Winter’s a-brewing and that is a downer for the everyday cycling enthusiast. There are certainly ‘bike trainers’ out on the market that will let you ride in your living room but they clamp to (or require replacing the) the rear axle. These bike trainers hold the bike in an upright position so that the rider can’t tip the bike and might feel a little boring for some. There is another indoor biking solution called a bicycle roller which is, just as it sounds, a few rollers on the ground that the bike wheels rest on and is not attached to the bike by any mechanical means. When the rider pedals the bike, the bike wheels spin the rollers. Even with the lack of forward momentum the spinning of the wheels is enough for the rider to stay upright.
[Sky-Monkey] wanted to bike during inclement weather and felt that a bike roller was simple enough for him to try building one. He likes building things and already had all the necessary parts kicking around his shop. The rollers are standard 3″ PVC pipe with plywood discs pressed into each end. The discs are counter-bored to accept standard skate bearings. Off the shelf steel rod make up the axles. The 3 rollers and axle assemblies are mounted in a wood frame made from dimensional lumber. It’s important that the front bike wheel also spins so [Sky-Monkey] made a power transmission belt out of cloth strap that spins the front roller with the rear.
The result is a fully functional bike roller that only cost a few hours of time to make. Video of this puppy in action after the break….
Continue reading “DIY Bicycle Roller Helps Cure The Winter Blues”
Several years ago [dan] saw some plastic frame bikes designed by MIT students. Ever since he saw those bikes he thought it would be cool to make an edge-lit plastic framed bike.
The frame is made from 1/8″ and 3/8″ thick polycarbonate sheet. The parts were designed with tongue and grooves so they fit together nicely. The joints were glued to hold everything together. Holes were drilled in the edge of the plastic large enough to fit an LED. Once the LED was inserted in the hole, it was wired up and secured with hot glue. There are about 200 LEDs on the bike, powered by a constant current LED driver circuit that [dan] designed specifically for this project.
The build process was certainly not flawless. For example, the plastic holding the bottom bracket (where the crank and pedals attach) broke. This can be avoided by increasing the amount of material in that area prior to cutting out the pieces. [dan] was able to fiberglass his broken parts back together.
[dan] admits that the bike is heavy and a little wobbly, but is definitely ride-able. He did us a favor and made all his CAD files available to anyone that wants to make one themselves. If polycarbonate is too expensive for your blood, check out this bike make from cardboard.
[Bcmanucd] must have been vying for husband of the year when he set out to build his wife a custom time trials bicycle. We’re not just talking about bolting together a few parts either – he designed, cut, welded, and painted the entire frame from scratch. Time trial racing is a very specific form of bicycle racing. Bikes are built for speed, but drafting is not allowed, so aerodynamics of the bike and rider become key. Custom bikes cost many thousands of dollars, but as poor college students, neither [Bcmanucd] nor his wife could afford a proper bike. Thus the bicycle project was born.
[Bcmanucd] created the basic geometry on a fit assessment provided by his wife’s cycling coach. He designed the entire bike in Autodesk Inventor. Once the design was complete, it was time to order materials. 7005 aluminum alloy was chosen because it wouldn’t require solution heat treating, just a trip to the oven to relieve welding stresses. Every tube utilized a unique cross section to reduce drag, so [Bcmanucd] had to order his raw material from specialty bike suppliers.
Once all the material was in, [Bcmanucd] put his mechanical engineering degree aside and put on his work gloves. Like all students, he had access to the UC Davis machine shop. He used the shop’s CNC modified Bridgeport mill to cut the head tube and dropouts.
The most delicate part of the process is aligning all the parts and welding. Not a problem for [Bcmanucd], as he used a laser table and his own jigs to keep everything lined up perfectly. Any welder will tell you that working with aluminum takes some experience. Since this was [Bcmanucd’s] first major aluminum project, he ran several tests on scrap metal to ensure he had the right setup on his TIG welder. The welds cleaned up nicely and proved to be strong.
The entire build took about 3 months, which was just in time for the first race of the season. In fact, during the first few races the bike wasn’t even painted yet. [Bcmanucd’s] wife didn’t seem to mind though, as she rode it to win the woman’s team time trial national championships that year. The bike went on to become a “rolling resume” for [Bcmanucd], and helped him land his dream job in the bicycle industry.
Echoing the top comment over on [Bcmanucd’s] Reddit thread, we’d like to say awesome job — but slow down, you’re making all us lazy spouses look bad!