Problem find Chainwheel for Half Step Gearing

[The Pomeranian]

Pete Geurds wrote:
>
> I have a 3 x 5 half step on an older Schwinn. I find it works out pretty good in rolling terrain.
> I can usually get in position where I can go big ring on the down slopes and middle ring on the up
> slopes. Any more and I just shift the rear. Remember you are under no obligation to shift a half
> step in exact sequence.

You are right, and I do this fairly commonly. However, if one *never* takes advantage of the
half-step, then there is no reason for having it.

> If you tried to shift a crossover geared bike in exact sequence from smallest to largest gear
> you'd go just as wacky.

But by definition that is *not* crossover gearing/shifting.

 

[The Pomeranian]

Pete Geurds wrote:
>
> From: The Pomeranian
> >> If you tried to shift a crossover geared bike in exact sequence from smallest to largest gear
> >> you'd go just as wacky.
>
> > But by definition that is *not* crossover gearing/shifting.
>
> I'm not sure I follow you on that.

Crossover in the most simple terms means: use up the gears in one ring and cross to the next (and to
whatever cog is right). A zig-zagging pattern is by definition not a crossover.

 

[Ryan Cousineau]

In article <[email protected]>, [email protected] (Robert
Taylor) wrote:

> A number of times I have been seduced by half-step gearing because of the lack of duplicates. Many
> so called 24 or 27 speed setups have so many duplicates that they have fewer distinct gears than a
> 15 or 18 speed half-step plus bulldog (sometimes called granny) setup.
>
> HOWEVER, in practice I found myself tending to just ride on the middle chainring, using the
> bulldog when necessary but rarely using the big ring. I've observed a lot of other people doing
> this as well. Once I conceded that I didn't actually use the half-step feature I decided that I
> could find some other way to use 3 chainrings. Also when I began to use 7 speed clusters and then
> 8 speed (no 9's or 10's yet) I decided that they were spaced so closely that half way between
> wasn't different enough to be worth the bother of shifting, the momentum loss (especially of a
> double shift) would mean that the new lower gear wouldn't feel any easier than the slightly higher
> gear I'd just left.
>
> Half-step plus bulldog is elegant but I never found it to be especially useful. I do have it on a
> restored mid 70's Follis which I look at but rarely ride and if I did ride it I'd probably quickly
> fall into riding mostly on the middle ring.

I had an interesting revelation on the weekend about half-step gearing.

Most of my riding is short, sharp commuting. Typical pattern for the last few months was 4 days/wk
(average) of my 12km-each-way commute with a big ridge in the middle, and lots of stoplight
sprinting.

For this stuff, I hated the half-step that came on my 3x6 commuter bike. With friction DT shifters
and a granny front ring, I couldn't execute shifts fast enough to take any advantage of the
half-step, and pretty much used the front rings for occasional "trim" shifts on long, moderately
steep hills or flatter sections. I dubbed the third ring the "ring of no return" because once you
checked in, the shift back to the second ring was so steep it was a cadence-trasher. Once you
checked into the little ring on a hill, you had to stay with it until it got very flat.

Then on Sunday I went on a 100 km ride on a flowing, fairly flat route. Revelation! I would click
into a gear, and use the half-steps for little trims into cadence and comfort perfection. It was
marvelous and intuitive. It was exactly the kind of long-distance tourist ride this gearing was
designed for, and it was very pleasant.

I defer to others on the relative merits of an outdated half-step 6s cluster versus a 9s
cross-geared modern drivetrain. But I believe the gearing choices some long-ago consumer made for
my pretty garage-sale Mikado were the best possible in the 6v era, at least for this
touring-oriented bike.

Share & Enjoy,
--
Ryan Cousineau, [email protected] http://www.sfu.ca/~rcousine President, Fabrizio Mazzoleni Fan Club

 

[Pooh]

My riding for the which I posted the half step for is on my longer weekend ride that have thus far
been from 32 to 72 miles. The bike I was going to use has been dropped and now I'm planning to use
it on a 12 speed 1980's Vitus. Right now I have a Suntour 42/53 front. I think my logarithmic
gearing chart said something like a 42/45 chainwheel would do it.

I received some spare chainwheels from my friends and darn, none of the bolt circles matched. Back
to the drawing board.

/Wynn/

Ryan Cousineau <[email protected]> wrote in message
news:<[email protected]>...
> In article <[email protected]>, [email protected]
> (Robert Taylor) wrote:
>
> > A number of times I have been seduced by half-step gearing because of the lack of duplicates.
> > Many so called 24 or 27 speed setups have so many duplicates that they have fewer distinct gears
> > than a 15 or 18 speed half-step plus bulldog (sometimes called granny) setup.
> >
> > HOWEVER, in practice I found myself tending to just ride on the middle chainring, using the
> > bulldog when necessary but rarely using the big ring. I've observed a lot of other people doing
> > this as well. Once I conceded that I didn't actually use the half-step feature I decided that I
> > could find some other way to use 3 chainrings. Also when I began to use 7 speed clusters and
> > then 8 speed (no 9's or 10's yet) I decided that they were spaced so closely that half way
> > between wasn't different enough to be worth the bother of shifting, the momentum loss
> > (especially of a double shift) would mean that the new lower gear wouldn't feel any easier than
> > the slightly higher gear I'd just left.
> >
> > Half-step plus bulldog is elegant but I never found it to be especially useful. I do have it on
> > a restored mid 70's Follis which I look at but rarely ride and if I did ride it I'd probably
> > quickly fall into riding mostly on the middle ring.
>
> I had an interesting revelation on the weekend about half-step gearing.
>
> Most of my riding is short, sharp commuting. Typical pattern for the last few months was 4 days/wk
> (average) of my 12km-each-way commute with a big ridge in the middle, and lots of stoplight
> sprinting.
>
> For this stuff, I hated the half-step that came on my 3x6 commuter bike. With friction DT shifters
> and a granny front ring, I couldn't execute shifts fast enough to take any advantage of the
> half-step, and pretty much used the front rings for occasional "trim" shifts on long, moderately
> steep hills or flatter sections. I dubbed the third ring the "ring of no return" because once you
> checked in, the shift back to the second ring was so steep it was a cadence-trasher. Once you
> checked into the little ring on a hill, you had to stay with it until it got very flat.
>
> Then on Sunday I went on a 100 km ride on a flowing, fairly flat route. Revelation! I would click
> into a gear, and use the half-steps for little trims into cadence and comfort perfection. It was
> marvelous and intuitive. It was exactly the kind of long-distance tourist ride this gearing was
> designed for, and it was very pleasant.
>
> I defer to others on the relative merits of an outdated half-step 6s cluster versus a 9s
> cross-geared modern drivetrain. But I believe the gearing choices some long-ago consumer made for
> my pretty garage-sale Mikado were the best possible in the 6v era, at least for this
> touring-oriented bike.
>
> Share & Enjoy,

 

[Paul Kopit]

On Sat, 1 Feb 2003 00:07:07 -0500, Mark Boyd <[email protected]> wrote:

>The inner plate on Shimano MTB derailleurs, like the Alivio, is designed for a minimum of an 8
>tooth difference between the middle and big rings. Half step needs half of that <grin>, so an MTB
>derailleur will not work. Assuming you aren't using indexed shifters, you could use an inexpensive
>Shimano road derailleur. If you are using indexed shifters, you'll have to do major surgery - use a
>Dremel tool with a cut-off disk - on the inner plate of a MTB front derailleur.

I don't know MTB stuff that well. I know one of the early 90s MTB derailleurs worked with ½ step. I
had a '91 Trek 1320 and it came with 50/45/28 and used a Deore DX front derailleur. Later in it's
life, the same derailleur shifted a 54/44/28 on a tandem.

 

[A Muzi]

> On Sat, 1 Feb 2003 00:07:07 -0500, Mark Boyd <[email protected]> wrote:
>
> >The inner plate on Shimano MTB derailleurs, like the Alivio, is designed for a minimum of an 8
> >tooth difference between the middle and big rings. Half step needs half of that <grin>, so an MTB
> >derailleur will not work. Assuming you aren't using indexed shifters, you could use an
> >inexpensive Shimano road derailleur. If you are using indexed shifters, you'll have
to
> >do major surgery - use a Dremel tool with a cut-off disk - on the inner plate of a MTB front
> >derailleur.

"Paul Kopit" <[email protected]> wrote in message
news:[email protected]...
> I don't know MTB stuff that well. I know one of the early 90s MTB derailleurs worked with ½ step.
> I had a '91 Trek 1320 and it came with 50/45/28 and used a Deore DX front derailleur. Later in
> it's life, the same derailleur shifted a 54/44/28 on a tandem.

I don't know MTB stuff all that well either but in that era, Shimano produced that changer in "Half
Step" and "Alpine" variants with a cute little sticker on the cage and on the box noting that
feature. DX and XT as I recall. No longer made.

At that time, Shimano or Trek included a very clever bottom-pull to top-pull conversion clip for
the anchor bolt. The anchor was removed, the adapter with a casing stop was fitted and the wire
fastened to an anchor on the frame behind the BB. It eliminated the need for one sku of front
changers so I liked it.
--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971