Half Step and Granny - which front derailleur?

[James Thomson]

For reasons I won't bore you with, I'd like to try a half-step and granny
gearing system. I'm willing to entertain suggestions that it's ill-advised,
but I'd like to try it for myself all the same, and I have most of the parts
I need to get started.

Likely gearing will be 45-42-granny at the front, and either
11-12-14-16-18-21-24-28 or 12-14-16-18-21-24-28-32 (eight of nine) at the
rear.

Questions:

What front derailleur would you choose, and why?

Given the above, what size granny would you shoot for?

Shifters will be either older Campag Ergos, Shimano barcons, or downtube
levers, so front indexing isn't an issue.

Thanks,

James Thomson

[dustoyevsky@mac.com]

On May 19, 12:28*pm, "James Thomson" <yosnap...@hotmail.com> wrote:
> "JG" <j...@cox.net> a écrit:
>
> > I'm pretty sure 1/2 step is dead... You have a close ratio with one
> > chainring already. *Back in the day when I was touring with a 1/2 step
> > 10 speed, I stopped bothering with the double shifts on the low
> > gears. *With your setup, I doubt you will bother with the double
> > shifts on the high gears. *There is a reason for the"road triple".
> > There may be no such thing as too many gears, but there is such
> > a thing as too many gears to bother shifting.
>
> I'll go into a little more detail.
>
> I tend to go off meandering on Sundays and ride as I feel, a mixture of
> roads and dirt, a hundred miles or so when I'm in shape for it. Sometimes I
> carry luggage, sometimes I hop on with impromptu chaingangs. My bikes tend
> to be put together with versatility in mind. Absolute top gear and absolute
> bottom aren't that important - I'm not racing, and I'm not too proud to push
> if nobody's looking. What I need is a mixture of narrow-spaced gears for
> cruising, and wider jumps for hacking about off-road. It doesn't make any
> sense to have a narrow range cassette and get stalled up trying to shift
> four sprockets at once on a dirt climb.
>
> I often ride a 2x9 system - 42-29 at the front with a standard (cheap) 11-32
> cassette. On the road, the 12-14-16-18-21 jumps feel a little large, and
> these are the gears I spend a lot of time in. Adding a 45 halves these steps
> pretty nicely, and gives a little more top end.
>
> Among my stash of parts I have a few Stronglight 130/74 42-30 chainring
> combinations which I was planning to use with a chainguard/bash in the outer
> position again as a 2x9. Then it struck me that I might as well add the 45
> (I have a few lying around) to give me the nice, smaller steps for road
> riding. The resulting combination looks something like a road triple with a
> small outer, or a mountain triple with a big middle, hence my uncertainty
> about which derailleur to try first. The size of the granny is negotiable -
> I'm happy to go a couple of teeth either way if there are likely to be
> shifting benefits to be had.
>
> Chainline's an issue too.
>
> I'm happy to accept that there may end up being no practical benefit over a
> more standard triple, but as I have the parts to play with I'd like to
> satisfy myself of that by experience.

Coming at this from the "what you want" (from your post) and not "what
you have":

Well, your 42x11 is a gear-chart 103 in., and you're interested in
having a little more top end.

You want smaller steps for road riding in your cruising range.

You need at least one low, low gear for "unimproved dirts".

"How do you get there"?

Ready supply of "free" parts notwithstanding, have you thought of
opening up the range on your triple front rings, and closing it
together on the rear? Start with a 13 or 14 (53x14 is 102") smallest
cog on the cassette, use a small inner (triple) chainring, so you
don't have to go so large for the biggest cog? Aiming for a few one-
tooth gaps in the 14-15-16-17-18 range, with chainrings chosen to give
you the ratios you're used to riding, with the holes filled in, and a
low low? Tighter ratios could also give you two or three usable
rations on the granny inner ring, without too much chain deflection,
which could make the off-roading more enjoyable. --D-y

[dustoyevsky@mac.com]

On May 23, 12:26*am, "James Thomson" <yosnap...@hotmail.com> wrote:

> Right, but I don't want to sacrifice useful medium-sized shifts on dirt. A
> corncob makes no sense if it just means more cogs skipped.

Perhaps a matter of a gear chart session, "what you got v. what you
want"?

> Those are all fair suggestions.

Thanks. Leading to "an examination of the situation", before turning
wrenches or help us, buying stuff.

Well, I have some ancient triple experience, with N. Record 36/42/53
crank and 12-23 (which was "custom" off the old Suntour cog board)
freewheel, which worked very well for semi-loaded touring in the
Rockies. Given the limitations of the shifters of the times, of
course, and a lighter, stronger body. I didn't use the 36 much, but I
did use it, on the 23 and the next one up, sorry it's in the Archives
but probably a 21, or maybe a 20. Which was a cool thing about that
Suntour cog board. Gear experimentation, even with "only 7", good.

OK, then we're back to "what kind of front derailleur do I need"? <g>.
Better than the old Campy, is all I can suggest.

I have a "new" triple project, road-style, that is comfortably stalled
due to disinterest in climbing a certain hill that is the reason for
getting the parts mostly together on the bike... "stopped just in
time!"

Anyhow, that's all "factory" Campy -road- stuff that at least looks
like the head-scratching has been done previously... My bikes have
historically at least done lots of dirt road riding, but were not set
up for real off-road. Although some of the Texas-style low water
crossings we used to blast through could certainly qualify. Ground
clearance per se (below) not an issue, IOW.

> My main objections are that a bigger outer
> chainring means less ground clearance, and a 13- or 14- up cassette with low
> gears seems to mean going custom. I've no real problem with that, but the
> attraction of the 9-speed 11-32 is that it's available cheaply (ding ding ding!)

There was a magic word!

> off the
> shelf, and can be split on a 7-speed hub to give either 11-28 or 12-32, both
> of which are half-steppable (the 11-12 jump excluded).
>
> The main attraction of half-step though is that I haven't tried it before,
> and I'd like to. Given that I have most of the parts here that's reason
> enough.

Yes it most certainly is and could you post a follow-up? --D-y

[James Thomson]

"Tom Kunich" <cyclintom@yahoo. com> a écrit:

> Keep us informed about how it works in practice James.

Will do. Thanks to all for the input so far.

James Thomson

[Michael Press]

In article <48302283$0$879$ba4acef3@news.orange.fr>,
"James Thomson" <yosnappyj@hotmail.com> wrote:

> For reasons I won't bore you with, I'd like to try a half-step and granny
> gearing system. I'm willing to entertain suggestions that it's ill-advised,
> but I'd like to try it for myself all the same, and I have most of the parts
> I need to get started.
>
> Likely gearing will be 45-42-granny at the front, and either
> 11-12-14-16-18-21-24-28 or 12-14-16-18-21-24-28-32 (eight of nine) at the
> rear.
>
> Questions:
>
> What front derailleur would you choose, and why?
>
> Given the above, what size granny would you shoot for?
>
> Shifters will be either older Campag Ergos, Shimano barcons, or downtube
> levers, so front indexing isn't an issue.

What is the lowest gear you want?
What wheel size do you run?
Is this fully loaded touring or heavy off-road going?
If not a 30 granny will be sufficient.

--
Michael Press

[bjw@mambo.ucolick.org]

On May 18, 5:35*am, "James Thomson" <yosnap...@hotmail.com> wrote:
> For reasons I won't bore you with, I'd like to try a half-step and granny
> gearing system. I'm willing to entertain suggestions that it's ill-advised,
> but I'd like to try it for myself all the same, and I have most of the parts
> I need to get started.
>
> Likely gearing will be 45-42-granny at the front, and either
> 11-12-14-16-18-21-24-28 or 12-14-16-18-21-24-28-32 (eight of nine) at the
> rear.
>
> Questions:
>
> What front derailleur would you choose, and why?
>
> Given the above, what size granny would you shoot for?
>
> Shifters will be either older Campag Ergos, Shimano barcons, or downtube
> levers, so front indexing isn't an issue.

Sheldon (R.I.P.) might have suggested an ordinary
road front derailleur for double chainrings.

http://groups.google.com/group/rec.bicycles.tech/msg/a3f6349501bb0926

I have a Shimano Deore FD with a sticker saying
"for half step". This is 80s vintage, from when Deore
was also a touring group, and originally on a Cannondale
with 50-45-28 chainrings. It has an essentially flat
inner plate, that hangs down a little more than a
road double FD of the 80s, but not nearly as much
as modern triple derailleurs.

You can futz with adding pins to the middle
chainring to aid in lifting the chain onto it. I did
this once by drilling and tapping the ring for a
couple of setscrews. (But for a regular triple, not
for half step! Half step is for people with 5 speed
freewheels and wool shorts.)

Ben

[Mike Jacoubowsky]

"James Thomson" <yosnappyj@hotmail.com> wrote in message
news:48302283$0$879$ba4acef3@news.orange.fr...
| For reasons I won't bore you with, I'd like to try a half-step and granny
| gearing system. I'm willing to entertain suggestions that it's
ill-advised,
| but I'd like to try it for myself all the same, and I have most of the
parts
| I need to get started.
|
| Likely gearing will be 45-42-granny at the front, and either
| 11-12-14-16-18-21-24-28 or 12-14-16-18-21-24-28-32 (eight of nine) at the
| rear.
|
| Questions:
|
| What front derailleur would you choose, and why?
|
| Given the above, what size granny would you shoot for?
|
| Shifters will be either older Campag Ergos, Shimano barcons, or downtube
| levers, so front indexing isn't an issue.
|
| Thanks,
|
| James Thomson

The problem you're likely to have, even with non-indexed shifters, is the
chain falling in-between the chainrings when shifting from your 45 to the
42. The spacing between chainrings has to be closer together when they're so
close in size, because as a chain moves further "down" it has more time to
move further "in." A 5-tooth gap is about the minimum I've found to shift
well. This is an area I have quite a bit of experience in, since I went
through a "half-step" phase during my junior racing days (many, many years
ago) when the gear restrictions at the high end meant that a large front
chainring wasn't useful.

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

[russellseaton1@yahoo.com]

My loaded touring bike uses half step plus super granny gearing. 7
speed cassette. Either 14-16-18-21-24-28-32 or 12-14-16-18-21-24-28.
Chainrings of 45-42-20. 1991 Deore DX 110/74mm bcd crankset with the
separate washers for the inner chainring so a Avid Microadapter 2
allows the use of a 20 tooth inner ring. Front derailleur is a
Shimano Sora 8 speed double. Bar end shifters.

With a 3 tooth spread in the front rings (45-42 or 42-39), a 12-32 8
speed or a 9 speed with 11-34 or 12-34 will work quite well as half
step cassettes.



On May 18, 7:35*am, "James Thomson" <yosnap...@hotmail.com> wrote:
> For reasons I won't bore you with, I'd like to try a half-step and granny
> gearing system. I'm willing to entertain suggestions that it's ill-advised,
> but I'd like to try it for myself all the same, and I have most of the parts
> I need to get started.
>
> Likely gearing will be 45-42-granny at the front, and either
> 11-12-14-16-18-21-24-28 or 12-14-16-18-21-24-28-32 (eight of nine) at the
> rear.
>
> Questions:
>
> What front derailleur would you choose, and why?
>
> Given the above, what size granny would you shoot for?
>
> Shifters will be either older Campag Ergos, Shimano barcons, or downtube
> levers, so front indexing isn't an issue.
>
> Thanks,
>
> James Thomson

[Tom Kunich]

<bjw@mambo.ucolick.org> wrote in message
news:874b807b-5fba-4031-87f3-0ac9efad751f@y22g2000prd.googlegroups.com...
>
> Sheldon (R.I.P.) might have suggested an ordinary
> road front derailleur for double chainrings.

Except that the man has a triple Ben. And it is a funny one as well with a
45-41 and a granny of some size. This would suggest using a clamp-on Shimano
Deore derailer. And if I were him I'd use a 24 tooth granny. Better to have
a gear low enough to lift a full load up Mt. Vesuvius than not.

> I have a Shimano Deore FD with a sticker saying
> "for half step". This is 80s vintage, from when Deore
> was also a touring group, and originally on a Cannondale
> with 50-45-28 chainrings.

If memory serves that 28 was about the smallest that FD wanted to shift. It
was actually designed for a 52 tooth large ring I believe. I had a similar
one on my Raleigh Kodiak touring bike. The modern mountain bike triple
derailers are more practical and shift better.

[Tom Kunich]

<bjw@mambo.ucolick.org> wrote in message
news:874b807b-5fba-4031-87f3-0ac9efad751f@y22g2000prd.googlegroups.com...
>
> Sheldon (R.I.P.) might have suggested an ordinary
> road front derailleur for double chainrings.

Except that the man has a triple Ben. And it is a funny one as well with a
45-41 and a granny of some size. This would suggest using a clamp-on Shimano
Deore derailer. And if I were him I'd use a 24 tooth granny. Better to have
a gear low enough to lift a full load up Mt. Vesuvius than not.

> I have a Shimano Deore FD with a sticker saying
> "for half step". This is 80s vintage, from when Deore
> was also a touring group, and originally on a Cannondale
> with 50-45-28 chainrings.

If memory serves that 28 was about the smallest that FD wanted to shift. It
was actually designed for a 52 tooth large ring I believe. I had a similar
one on my Raleigh Kodiak touring bike. The modern mountain bike triple
derailers are more practical and shift better.

[James Thomson]

<bjw@mambo.ucolick.org> a écrit:

> I have a Shimano Deore FD with a sticker saying
> "for half step". This is 80s vintage, from when Deore
> was also a touring group, and originally on a Cannondale
> with 50-45-28 chainrings. It has an essentially flat
> inner plate, that hangs down a little more than a
> road double FD of the 80s, but not nearly as much
> as modern triple derailleurs.

Thanks. I've never actually seen one of these units close up - though I
recall "alpine" and "half-step" versions, and the Biopace half-step gears
that touring Cannondales once came with. Do you happen to know the part
number? Could you point me to a picture?

Thanks.

James Thomson

[Jenny Brien]

On Sun, 18 May 2008 21:10:11 +0100, Tom Kunich com> <"<cyclintom"@yahoo.>
wrote:

> <bjw@mambo.ucolick.org> wrote in message
> news:874b807b-5fba-4031-87f3-0ac9efad751f@y22g2000prd.googlegroups.com...
>>
>> Sheldon (R.I.P.) might have suggested an ordinary
>> road front derailleur for double chainrings.
>
> Except that the man has a triple Ben. And it is a funny one as well with
> a 45-41 and a granny of some size. This would suggest using a clamp-on
> Shimano Deore derailer. And if I were him I'd use a 24 tooth granny.
> Better to have a gear low enough to lift a full load up Mt. Vesuvius
> than not.
>

Any derailleur for a double should work just fine if it can handle the
spead. What he needs to avoid is a triple with a deep inner plate which
would foul the middle ring on the upshift.

[Tom Kunich]

"Jenny Brien" <jennifer@figuk.plus.com> wrote in message
news:op.ubd86ndlaozhuq@sna123456789...
> On Sun, 18 May 2008 21:10:11 +0100, Tom Kunich com> <"<cyclintom"@yahoo.>
> wrote:
>> <bjw@mambo.ucolick.org> wrote in message
>> news:874b807b-5fba-4031-87f3-0ac9efad751f@y22g2000prd.googlegroups.com...
>>> Sheldon (R.I.P.) might have suggested an ordinary
>>> road front derailleur for double chainrings.
>>
>> Except that the man has a triple Ben. And it is a funny one as well with
>> a 45-41 and a granny of some size. This would suggest using a clamp-on
>> Shimano Deore derailer. And if I were him I'd use a 24 tooth granny.
>> Better to have a gear low enough to lift a full load up Mt. Vesuvius
>> than not.
>
> Any derailleur for a double should work just fine if it can handle the
> spead. What he needs to avoid is a triple with a deep inner plate which
> would foul the middle ring on the upshift.

I don't think you understand - the curvature of the front derailer is
important if you don't want dropped chains. A "standard" double is sized for
a 53 ring which is a great deal larger OD than a 45.

[JG]

I'm pretty sure 1/2 step is dead... You have a close ratio with one
chainring already. Back in the day when I was touring with a 1/2 step
10 speed, I stopped bothering with the double shifts on the low
gears. With your setup, I doubt you will bother with the double
shifts on the high gears. There is a reason for the"road triple".
There may be no such thing as too many gears, but there is such a
thing as too many gears to bother shifting.

JG

[James Thomson]

"JG" <jchg@cox.net> a écrit:

> I'm pretty sure 1/2 step is dead... You have a close ratio with one
> chainring already. Back in the day when I was touring with a 1/2 step
> 10 speed, I stopped bothering with the double shifts on the low
> gears. With your setup, I doubt you will bother with the double
> shifts on the high gears. There is a reason for the"road triple".
> There may be no such thing as too many gears, but there is such
> a thing as too many gears to bother shifting.

I'll go into a little more detail.

I tend to go off meandering on Sundays and ride as I feel, a mixture of
roads and dirt, a hundred miles or so when I'm in shape for it. Sometimes I
carry luggage, sometimes I hop on with impromptu chaingangs. My bikes tend
to be put together with versatility in mind. Absolute top gear and absolute
bottom aren't that important - I'm not racing, and I'm not too proud to push
if nobody's looking. What I need is a mixture of narrow-spaced gears for
cruising, and wider jumps for hacking about off-road. It doesn't make any
sense to have a narrow range cassette and get stalled up trying to shift
four sprockets at once on a dirt climb.

I often ride a 2x9 system - 42-29 at the front with a standard (cheap) 11-32
cassette. On the road, the 12-14-16-18-21 jumps feel a little large, and
these are the gears I spend a lot of time in. Adding a 45 halves these steps
pretty nicely, and gives a little more top end.

Among my stash of parts I have a few Stronglight 130/74 42-30 chainring
combinations which I was planning to use with a chainguard/bash in the outer
position again as a 2x9. Then it struck me that I might as well add the 45
(I have a few lying around) to give me the nice, smaller steps for road
riding. The resulting combination looks something like a road triple with a
small outer, or a mountain triple with a big middle, hence my uncertainty
about which derailleur to try first. The size of the granny is negotiable -
I'm happy to go a couple of teeth either way if there are likely to be
shifting benefits to be had.

Chainline's an issue too.

I'm happy to accept that there may end up being no practical benefit over a
more standard triple, but as I have the parts to play with I'd like to
satisfy myself of that by experience.

James Thomson

[Hank]

On May 19, 10:20*am, "Tom Kunich" <cyclintom@yahoo. com> wrote:
> "Jenny Brien" <jenni...@figuk.plus.com> wrote in message
>
> news:op.ubd86ndlaozhuq@sna123456789...
>
>
>
>
>
> > On Sun, 18 May 2008 21:10:11 +0100, Tom Kunich com> <"<cyclintom"@yahoo.>
> > wrote:
> >> <b...@mambo.ucolick.org> wrote in message
> >>news:874b807b-5fba-4031-87f3-0ac9efad751f@y22g2000prd.googlegroups.com....
> >>> Sheldon (R.I.P.) might have suggested an ordinary
> >>> road front derailleur for double chainrings.
>
> >> Except that the man has a triple Ben. And it is a funny one as well with
> >> a 45-41 and a granny of some size. This would suggest using a clamp-on
> >> Shimano Deore derailer. And if I were him I'd use a 24 tooth granny.
> >> Better to have a gear low enough to lift a full load up Mt. Vesuvius
> >> than not.
>
> > Any derailleur for a double should work just fine if it can handle the
> > spead. What he needs to avoid is a triple with a deep inner plate which
> > would foul the middle ring on the upshift.
>
> I don't think you understand - the curvature of the front derailer is
> important if you don't want dropped chains. A "standard" double is sized for
> a 53 ring which is a great deal larger OD than a 45.- Hide quoted text -
>
> - Show quoted text -

Actually, she nailed it spot-on. The curvature is FAR less important
than the depth of the inner cage plate, or the placement of ramps on
the outer cage. Modern triple FDs are basically paired with chainring
sets, and if the expected gaps aren't observed, it just won't shift,
period. A double with a high inner plate and no ramps on the outer
plate is the ideal solution, especially when the gap between big ring
and granny is less than 20T.

[Tom Kunich]

"James Thomson" <yosnappyj@hotmail.com> wrote in message
news:4831b8d2$0$862$ba4acef3@news.orange.fr...
>
> I'm happy to accept that there may end up being no practical benefit over
> a more standard triple, but as I have the parts to play with I'd like to
> satisfy myself of that by experience.

Keep us informed about how it works in practice James.