Can We Use a Bicycle Tire and Rim?

[waialua359]

Can we use a bicycle tire and rim for our robot shooter?

Waialua, HI 359

[JBotAlan]

I don't see why not. It seems to be legal after looking at the flowchart provided in the manual.

For future reference, the rules can be found at http://www.usfirst.org/robotics/2006/frcdocs.htm. Get to know them. They are your best friend!

JBotAlan

[Eric Scheuing]

I'm not sure on the ruling of that, but I don't think that it would be that great.

If the bot is ~120lbs with ~15lbs of bumpers, I doubt bike tire spokes will be able to support it.

[JBotAlan]

The way I understood it was they want to use a flywheel-type design with the bicycle wheels as the flywheels. I see no problem with this. They could, according to the flowchart, use the wheels as the drive wheels, too.

[Andrew Blair]

Originally Posted by Eric Scheuing

If the bot is ~120lbs with ~15lbs of bumpers, I doubt bike tire spokes will be able to support it.

Well, if they did decide to use it, I'm sure it would hold up fine. A bike weighs fifteen pounds, the average weight rating on a cheap bike is 180 lbs. Seems alright to me. Actually, there was a team who did use bike tires one year. Sorry, don't have the pic.

[Lil' Lavery]

You should be able to provided you can keep it entirely withing the starting robot dimensions as stated in rule <S03>.

[KenWittlief]

bike wheels are very strong if the weight is kept perpendicular to the axle. When you ride a bike you lean into turns, so the weight load stays on that line

but they are not good with side-loads. Long story, ask me sometime! :^)

[Not2B]

Bike tires are awesome. The spokes are almost strings they are so thin. In fact... a fun project (after build season) is to make a SAMPLE bike tire out of actual string. It works! (But don't use it...)

[Al Skierkiewicz]

Originally Posted by KenWittlief

Long story, ask me sometime! :^)

Nope, not falling into that one again.

[Peter Matteson]

First I weigh 180 and and ride wheels with 20 radial spokes, so strength isn't an issue on a bike wheel.

Second a fairing fopr the wheel could be made out of 1/32 polycarb to keep fingers out of spokes.

Third the OD of a road bike wheel is 700mm ~ 29 inches. That is reeeeeeally big.

Oh and you can get a pair of inexpensive wheel in the 1400gm range easily.

[EricH]

Originally Posted by Eric Scheuing

If the bot is ~120lbs with ~15lbs of bumpers, I doubt bike tire spokes will be able to support it.

I'm about 160 pounds. My bike is about 15 pounds. That's about 175. The robot is 150 max (with battery and bumpers). 'Nuff said.

[Conor Ryan]

Ahh one thing that hasn't been talked about here. Safety.

Remember how in the kickoff video, they had the softball shooter, that had a big flywheel and they talked about it a little bit. One of the things they talked about was safety. It's fully legal, just make sure however you fit it into the robot it'll pass all the safety standards that first has in place.

Safety First everyone, you don't want to have your robot fail inspection because you forgot to make it safe. Also take safety into consideration while your designing too, make sure you allow room and weight for it.

[sanddrag]

Originally Posted by Conor Ryan

Safety First everyone, you don't want to have your robot fail inspection

I'd be more worried about losing a finger, or a head of hair!

Everyone please keep in mind how much potentially dangerous energy a spinning flywheel has. And do not wear gloves while rowkiong on/near rotating machinery/mechanisms.

[nexusmaster]

My understanding is that bike tires are indeed legal, but if your robot takes a solid shot to the side I think that there is a good chance that the bike tires will deform and become useless. The spoke design is one that assumes the outside forces will be vertical to and not perpedicular to the spokes. However, I could be wrong. It might be a good idea to stress test a bike tire and collect some data.

[s_forbes]

Bicycle wheels are definately strong enough to hold up a robot, especially when the weight is divided upon all 4 wheels. Depending on the wheel, they can be strong on side loads too.

Why are you choosing a bik wheel for a shooting device though? Most wheels are free spinning, and most back wheels from bikes have coaster hubs. Unless this is part of a secret strategy...