Touring - touring gearing

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View Full Version : touring gearing


jbpence
09-08-07, 07:01 AM
just double checing my LBS

for a loaded trek 520, he's recommending a 48-39-22 triple on the front, an 9 speed 11-34 on the rear. this sounds good to me with an couple exceptions.

He thinks that the higher gearing provided b y the 48-39 big and mid rings will allow me to get in the 'groove' wrt sailing along, and I totally get the point. but does this matter? i keep reading about closer spacing for touring. this combo doesnt look very close. check it out on sheldons gear inch calculator (172.5 crank, 770c 32) .

dropping from middle ring to small ring looks to me like a big drop, IE if using 39 front, 34 back thats 31 gear inches. looks like when moving to the 22 tooth small ring, I'll be racheting all the way to the 23 tooth (three shifts on the cassette) , to get 25.8 gear inches. a little crosschaining and one more click gets me 29.7. thats a lot of clicking on bar end shifters and a full load. i dunno.

my first touring bike and first tour coming in about a week, so i'd like to get as close as I can to 'good'. the 39 mid and 22 small looks to me like a panic wha-oops unclicking of a cleat and a tipsy stop on a steep hill coming down the road.

using a 46-36-22 on the front would make that small ring change require three cassette shifts to get from 28.6 gear inches to 25.8 - is that a 'close enough' drop in gear inches? its closer than using a 36 middle ring and 3 shifts. and doing 4 shifts raises the gear inches so not an option. and only a drop of 1.1 rpm at 80 cadence RPM at the top end.

AND: looks like 44-32-22 is the real sweet spot though (this was recommended in another thread about my tour). WIll it shift OK with (tiagra front der). should I EVER i give a rip about top end?


tuz
09-08-07, 07:19 AM
I though front derailleurs could only handle 22 teeth difference, so 48-39-22 wouldn't work. Perhaps in practice no?

Anyways 22-32-44 is very common for mountain/touring bike cranks. Take it!

valygrl
09-08-07, 07:20 AM
I'm running 48-36-22, 11-34 with a chain-watcher and i'm happy with it.


jbpence
09-08-07, 07:48 AM
I'm running 48-36-22, 11-34 with a chain-watcher and i'm happy with it.

what bike do you own? what front der do you use? bar end shifters?

thanks

valygrl
09-08-07, 08:00 AM
2007 Trek 520 17", stock except:

gearing as above, had bike shop change at time of build, since I ordered the bike
swapped stem for 60mm (fit)
shimmed brake levers for short reach
my own favorite saddle & pedals
tubus cargo/tara racks
fenders - unknown model

stock der's, stock bar end shifters. I used Conti TravelContact tires for part-dirt tour last year, they were great. I'm just now trying the stock tires (Bontrager HardCase) and only have 150 miles on them, but they seem fine so far. I used to use Conti TopTouring 28(f)/32(r) and LOVED them, but they don't make them any more.

Couldn't be happier with the 520, by the way. It's my second one, my first died in a crash, and i just replaced it exactly, except taking the opportunity to get the gears I wanted. Before I had the stock front crank, and had put a 26 tooth small ring on it. This was good enough for all but the steepest of hills (and a cheaper solution if you have to do it yourself post-build), but I like riding in the mountains, so I wanted the smallest gearing possible. It still wasn't low enough for some of the hills in Tasmania.

Only thing i don't love about the 520 is the weight.

jbpence
09-08-07, 08:14 AM
thanks so much - called the shop, and the tech (the owner, who tours) liked that 36-22 combination and we are going with 44-36-22 on front and 11-34 on rear. Could go 46 on the big ring, but looking at the gear calculator 44 looks good too. when am I going to exceed 25 MPH - i LIKE coasting downhill. I was most concerned about the low end.

glad to hear this is good for a stock front der and shifter equipped 520 too. He like it because he thinks there is a sweet spot WRT gear-inch spacing, closest not alwasy best if it means having to shift UP to mid ring while climbing. or so he says anyway. he didn't really like 44-32-22 as much.

even if folks chime in - you are experienced and like 36-22, and are using it, and recommend like it, so I'm going with it too.

I'm taking this bike on the Katy trail in MO, ending up in Taos NM. I'm moving there so the rig stays in the mountains for a long time. The dirt roads there get STEEEEEEP. some of the paved ones are dogged steep too. even for a triple 15 pound road bike. my first touring bike and i leave for a 1100 mile solo trip on the 17th. want to do a good job thinking things thru. have to stop the churn and make a call so --- THANKS

wow, now I can focus on the packing list. panniers come in mid next week, doing a local 30 mile camping trip to provide a shakedown cruise probably next thursday, leaving 17th...... excited is the word.

nun
09-08-07, 08:56 AM
Could go 46 on the big ring, but looking at the gear calculator 44 looks good too. when am I going to exceed 25 MPH - i LIKE coasting downhill. I was most concerned about the low end.



I agree, I use a 42/26 double with an 11/34 rear. I never find myself wishing for gears higher than my top end of 103". A nice combo is to to do half step 42/39/24 with and 11-34 rear

NoReg
09-08-07, 09:05 AM
Much of any "problem" you might have will be with the rear cluster. IF you use the widdest imagineable range back there it will have a huge impact on the gear spacing. I try to find tighter ratios like 13-32, and combine that with tighter ratios up front like 46-42-26. The real output depends on your wheel size but the spacing is independant.

An explanation of half step gearing can be found here:

http://www.crazyguyonabike.com/doc/page/?o=QzzM&page_id=56277&v=s

jbpence
09-08-07, 10:19 AM
thanks, a really do appreciate the help.

I'm going tp try this cassette and front ring combo and see how I like it.

gregw
09-08-07, 01:23 PM
I'm using a 22/32/44 chained to 11-34, which shifts very well for me. My middle chain ring (32) seems good for 85% of the average day, not too high not too low, but this is a very personal thing to judge. Oh, and I've never used my highest gear, if that tell you anything.

nun
09-08-07, 01:36 PM
Much of any "problem" you might have will be with the rear cluster. IF you use the widdest imagineable range back there it will have a huge impact on the gear spacing. I try to find tighter ratios like 13-32, and combine that with tighter ratios up front like 46-42-26. The real output depends on your wheel size but the spacing is independant.

An explanation of half step gearing can be found here:

http://www.crazyguyonabike.com/doc/page/?o=QzzM&page_id=56277&v=s

With a wide spaced 9 speed ie 11-34 you sort of (but not quite) get back to the old situation of the widely spaced cogs on freewheels, so using a half step setup to "fill in" the large rear shifts is an interesting idea, but its a personal preference whether you are ok with 15% or 7% between shifts.

Michel Gagnon
09-08-07, 10:50 PM
I'm not a fast rider (built for the long run, I guess), but I have 44-34-22 and a 12-14-15-16-17-19-21-25-34 customised cassette. I very rarely use the 44/12 or even the 44/14 combo.

As for the middle ring, it depends on the terrain you're riding through. I was hesitant between 32, 34 and 36 and now find that 34 is the best I could have chosen. Why? With the large and middle rings (44-34), there is just enough overlap so that I use the middle ring for slight inclines, slight headwind... and the large ring for slight tailwinds. The middle ring is also the one I use all the time except for steep hill climbing. Only once did I find the gap between 22 and 34 a bit too wide; that was when riding through a very strong headwind that required me to stay in the granny most of the time.

NoReg
09-08-07, 11:03 PM
" but its a personal preference whether you are ok with 15% or 7% between shifts."

You're right on both counts. I still haven't come to the 9 speed party. I'm a little less passive about attacking into a hill rather than just hoping I can solve the problem with a gear change. What that guy on CGOAB said about wind, though, rang my bell. In fact one thing I am interested in finding out on the Rohloff is whether the 13 percent jumps are a good idea. Seems like it is going to be a while before I get that project on the road though. I hope my hub is good because it is just sitting in a box for the time being. On the C+ site a while back there was some gearing discusion and I was surprised how low they were gearing on the Rohloff. Sorta in the 18-80 range.