Friday, October 21, 2011

strange front suspension

D - I saw what initially appeared to be a standard cruiser at the local bicycle shop.
Looking closer, it had a squat lil' spring shock mounted inside the frame just above and behind the front steering tube. I have never seen anything like that before!

D - it looked a bit like this, but was inside the bike frame triangle.
Intriguing, since it raises the suspension to , say, inside a fairing on a 'bent bike.


Aside - for the purpose of my internal-chainline-in-bike-frame SWB 'bent concept, I may have figured out a better way to set up a Freelight dynamo. Basically, I set up kind of a 'mirror image' chainring on the left hand side of the frame (keep in mind the frame is dual side-by-side tubes).
I need clearance away from ferrous frame parts.
I have often lamented that Shimano has the patent on a bottom bracket dynamo, but is not building one- they're just sitting on it. My thought experiment to build one externally went nowhere- I simply could not non-invasively get the clearances required.
Anyway, the pedals spin at pretty much the same rate at any speed, about 60-90rpm, regardless of bike speed - unlike the tires! So the pedals seems the place to locate a dynamo.
By placing the magnets on the edge the rim of a flat disc mounted on the crank axle, we should manage to keep the magnet, mounted on a boom, away from the mass of steel bike parts.
This has the benefit with my proposed bike design to even appear pleasingly symmetrical with the chainring located in the 'mirror image' opposition position.
Possibly inserts to extend the pedals out, often used for those with knee pain, will be needed to gain the necessary clearances.

I've thought through my Freelight 'amber sideways running light' idea.
I've decided that the 3 (not 4) single row LEDs are ideal. I can chop the base so the 3 aim over a broad range of angles. This should address any sideways directions not addressed by the front or rear lights. LEDs are notoriously highly directional.

Who knows- maybe a dynamo could power a music player, or a cell phone on standby when not in use powering lights. This would require more complex power management.
Most current mobile phones currently have standby power in the range of 150 to 300 mW.

I'm thinking about how to incorporate brake/signal lights mounted on the extra-wide 3-basket rear luggage rack.

The left-hand frame tube can be used to route all necessary power cables.

Friday, October 14, 2011

wireless bicycle brake

To brake with the wireless brake, a cyclist has just to clench the rubber grip on the right handle. The more tightly the grip is clenched, the harder the disk brake on the front wheel works. It seems as if a ghost hand is in play, but a combination of several electronic components enables the braking. Integrated in the rubber grip is a pressure sensor, which activates a sender if a specified pressure threshold is crossed. The sender is integrated in a blue plastic box which is the size of a cigarette packet and is attached to the handlebar. Its radio signals are sent to a receiver attached at the end of the bicycle's fork. The receiver forwards the signal to an actuator, transforming the radio signal into the mechanical power by which the disk brake is activated. To enhance reliability, there are additional senders attached to the bicycle. These repeatedly send the same signal. In this way, the scientists hope to ensure that the signal arrives at the receiver in time, even if the connection causes a delay or fails.


D: fancy. Clean looking.
But just running the cables inside the frame can accomplish that.

Update- getting bro-in-law civ engie to run stress calcs on my what-if bike frame.
See 'my entry into bicycle design contest'.
2 parallel side-by-side tubes need to match the strength of a SWB's single monolithic boom.
Note that mine is not perforated by the central tubes from steering and seat post.
My latest tweak makes keeping water out easier.
The chain return line is line with the bottom bracket now.