat tube. And if he can access them on some of his frames, seat stays and chain stays too. He says that not only does it lighten things up, but the special balloon material layer actually stiffens up the frame for better power response.

He is putting in a patent on it so please keep it quiet for the time being.

Wow. These are all great ideas and are bound to show up on bikes at the TdF.

One thing I was loathe to mention--I didn't want anyone stealing my idea so that they could go faster than me--is that lately I've been conditioning the air I pump into my tires by stirring it up real fast so that some of the electrons get knocked off. Conservative calculations lead me to believe that I can remove several hundred thousand electrons from the air that goes in each tire. And anytime you can ride without several hundred thousand of anything, you're gonna go way faster.

alienator said:

Has anyone ever tried trimming off the excess thread on the presta valve stem cores on their tubes so that the MOI of their wheels will be less? There has to be a time advantage, here, because less weight on the wheels means you go faster.

This is why I hawk the biggest loogie I can manage before climbing. The weight reduction is sure to make me faster. The physics prove it.

For a while I dremeled the end threads off of presta valves because I did not like how they chewed up my pump chuck. It was too much work to keep doing it just to save my pumps; but if I would worked out that it would make me faster, I would have kept at it. Better dig out the old dremel tool.

alienator said:

is that lately I've been conditioning the air I pump into my tires by stirring it up real fast so that some of the electrons get knocked off. Conservative calculations lead me to believe that I can remove several hundred thousand electrons from the air that goes in each tire. And anytime you can ride without several hundred thousand of anything, you're gonna go way faster.

you mean you haven't got a Silca Centrifuge yet?

Pffft!

This is mine

[img]ceae.colorado.eduedgepeople.jpgOpen ↗[/img]

Bro Deal said:

This is why I hawk the biggest loogie I can manage before climbing. The weight reduction is sure to make me faster. The physics prove it.

Dang! I used to drink very little water when in the mountains for this very reason. I found that the more dehydrated I got, the easier the tough, manky sections of vertical got, and the faster I climbed.

I lost 10+ pounds last week from salmonella, so right now I'm so much faster than I was then.

531Aussie said:

you mean you haven't got a Silca Centrifuge yet?

Pffft!

This is mine

[img]ceae.colorado.eduedgepeople.jpgOpen ↗[/img]

Does that come with a chuck just for presta valves, or can you get a dual chuck, too?

alienator said:

Does that come with a chuck just for presta valves, or can you get a dual chuck, too?

the 2007 model comes with 3 extra chucks and 4 extra rubber washers, manily in case of damage due to the
15,000 Gs generated.

The only thing that annoys me is that it takes 15 mins to get up to full speed, then a further 20 mins for full electron detachment, which is a bit embarrassing in the car park at my local crit circuit -- it creates a bit of a scene around back of my Hummer

alienator said:

Does that come with a chuck just for presta valves, or can you get a dual chuck, too?

You have to purchase it separately on the older models; plus also have to pay extra to get a slightly heavier counterweight for the schrader applications. Besides I keep having problems with ruining the tube by pulling it through valvestem hole (even with a grommet) every time I get above even 175G's. As a consequence I was thinking of returning mine, but you wouldn't believe what UPS wants for shipping.

531Aussie said:

you mean you haven't got a Silca Centrifuge yet?

I was almost set to plop down the money on this and the associated portable power generation equipment. But when I started to consider the possible increase in Lorentz forces from accelerating the additional net charged particles in the earth's magnetic field, I became unconvinced that this was really of much better benefit/cost than replacing the stock multi-colored vinyl streamers on my handlbar ends with single strand carbon nanotube ones.

alienator said:

There has to be a time advantage, here, because less weight on the wheels means you go faster.

Here's a radical thought. Why not abandon wheels altogether?

Fill the empty space in the front triangle with a bag that will take enough helium or hydrogen to make it float above gound, stick a small high modulus carbon nanotube propeller on the end (instead of derailleur and rear wheels), and you've gotten rid of two major problems:

1) Rotational mass is reduced to almost nothing (especially if the propellor is made of carbon, since the forces subjected to it are much less when pushing air compared to supporting one's body weight)

2) There's no rolling resistance. None. Zero.

I should patent this one...

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