"John Rees" <
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> "David Storm" <
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>
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> |
> | "Roy Zipris" <
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> |
news:[email protected]...
> | > A recreational club rider, I climb the hilly, rolling terrain around here (SE Pennsylvania)
> | > not too badly, but sometimes wish I had one more gear to shift into when the hills get too
> | > long and I slow down
> to
> | > the mid-single digits. More of a masher than a spinner, I ride a Lemond Buenos Aires with 105
> | > triple components; the front chainrings are, I think, 30-42-52 (but I rarely use the 52), and
> | > on the rear, nine cogs (12-25, I think). What changes to the front and/or rear gears could I
> | > consider to give me that extra gear to spin a bit more on grueling climbs? I'm getting older
> | > and it's not getting any
> easier.
> | > Thanks. Roy Zipris
> |
> | On my new Trek I had the LBS switch me over to an 11-32 cassette and XTR rear mountain
> | derailleur. Works great, but XTR derailleur are pricey....could go with cheaper XT. On my old
> | Cannondale I've got an Ultegra triple with an 11-32 cassette. The triple derailleur can
> handle
> | that setup, but just barely....grumbles at bit when using 32 cog.
>
> I think the XT rear plus an 11/32 or 12/32 are a good, and easy to do combo. I did this on my
> wife's bike so I could swap back and forth between a 12-27 for riding around here, or the 12-32
> when she's in very hilly conditions.
>
> However, if you are finding yourself rarely in the 52, why not move all three front rings down a
> notch, and keep close spaced gearing? Swap the 105 crankset for a mountain crankset, like an LX or
> a Deore. You would end up with a 44 as your big ring, and something like a stump pulling 24 for
> your granny.
>
> To do this, you would need to change the crankset and the front derailleur. The part you have to
> be careful on with the front derailleur is you need a BOTTOM PULL mountain (or hybrid) model,
> since most mountain bikes use a top pull.
>
> Also, the newer Shimano mountain cranks use the ES71 splined bottom bracket, which has deeper
> splines than the original Octalink. So, you would have to either get a bottom bracket or go with
> mountain crankset that mates with the original octalink. Most bike shops have 'take offs' from
> mountain bikes that were upgraded when purchased. You should be able to find a crankset that
> matches your existing bottom bracket at a reasonable price.
Alternatively, instead of swapping out your crank/bb to a "mt" one, a simplier solution may be to do
what others have said and downsize your current chainrings. The 105 triple crank has a 130/74mm bcd.
That means you could do something like the following: big chainring 52 -> 48 or 46 middle chainring
42 -> 38 (smallest middle ring size) small/inner chainring 30 - >as low as 24 Something like a
48/38/24 with your 12x25 in the back should gear you down low enough....