HDTenEightyP/NetNews huggingface dataset:
Newsgroups: rec.bicycles.tech
Subject: Re: MBA LX review.
From: news@massey.ac.nz (USENET News System)
Date: Wed, 13 Jan 93 03:54:10 GMT
Followup-To: rec.bicycles.tech
Organization: SMIS, Massey University

truesdel@ics.uci.edu (Scott Truesdell) wrote:

> [...] but the jump from DX to XT is quite small. The main differences seem
> to be in finish and bearings. I think the performance between DX and XT is
> almost unnoticible. I'd venture that the main reason to have XT on your
> back as opposed to DX is status.

There are minor differences: one is weight -- many XT parts are lighter;
the XT rear derailleur is all cast alloy -- the DX has one stamped steel
arm; the XT rear derailleur has a ceramic-bushed guide pulley (excellent!);
the front derailleur has more hardware around the spring (but what it
acheives I couldn't tell you); the hubs appear to have better seals; the
rear hub appears to be beefier; the (STI SLR Plus) brake levers have a cam
system so less lever movement is required to pull in the same amount of
cable (I like these although am dubious about their reliablity and
durability); the brake levers also have stronger adjusters and rubber
covers to keep out the mud (a nice touch); XT used to have higher quality
cantilever straddle cable yokes than DX, but I'm not sure if this is still
the case with LX.

Personally, the small advantages all add up to make XT worthwhile, but DX
(or LX now) is still a good group.

> However I detect some wear internally [in XT RapidFire shifter] and it has
> gradually become increasingly more difficult to drop to a smaller rear cog.
> Like an internal pawl is wearing.

I had the same problem and took them back to the shop expecting replacement
under warranty.  What happened was they replaced the cable housings and it
shifted like new again.  Now, I clean the cable then lube with a teflon
impregnated oil, especially at the lower housing.  If I clean and lube
sufficiently often, I rarely have shifting problems.

--
  PLEASE USE THE ADDRESS BELOW FOR E-MAIL REPLIES
Phil Etheridge               P.Etheridge@massey.ac.nz
Macintosh Consultant         Phone: +64+6-356-9099 x8689
SMIS, Massey University      Fax:   +64+6-350-5611
Palmerston North, NZ         40*23'S 175*37'E,    GMT+13
Newsgroups: rec.bicycles.tech
From: josh@Happy-Man.com (Joshua_Putnam)
Subject: Re: wide-range gearing
Reply-To: Joshua_Putnam@happy-man.com
Organization: Happy Man Corp., Vashon Island, WA 98070-7399
Date: Fri, 8 Jan 1993 20:51:33 GMT

In <1ij315INNl7f@darkstar.UCSC.EDU> karplus@cse.ucsc.edu (Kevin Karplus) writes:

>I noticed that jtyl@ubvmsb.cc.buffalo.edu posted a message about the
>new xc-expert microdrive, claiming a 20-32-42 front sprocket and 11-28
>rear sprocket.

>My computations show that as a 5.35:1 ratio, the widest I have ever
>seen.  

It's one of the widest stock ratios I've seen, but good shifting
is possible with wider ranges.  My hybrid is currently running an
11-32 SunTour cassette with 54-38-26 chainrings.  This is my
winter setup -- I use a much flatter set of cogs in better
weather.  Also, the 11-32 isn't proportional.  I have a fairly
normal gear selection on the first five cogs, then two big steps
to the 32.  It makes for an unusual shifting pattern if you want
to hit all the gears in order, but has advantages when large
changes need to be done rapidly.

>I'm wondering who this set up is intended for, since racers will not
>be happy with such a low top gear, and the low gear seems too low for
>anything other than hauling large cargo trailers up steep hillsides.
>(Even with a cadence of 85rpm, ground speed in low gear is only 2.2m/sec
>or 5mph.  Most hill-climbing is done with a cadence between 40 and 60rpm,
>giving 2.3--3.5 mph---that's slower than walking up the hill!)

Slower, but easier, too.  I suspect the big cog gets used most in
the middle ring to give a momentary low gear without switching to
the granny ring.  That's what I usually do, except when I'm
hauling heavy loads up steep hills (e.g. carrying a variable
transformer to the office on the rear rack along with a big
battery for my lights and all my other commuting gear.)  The
really low gears let me spin a long time at a comfortable 80+ RPM
while climbing steep hills under load.

>I might be happy with such a system, but past experience has showed
>that bike manufactures do not see any market in people like me.
>So who else would buy this?

I might think about it next time around, but the top end seems
too low for me.

>Or are we seeing the extreme low gear setup for the group---one the
>manufacturer only included so they could claim to have the widest
>range on the market?

Non-microdrive XC-Pro already has a wider range available if you
swap a chainring or two.
-- 
 Joshua_Putnam@happy-man.com    Happy Man Corp.  206/463-9399 x102
 4410 SW Pt. Robinson Rd., Vashon Island, WA  98070-7399  fax x108
 We publish SOLID VALUE for the intelligent investor.  NextMail OK
Info free; sample $20: Send POSTAL addr: Solid-Value@happy-man.com
Newsgroups: rec.bicycles.tech
From: Richard_Hennick@mindlink.bc.ca (Richard Hennick)
Subject: Re: Plastic Ring on rear Wheel
Organization: MIND LINK! - British Columbia, Canada
Date: Tue, 12 Jan 1993 16:33:21 GMT

> Michael Dinsmore writes:
>
> Hi.
> I have what might seem to be a trivial question?"
> Is the plastici ring next to the freewheel on the
> back tire important?


It's a spoke protector.  If the rear derailleur gets bent (such as by the
bike falling over), the plastic ring is supposed to prevent the chain from
possibly shifting past the largest sprocket and into the spokes, which could
wreck the derailleur and the wheel and could also cause an accident.

--
| "To use interrupt, master the operations of 8088 and 8259A beforehand" |
| (from Sanyo MBC-550 series Operators Guide, 1984)                      |
|                                      Richard_Hennick@mindlink.bc.ca    |
| interrupt trap halt                                                    |


Newsgroups: rec.bicycles.tech
From: frank@molbio.cbs.umn.edu (Frank Williams)
Subject: Re: Rohloff chains
Organization: University of Minnesota
X-Newsreader: Tin 1.1 PL5
Date: Tue, 5 Jan 1993 20:02:13 GMT

Regarding Rohloff chains, David Casseres (casseres@apple.com) wrote:
: Somebody out there must be riding with these
: chains, so how about it, folks?  Do they work well?  Do they last a long
: time?  More specifically, do they work *better* than, say, HypeGlide, and
: do they last longer?  Are they worth the higher price?
: 
They do work well.  Their life depends on how you treat them, but I have
not worn one out yet.  They definitely work better than any other chain
I've used, but I've never used HyperGlide.  Are they worth the price?  In
my opinion, they are at their best in cases where alot of flexibility helps.
In my case, a short chainstay frame and an 8 speed cassette.  I believe that
the chain contributes significantly to the reliability of the index shifters.
In other applications it might be impossible to distinguish between the
performance of the Rohloff and a $7 Sedis.

Frank Williams
frank@molbio.cbs.umn.edu
Newsgroups: rec.bicycles.tech
From: ezag637@chpc.utexas.edu (Steve Manifold)
Subject: Re: MBA LX review.
Summary: Diminishing returns
Organization: The University of Texas System CHPC
Date: Mon, 11 Jan 93 15:58:46 GMT

Somebody writes:

(Lots of stuff deleted)
> 
> I would agree that while XTR costs twice as much as XT, it doesn't work
> twice as well or last twice as long.  But it does work a little better
> and it is a little lighter.
> 
> But, I don't think Shimano cared one bit about quantifying how much better
> the stuff works and setting the price accordingly.  I'm sure Shimano employs
> some economists, who made a pretty good guess as to what the market would
> support, and set the price accordingly.  People do buy the stuff (and I'll
> admit pay too much for it).  I'm sure that's what Shimano's chief concern
> is.
> 
> Bill
> 
> 
In the engineering world, it is fairly inexpensive to improve on a cheap and    poorly working design.  In this case, you may be able to get 100% improvement
in performance with 100% increase in cost.  When trying to improve something
that already works well, you enter the realm of diminishing returns.  Thus,
for example, improving XT by 20% ( a guess, I have never used either XT or XTR)
to result in the performance of XTR results in an increased cost (in the form
of engineering design and analysis time, testing, etc. as well as material cost)of 100%.  I guess I should say MAY result in 100% increase in cost, since you 
can be sure the bean counters and market analysts also have a hand in determin-
ing final cost to the customer.

Steve

-- 
_______________________________________________________________________________
Steve Manifold                                              University of Texas 
ezag637@hermes.chpc.utexas.edu                           College of Engineering
tasc637@crovax.cem.utexas.edu                       Center for Electromechanics
Newsgroups: rec.bicycles.tech
From: mpb@nomad.JPL.NASA.gov (Michael Batchelder)
Subject: Re: Help with Top Pull Der.!!!
Organization: Jet Propulsion Laboratory, NASA/Caltech
Date: Tue, 5 Jan 1993 10:58:56 GMT

In article <1i86f7INN688@agate.berkeley.edu>, stephen@ocf.berkeley.edu (Stephen Tu) writes:

|> In article <1992Dec31.030621.20278@elroy.jpl.nasa.gov> mpb@nomad.JPL.NASA.gov (Michael Batchelder) writes:

|> >In article <92358.233138U3C@psuvm.psu.edu>, <U3C@psuvm.psu.edu> writes:
|> >
|> >|> Trek just replaced my mtb fram....I decided to upgrade to a 7000/8000
|> >|> frame which has top tube cable routing.....They sent along with the
|> >|> Thanks in advance....steve
|> >
|> >Yes, the bolt btw the chainstays is part of this mystery.  If Trek was in
|> >
|> >Michael Batchelder
|> >mpb@nomad.jpl.nasa.gov
|>
 
|> No, that's not right.  Referenceing the 7000 I just got, the bolt between
|> the chainstays near the bottom bracket is used to attach the anti-chain jam
|> device that Trek fits on its bikes.
|> 
|> The front derailleur cable should run through the cable guides on the left
|> side of the top tube.  There is an additional cable guide located on the top
|> of the left seatstay, just behind the seat post.  Run the cable through that
|> guide and directly to the top pull front derailleur.
|> 
|> Stephen Tu
|> stephen@ocf.berkeley.edu

Yes, it is right, at the very least if his replacement frame is a 1992
frame.  There is a bolt on the chainstay BRIDGE for the Anti-Chainsuck
Device.  The bolt he mentioned was between the chainstays at the back of
the bottom bracket.  If he's got a bolt ON the bottom bracket shell,
not simply NEAR, wherever that is, then the cable doesn't have an exposed, direct route to a binding bolt on the derailleur, like last year's
830 or 850.  If your cable does bind directly to the derailleur, then
you don't need/have a bolt on your bb shell.

Michael
From: jwgst2+@pitt.edu (James W Gourgoutis)
Newsgroups: rec.bicycles.tech
Subject: Re: MBA LX review.
Date: 11 Jan 93 19:08:35 GMT
Organization: University of Pittsburgh

In article <C0p9IJ.11B@cs.uiuc.edu> tthiel@cs.uiuc.edu (Terry Thiel) writes:
>
>BTW I've noticed that alot of bike manufacturers are putting XT derailluers
>on their otherwise LX equipped bikes.  There's only a couple $$ difference
>in price between the LX and XT derailluers so I guess it's cheap way
>to upgrade a production bike.

     I have read about a bike (I think a Parkpre, but I'm not sure) that uses
an XTR rear derailleur and rear hub, with everything else LX (even the front
hub!) to give 24 speeds at a cheaper price.  This sounds like a great idea to
me!

>
>quickly but I would guess that it's much more likely to rust once the paint
>comes off.
		Aluminum alloy does NOT rust in the traditional sense.
Rust is iron oxide.  Aluminum "rusts" by forming Aluminum oxide, which nicely
covers and forms a protective coating for the rest of the al.  Then the
"rusting" stops.  The aluminum DOES NOT get eaten away like a metal car fender
does.
	However, cheaper components, like my 300LX stuff, has steel chainrings,
which I've noticed lately having a small amount of surface rust.  So maybe 
this is what Terry is refering to.  I like my steel rings, though, since I 
think that they will not wear out as fast.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
James Gourgoutis       				   
Mechanical Engineering                                O   
University of Pittsburgh                           _ /__,     
e-mail me at:  JWGST2@unixd.cis.pitt.edu          (_) /(_) 
	       or JWGST2@vms.cis.pitt.edu
Thanks!           			   "Why am I so late?  It took me 
					    25 minutes to decide which bike
					    to ride!"--me. 
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-       
-- 
Newsgroups: rec.bicycles.tech
From: EHOGNASB@pamir.wasa.shh.fi (Esa Hgnsbacka)
Subject: Scott ADF 901 frame
Organization: SHH Vasa
Date: Fri, 8 Jan 1993 11:49:03 GMT

Does somebody own this kind of bike? If you compare it with other frames 
(like Eddy Merckx Columbus SLX or other's) what's your opinon?

---------------------------------------------------------
EHOGNASB@WASA.SHH.FI  (ESA HGNSBACKA)
FINLAND
Newsgroups: rec.bicycles.tech
From: H.ZIERKE@BI-LINK.owl.de (Hans-Joachim Zierke)
Organization: Private Site in Berlin
Subject: Re: Wheel Wonderings
Date: Tue, 12 Jan 93 13:00:00 +0100
X-Mailer: CrossPoint v2.1 R/211
X-Gateway: ZCONNECT UI bi-link.owl.de [RFC/Connect v0.93]


On 08.01.93, jbrandt@hplred.HPL.HP.COM writes:

> All these
> effects are in a magnitude that you cannot see them without
> instrumentation.  

I cannot see it, but I can hear it. All I have to do is plugging
the spokes without a load, then let a friend sit on the bike and try
again.

Yes, it's not a very scientific nor a precise approach.  ;-)


Ciao
Hajo

--
Hans-Joachim Zierke  ##  Tel.: +49-30 / 394 8445  ##  Fax: +49-30 / 394 8447
                         h.zierke@bi-link.owl.de
Newsgroups: rec.bicycles.tech
From: mkgust@vpnet.chi.il.us (Michael Gust)
Subject: Re: Re: measuring chain wear? [summary]
Keywords: chain wear 
Organization: Vpnet Public Access
Date: Sat, 9 Jan 1993 03:44:15 GMT

I vaguely remember the rule you are referring to. However, I don't
recall it either. According to the "Chain Tech" section in the 
"Chain Care and Maintenance" article in the January 1993 issue of 
Mountain Biking, you can eyeball wear by lifting the chain from the top
of the largest BB chainring. If you see a tooth, there's too much 
play.
They also mention a chain wear indicator by the name of Speed Tech 
and a 1 percent figure, but I don't know what it actually measures.

michael
mkgust@vpnet.chi.il.us

Newsgroups: rec.bicycles.tech
From: grande@cbnewsd.cb.att.com (brad.l.grande)
Subject: Re: Flaky halogen/lead acid light
Organization: AT&T
Date: Thu, 7 Jan 1993 13:20:20 GMT

In article <1ifpeeINN2t2@network.ucsd.edu>, wade@hobbes.ucsd.edu (Wade Blomgren) writes:
> I've got a 2.5w "brite lite" halogen headlight (and companion normal
> bulb taillight) system driven by a 7.5v lead acid battery pack.
> 
> The light is flaky in the following way:
> 
> Sometimes, when turned on, it does not come on right away.  It springs
> to life an arbitrary number of seconds (or minutes) later, with no
> "help" (no wiggling of wires, thumping of battery, etc).  Sometimes
> it will come on dimly right before lighting up fully.  Once lit, it
> burns brightly until turned off (most of the time).
> 
> Other times (this is happening more frequently over the last few days),
> it will come on (after a few seconds) brightly, then dim dramatically
> and stay dim for a while, then (again arbitrarily, it seems to me)
> go to full brightness after some number of minutes (up to 10 minutes),
> and continue burning bright.
> 
> I've done a cursory check of the connections.  It seems to be charging OK, 
> and when it burns it burns bright (well, 2.5 watts worth of bright
> anyway.)
> 
> My questions are:  is a delay on startup expected with this type of
> light?  and what might be wrong that would cause it to remain (or go)
> dim periodically, only to go fully bright again later (and typically
> stay bright once it decides to stay on)?  I have theorized that it
> might be a flaw within the battery, or the switch, but I don't know
> how to go about testing or what I would be looking for.
> 
> Any suggestions would be appreciated,
> 
> Wade Blomgren
> 


No, delay startup is not an expected behavior.  I experienced similar behavior
in my homebrew 55W system and it turned out to be a lose connection in the
bulb housing that corroded as a result of arching.  Cleaning it and insuring
that it was mechanically sound solved the problem.  It is feasible that the
battery could be at fault with a mechanical problem.  Normally, the bulb
should not be involved in the charging process.

Areas that can exhibit lose/corroded connections include rivets that connect
metal in the circuit path, screws doing the same thing, insulation displacement
lugs at the end of wires, contacts that connect to the battery, and as
mentioned earlier the bulb socket.

Good luck, take it back from whence it came if you can't determine the cause.


Brad Grande	WB0OYX
Another bike riding beer brewing kite flying amateur radio operator who
	still likes CD's!

AT&T Bell Labs
Naperville Illinausea
PLEASE SEND RESPONSES TO:	grande@iwtil.att.com
att!iwtil!grande
(708)-979-7853


Newsgroups: rec.bicycles.tech
From: tthiel@cs.uiuc.edu (Terry Thiel)
Subject: Re: MBA LX review.
Organization: University of Illinois, Dept. of Comp. Sci., Urbana, IL
Date: Mon, 11 Jan 1993 17:20:43 GMT

paynter@bnr.ca (Stuart Paynter) writes:
>There has ben lots of discussion about the new (LX), the existing, and the
>expensive.  I was just wondering what do the commentors use.  What are 
>you basing your opinions on?  Maybe we could have an informal survey
>of component usage.  I run a full Shimano DX package (with RF - sorry 
>Terry but I like them ;)  ).  I noticed a subjective 85-90% improvement 
>from the Exage 400LX on my previous bike.  I have not rode using XT,XTR,
>or the new LX and can only comment on the way they look.

BTW I've noticed that alot of bike manufacturers are putting XT derailluers
on their otherwise LX equipped bikes.  There's only a couple $$ difference
in price between the LX and XT derailluers so I guess it's cheap way
to upgrade a production bike.

>Let's try to leave the looks of components as it is totally 
>subjective.  Is there anything else that I've missed in the above?

Well everything is subjective but the painted components go directly
to the issue of durability.  Not only does it look like hell pretty
quickly but I would guess that it's much more likely to rust once the paint
comes off.
-Terry
-- 
-Terry
From: jcollias@src.dec.com (Jim Collias)
Newsgroups: rec.bicycles.tech
Subject: Anyone tried the CV Posi-drive system?
Date: 11 Jan 93 22:03:10 GMT
Organization: DEC Systems Research Center

Hi all,

I just got this info in the mail from the CV Posi-drive corporation describing
their Terry paradigm bicycle drive train system.  The system consists of a huge
rear hub with totally self-contained internal workings that can produce a 4:1 
gear ratio.  You have a single 24-tooth chainring up front and a single 28 tooth
cog in back, and one grip-shifter (or custom thumb shifter), and that's it. 
(Actually, you can choose the external gear combination... this'll be your granny
gear and the system takes it from there..)

So 24-28 would be your granny gear, then you'd have infinite adjustability all 
the way up to 4:1, or the approximate equivalent of a 46-13 top gear.  Sounds
promising.  No pre-set gears except for the top & bottom.  All from a single
grip-shifter, and no missed shifts or dropped chains.  ever.

I called them looking for a dealer, and they say there are none yet.  Oh well.

Has anyone out there in the rest of the universe actually tried this set-up? 
It's supposed to cost about $450 (ouch).

There number is 800/473-6457.

Thanks...

- Jim 
From: jbrandt@hplred.HPL.HP.COM (Jobst Brandt)
Date: Fri, 8 Jan 1993 00:17:56 GMT
Subject: Re: Wheel Wonderings
Organization: Hewlett-Packard Laboratories, Palo Alto, CA
Newsgroups: rec.bicycles.tech

Aurelio Barranco writes:

> Correct me if I am wrong but I thought that the hub at the centre
> of the wheel is suspended from the top of the rim by the spoke
> under tension. In other words the spoke under the hub (between the
> hub and the ground side of the rim) plays no part in the process.
> Spokes at the side stop the wheel from buckling.

As Tim Smith adequately explained, the prior knowledge that wires
don't work in compression, is a disadvantage in analyzing what's
going on in a bicycle wheel.  I have additional examples that might
make the "compression" of spokes more visual.

If you mount a wheel horizontally in a fixture that holds it by its
axle, and you were to press inward on this wheel lying on its side,
where would you expect the rim to deform?  I would expect the rim to
deflect inward at the point of loading.  I would not expect anything
to occur at the far side of the wheel,.  At least nothing even
slightly like the deflection that a sensitive instrument would
detect at the disturbance.  You must imagine materials that are
consistently many times more flexible that the real materials
because they only deform a few thousandths of an inch at most, an
amount not visible to the eye but significant to the materials.

If you can visualize a strain gauge as a fine metallic tape whose
electrical resistance changes with its change in length, you could
also epoxy such an element to a spoke of a complete bicycle wheel.
As you looked on your meter that is calibrated in pounds force or
Newtons, it would read zero because it doesn't know that the spoke
was prestressed to 200 lbs tension.  With the instrumented spoke at
the bottom of the wheel you get on the bike.  The display would show
a compression in the order of 30-40 lbs compression while in fact
the spoke is still under ~170 lbs tension.

As you roll the wheel around you would find that the remainder of
the spokes, including the ones below the center, to be a fraction a
pound tighter because the rim is flattened at the bottom and because
the perimeter of the rim doesn't shrink, the remainder of the circle
is slightly enlarged.  The net up/down force from this secondary
effect is zero and is not what supports your load.  All these
effects are in a magnitude that you cannot see them without
instrumentation.  However, instrumentation makes the spokes look
like compression columns and that is the reason for using the term.

jobst_brandt@hplabs.hp.com