Bruce W.1 wrote:
> I was thinking of attaching a bubble level to my road bike frame to
> serve as a grade indicator. Has anyone here ever tried this?
>
> I'm wondering if the vibrations would mess this up.
Somebody's got to stand up for this gadget, right? IMHO, it's good enough.
It's only $25 at
http://www.adventurecycling.org/store/moreinfo.cfm?Product_ID=265, and
weighs approximately nothing. The fluid is a rather viscous oil, so
minor road vibrations get damped out. Yes, it's susceptible to
acceleration. OTOH, you can stop if you really want to know the grade,
or you can hit a constant (maybe low) speed going up the hill, and
maintain that speed 5 seconds to see what it damps down to read. It's a
minor hassle to get it installed level, but after that, you're good to
go. And it's always on the bike, so when you hit that 16% grade right
as you overheat AND bonk, you'll know why.
When I say it's good enough, you may ask, "Compared to what?" Well,
this bubble level gives you a reading that is, at a guess, accurate to
1-2% _where you read it_. Compared to a $6 topo map, where you'd
probably get an average grade over 1/2 to 1 mile, this level lets you
estimate the grade on a shorter hill. Compared to a GPS ($100 and up?),
it's cheaper, lighter, uses fewer batteries, isn't susceptible to
interference from trees, and you can measure a shorter hill again (with
the average 10-30' standard deviation on a GPS, how big a hill do you
have to measure to get down to 1-2%?). I'll admit, it's not as accurate
as surveying equipment or even a 4-6' level with measuring stick, but
it's smaller, lighter, and cheaper. (And have you priced 6' levels lately?)
I know somebody will grouse about the additional accuracy that means you
need to stop the bike on a hill to measure it. But really, how many
hills do you want to measure? And how many are so short that you never
hit a steady speed while climbing?
The other downside is it only measures to 20%. Beyond that, I guess
you've got to wait for CalTrans to survey it and put up a warning sign.
So for rolling terrain, cost, ease of use, and availability, it's good
enough. Go ahead and try one!
Pat