Bubble level as a grade indicator?



B

Bruce W.1

Guest
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.

Thanks for your help.
 
D

Dan

Guest
"Bruce W.1" <[email protected]> wrote in message
news:[email protected]
> 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.
>
> Thanks for your help.


What throws a bubble level off is the forward and rearward acceleration of
pedaling and braking. Even coasting up or down hill induces fore and aft
accelerations. What happens is that the bubble doesn't sit still because a
bike almost never travels at a constant velocity. Filling the level vial
with a more viscous fluid would damp out some occupations but a vial level
is really only useful for static measurements. If you want to measure slope
on the cheap, use a level but stop to get a measurement. A step up would be
to take a digital level along - maybe a small one taped to the top tube. You
can also estimate slope fairly well by looking at topo maps, see
www.topozone.com

Consider a bike computer with barometric altimeter or small GPS unit which
downloads data to your computer. Either of which can be had in the $150 to
$250 range.

The ultimate would be to attach gyros to the bike. You would need at least a
2-axis gyro since a bike leans in the turns. But why stop there, get a
3-axis gyro and 3 axis accelerometer inertial unit and map you whole route
in 3-d. Something like this:
http://www.xbow.com/Products/productsdetails.aspx?sid=104
Better have $10k-20k to get going though.
 
G

Guy F. Anderson Sr.

Guest
On Mon, 07 Feb 2005 14:45:27 GMT, "Bruce W.1"
<[email protected]> 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.
>


Bike Warehouse, now Bike Nashbar, sold a bubble level back in the '80s
which attached to the top tube. I never used one, but I heard that
they were pretty useless.

Guy A
Ripley, TN
 
W

Werehatrack

Guest
On Mon, 07 Feb 2005 14:45:27 GMT, "Bruce W.1"
<[email protected]> may have said:

>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.


You'll find that the bubble will float around somewhat due to small
ride motions. It's not a very precise indicator in any event since it
doesn't compensate for accelerations.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.
 
G

Gary

Guest
You need to keep your eyes on the road, Mate.

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.
>
> Thanks for your help.
 
D

Dan

Guest
"Gary" <[email protected]> wrote in message
news:[email protected]
> You need to keep your eyes on the road, Mate.
>
> 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.
> >
> > Thanks for your help.


No watching bubble levels or Sheilas
 
W

Werehatrack

Guest
On Mon, 7 Feb 2005 10:53:35 -0800, "Dan" <[email protected]> may
have said:

>
>"Gary" <[email protected]> wrote in message
>news:[email protected]
>> You need to keep your eyes on the road, Mate.
>>
>> 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.
>> >
>> > Thanks for your help.

>
>No watching bubble levels or Sheilas


If you're following one, you'd bloody well better watch her.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.
 
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.
>
> Thanks for your help.


I got one as a Christmas gift.

The vibrations don't bother it, but the accelerations do, as expected.
That is, if you're not rolling at a constant speed, its reading is not
accurate. On a downhill, it reads off until you stop accelerating. On
a stiff climb, the bubble wobbles forward and backward with each surge
of the pedals.

But these can be overcome. On a hill, if you're not already at
terminal velocity, you can use your brakes to hold the speed steady for
a few seconds and get a decent reading. And on steep uphills, you can
take care to "pedal circles" - that is, very smooth pedaling with no
surges - and get a decent reading. And if that didn't work well
enough, there's always the option to stop the bike and take a
stationary reading.

I've found the thing to be fun. It would be better if they had a more
viscous fluid in it, to damp out some of the accleration effects, but
it gives good enough data for my purposes. And it certainly reads
short stretches far better than any contour map estimates, and at far
less expense than any GPS or altimiter based electronic system.
 
P

Pat Lamb

Guest
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
 
H

HardwareLust

Guest
"Bruce W.1" <[email protected]> wrote in message
news:[email protected]
> 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.
>
> Thanks for your help.


My $25 Specialized computer does this. Very, very nice feature. Every
year, my buddy and I go searching for the steepest road we can find. So
far, best (worst?) we've found is 15% (and that was only for about 2/10ths
of a mile,) but I have high hopes that there are steeper ones around. It
only updates once every meter or so, which is fine for me.

That is one feature that my next computer will definitely be required to
have, if I ever have to replace the one I have now.

Regards,
H.
 
A

A Muzi

Guest
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.


We have a customer who rides a route that's partially on a
converted rail grade. He has a spirit level epoxied on his
top tube. I asked and he explained that when the bubble
touches the line it's time to shift.

I'm not kidding.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
 
C

catzz66

Guest
A Muzi wrote:
> 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.

>
>
> We have a customer who rides a route that's partially on a converted
> rail grade. He has a spirit level epoxied on his top tube. I asked and
> he explained that when the bubble touches the line it's time to shift.
>
> I'm not kidding.
>


I had thought about bringing along my portable GPS on a ride sometime,
just to how it registered. It's about the size of an older cell phone.
It reads altitude and refreshes at the rate of once per second. I
decided I already had enough things to think about, so I have not tried
it yet.
 
M

Mark Janeba

Guest
Pat Lamb wrote:
> 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.


Another data point - got one for Christmas, it's nice for what it is -
an inexpensive simple way to approximate grades (probably measures them
fairly accurately if you stop to read it).

Note: If you want to read grades above 20%, set the device off-level to
begin with, say so that level ground reads as -10%. The scale appears
to be sufficiently linear that no great loss of accuracy ensues
(assuming you remember to add 10% to the readings!)

Mark Janeba
 
R

RonSonic

Guest
How about we dangle some pendulum from the top tub and clamp a longish
protractorish assemblage between the down and seat tubes. Appropriate damping of
the pendulumish device as well as limiting it's motion to the plane of interest
(very important) would result in something no less useful than a bubble level
and far more interesting.

Ron
 
On Tue, 08 Feb 2005 15:11:57 GMT, RonSonic
<[email protected]> wrote:

>
>How about we dangle some pendulum from the top tub and clamp a longish
>protractorish assemblage between the down and seat tubes. Appropriate damping of
>the pendulumish device as well as limiting it's motion to the plane of interest
>(very important) would result in something no less useful than a bubble level
>and far more interesting.
>
>Ron


Dear Ron,

For accuracy, drill a hole in a penny, tie a two-foot thread
to it, stop facing uphill, tie the thread to the same spot
on the top tube, slip the penny between the down tube and
the shift cable, and see where the thread crosses the down
tube. The wheelbase and the length of the "protractor"
formed by the thread and frame gives considerable accuracy.

Later, raising the front wheel on a level floor until the
thread reaches the same spot will let you calculate the
grade percentage and waste an evening.

The need to stop and fiddle is balanced by the cheapness of
the thread and pennyweight parts.

You can tape a piece of paper to the same spot on the down
tube and mark it with a pen in order to accumulate more
precise and lasting information of inexpressible value, but
after a few times you may simply bask in the warm glow of
knowing how wellt you could measure the slope under your
wheels and keep riding.

Carl Fogel
 
M

Mike Jacoubowsky

Guest
>> 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.
>>
>> Thanks for your help.

>
> What throws a bubble level off is the forward and rearward acceleration of
> pedaling and braking. Even coasting up or down hill induces fore and aft
> accelerations. What happens is that the bubble doesn't sit still because a
> bike almost never travels at a constant velocity. Filling the level vial
> with a more viscous fluid would damp out some occupations but a vial level
> is really only useful for static measurements.


My experience has been otherwise; while climbing, I've seen very little
movement (due to changes in acceleration). The fluid they're filled with
appears viscous (thick) enough that this isn't much of an issue, at least
for me.

But the reality is that, the few times I use one, it's not for scientific
accuracy. Rather, it's for fun. When you look down and see that it not only
feels steep, but *is* really steep, it provides feedback that keeps you
going. Or not, depending how you're mental state is at the time.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com
 

Dan Burkhart

New Member
Nov 27, 2003
333
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69
Bruce W.1 said:
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.

Thanks for your help.

You can always tell a guy is on the level if his bubble is in the middle.
Signed
A fat guy