We’re building an LED brake light for our formula students car, 15W power. We had some work accidents with the last one, someone tests the brake while someone works at the rear of the car - dang instant blindness. So this year we’re building it with a brightness regulator. We’re using an LED driver with configurable current, that can be controlled via PWM by our µC. The circuit goes right into our automatic fuse box, so we just need one cable to the rear for the light.
I know it’s semi-off-topic, but I couldn’t resist.
Not quite as off-topic:
Busch&Müller has come up with a reliable brake light for bicycles… “toplight line brake plus”, the model is called (B&M’s chain names get longer and longer with every feature…).
Very simple and ingenious: it detects deceleration of the bicycle via the frequenzy change of its power supply.
So it’s for dynamo lighting systems only. People who use galvanic lighting have to look out for a model with an accelerometer… I have one of those, doesn’t work too well…
You can just add a pressure switch into you braking system, they’re pretty cheap. You need a thread somewhere. The easiest would probably be to enlarge the thread for the liquid release in the caliper.
You can, but the accelerometer type devices have the advantage of being self-contained. The trouble is, how do they tell you haven’t just hit a steep uphill?
They don’t. That of course applies for the frequency change system as well…
I think that it’s good if the thing actually detects deceleration, not braking. Cars travel so fast and have such catastrophic cw*A and rolling resistance that the mechanical work they spend on height change when climbing is quite negligible to the energy they are still heating their environment with (via friction).
So they don’t get much slower when they hit the hill, because they are just putting out so much power to compensate for their inefficiency - in contrast to the cyclist in front of them. And I don’t see anything negative about it if the half-asleep commuter in the car gets the information that the cyclist in front of him is losing speed, and surely more than him, at that.
I think that for a car I’d rather be in favour of the switch solution…
Undecided: Thomson vs. KH Seatpost. If KH, adjustable vs Fixed.
KH Freeride rims: 26 and 29.
KH Moment Hub, CroMolly
KH Rim strips... color... No idea.
36 Spokes, 3x crossover. SS. Undecided on black vs silver. Looking at Wheelsmith 2.0mm (14G) but subject to change. Cost of Ti not worth the weight differential.
Nipples... looking at AL as an alternative to standard brass.
Tires... totally undecided. The 26 will be gated more toward off road while the 29 will need to be more road friendly.
Pedals... like tires... they will change anyway. I like the wellgo but the ubiquitous oddessy twisted PCs are tough to beat on price vs weight vs usability
Planned events for this new unit:
[LIST=1]
Urban bike ride on 4/1 (Urban Assault Ride)... This uni will be ready by then.
Vacation at the beach... early June
24 hour Charity bike ride... end of July
This is my second year riding one wheel... it's time to tackle some single track.
[/LIST]
I’ve been falling on ice a lot lately so I decided to make myself a studded tire. I’m thinking about cutting down the center-most studs a little, as they seem a bit long. I’ve got about 4 hours and 200 studs into it so far. I’m hoping it works out.
Trials:
2012 KH street seat black
Nimbus equinox frame
and a nimbus blizzard
some metal trials pedals
MUni
KH frame and seat post.
some tires
good pedals.
150 moments.
No vehicle driver expects a cyclist to retain his full speed uphill. You don’t need to advertise that with brake signal. The difference is in the abruptness of the stop. And the pressure switch is a very reliable solution.
Any way, I just have a permanent red light to the back and a permanent white light to the front. I don’t really see the need for a brake light at all. Any vehicle driver knows what kinds of things can make a cyclist slow down and will drive with appropriate caution.
Some don’t expect anything because they are driving with their brain stem only. I was pessimistically assuming a half-asleep commuter, who is dizzily directing his warm high-speed uterus…
Edit: Oh and I don’t want to write against car drivers only. Many bicyclists ride in each other’s slipstream, although it’s illegal in traffic for good reason. Even in the slipstream of cyclists they don’t know - putting them into danger.
Sure, people always notice everything and give traffic their undivided attention.
By the sheer luck of coming across nothing too unexpected on the day of their test.
It occurs that people lose their licenses. Do you think they just begin to be bad drivers that exact day and are then caught immediately?
Here’s my latest. A mini jump ramp for 5yo son’s birthday. Finished just as he arrived home from school! He says it’s his favourite birthday present - ahead of a stomp rocket and bike horn, so it must be good, which makes me think it was worth all the effort.
A bit big for 2 1/2yo to cope with on his scoot bike, so I made him his own by tacking a little bit of board to a 2x2 (not pictured), which he also seems to really like.
Sorry for the badly framed action shot - 5yos won’t session jumps for the cameraman, and it’s not an easy shot to get right with a cheap compact in bad light, but I thought I should show it in action.
Unfortunately shortly after these photos were taken I discovered that 3mm MDF isn’t up to taking a 77kg adult on a uni - not without more support underneath (though it was OK for me on a bike). So tomorrow I’ll be replacing the top with something a bit thicker and maybe also putting in more cross braces. I have to admit I did think my surface might be a bit thin - though a similar sheet propped on bricks had previously worked - and was kind of expecting to redo the top, though not quite so soon.
