HDTenEightyP/NetNews huggingface dataset:
Newsgroups: rec.bicycles.tech

Jay Nabedian writes:

> I am an electrical engineering student at Marquette University.  As
> a project for one of my classes, I have chosen to build a bicycle
> computer.  What I need to obtain is a sensor to interface with our
> processor (8086) to obtain the speed of the bicycle.  What I had in
> mind was some sort of spoke-mounted magnet which, when passing a
> fork-mounted sensor, would produce a small electrical signal to be
> interfaced with the processor.  Does anybody know where I may be
> able to obtain this sort of device?  Am I looking at this problem
> the wrong way?  Are there other (better) ways to accomplish the same
> task?

I don't know what the objective of your project is from the design
point of view so let me assume it is both hardware and software.  In
this respect, the hardware is the major part of the problem and it
will not be solved by asking the net.  Don't try to solve this from
first principles or you are doomed to failure.  People have been
working on this problem for many years and the clean and easy solution
has not been found, neither in the motion sensor or the operation of
the instrument.

Since processors require digital signals, most processor based units
(t Avocet) use reed switches for detecting wheel rotation.  These
devices are vibration sensitive and although they work well most of
the time , they give false inputs often enough to make any maximum
speed (above 40 mph) reading questionable.  In contrast, an analog
inductive pickup as used by Avocet requires a cleaver detector that
can work over a wide voltage range that goes from zero to several
volts.  The avocet inductive pickup will sense spokes at high speed
without any magnet just from induced current from the earth's magnetic
field.  For this reason the transmitter must be a continuous magnetic
ring of alternating poles.

Control buttons, battery suspension (vibration) and display contacts
are just the beginning of the design problems.  Most chips are UV
sensitive and most plastic cases do not block UV so that mysterious
computational errors develop at the oddest times when field testing.

If your design instructor is doing his job he should have told you to
buy several of the leading instruments on the market and to mount them
all on a test bicycle before doing an autopsy on each of them so that
you can get a feeling of prior art that was not gained from the pages
of a text book.  NIH is a grave illness that develops largely from
failing to learn from other's experience.

Maybe the purpose of the exercise is to make you realize how complex
the design of even a seemingly simple device is.  I am sure you will
discover this if you truly follow through making a working instrument.

jobst_brandt@hplabs.hp.com
Newsgroups: rec.bicycles.tech
From: jsketchl@engr.UVic.CA (Jeff  Sketchley)
Subject: Re: Cateye Micro average speed algorithm?
Reply-To: jsketchl@engr.UVic.CA
Organization: University of Victoria, Victoria, BC, Canada
Date: Thu, 8 Oct 92 21:54:56 GMT

I'v had similar things happen to me as well, though rarely
with the average speed.  However, with the current speed I've
experienced the function to suddenly stop working,
(current speed = 0 km/h), occuring just after the speed
reached in excess of 70 km/h.

Also, the current speed has jumped from a (presumably) correct number
(say 72 km/h) to a number in the hundreds (it would become say 157 km/h)
and stay there about five seconds.  Once it even jumped to
about 175 km/h before displaying 0 km/h.  That time I had to
reset everything but ODO.  It's weird, but infrequent.


For the guy who wrote "I've always just assumed that they
got their math chips out of boxes of CrackerJacks," 
I say this:

"You're probably right."
Newsgroups: rec.bicycles.tech
From: hersey@gecko.cis.ohio-state.edu (james arthur ii hersey)
Subject: Re: Wanted - Comments on Bullseye Pulleys
Organization: The Ohio State University Dept. of Computer and Info. Science
Distribution: usa
Date: Thu, 15 Oct 1992 00:14:17 GMT

Shimano has a new policy on warranties.  Dealers may now skip the 
distributer and call Shimano direct via a 1-800 number.  Shimano
has several numbers and one is specifically for warranty.  
Go to your dealer and demand that they contact Shimano.  The 
shop I work for will warranty parts not even sold by us.  

*****Demand good service*******

Suggestion:  Don't shop at stores that will not back up their products.
The manufactures will back the shop 100%.  Shops are not charged a dime.
They do not pay shipping or handling fee's.  

If they refuse to call Shimano and you can't convince them how easy it is,
then have them get the part from the frame manufacture(assuming you
purchased the bike as a whole).  From personal experience Raleigh,
Specialized, Trek, Giant will gladly send out parts or credit the
shop for warranty items, no questions asked other than serial #, of course.

ONCE AND FOR ALL DEMAND THEY BACK UP THE PRODUCTS THEY SELL!!!!!!!!!

P.S.  Use your best judgement don't start ripping of the manufactures as
a way to get new parts.

Jim
From: king@reasoning.com (Dick King)
Newsgroups: rec.bicycles.tech
Subject: Re: SPD Shoe Modification
Keywords: Adding heel material
Date: 9 Oct 92 17:04:02 GMT
Organization: Reasoning Systems, Inc., Palo Alto, CA

In article <1992Oct7.210714.21272@cbfsb.cb.att.com> naidu@cbnewsg.cb.att.com (naidu.gandham) writes:
>
>I just got a pair of Specialized's SPD Ground Control Sport Shoes.
>I plan to use them mainly while touring/recreation riding (road) 
>and for walking around when I'm not on the bike.  
>
>The heels of these shoes are a 1/2" to 3/4" lower than the front
>portion of the shoe, making them uncomfortable for walking around.
>I was wondering if I could add material to the heel area of the sole 
>for a more even walking position.
>
>Has anybody with these shoes tried this?  Any pros and cons?
>
>PS: I'm not sure if this belongs in r.b.tech.  Please re-direct if
>it does not.  Thanks.


I don't know about SPD shoes, but i will relate what i have done for my
LOOK-equipped Nike Echilons.  Perhaps it will work for you too, although i
honestly doubt it because i understand that SPD shoes do not have any hard
plate. 


I bought four crutch tips.

Crutch tips are like large rubber thimbles, except that the walls are thick and
the roof is very thick.  I cut off the walls and removed a metal disk that is
there to prevent the crutch from poking through the roof.

I also bought a set of threaded inserts designed to attach makes of clipless
pedals to the "wrong" kind of shoes, and used these to create two threaded
holes near the heel of each of my shoes.  Then i used a bolt and a washer to
screw two crutch tip roofs [actually thick rubber disks] to the bottoms of the
shoes.  I screwed it in very tightly so the washer was pushed deeply enough
into the rubber that when i walk only rubber touches the floor.


Seems to work pretty well, although i might remove the crutch tips when the
rainy season comes to Central California and i start feeling the need for
booties. 


-dk
Newsgroups: rec.bicycles.tech
Subject: Re: helmet mounted lights?
From: alanb@sdl.mdcbbs.com (Alan Braggins)
Date: 08 Oct 92 16:32:54 GMT
Organization: Shape Data (Division of EDS), Cambridge UK
In-reply-to: conway@cstr.ed.ac.uk's message of 6 Oct 92 17:29:52 GMT

>>>>> On 6 Oct 92 17:29:52 GMT, conway@cstr.ed.ac.uk (Steve Conway) said:

>>>On 6 Oct 92 14:24:48 GMT, william@castle.ed.ac.uk (William Warburton) said:

>> I believe that both this [helmet/head mounted lights]
>> and LED taillights are technically illegal
>> in Britain, however I would be surprised if you were troubled using
>> them. 

> I don't think they are actually illegal, they just don't meet the
> legal requirements for lighting (incandescent lights, white front, red
> rear with some voltage/wattage specs, plus rear reflector, I think).
> So, you can wear a headlight, and use the LED taillight as long as you
> use standard bike lights as well.

I recently bought a Vetta which has a sticker on the box saying it
can not be used as the primary rear light on cycles bought after
(I think) 1st October 1990, because it doesn't meet the requirements
of <standard I forget>.

> I've also thought about borrowing my friend's Silva head-torch setup
> (used for night orienteering - 30W standard light switchable to 60W if
> I recall correctly) to take on a run (not cycling) I do, where I am
> mainly on unlight roads, with sidewalk, and the motorists never dip
> their headlights for mere pedestrians - "If you won't dip neither will
> I !!!" :-) 

I have a similar night orienteering headlight. 40W halogen. However, it
takes 12 hours to charge the NiCads (12 of them) which last about an
hour and a half, which limits its use for other situations.
I have considered mounting a flashgun on my handlebars beside the light
for motorists who won't dip for cyclists though...
--
     Alan Braggins, alanb@sdl.mdcbbs.com, abraggins@cix.compulink.co.uk
Shape Data - A division of EDS-Scicon Limited.   Cambridge, UK +44-223-316673
   "Any technology distinguishable from magic is insufficiently advanced."
 "My employer does not necessarily share my views - but I'm working on it."
From: truesdel@ics.uci.edu (R. Scott Truesdell)
Subject: Re: Helmets - keeping a cool head
Newsgroups: rec.bicycles.tech
Organization: University of California, Irvine
Distribution: na
Date: 12 Oct 92 19:18:23 GMT
Followup-To: rec.bicycles.tech

In article <BvtE6A.4Lo@visix.com>, ken@visix.com (Ken Mayer) wrote:
>
> [The saga continues]
>
> Fact #1: ... [brain has lots of blood circulation]
> Fact #2: ... [blood is a heat transporter]
> Time to start using the ol' noodle:
> Conclusion #1: ... [you radiate lots of heat from your head]
> Conclusion #2: ... [helmets block heat radiation from head]

Although he didn't come out and say it, I got the impression that Ken is
fairly strongly anti-helmet. I'm not a doctor, or a bike racer, but I do
have my own experiences to draw on so I'd like to add a few simple
observations.

1. I ride mountain bikes off-road at least 3 days per week. (slower average
speed and less uniform energy output levels than on a road bike). I always
finish my rides drenched in sweat.
2. I ALWAYS wear a helmet while riding a bike.
3. I notice that after a strenuous ride, when I remove my helmet, my head
starts to feel cooler.
4. I do not, however, notice my entire body feeling cooler as a result of
removing my helmet, as Ken Mayer suggests I should. My body may in fact get
cooler, but it is not by an obviously noticeable amount.
5. Head heat, or overal body heat, has never been a factor in my
performance or my ability to keep riding. The exception to this is the
extremely rare occurance when dehydration has been a factor.
6. I notice that in the temperature range in which I normally ride (50
degrees to 100 degrees Farenheit) that my body quickly builds to an
[preceived] ambient temperature and maintains it via the normal
physiological functions.
7. It has been proven to my satisfaction that in the case of a serious
accident, head injury is greatly mitigated by wearing a helmet.

In conclusion, for the kind of riding I do, it appears that my body has the
capability to maintain body temperature via sweating and possibly radiation
from other parts of my body to at least compensate for the loss of
radiation cooling from my head.

Since I don't perceive a performance difference caused by the wearing or
not-wearing of a helmet, it is my choice to wear a helmet to lessen the
chance for brain damage in the case of a serious accident.

  --scott
Newsgroups: rec.bicycles.tech
From: dlp@zule.Eng.Sun.COM (Dan Pritchett - SunSoft Engineer)
Newsgroups: rec.bicycles.tech
Subject: Re: SPD pedals: any float?
Date: 14 Oct 1992 23:25:40 GMT
Organization: Sun Microsystems Inc., Mountain View, CA, USA
Distribution: world
NNTP-Posting-Host: zule

In article <1992Oct14.103507.1@pomona.claremont.edu>, oplascencia@pomona.claremont.edu writes:
|> I'm interested in buying a pair of SPD pedals but I'm holding off my purchse
|> until I hear from other people with knee problems who have used them. I've
|> heard that they don't have any float. If that's true I would assume that people
|> with knee problems such as myself cannot use them. Anybody out there got
|> anything to say?
|> 
The SPD's currently available do not have any float. I've had knee problems
in the past and continued to have them with the SPD until I had them adjusted
with a fit kit. I would recommend that you definitely have this done if you
get the pedals. I went from disabling knee pain to no pain at all in about
2 weeks after the adjustment.

The new SPD road pedals (that aren't out yet) are supposed to have float.
I will upgrade my pedals as soon as I see those beasts. The current SPD
road pedals do not have float so make sure you verify whether you are getting
the '92 or '93 models.

Other than the problem mentioned, I have over 2,000 miles on my pedals
and would hate to think of life with clips or funny bumps on my feet
when I walk.:-)

Dan Pritchett               | ARPA/Internet: dlp@zule.Eng.Sun.COM
SunSoft Desktop Prod. Tools | GEnie: D.PRITCHET3
                            | Packet: KM6PR@N0ARY.#NOCAL.CA.USA.NA
--------------------------------------------------------------------------
I used to think that I was cool.
Running around on fossil fuel.
Until I saw what I was doing.
Was driving down the road to ruin.
            James Taylor
From: vinson@shiva.seas.upenn.edu (Jack Vinson)
Newsgroups: rec.bicycles.tech
Subject: Re: SPD pedals: any float?
Date: 16 Oct 92 14:58:14 GMT
Organization: The University of Pennsylvania

<1992Oct14.103507.1@pomona.claremont.edu> writes this in article oplascencia@pomona.claremont.edu
>I'm interested in buying a pair of SPD pedals but I'm holding off my purchse
>until I hear from other people with knee problems who have used them. I've
>heard that they don't have any float. If that's true I would assume that
>people with knee problems such as myself cannot use them. Anybody out
>there got anything to say?

I don't have knee problems, but I recently put a pair of SPuD's on my bike
and they DO have some freedom.  There is a position at which the pedals
tend to rest, but they do allow some heel motion.  This is my first pair of
clipless pedals, so I can't compare to any other system.

The Purple Puddle Eater
Jack Vinson			vinson@unagi.cis.upenn.edu     
Newsgroups: rec.bicycles.tech
From: goell@nomad.jpl.nasa.gov (Jeremy Goell)
Subject: Re: Malfunctioning rear mech
Organization: Jet Propulsion Laboratory, NASA/Caltech
Distribution: uk
Date: Tue, 13 Oct 1992 22:25:34 GMT

In article <10639@baird.cs.strath.ac.uk>, dmarsh@cs.strath.ac.uk (David R Marsh CS91) writes:

|> I have a '91 Trek 950 which is (7 speed) Deore LX equipped. The problem is
|> this: my rear derailleur occasionally (well fairly often) skips between
|> adjacent "internal" gears (ie those in the middle of the cassette (?)), and
|> no amount of twiddling with the adjustment screws seems to sort it. One of
|> my bikefreak friends says (disparagingly) that it is because I have 
|> push-push STI shifters, and that "if I had friction shifters it wouldn't
|> be a problem". However, I quite like indexing and don't want to change my
|> shifters. Can anybody help solve the problem so that my gears work
|> perfectly again?
|> 
|> Dave.--dmarsh@cs.strath.ac.uk  or  cad129@ccsun.strath.ac.uk {or sthg 

Your post states that you "twiddled with the adjustment screws".  If this
is an accurate description of what you did, then it would not have affected
the problem.  These two screws set the farthest inboard and outboard 
positions that your rear derailleur can achieve.  Since your problem
lies in the middle cogs, moving these two screws will not do anything.
You probably need to be moving the tension barrel adjustment, which is
the screw-like end where the derailleur wire/housing enters the derailleur.
If you have slack in your wire due to stretching, turn the barrel ccw.  If,
for some reason, you have excessive tension, turn cw.  Most likely to be
the former, however.  To get good SIS adjustment, put the chain on the second
smallest rear cog and in the big chainring, then pedal and turn the barrel
in the appropriate direction (again, probably ccw).  Stop when the chain
sounds like it's clattering/about to jump to the third cog.  Back off about
a quarter turn so that the clattering goes away.  That's one way to "calibrate"
SIS.

Your friend is correct in saying that this wouldn't happen w/friction, but
it's as meaningful as saying "If you did computational fluid dynamic modelling
with pencil and paper, you wouldn't have to worry about bugs in the code."

Michael Batchelder
mpb@nomad.jpl.nasa.gov 
Newsgroups: rec.bicycles.tech
From: jsketchl@engr.UVic.CA (Jeff  Sketchley)
Subject: Re: Gearing question
Reply-To: jsketchl@engr.UVic.CA
Organization: University of Victoria, Victoria, BC, Canada
Distribution: na
Date: Thu, 8 Oct 92 22:30:05 GMT

You could learn to climb better.  If it's really steep, 
then don't worry about it.  Some hills just weren't meant
to be biked up.
From: jbrandt@hplred.HP.COM (Jobst Brandt)
Date: Tue, 6 Oct 1992 16:44:37 GMT
Subject: Re: Wheels
Organization: Hewlett Packard Labs, Palo Alto CA
Newsgroups: rec.bicycles.tech

Naru Takashima writes:

So I ask you, what should I do?

> (1) Have the wheel trued by a qualified mechanic?
> (2) Have the wheel rebuilt? (Assuming it was built poorly)
> (3) Get myself a better wheel w/ 14 gauge spokes?
>
> Your comments and any other suggestions will be appreciated,

(1) This sounds like the best approach as a first course of action.

(2) There is at this point no reason to throw out spokes or rim if
    there is nothing wrong with them.  This course of action points
    toward number one.

(3) Don't go to heavier, stiffer spokes.  This is where your problem
    lies in the first place.  The spokes are most likely too loose as
    a whole to stay put.  WIth too little tension, spokes become slack
    in the ground contact zone and gradually unscrew their nipples.
    To prevent this, the wheel must be tensioned higher so that the
    spokes are stretched (elastically) and  can absorb some shock
    loads.  Thinner swaged spokes permit such elasticity and are,
    therefore better able to keep a wheel in true in the long run.

You can do all this yourself and from your description, you are not
spoke wrench shy.  You might get the book on bicycle wheels at your
local bike shop.  "the Bicycle Wheel" describes all these things in
detail and has an easy to follow description of how to lace wheels.

Build wheels, ride bike!

jobst_brandt@hplabs.hp.com
Newsgroups: rec.bicycles.tech
From: stecko@cntrol.enet.dec.com ()
Subject: Cassette hub maintance
Reply-To: stecko@cntrol.enet.dec.com ()
Organization: Digital Equipment Corporation
Date: Sat, 10 Oct 1992 14:45:28 GMT




	   When performing maintance on my Ultegra cassette type hub,
	besides greasing the bearings should I take the cassette holder
	off the hub and lube it everytime I service the bearings?
	   How is this done?  I noticed that a large (9 or 10mm) allen
	head wrench is needed to remove the cassette holder from the 
	hub.

	TDS
Newsgroups: rec.bicycles.tech
From: weird@cbnewsf.cb.att.com (john.t.erhardt)
Subject: Re: Wanted - Comments on Bullseye Pulleys
Organization: AT&T
Distribution: usa
Date: Wed, 14 Oct 1992 21:51:18 GMT

In article <1992Oct14.200636.1588@cbnewsm.cb.att.com> hwk@cbnewsm.cb.att.com (henry.w.krautter) writes:
>In article <RFLOYD.92Oct14124829@romeo.cs.duke.edu>, rfloyd@cs.duke.edu (Rick Floyd) writes:
>
>Yes! What is it with the rubber seals on Shimano pulleys. My Trek  2300 was
>about 5 weeks old when I was cleaning the chain and noticed three of the
>rubber seals on the rear derailleur were off. They had expanded from being

What rubber seals?  You know, in the old days we didn't have rubber seals
on our derailleurs.  If dirt got in the pulley we lived with it and liked
it!  :-)  
Seriously though.  I've never heard of this from anyone before.  Could
it be an isolated thing.  It probably wouldn't hurt you if you didn't 
have the seals in there.  But then again, you paid big money for Dura-Ace
and should be able to expect it to work.  In that case the shop where you
got it should replace either the seals, pulleys, cage, or whole deraileur.
If your shop doesn't want to help you you could threaten to speak with
the BBB.

FYI, my RX100 derailuer doesn't have seals on the pulleys and it shifts
fine.  Recently I replaced the lower pulley with a BullsEye but the upper
is still Shimano.

John
From: mackinto@oasys.dt.navy.mil (David Mackintosh)
Newsgroups: rec.bicycles.tech
Subject: Re: TIME pedal maintenance
Date: 13 Oct 92 11:48:30 GMT
Reply-To: mackinto@oasys.dt.navy.mil (David Mackintosh)
Organization: Carderock Division, NSWC, Bethesda, MD

In rec.bicycles.tech, paul@panix.com (Paul Gatker) writes:
> A problem I have had with Time "Racing" pedals is the rear plastic cover
>that goes over the major spring. On both pedals the cover just flops around
>as the tiny springs in them have escaped to the road. I fixed the problem
>by prying the covers off completely. Pedals still work fine, are nominally
>lighter in weight, but aesthetically I can't really tell as I can't see the
>back of the pedals while I'm riding them.

One of these plastic covers came off of my Racing pedals when I wacked
it by pedaling through a corner.  I thought that they were purely aesthetic
before it came off, but the cover does have a purpose.  It covers the
retaining spring and is angled to keep the rear cam from hooking the
back of the spring while you're trying to step in.  Without this cover,
I found that I had to more precisely position my foot on the pedal before
clipping in.

Fortunately, a couple of weeks later, I found another one of these covers
(the first had broken) in a parking lot at a local race!

David Mackintosh
Newsgroups: rec.bicycles.tech
From: xmeyer@athena.mit.edu (F Thomas Korsmeyer)
Subject: Re: Vitus with Aluminum Steerer Tube 
Organization: Massachusetts Institute of Technology
Date: Thu, 8 Oct 1992 13:42:54 GMT

I have been riding an early Vitus with an al steerer for 5 years or so without a problem.
Famous last words, perhaps, but I have never actually heard a credible story of a 
failure.  Has anyone else?  

Newsgroups: rec.bicycles.tech