[ÆX]

here is my ride for the fat tire bike week chainless race.
you can see the road on googel earth. its the road that
goes west out of the Butte. starts dirt then goes paved
then back to dirt for the last left into main St.
i'm gona kill'em!

just need a rear brake.

 

[Jimmy_Pop]

that's kickass !!

wear a Cape, a T-back and a gold chain!

 

[seismic]

?????

 

[jimmydean]

There was someone on here who had a BMW race link or something that was 72# I thought.

Man, that thing is sweet!

 

[LaharDesign]

don't get the headtube up your nostril!

Can you get your knees on the bb pegs with your feet on the rear ones?
Darn nice tuck if you can!

 

[ÆX]

that's kickass !!

wear a Cape, a T-back and a gold chain!

i cap, yeah, that would be good.

i have a green coverall that is a old BP workers

outfit, with my greem lid, but i might add the cape.

 

[Secret Squirrel]

here is my ride for the fat tire bike week chainless race.
you can see the road on googel earth. its the road that
goes west out of the Butte. starts dirt tehn goes paved
to the last left into main St.
i'm gona kill'em!

just need a rear brake.

And you didn't put Gustavs or Hope 6's on why?? They would've just helped ya in the weight department too....

It's not good when you melt your brakes to your rims....there's a little technical term I like to use when that happens......




Bad.


That should be an absolute blast to just hang onto....heh...Awesome!

 

[Slugman]

What, no 29er ....

 

[jonKranked]

cool! i'm assuming the road is a decline...

 

[sanjuro]

You need a Monster T in the front...

 

[dan wask]

no its uphill.

 

[Jimmy_Pop]

can you cover the spokes with some kind of solid disk covering? do they make 20" road, slick wheels??

 

[jvnixon]

no slicks? You should put water in your tubes as well. haha

 

[Jimmy_Pop]

are your going to be "laying" down on the bike with your chest on the Toptube and your knees going to rest on the weight axle??

 

[ÆX]

two way. like you said knees on the weight axle with ancles on the pegs

or

foot arches on the pegs only. i'm going to do a few runs tonight and see what is comfy

 

[LaytonDH]

Back about 15-20 years ago, people used to do these "GPV" races, similar to that on courses like they use for street luge. If you flip the frame upside down, then it will rake out the fork angle a bunch and make it more stable at speed. You should rig up a steering damper of some sort, or you will get a ton of speed wobble. I used to have a modified GT cruiser like that that I got up to 62mph once.

 

[in the trees]

I don't think that it's actually 72lbs. Show us a picture of it on a scale.

toby

 

[HGR Frucci]

can you cover the spokes with some kind of solid disk covering? do they make 20" road, slick wheels??

My little bro had some wheel covers on his huffy bmx back in the 80's - you need something like that on there. Try Walmart.

Or maybe some fairings on the plates...

 

[in the trees]

Back about 15-20 years ago, people used to do these "GPV" races, similar to that on courses like they use for street luge. If you flip the frame upside down, then it will rake out the fork angle a bunch and make it more stable at speed. You should rig up a steering damper of some sort, or you will get a ton of speed wobble. I used to have a modified GT cruiser like that that I got up to 62mph once.

I remember those back in the day. BMX Action (or Freestylin') did an article on them and racing in the 80s.

toby

 

[LaharDesign]

Man, If you can get those steel donuts on the ground in turns there'd be a 20ft rooster tail of sparks.
Now thats a pic I'd like to see!:love:

 

[DHS]

anychance you can show a pic of the handle bars welded to the fork?

 

[ÆX]

i found a group of gravity bike racers online before i started

http://www.gravitybike.com/

its big in spain too.
http://www.zonagravedad.com/modules.php?name=News&file=article&sid=3

i don't want a disc cover.
the track might get fast enough for 40, so i should be ok w/o
otherwise i think i would have flipped it to slack it out some.

i got them pretty close, like 1/16th

 

[Kornphlake]

You might want to think about that seat a little bit, it looks to me like you want something that is a little bit narrower and longer so you can comfortably reach the handlebars. Then again with your knees on the weight bar you might not need the seat at all. I'd wrap the weight bar or my knees with some latex foam too.

 

[atrokz]

Sooooooo hot!!

 

[OGRipper]

Is there a simple explanation for why heavier things go downhill faster?

My 200 lbs goes faster downhill on a road bike than my lighter friends, but didn't Galileo or someone drop objects of different weight from the tower of Pisa and decide they move at the same speed? There's gotta be an easy answer here...

 

[ragin-sagin]

Hows she bunny hop?

 

[atrokz]

Is there a simple explanation for why heavier things go downhill faster?

My 200 lbs goes faster downhill on a road bike than my lighter friends, but didn't Galileo or someone drop objects of different weight from the tower of Pisa and decide they move at the same speed? There's gotta be an easy answer here...

More mass overcomes friction from air (although too much mass can act as a parachute), contact patches etc.

 

[offtheedge]

just awesome!

so, i'm guessing from the sanctioning bodies involved they will be replacing power bars and gatorade with chili dogs and PBR?!?!?!

 

[ragin-sagin]

Is there a simple explanation for why heavier things go downhill faster?

My 200 lbs goes faster downhill on a road bike than my lighter friends, but didn't Galileo or someone drop objects of different weight from the tower of Pisa and decide they move at the same speed? There's gotta be an easy answer here...

They don't...they are just harder to stop. If you go faster you have either less friction (rolling, rotational etc) or less drag...or both.

 

[GeminiRider625]

no slicks? You should put water in your tubes as well. haha

thats actually a great idea. water is heavy and if you put it in your tubes it will be even heavier because its rolling weight.

-Dean

 

[Hailight]

yup, heavier things don't go downhill faster
that's why I would try to get rid of all these weights, they just add to your rolling resistance. And I wouldn't flip the frame either, that would probably give you a bit of the 'shopping cart' effect. get a really slack headangle and you'll get the same stability but more control.
Think about aerodynamics -> get discwheels and something to duck yourself behind

 

[merrrrjig]

thats gunna be a bit sketch, good luck

 

[OGRipper]

More mass overcomes friction from air (although too much mass can act as a parachute), contact patches etc.

Thanks. The friction part makes sense. I guess the wind resistence part makes sense too, if the advantage of more mass is more than the disadvantage of more surface area.

[I slept through physics.]

 

[LaharDesign]

the mass/aerodrag ratio. Thats what determines terminal velocity.

Weight in your tyres will make you accelerate slower under gravity (or any other force) as the rotational inertia subtracts from the f=ma that G is providing unlike linear inertia that is in proportion to the amount of mass like the force of Grav.

 

[Red Bull]

thats actually a great idea. water is heavy and if you put it in your tubes it will be even heavier because its rolling weight.

-Dean

dear god i hope you are kidding.

 

[Ciaran]

Back about 15-20 years ago, people used to do these "GPV" races, similar to that on courses like they use for street luge. If you flip the frame upside down, then it will rake out the fork angle a bunch and make it more stable at speed. You should rig up a steering damper of some sort, or you will get a ton of speed wobble. I used to have a modified GT cruiser like that that I got up to 62mph once.

Those were fun. A group of us used to do that when we were kids. We didn't flip the frame upside down though. We used 20"BMX bikes, put banana seats on them (helps with the lay down), rear axle pegs, no drivetrain, and fliped the bars around and mount them upside down. Find a big hill with a fast, long steep twisty road and have fun!

 

[konastab01]

Thats sick alex,Can you make me one

 

[PaulE]

If you want fairly good brakes, you can mount a magura on bmx mounts by flipping the evolution adapters upside down.

Good luck - looks fun! I marshalled at a uk gravity sports race as my mate was racing longboards, and I had a go on one of those (with slick tyres at 130psi) and it was super fast and fun.

 

[binary visions]

[I slept through physics.]

Correct me if I'm wrong, but doesn't a heavier object also have more potential energy, thus making it harder to slow down? That would allow you to maintain higher speeds through flatter sections of a course.

 

[Mackie]

here is my ride for the fat tire bike week chainless race.

Hey Alex, what's holding the fork in the headset? Just the compression cap? I hope not.