'Homebrew' Roller Racing Set-ups
 

anybody got any insight on this? a site perhaps or personal experience.

i wanna set something up here. got the 'urge' to do it just now at work. looking for a starting point!

I was thinking of gluing a rare earth magnet on my lollers.. then bolting a hall effect sensor to the frame of it.. runnning that into 1 channel of my o-scope and querying it's frequency off GPIB. Feed that through a Labview GUI with some gearing dropdown menus, and a start stop button with race length selector and scoring.

Ok. who's a bigger nerd? You, for writing that? or me, for understanding what you wrote?

ahahahaha

lollers

there are a few people on chifg.com that built their own set its called irosprints
http://farm2.static.flickr.com/1037/...80970e2c_d.jpg

badass

I've tried this except with my trainer. I can attach the Labview VI I made if you want but it's not super fancy. I used the parallel port with a reed switch (exactly the same one that's on my bike computer) but the hall would work too. (I also built a receiver for my HRM that also plugs into the parallel port).

One thing I can say is that your magnet gluing idea will definitely not work unless by glue you mean weld. Think about it. Let's say you're cranking along at 90rpm. With a reasonable gear ratio of around 2.8, your rim spins at 252rpm. Your rollers and the wheel are locked in motion and thus also have a multiplying "gear ratio". The roller rpm is the wheel rpm multiplied by the ratio of the diameter of your wheel (622mm for 700C) to the diameter of the roller (say 70mm). That's 2239rpm, which is more than enough to fling that magnet loose no matter how many layers of duck tape, jb weld, crazy glue, etc you apply. I have magnet shaped divots on my walls and ceiling to prove it :)

If you're still not convinced calculate the angular acceleration and convert to force (F=ma) using the magnet's mass, and compare this to the yield strength specs of whatever glue you plan to use.

Basically it's much easier to just put the magnet on the rim or spokes.

I can see fitting a small magnet to the inside of the plastic roller drum, or drilling a hole for it in the end cap (bearing housing) of my rollers, and then gluing it in place. Sorry to not be more clear the first time around. I agree that it would eventually fling off the outside of the drum.

I am totally interested in checking out the VI you wrote for this. I didn't really think a parallel port could sample that fast.

Can you send it to me @ lyledriver at gmail?

I like the mounting the inside the drum idea. I didn't have that option since my trainer's roller was solid steel. If you found a way to drill a hole through it and thread it to the drum that may work too (although I think rare earth magnets are too brittle for that).

Anyways I'll just put the software up here. Pick the version that corresponds to your operating system. There's a readme attached. Also the VI diagram is sort of commented so you can easily figure out what to change. It's a big mess of code, but I blame the LabView graphical programming paradigm for that more than my inexperience :D

Attachment 58066

Attachment 58067

Here's a screenshot of what it looks like:
http://img248.imageshack.us/img248/2...eteryk2.th.jpg

A truely fantastic movie.

meh, those kinda suck imo. locked down and not everyones size either. something using your own ride is always gonna be 100x cooler.

I think the bikes are replaceable. The system is only the rear roller and the front fork clam, no?

deathhare hates everything, he's like a hip dutret.

they suck based on appearance? because I know for a fact you have never ridden these.
the set-up is pretty good and most everything was donated. if i remember correctly, these were based on the goldsprints set-up (not sure, but they are close in design, sans the software). two different sized frames that can be adjusted to fit most sizing needs. they have been used a good number of times. i have never heard anyone whining about how unfun these were because they don't fit everyone. then again, most people don't care about how "cool" it is - they just want to ride against one another. additionally, this is faster as no one has to mess around with changing equipment from bike to bike (which is not a huge problem, but would add up over the span of a night) and it also allows people who have never raced on full rollers to give it a shot. i would say that is more important then you being able to race on your bike. it's not like you're racing a stage in the tour - it is all of 30 secs on the bike.

we probably have it all wrong since it appears cool is more important than fun. however, we all had a blast racing these.

Badass VI Kmart!
I'll have to play around with the In Port VI to get it to work.
Did you find this helped you with your training?

I dunno about homebrew rollers, sounds sketch--
I love the $50 used rollers I got from a shop in
Berzerkeley--

No, i didnt say they suck based on appearance. And no i havent ridden that rig but i have ridden a bike more than a few times and i know its not like that. Ive also done tons of roller sprinting on BMX bikes. This irosprint thing sucks because its not your own bike and its locked down. Locked down being the stupidest part of their design of the thing beause it isnt at all like a real sprint. Real roller racing is way different. Where youre on ****ing rollers and its about a whole lot more than just cranking hard and long. It takes more skill and is more realistically like racing.
The irosprint rig just fails as a solution to something thats already been out there for decades.
Roller racing has been around since atleast the 40s man...it aint like this.

Im sure they have a blast with that rig though.

What about using a DC motor like:
http://www.surpluscenter.com/item.as...tname=electric

Connect motor to the roller with belt or drive wheel and measure total output?

I know it would take some tweaking, but it might be easier that tryint to setup the magnet system.

IROSprints (and their predecessor, Goldsprints) are locked down because it's more inclusive that way. Not only can bike people who don't know how to ride on rollers get a chance to race but also non-bike people who want to give it a shot.

I agree that real roller racing is way more fun but you'd get far fewer people racing. Plus Goldsprints are usually held at bars and some of those bars may not be happy with a ton of people bringing their bikes inside and also wouldn't be too happy with the liability issues.

its like taking a spinning class in a bar

*envisioning: beer + roller racing = bicycles and people flying all over the place*
hahaha

That's awesome that the IROsprints make roller riding more accessible but if you never
start riding on rollers without the lockdown then you won't ever develop those skills--
start in a hallway--its easy it you are cautious about it and
stick your hands out when you start to fall--the IROsprint
thing looks damn fun in any event