Cyclocross drivetrain bliss?

Ryan Cousineau said:

So I was thinking about cyclocross drivetrains as I dragged my mountain
bike out of the shed today, in the hopes of giving my dog something to
chase while we explored the ravine.

There are some theoretical advantages to top-pull front derailers in
dirty conditions. Notably, the obvious cable routing takes the cable
along the top tube and down the seat tube, away from the dirt under the
BB and on the downtube.

Now, of course, nobody makes a top-pull front derailer. A few CX bike
makers have used this routing by adding a pulley just below the derailer
on the seat tube, so the cable could go down the seat tube then connect
to the derailer from below. But that is of course Goldbergian.

There are well-understood indexing issues with trying to drive a Shimano
MTB fder with a Shimano road (STI-type; brifter) shifter.

Wishing to build a better mousetrap, I wondered: has anyone tried
driving a Shimano (or other, say SRAM) top-pull front derailleur with a
Campagnolo Ergo brifter? Does it work? Is it good?

Of course, I just bought my new CX frame, and it only has one set of top
mounted cable eyelets.

Maybe I should drill the frame for internal cable routing...

Top pull changers are around, try one. An Ergo will not cause any
further difficulties.

Top pull fronts generally shift "stiffer" than a bottom pull and very
stiff with a pulley.

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

Ryan Cousineau said:

So I was thinking about cyclocross drivetrains as I dragged my mountain
bike out of the shed today, in the hopes of giving my dog something to
chase while we explored the ravine.

Don't throw your MTB into the ravine for the dog to chase.
That's littering.

Quoted message said:

There are some theoretical advantages to top-pull front derailers in
dirty conditions. Notably, the obvious cable routing takes the cable
along the top tube and down the seat tube, away from the dirt under the
BB and on the downtube.

Now, of course, nobody makes a top-pull front derailer. A few CX bike
makers have used this routing by adding a pulley just below the derailer
on the seat tube, so the cable could go down the seat tube then connect
to the derailer from below. But that is of course Goldbergian.

Before eight zillion people correct you, I know that you meant
nobody makes a top-pull _road_ front derailer. The issues being
both STI cable pull compatibility, and big-ring capacity.
FWIW, the pulley thing does work.

Some Shimano MTB derailers have the capacity for a 46 or 48t
big ring. My cross bike has a pulley, but I'm actually using a
top pull MTB derailer right now. I have bar end shifters. I
think Ergos would work if they pull enough cable: if they can
shift a road triple they should be able to pull a MTB double.

If you run top-tube cable routing with road shifters, you need
cable adjusters somewhere in the system. On the rear you
have one on the RD. In the front ... on my bike, Specialized
kindly thought to put an adjuster in the seat tube cable stop.
Otherwise you may need an inline adjuster.

Quoted message said:

There are well-understood indexing issues with trying to drive a Shimano
MTB fder with a Shimano road (STI-type; brifter) shifter.

Wishing to build a better mousetrap, I wondered: has anyone tried
driving a Shimano (or other, say SRAM) top-pull front derailleur with a
Campagnolo Ergo brifter? Does it work? Is it good?

Of course, I just bought my new CX frame, and it only has one set of top
mounted cable eyelets.

Maybe I should drill the frame for internal cable routing...

Nuts to that. Be the first person on your block to ride
cyclocross on a fixed gear. Or just use the under-the-BB
cable routing. It isn't that bad really. It rarely gets
completely packed up, and if it does you're going to be so
far in oxygen debt you won't remember which click shifts
up and which down anyway.

Ben
If you can finish the race with both shoes on you're
ahead of the game.

Ryan Cousineau said:

So I was thinking about cyclocross drivetrains as I dragged my mountain
bike out of the shed today, in the hopes of giving my dog something to
chase while we explored the ravine.

There are some theoretical advantages to top-pull front derailers in
dirty conditions. Notably, the obvious cable routing takes the cable
along the top tube and down the seat tube, away from the dirt under the
BB and on the downtube.

Now, of course, nobody makes a top-pull front derailer. A few CX bike
makers have used this routing by adding a pulley just below the derailer
on the seat tube, so the cable could go down the seat tube then connect
to the derailer from below. But that is of course Goldbergian.

There are well-understood indexing issues with trying to drive a Shimano
MTB fder with a Shimano road (STI-type; brifter) shifter.

Wishing to build a better mousetrap, I wondered: has anyone tried
driving a Shimano (or other, say SRAM) top-pull front derailleur with a
Campagnolo Ergo brifter? Does it work? Is it good?

It works fine. Biggest problem is finding a MTB FD with the proper arc
for the rings used. Most are made for 42-ish rings, not the 48/50
commonly found on cross bikes. We have used in the past older XTR FDs,
made for their 46t crank befiore they got all microsdrivey. Otherwise,
the pulley thing works pretty well.

Quoted message said:

Of course, I just bought my new CX frame, and it only has one set of top
mounted cable eyelets.

Maybe I should drill the frame for internal cable routing...

--
Ryan Cousineau [email hidden]://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

Ryan Cousineau said:

Now, of course, nobody makes a top-pull [road] front derailer.

Sachs did. I remember that Recycled Cycles in Seattle used to have a
boatload of these oddball, top-pull, braze-on road triple FDs. They're
all gone now. I kinda wish I would have grabbed one in the unlikely
event of ever needing one.

Qui si parla Campagnolo said:

It works fine. Biggest problem is finding a MTB FD with the proper arc
for the rings used. Most are made for 42-ish rings, not the 48/50
commonly found on cross bikes. We have used in the past older XTR FDs,
made for their 46t crank befiore they got all microsdrivey. Otherwise,
the pulley thing works pretty well.

I'll confirm that the older Shimano F derailleurs work best on 48/50
or larger rings. On newer vintage front, triple derailleurs, the DA
7700 works very well with your cyclecross gears.

"Ryan Cousineau" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

So I was thinking about cyclocross drivetrains as I dragged my mountain
bike out of the shed today, in the hopes of giving my dog something to
chase while we explored the ravine.

There are some theoretical advantages to top-pull front derailers in
dirty conditions. Notably, the obvious cable routing takes the cable
along the top tube and down the seat tube, away from the dirt under the
BB and on the downtube.

Now, of course, nobody makes a top-pull front derailer. A few CX bike
makers have used this routing by adding a pulley just below the derailer
on the seat tube, so the cable could go down the seat tube then connect
to the derailer from below. But that is of course Goldbergian.

There are well-understood indexing issues with trying to drive a Shimano
MTB fder with a Shimano road (STI-type; brifter) shifter.

Wishing to build a better mousetrap, I wondered: has anyone tried
driving a Shimano (or other, say SRAM) top-pull front derailleur with a
Campagnolo Ergo brifter? Does it work? Is it good?

Of course, I just bought my new CX frame, and it only has one set of top
mounted cable eyelets.

Maybe I should drill the frame for internal cable routing...

Run a single ring, anything from a 39-42 ought to work fine with a 12x27
cassette. Double guards are the safest bet, but you can get away with a
single guard an an N-Gear Jump Stop (superior to the other inner
"watchers"😉. Make sure to shorten the chain so the derailleur pulleys are
aligned vertically when in the 12, leave it much looser and you'll drop it.

Much simpler than running all that extra [censored] for front shifting, and you
can use a Cane Creek or Tektro brake lever on the left that looks just like
an ergo lever (or yank the guts out of an STI lever, if you muct have
matching levers).

Lighter, simpler, more reliable.

John Verheul

In article <[email hidden]>,

John Verheul said:

"Ryan Cousineau" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

So I was thinking about cyclocross drivetrains as I dragged my mountain
bike out of the shed today, in the hopes of giving my dog something to
chase while we explored the ravine.

There are some theoretical advantages to top-pull front derailers in
dirty conditions. Notably, the obvious cable routing takes the cable
along the top tube and down the seat tube, away from the dirt under the
BB and on the downtube.

Now, of course, nobody makes a top-pull front derailer. A few CX bike
makers have used this routing by adding a pulley just below the derailer
on the seat tube, so the cable could go down the seat tube then connect
to the derailer from below. But that is of course Goldbergian.

There are well-understood indexing issues with trying to drive a Shimano
MTB fder with a Shimano road (STI-type; brifter) shifter.

Wishing to build a better mousetrap, I wondered: has anyone tried
driving a Shimano (or other, say SRAM) top-pull front derailleur with a
Campagnolo Ergo brifter? Does it work? Is it good?

Of course, I just bought my new CX frame, and it only has one set of top
mounted cable eyelets.

Maybe I should drill the frame for internal cable routing...

Run a single ring, anything from a 39-42 ought to work fine with a 12x27
cassette. Double guards are the safest bet, but you can get away with a
single guard an an N-Gear Jump Stop (superior to the other inner
"watchers"😉. Make sure to shorten the chain so the derailleur pulleys are
aligned vertically when in the 12, leave it much looser and you'll drop it.

Much simpler than running all that extra [censored] for front shifting, and you
can use a Cane Creek or Tektro brake lever on the left that looks just like
an ergo lever (or yank the guts out of an STI lever, if you muct have
matching levers).

Lighter, simpler, more reliable.

John Verheul

An excellent suggestion! In fact, probably the right thing for a
dedicated race bike, at least on most courses.

I actually do have a chain watcher (not sure what brand, probably not a
Jump Stop), but I have two reasons for staying two-ring:

1) [the excuse]: I use a compact double on my bike* (50-34) because it
allows greater versatility for stuff like throwing slicks on and road
riding, and because I'm so slow that a 34x12 is often all I need on the
top end, and at the bottom end a 34x27 is a pretty handy gear sometimes.

2) [real reason] I got this sweet-looking Truvativ Rouleur carbon
compact double drivetrain at a Boxing Day sale (for a song!), and I'll
use any justification for keeping it and its sweet chrome rings on my CX
bike. I'm so lazy that I have no interest in changing the rings to a
single setup, because then I would have to buy and install an outer
guard and a new inner ring.

--
Ryan Cousineau [email hidden] http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

In article <[email hidden]>,

Quoted post said:

Ryan Cousineau said:

So I was thinking about cyclocross drivetrains as I dragged my mountain
bike out of the shed today, in the hopes of giving my dog something to
chase while we explored the ravine.

Don't throw your MTB into the ravine for the dog to chase.
That's littering.

Being half Aussie Cattle Dog, she follows me everywhere. She's also
generally faster than me. I'll be bombing down descents, and all I hear
behind me is "pant, pant, pant."

This from a dog that weighs less than my weight problem.

Also, the MTB is far too nice for tossing. I may be a CX devotee, but
even hardtails have their uses.

Quoted message said:

Quoted message said:

There are some theoretical advantages to top-pull front derailers in
dirty conditions. Notably, the obvious cable routing takes the cable
along the top tube and down the seat tube, away from the dirt under the
BB and on the downtube.

Quoted message said:

Quoted message said:

Wishing to build a better mousetrap, I wondered: has anyone tried
driving a Shimano (or other, say SRAM) top-pull front derailleur with a
Campagnolo Ergo brifter? Does it work? Is it good?

Of course, I just bought my new CX frame, and it only has one set of top
mounted cable eyelets.

Maybe I should drill the frame for internal cable routing...

Nuts to that. Be the first person on your block to ride
cyclocross on a fixed gear. Or just use the under-the-BB
cable routing. It isn't that bad really. It rarely gets
completely packed up, and if it does you're going to be so
far in oxygen debt you won't remember which click shifts
up and which down anyway.

Ben
If you can finish the race with both shoes on you're
ahead of the game.

Good advice all around in this thread. And Ben, the last (literally the
last, a bit of end-of-season dementia in early November) CX race I was
in started with a 200m or so run to a Le Mans style start(!) and a
tricky water crossing which was so deep I figured the race technically
qualified as a triathlon.

Which disturbed me greatly. But I finished with all the shoes I started
with.

This has been an interesting theoretical discussion, but I think for now
I'll go with what I have: cheaply-acquired 105 9-speed brifters, and
whatever fder I had on my old bike. I think it was a Shimano 600.

The wish list is a set of black Campy 9-speed brifters (ie Mirage,
Xenon, or...one of the carbon-based groups), black cantis, and other
black components.

For the rear der, I have the tough question: Shimano 105 of 6-speed
vintage from my "current" CX bike (ie, the one that has been
disassembled into its component parts), or the Dura-Ace 9-speed in my
parts box?

Also, suggestions on especially black parts are welcomed. The frame came
to me finished in decal-less matte black (completely unadorned: no head
tube badge, no frame stickers, no tubing sticker, I haven't even checked
the serial number), and with a matching black fork (carbon legs, Al
steerer). This has inspired me to build the bike as blackly as possible.
I have black wheels, black bars, a black stem, black seatpost (sweet
Syncros (pre-Ritchey) Thompson-type two-bolt), and black saddle.

I'm thinking of black cantis (should I go old-school with something like
black LX cantis, or for insani-boutique carbon fibre wide-profile
cantis?), maybe a black drivetrain, and possibly even getting new front
covers for the 105 brifters so they will be blacker.

Hm. I'm warming to this idea. I have a set of dark grey Crank Bros Candy
pedals, what else should I enblacken on this bike?

No colours anymore,

--
Ryan Cousineau [email hidden] http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos