Will a different cassette help with climbing?
I have changed my original road chainrings from 52/42/30 to 46/36/24, and I am very happy with the difference in climbing ability. Can I expect to realize any additional climbing ability by changing my cassette to something other than the 11-32 that I have now? Thanks!
From 11-32, about all there is left is 11-34. That would get you an extra gear-inch or so at the bottom end. You could still go from 24 to 22 in the front, I suppose (give or take shifting constraints). And, oh yes, could use longer crankarms if it doesn't mess up your pedalling.
Has opinion, will express
Well, I think you can only go as low as 34T as the granny cog on the rear.
With the 24T chainring, and assuming your bike has 700C wheels (using 27 inches in the ratio calculation), you currently have a gear-inch reading of around 20.25gi with the 32T cog.
If you go to a 34T cog, that would come down to 19gi.
My Fuji Touring with an MTB chainset (22T as granny) and 32T rear has a ratio of 18.5gi, which is about as low as I would like to go. It gives me a speed of around 5.5km/h on, say, a 15% gradient unloaded.
Has opinion, will express
Not on the crankset he is using, I think. Unless he goes with an expensive adapter. The 22 really is only doable on the MTB crankset.
Originally Posted by HardyWeinberg
The cranks they put on road bikes are too tall for most riders IMO. Who the heck can spin a 52 except going downhill? Thats more a marketing decision than trying to match the product to the users needs. The recent trend towards so-called "compact road" cranks is a logical move towards a more useful gear range.
A 34t gives you 2/32= 1/16 = 6% "lower" gear than your current cassette. Standard cassette offerings don't go beyond 34. So that may be helpful. There are a few sources for touring specific cassettes http://www.sheldonbrown.com/harris/k7.html#9cassettes . You can build your own too from say, 11-34 and 13-25 hg-70 cassettes. Worse thing that can happen is they don't shift super smooth at one or two transition points.
Also, you can probably find a 22t inner chainring - if thats a sugino crank i know they sell them for ~10 bucks at aebike.com. Whether your FD will take it or not another issue, most shimano derailers spec 22t range from high to low gear, although i have read several people seem to get beyond this range a bit, i personally haven't tried it.
Finally a narrower tire will generally have a smaller diameter - easier to turn.
After that its all you - grow bigger lungs/legs, lose weight (you or vehicle), or choose a flatter route.
Year ago I had this thing you could put on the bolt pattern somehow and it was a fourth ring, about half the size of the 26 front. Not sure who made it or whether it is still made, it was good quality back when I got it. Sadly that bike was stolen. Not really practical but it did get used now and again.
On a more serious vane, I would look for the 13-34. Anyone (like a lot of us), who needs 32-34 has no business with an 11 sproket, and it ends up robbing some nice extra gears that are useable when you are trying to do 95% of the remaining spinning.
I had thought the 11t cog was absurd, but the more I realize that even 50t is overkill for the big chainring, eventually the 11t cog in the back comes back into play. I use it a couple times each way on my commute (44t big chainring).
Originally Posted by Peterpan1
I can see that, I find though that when I ride around without paniers I ride mostly in the two big rings, and when I ride with panniers I ride mostly in the two small rings. Mostly I ride in the middle ring, so scouring the density there to get me an extra inch or two where I don't use it is pretty pointless. Now if this was a "how to have more fun on my comute" thread...
Also I think it depends on the kind of riding one does. Actually in my small neck of the woods there are lots of 13% hells out on tour, I try to avoid them. But I imagine that crossing the rockies (I hear it's 6% at worst I know at least one much worse hill but anyway) is all uphill and then really fast long downhill. So mega range makes sense. But if your tours are less mega, then fitting a gear to the wind etc... can be much more important than the widest range. At least that is the theory.
Mad bike riding scientist
You must be talking about the Mountain Tamer Quad which, apparently, is still available.
Originally Posted by Peterpan1
On the 13-34 vs an 11-34, I'd agree that if you are running a 52/40/24, a 13-34 would be an excellent choice but if you are using a 44 or 46 or even a 48 outer ring, a 13 tooth cog is too low. I've ridden mountain bikes that have this combination and you spin out very quickly since you have either a 91", 95" or 100" gear. The only one that would be useful would be the 48/13 combination.
Using Sheldon Brown's gear calculator, you'd reach 25 mph at 90 rpm with a 44/13 which is pretty slow. Lots of places here in the west would have you coasting for miles, literally, with that gear. And if you coast too long, your knees won't be your friend when you hit the next uphill. Trust me
According to my calculations, with the 11/34 you'd only go from 23gi to 21.6gi. And that means:
With the 11-32T cassette, with your cadence @60 = 4mph, @80 = 5.5mph, @100 = 6.8mph.
With the 11-34T cassette, with your cadence @60 = 3.8mph, @80 = 5.1mph, @100 = 6.4mph.
Considering that at low cadences you're barely above walking speeds to begin with, I don't think this change will help that much. 23gi is pretty low as it is.
An additional problem is that an 11-34 cassette may require a chain guide / chain tensioner.
I have heard of some bikes that have a huge range, specifically folding bikes that use the SRAM DualDrive instead of a triple up front. The DualDrive is a 3-speed internal hub / planetary gear that, combined with a rear derailleur, gets you a gearing range from 18" - 110". But IMO that's kind of excessive, since at such a low gear you are practically walking.