Title: How About A Wooden Bicycle? Post by: Conan71 on September 03, 2010, 12:45:19 pm "Wood is carbon fiber- naturally"
I saw a display of these at the Hotter 'N Hell Hundred trade show last weekend. Truly amazing works of art. The fellow I talked to said the frames are guaranteed for 10 years even against termites & beavers. Weight and cost is in line with carbon fiber frames and the ride is supposedly even smoother than an all carbon bike. Title: Re: How About A Wooden Bicycle? Post by: nathanm on September 03, 2010, 12:52:52 pm The wood would be much more flexible than carbon fiber, which is very brittle. So you'd get a better ride, but waste more energy in flexing and relaxing the bike frame.
Are they as light as carbon fiber frames? Title: Re: How About A Wooden Bicycle? Post by: Red Arrow on September 03, 2010, 01:15:14 pm The wood would be much more flexible than carbon fiber, which is very brittle. So you'd get a better ride, but waste more energy in flexing and relaxing the bike frame. Are they as light as carbon fiber frames? Did you intend to compare flexible wood with stiff carbon? These would be a measure of springiness. Brittle is a mode of failure. Glass, for example, can be very flexible but it breaks in a brittle manner, all of a sudden. Ductile failure would be the opposite of brittle failure. See "Young's Modulus" for an explanation of the springiness. Title: Re: How About A Wooden Bicycle? Post by: nathanm on September 03, 2010, 02:23:51 pm Did you intend to compare flexible wood with stiff carbon? These would be a measure of springiness. Brittle is a mode of failure. Glass, for example, can be very flexible but it breaks in a brittle manner, all of a sudden. Ductile failure would be the opposite of brittle failure. See "Young's Modulus" for an explanation of the springiness. Carbon fiber is both stiff and brittle. As in it is prone to fracture instead of bend. Maybe I'm getting my engineering terms confused. Title: Re: How About A Wooden Bicycle? Post by: Conan71 on September 03, 2010, 02:35:34 pm Anything and more than you ever wanted to know about bicycle frame stiffness, Nathan:
http://www.renovobikes.com/testing/ The frames weigh 3.5 to 4.9 pounds which is comparable to durable road frames but heavier than throw-away race frames, total build weights are 16.5 to 20.0. Frame pricing is similar to carbon frames at $1500 to $3100. For comparison, my primary road bike is a Bianchi 928 high modulus carbon and kevlar frame. Frame and fork is 4.1 pounds which is beefy, but the only racing I do on it is longer road races. It's mainly for training and long endurance rides. It takes a pounding on the roads so I want something which will last a long time, as well the kevlar helps with damping road vibration. Title: Re: How About A Wooden Bicycle? Post by: Ed W on September 03, 2010, 04:10:32 pm I've seen bamboo frames reinforced with carbon fiber in addition to those wood frames. Back in the 1930s, wood was used for rims on track bikes, but once aluminum rims became widely available, wood rims were obsolete. While it does offer some interesting properties, it tends to splinter in a crash. Road rash is bad enough, but getting puncture wounds is worse.
Still, those hickory rims were pretty. Title: Re: How About A Wooden Bicycle? Post by: Rico on September 03, 2010, 04:26:14 pm So let's see if I get the basic concept of this....
Many, many, many, years ago, when they made my "sportster" as I like to refer to it. (http://i5.photobucket.com/albums/y179/rico2/woodenbike.jpg) They actually had the concept that now is above and beyond all technology has been able to muster in the years in between...... That does it. I am throwing away the cell phone and getting a bullhorn. Pitching the Benz and getting a buggy. Disconnecting the plumbing and installing an outhouse. Sarcasm aside.... I would like to see a return of "handcrafted" ornate details in our every day lives. This seems to be a very large step in the right direction. But what do I know... I only ride my "sportster" indoors. Title: Re: How About A Wooden Bicycle? Post by: Breadburner on September 03, 2010, 04:28:14 pm What kinda Beaver is this frame gauranteed against....
Title: Re: How About A Wooden Bicycle? Post by: Red Arrow on September 03, 2010, 08:57:34 pm Maybe I'm getting my engineering terms confused. You are. I remember in an engineering lab bending a piece of glass rod. It was amazing how much it bent before it broke. Then it went abruptly (brittle failure). Steel and other ductile materials give more warning by reducing cross section and a few other engineering things before failing. Title: Re: How About A Wooden Bicycle? Post by: Conan71 on September 04, 2010, 10:19:57 am I like the videos of bending airplane wings until they break. I was told one time that the wooden-framed wings on the Bellanca Viking were the only ones which would not break on flex testing. No idea how true that was
Title: Re: How About A Wooden Bicycle? Post by: Hoss on September 04, 2010, 10:44:13 am I like the videos of bending airplane wings until they break. I was told one time that the wooden-framed wings on the Bellanca Viking were the only ones which would not break on flex testing. No idea how true that was When I first started flying (as a comm passenger, not as a ASEL) it always amazed me to watch how the wings flexed upon takeoff and on landing with the ground load. My former wife used to be scared out of her mind watching that, so she would NEVER sit by the window. I'm still trying to find documentation about Conan's Bellanca statement. I love Bellanca aircraft. Title: Re: How About A Wooden Bicycle? Post by: sauerkraut on September 04, 2010, 01:18:31 pm I would not trust a wood bike- does that mean the forks are wooden too? Wood is not very strong and it changes in moist weather and in dry weather. I'm not much of a bike rider I have not ridden my bike in years, I have a 10 speed road bike that I bought in the 1980's and it's made of steel, the only thing I trust- however I don't know much about bikes but I'd guess unseen cracks in aluminum bikes or carbon bikes can result in severe failure, Metal fatugue once cracked the aluminum handle bars off of a neighbors bike a few years ago, lucky he was not hurt, the bar broke off right where it pases thru the center stearing bracket, if your riding at a good speed and that happens the results could be grim.
Title: Re: How About A Wooden Bicycle? Post by: nathanm on September 04, 2010, 01:58:06 pm I like the videos of bending airplane wings until they break. I was told one time that the wooden-framed wings on the Bellanca Viking were the only ones which would not break on flex testing. No idea how true that was I'm pretty sure the FAA requires that you test the wing to destruction during the test, so that its load limit is known.Title: Re: How About A Wooden Bicycle? Post by: Red Arrow on September 04, 2010, 10:25:24 pm If you want to see some flexible wings, check out pictures of some open class sailplanes. Google images for ASH25, ASW22, Nimbus 4. Make sure you are looking at pictures of the full scale planes and not the smaller scale models.
Title: Re: How About A Wooden Bicycle? Post by: Breadburner on September 05, 2010, 10:30:38 am The all wood Nimbus 2000....
(http://www.universcollector.fr/images/nimbus%202000%202.jpg) |