While stranded on the hard shoulder of the information super highway email@example.com typed:
> A tube half filled of water just added extra resistance to forward
> It’s also very difficult to fill!
Tractor tyres are full of water to add weight for traction.
You have to fill the tyre until the level of the water is
above the top of the rim. This enables the water to flow
over the top; if you don’t standing waves form and you get
a very juddery and uncontrolable ride. You still pump the
gap up with air, which has a dampening effect on the
surface of the water.
Trog Woolley | trog at trog hyphen oz dot demon dot co dot uk
(A Croweater back residing in Pommie Land with Linux)
Isis Astarte Diana Hecate Demeter Kali Inanna
my tube in my 24 inch street “racing” type unicycle has some liquid in it, which you can hear go around when you spin it. I’m pretty sure it’s designed to seal the small puntures as they happen, but i’m not sure. This would be cool to ride, but i c’ant see too much practical use for it. I c’ant tell the difference when i’m riding with this tube that has the sealant in the bottom.
Funny. I was pondering this just the other day. I wanted to increase the momentum of my wheel. It seemed to me that unless the tube was tight with water, you’d wobble too much. And it would make for a jarring ride.
What about something similar to these Lead Strips woven through the spokes out towards the wheel? Something like this would add mass but maintain your air cushioning effect.
Golfers use some stick-on lead strips on their club heads. Maybe 6 or 8 evenly spaced.
>If the tyre was fully filled with water it would not compress, therefore
>it would be pretty useless for MUni!
The water itself would not compress (well, very slightly) but maybe
the tyre would still exhibit reasonable ‘compression’ becasue of
redistribution of water. Especially if you don’t pump it too hard.
> It would have all the momentum of the Coker
Not sure. I think if you suddenly would decelerate the wheel, the
water would for a while continue rotating -within- the tyre so the
effect would be less perceived (angular) momentum than if all that
weight were solid.
>If you could solidify the water somehow then this could be a cheap way
>of adding inertia to a wheel
Put the wheel in the freezer, then even in summer you could for some
time ride with a solid tyre. If you like the effect, replace the water
with liquid parafin which is solid below 52 deg C. But prepare
yourself for a very bumpy ride!
I think that the effect on total momentum would be very small: your
momentum is comprised of both the angular momentum of rotating parts (wheel)
and your forward momentum being a multiple of mass and velocity. No
contest really, almost all momentum in the system is due to your forward
motion. I don’t see any real point in adding weight to the uni. I
suppose it might reduce side to side wobble of the wheel slightly.
I missed, I guess, the start up thread on the subject, so don’t really know
why anyone wants to do this.
Golfers are different, the addition of lead makes a significant difference
percentage wise to the club head.
The reason I wanted to increase the inertia of the wheel is for longer road rides. Once you get that heavy wheel going, little bumps (and my sometimes jerky technique) are absorbed by the mass of the heavy wheel.
Again, once you get it going it wants to remain in that state, so its easier to keep it going. Takes less effort (once your moving). Less effort = easier, smoother.
You know, “an object in motion tends to stay in motion uless acted upon by …”
The inherently heavy Coker wheel takes advantage of this. Once you get her going, she’s not too tough to keep going. (Turning and stopping are trickier tho) To further expand the versatility of the 29er, I think I’ll try lead strips for long rides. The 29er’s lightness can work against it in this arena. It is more affected by bumps (and jerky technique), therefore wears you out adjusting to them over a long ride. If I’m going on a ride with lots of twists and stop/starts, I’ll remove the weight.
Hopefully, for a couple of $$, I can gain some Coker-like attributes. (and then lose them when not wanted).