Triple experiment ongoing

On Sep 15, 8:55*pm, Mark wrote:
wrote:
The Campy triple bike is finally built and used for a couple of rides
now. A conglomeration of Tommasini SLX Prestige frame, Record 8sp
brifters/cassette, Valacchi long (medium? I think it's a medium) cage
rear derailleur, Racing T front derailleur, Valacchi 30/42/52, 170mm
triple crankset.

As expected, the brifters and Racing T front derailleur (extended
inner cage) seem to have solved the problem with dicey front shifting
seen with my old Nuovo Record (friction DT shift levers, N. Record
front derailleur) setup. Yes, I have to trim the front derailleur
after shifting onto the middle ring-- especially with an "up" shift
from the inner ring-- but that drill is close to automatic on only my
second ride. Campy front derailleur trimming works very well in this
application, it seems.

Most important: the drop from big ring to middle, the biggest problem
with the old N. Record front derailleur, is essentially the same as on
my double-ring bikes, about the same thumb button movement, and no
tendency to shift to the little ring or spill off completely as seen
with hurried shifts on the old stuff.

I probably won't get stuck in the middle ring part way up a hill again
(only once so far), having gotten used to the idea that I can "pop"
shifts on the front, up or down, and not be fairly sure of unshipping
the chain as with the "vintage" (gag me) gear-- which worked, but
required care and some precision (and a little luck) to get the
chainring you wanted, and not spill the chain off. I was pleasantly
surprised at how positive the shift onto the small ring is given a
proper control input on the thumb button.

Shifting up to middle or large rings seems to take a longer push than
on the double bikes but that's becoming automatic as well; again, the
front derailleur seems to contain the chain very well. No "dumps", in
or out, so far. We'll see on that as I get more aggressive with the
shifters, no doubt.

The 30t (way better than the old N.Record 36 smallest) inner ring is
"almost low enough" with the 12-23, 8sp cassette that came out of the
parts depot. Looking for a 26 cog or cassette, [...]

28t rings are cheap and easy to find if your crank has the common inner
ring BCD. *My 52/42/28 still shifts well in front; not quite as low as
the 26T cog, but close, and a cheaper "up"grade.

Campy triple is 74 BCD, inner ring.

I'll have to look for "common" g to see what it is in mm.

Pending, a trip to:

http://www.branfordbike.com/chains/chains1.html#item3

shows TA-mfg'd inner rings in 74mm BCD available down to 25t.

Thank you; frankly, I hadn't thought to go in that direction ("lower
the river" so to speak).

But, thanks for the recommendation and the shifting report. I'd rather
have spread-out ratios on the crank end and close ratios on the
cassette end-- wider range without giving up close ratios in each
range. Which, again, is reason to have 9 or 10 (or 11!) cogs on the
back, double or triple (opinion).

And now, back to the gear charts! --D-y

wrote:
On Sep 15, 8:55 pm, Mark wrote:
wrote:
The Campy triple bike is finally built and used for a couple of rides
now. A conglomeration of Tommasini SLX Prestige frame, Record 8sp
brifters/cassette, Valacchi long (medium? I think it's a medium) cage
rear derailleur, Racing T front derailleur, Valacchi 30/42/52, 170mm
triple crankset.
As expected, the brifters and Racing T front derailleur (extended
inner cage) seem to have solved the problem with dicey front shifting
seen with my old Nuovo Record (friction DT shift levers, N. Record
front derailleur) setup. Yes, I have to trim the front derailleur
after shifting onto the middle ring-- especially with an "up" shift
from the inner ring-- but that drill is close to automatic on only my
second ride. Campy front derailleur trimming works very well in this
application, it seems.
Most important: the drop from big ring to middle, the biggest problem
with the old N. Record front derailleur, is essentially the same as on
my double-ring bikes, about the same thumb button movement, and no
tendency to shift to the little ring or spill off completely as seen
with hurried shifts on the old stuff.
I probably won't get stuck in the middle ring part way up a hill again
(only once so far), having gotten used to the idea that I can "pop"
shifts on the front, up or down, and not be fairly sure of unshipping
the chain as with the "vintage" (gag me) gear-- which worked, but
required care and some precision (and a little luck) to get the
chainring you wanted, and not spill the chain off. I was pleasantly
surprised at how positive the shift onto the small ring is given a
proper control input on the thumb button.
Shifting up to middle or large rings seems to take a longer push than
on the double bikes but that's becoming automatic as well; again, the
front derailleur seems to contain the chain very well. No "dumps", in
or out, so far. We'll see on that as I get more aggressive with the
shifters, no doubt.
The 30t (way better than the old N.Record 36 smallest) inner ring is
"almost low enough" with the 12-23, 8sp cassette that came out of the
parts depot. Looking for a 26 cog or cassette, [...]
28t rings are cheap and easy to find if your crank has the common inner
ring BCD. My 52/42/28 still shifts well in front; not quite as low as
the 26T cog, but close, and a cheaper "up"grade.

Campy triple is 74 BCD, inner ring.

Umm, yeah, I thought you said you had a non-Campy brand crank.
If your inner ring is 74 BCD, you can use any of a wide selection of
cheap inner rings that go down to 24T - but I haven't tried shifting a
bigger jump than 16T with a campy triple front changer, and 14T or less
works better, in my experience.

Pending, a trip to:
http://www.branfordbike.com/chains/chains1.html#item3
shows TA-mfg'd inner rings in 74mm BCD available down to 25t.

You can get 'em a lot cheaper than TA's rings. I expect TA's are quite
nice, but the inner ring doesn't get that much business that it needs to
be high quality - unless you're a real masher. I put a Campy steel 26T
ring (of Centaur off-road vintage) on my tandem. On my singles I'm
using whatever's cheap.

But, thanks for the recommendation and the shifting report. I'd rather
have spread-out ratios on the crank end and close ratios on the
cassette end-- wider range without giving up close ratios in each
range.

That is the chief benefit of a triple, yes. Good luck,

Mark J.

On Sep 15, 11:17*pm, Mark wrote:

(read, snipped for conservation)

Thanks again. Checkin' it out here, boss g.

Yup, the close-ratio cogset and wide range chainring setup is the way
to go for what I want to do.
--D-y

"Which, again, is reason to have 9 or 10 (or 11!) cogs on the back,
double or triple (opinion). "

Well, sort of. Against a 12, a 52-42-30 crosses over at 15T and 17T.
So if you have a 12-13-14-15-16-... you have gears as tightly spaced
as you can (unless you hunt for your double shifts...) down to 50".
Then you have 3, 4, or 5 gears to set up the bail-outs... Of course
cassettes are made like that, and there is some use for redundant
overlap - but crosschaining is a thing of the past with modern
chains...

JG