Bicycle Mechanics - Suggestions for touring bike gearing

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Supertick
06-18-08, 10:42 PM
I have done a lot of touring and am not a novice. I did a 3150 mile tour last year and two tours this year totalling a bit over 1000 miles. The gearing on my old touring bike is 44/32/22 with an 11-34 cassette with 700c tires. I like this gearing. I debated posting this on this forum or the Touring forum but this one seems to be the best for this question.
I recently purchased a 62cm Surly Long Haul Trucker complete touring bike. It came with 48/36/26 chainrings with an 11-34 cassette. I want to lower the gearing to the gearing on my old touring bike.
Which of the three choices would be better. The current cranks have a standard bottom bracket.
1. Replace the cranks with the new style cranks with the built in bottom bracket, say maybe Shimano LX.
2. Replace the cranks with a square taper mountain bike crank like Deore.
3. I have a set of old Cannondale cranks with 42/32/22 from an old Super V900 96 model mountain bike that would fit. I don't know the quality of these cranks.
Any ideas. Thank you.
mechBgon
06-18-08, 10:54 PM
I would pick #1, the modern LX or the upcoming SLX. Or you can opt for XT if you have the money. XT will have an alloy inner ring, an extra-long-wearing middle ring (steel teeth on a carbon body, no less!), and a nicer, thicker, forged outer ring, and is available in 180mm lengths to complement your 62cm frame.
clarification: the carbon/steel composite 32-tooth chainring is a new feature on Deore XT, so if you want that, then you want the FC-M770 cranks, and not the old 760-series version. From what I heard, wearout life on the 32-tooth ring is about doubled due to the steel teeth, which sounds like a worthwhile improvement on your workhorse chainring.
Bill Kapaun
06-18-08, 11:24 PM
Is there a difference in the crank length, old vs new? That has an effect. Longer arms apply a bit more torque, which basically is like a lower gear.
How about just replacing the granny ring with a 22?
How largew of a top cog can you live with?
Possibly one of these 13/14-34's might add a bit closer spacing in the mid to upper ranges, while still giving you the "bail out" bottom end.
://sheldonbrown.com/harris/k7.html#9
cyccommute
06-19-08, 08:12 AM
Is there a difference in the crank length, old vs new? That has an effect. Longer arms apply a bit more torque, which basically is like a lower gear.
How about just replacing the granny ring with a 22?
How largew of a top cog can you live with?
Possibly one of these 13/14-34's might add a bit closer spacing in the mid to upper ranges, while still giving you the "bail out" bottom end.
://sheldonbrown.com/harris/k7.html#9
I doubt that the Sugino crank can take a 22. I haven't looked at the BCD but I think (from other discussions I've read) that it's limited to a 24.
I'd go with the external bearing crank. Like threadless headsets, it's a lot easier to fix in the field than spline or square taper.
tellyho
06-19-08, 09:05 AM
Why not just swap out some chainrings? You can at least replace the large and middle. It's an easy thing to try before you spend several hundred on a new crank and BB.
The gearing on my old touring bike is 44/32/22 with an 11-34 cassette with 700c tires.
Just curious. Did you ever use the 22-34 low gear combination when you were touring? And wouldn't using that gear generally be slower than walking?
If your current crankset is a 110/74 BCD, which I think it is, you can change out the small ring down to a 24 tooth ring, and change the middle and large rings to anywhere from 33 to 54 tooth. That gives you a lot of options. Your current crankset, presumably a Sugino XD 600, is a pretty, versatile touring crankset imho.
Edit: I see from the Sheldon Brown gear calculator that spinning a 22-34 low gear at 80 rpm with 700*38C tires and 175mm crank still gives you 4.2 mph. That still beats walking!! I vote number three. Use the Cannondale cranks that you already have on hand.
Supertick
06-19-08, 12:16 PM
I should have explained a bit more. It is the lower gears that I am looking for. And I have used the 22/34 combo on a few hills and I am not getting any younger (62) so lowering the gearing seems like my best option. I am not too worried about the high end, just the low end.
well biked
06-19-08, 01:28 PM
I like the idea of sticking with the Sugino crankset, which has BCD of 110/74. You can go as small as a 24t granny ring. Would that combined with the 34t large cog be low enough?
You could always go QUAD (http://www.abundantadventures.com/quads.html)
The reason I voted for the Cannondale 22-32-44 crankset that you already have sitting there on hand is that when it comes to cranksets, the main difference between a new high end crankset and an older mid level crankset is weight and stiffness, neither of which are very important considerations for a touring bike imo. The durability and reliability on the older crankset, especially coming off a Cannondale MTB with a 1996 MSRP of $1,700, should be quite good, and you can always spend as little or as much as you want on the chainrings when it comes time to replace them. Some tourers purposely opt for less expensive, heavier steel chainrings because they last longer than modern, lightweight machined aluminum rings.
I still have a mountain bike Deore LX 110/74 BCD crankset from about 1990 on my touring bike, and I have never had the feeling when I get off my modern Dura Ace equipped race bike and jump on my touring bike that I am putting up with an inferior crankset. Different bikes. Different purposes. And just my opinion.
Michel Gagnon
06-19-08, 07:44 PM
You said that on your old bike you used your 22/34 often enough to make it useful. With the stock crankset, you are limited to a 24-tooth granny and a 34-tooth middle ring.
1. Would you be OK with a 24-tooth granny (i.e. 24/34)?
I know I prefer as low as possible, but you are the one who decides. 24/34 is similar to 22/31. In other words, if your previous bike had 11-13-15-17-20-23-26-30-34, you would be loosing almost one gear... but not quite.
If you feel you really want your 22, then either move the crankset you have on the old Cannondale or get a new mountain one.
2. In terms of quality, I don't know what makes your old Cannondale crankset a "lower quality" crankset. Most of the differences between "lower" and "higher" quality cranksets are weight issues or things related to STI shifting.: i.e. not a problem here. So unless you have worn parts, I don't see any problem here.
3. I like low gears. My single bike has an XT crankset with 44-34-22 (BTW, I prefer the smaller gap at the top), but my tandem came with a road crankset (48-38-24). Because I ride with two children in tow and do self-contained tours, I wanted lower gears than that. So I got a quad (http://www.mgagnon.net/velo/pedalier4.en.shtml). Great, but I needed lots of fine tuning to make it work properly (it now shifts beautifully), and I think it only makes sense if you have rather high gears. In other words, with the stock LHT, I would go with 48-38-28-21 or 48-38-26-20.
BCRider
06-19-08, 09:25 PM
3 people that I've heard about the external bearing style cranks from all said that they are amazing. Very stiff with no flex at all. And they are lighter overall than the cranks and sealed BB setup. Win-win all around. However they were all 20-something chargers that can really pump out the pace.
Us "more mature" riders may not notice the gains since I suspect our long term mashing is behind us..... :D Still, if you don't mind the cost it's a nice bit of bling to put on the new bike.
mechBgon
06-19-08, 10:17 PM
Us "more mature" riders may not notice the gains since I suspect our long term mashing is behind us..... :D Still, if you don't mind the cost it's a nice bit of bling to put on the new bike.
In point of fact, Shimano now uses external-bearing cranks/BBs in almost all their road groups, all the way from Dura-Ace down to 3400-series Sora. Only the absolute bottom road group, namely Shimano 2200, uses anything else. So I expect to see the external-bearing "bling" coming right down the mountain/trekking lineup too :) Vanilla Deore will probably be next to get the treatment.
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