Gearing Question: 48/36/26 vs. 44/32/22

[Will]

Consider a setup many of us have on our Rivs: a Sugino 48/36/26 triple
and 12-27 nine-speed cassette. One can show using Sheldon Brown's
calculator (www.sheldonbrown.com/gears), that a standard 44/32/22
"mountain" crank with an 11-21 cassette gives nearly an identical
range (from about 26-27 to 107 gear-inches). The difference is that
the latter has tighter spacing between adjacent cogs, which is
something to appreciate for those of us who spend a lot of time on
long sections of smooth pavement. I see two potential disadvantages:
more shifting in hill country and greater gaps between crank rings.
Are the other disadvantages to this setup? Do chains wear faster when
mated to smaller cogs all around? Thoughts?

[Bruce]

I think that chain line affects wear more so than gear size. Chains last longest when they pull in a straight line. More wear occurs when they are at an angle (cross chained) Consider both set ups based on the gear combinations you will use most of the time. Where is the chain line for each?

Tire size matters also, in coming up with gear inches and travel speed based on an rpm and ratio.

Having said all that, most chains last a long time in any front - rear gear ration set up if they are properly adjusted and lubricated.

Tailwinds!

Bruce

----- Original Message ----
From: Will <william....@gmail.com>


Consider a setup many of us have on our Rivs: a Sugino 48/36/26 triple

and 12-27 nine-speed cassette. ..., that a standard 44/32/22

"mountain" crank with an 11-21 cassette gives nearly an identical
range (from about 26-27 to 107 gear-inches).

---

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[Steve Palincsar]

You can set up 26/36/48 and 22/32/44 to be essentially identical. I
have one bike set up with 22/32/44, 12-27 9spd cassette, more with
26/36/48 and Sheldon's Century Special 13-30 (remove the 12 from the
12-27, add a 30 in back).

Biggest disadvantages to the microdrive setup are faster wear
(everything carries a greater load and wears more quickly when the rings
and sprockets have fewer teeth) and the cranksets available in
microdrive bolt circle diameters. You have two basic choices I'm aware
of for microdrive: MTB cranks (huge Q factors, grotty appearance) or TA
Carmina. The options in 110/74 are limited as well (Sugino XD, TA
Carmina or NOS discontinued models) but at least the Q factors are more
reasonable and they're less ugly.

One other thing: the 22/32/44 occasionally experiences chain suck on the
44/32 downshift that jams the crank right up. I've never seen that on
anything else.

[NickBull]

I ran 22/32/44 for the year I did BMB (on an FSA MTB crankset) and ran
24/36/46 Sugino XD this year on PBP. Generally, I like the Sugino
better as I find myself not having to make as many shifts in the front
-- I guess that for my SRAM cassette (11/32 or 11/34, depending on
wheelset), the FSA crankset middle ring topped out too "early"
relative to the cassette, so I'd find myself shifting up to the big
ring more often for randonneuring speeds. The slightly bigger middle
ring on the Sugino is still low enough for most hills without dropping
to the granny, but at the same time the high gear on the middle ring
is high enough that I'm not as likely to run out of gear before the
next hill. But for the mountainous terrain of BMB, it really was nice
to have the bailout of a 22/34 when I hit the really steep spots.