Author Topic: Tour Bike Gearing  (Read 5120 times)

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Offline HWP

Tour Bike Gearing
« on: July 03, 2012, 11:08:12 am »
I just purchased a Gunnar Grand Tour frame as a retirement gift to myself and am now struggling to select components, particularly gearing.  I live in Wisconsin and will be touring the Midwest (trip planned to Traverse City/Mackinac) and am considering a TA in the future, so I want to make sure I have adequate low end for the mountains.  I could have used gearing lower than my Madone (50/39/30:12-27) while riding (unloaded) the hills around the Mississippi in western WI!

I have been looking at other tour bike set-ups to get an idea on gear selection (Co Motion, Surly, Novara).  I thinking a triple 48/36/26 or 48/36/24 with an 11-34 cassette.  Front derailleur selection seems to be problematic (according to specs) with a max difference of 22 or 24T.  The Co Motion Americano offers a FSA Afterburner 48-36-26 crank with a Shimano XT 11-34 10-speed cassette and an option for Shimano 6700 Ultegra STI shifters, which I really like on my road bike.  Any concerns with this setup?

Wheels are my next big challenge...thinking 700X28 tires as I plan to ride mostly roads, with occasional gravel trail/road.  Need to be rugged to support loaded touring....36, 44 or 48 spoke count?

Appreciate any help provided.

Offline jrswenberger

Re: Tour Bike Gearing
« Reply #1 on: July 03, 2012, 12:28:19 pm »
My personal preferences and experiences lead me to recommend:

1. Your gearing cannot be too low. Even if you rarely use the lowest gears, your knees will thank you.  The high end tends to be ridiculously high in a touring set up. If I'm going that fast, it's time to coast!!!

2. 28 mm tires would be my absolute minimum size for touring and that would be only on a credit card tour. If you are self-supported, think 38+. Think tortoise, not hare when loaded down.

I ride slick 28s on my regular road bike on all sorts of roads, paved and unpaved, graded and double track trails. They handle all conditions well. For me to enjoy myself on a long tour however, comfort is paramount above all else. This has led me to put 50 mm tires on my current touring bike. They are plenty fast enough for a loaded bike that will likely see less than ideal conditions on tour.

Of course, YMMV.

Good luck and maybe we'll see you down the road,
Jay
ACA Life Member 368

Offline paddleboy17

Re: Tour Bike Gearing
« Reply #2 on: July 03, 2012, 12:31:13 pm »
It is hard to beat a mountain bike crank (22/32/42) on a touring bike.  You would need to get the matching front derailleur.  Sometimes you can get a road front derailleur to work.  I think they changed the pull ratios so that road and mountain rear derailleurs are different, but I think fronts are still the same.

I would run a bigger tire.  32s would be fine for everyday use and 35 for touring.  I think you could get by with 36 spokes--I hear 48s are like naughty children with a tendency to just do their own thing.

You thinking of taking the ferry (USS Badger) to Ludington?  The ride along Lake Michigan is suberb.
Danno

Offline staehpj1

Re: Tour Bike Gearing
« Reply #3 on: July 03, 2012, 12:44:21 pm »
Wheels are my next big challenge...thinking 700X28 tires as I plan to ride mostly roads, with occasional gravel trail/road.  Need to be rugged to support loaded touring....36, 44 or 48 spoke count?
How much will you be carrying?  That will effect both what wheel choices you make and what tire size you use.

Personally I like 28's for my heavier loaded tours.  That is for 30 pounds or so of gear and a rider weight of a bit over 200.

On my last tour carrying about 15 pounds of gear, I used 23's for a while since they were already on the bike and found the buzz when on chip seal to be unpleasant.  It was greatly improved when I switched to 25's.

Wheels with 36 spoke are plenty robust for all but really heavy loads and rough roads.  Even 32 spokes should be fine if the load is reasonably light.  The key thing is that the wheels were tensioned properly.   Either hand built wheels or machine built wheels stress relieved and tensioned by hand are a good idea.

Offline Pat Lamb

Re: Tour Bike Gearing
« Reply #4 on: July 03, 2012, 02:42:23 pm »
It is hard to beat a mountain bike crank (22/32/42) on a touring bike.  You would need to get the matching front derailleur.  Sometimes you can get a road front derailleur to work.  I think they changed the pull ratios so that road and mountain rear derailleurs are different, but I think fronts are still the same.

I think you've got that backward (unless it changed this year).  Shimano rear derailers have been agnostic for road/mountain and number of speeds for a long time.  My 2009, 9-speed Novara Randonnee works well with a Tiagra front and Deore rear derailer, both with STI brifters.  The small chainring is a 26, IIRC, although I may get a round tuit and change it to a 24 one of these days.

There's no need for a big chainring on a touring bike.  The only time you might need it would be if you take it on a fast group ride, and the bike gives you a ready excuse to drop when pack speed exceeds 30 mph.


Offline Old Guy New Hobby

Re: Tour Bike Gearing
« Reply #5 on: July 03, 2012, 05:34:05 pm »
Don't start with gear sets. Start with what gearing you want. After you decide that, you can decide how to get there. I think a granny gear of 17 gear-inches is ideal. That's around 3 to 4 MPH with decent cadence. Any lower, and the bike might tip over. This should let you get somewhere around 90 gear inches on the high end. For me, this means spinning out at about 25 MPH. Sheldon Brown's gear calculator may be helpful. http://sheldonbrown.com/gears/

There is little disadvantage to fatter tires in road touring, provided you don't use "knobby" tires. I used 700c x 32 and 700c x 38 at different times. Both worked well. Keep in mind that gravel trails aren't always dry, and that the bottom of that puddle might be slick mud. Make sure you get high quality touring tires. Otherwise, you'll go crazy fixing flats. Also, get high quality tubes.

The quality of the wheel build is more important than the spoke count.

Offline DaveB

Re: Tour Bike Gearing
« Reply #6 on: July 03, 2012, 07:23:34 pm »
I think you've got that backward (unless it changed this year).  Shimano rear derailers have been agnostic for road/mountain and number of speeds for a long time.  My 2009, 9-speed Novara Randonnee works well with a Tiagra front and Deore rear derailer, both with STI brifters.  The small chainring is a 26, IIRC, although I may get a round tuit and change it to a 24 one of these days.
Almost right.  Until the current 10-speed MTB "Dyna-Sys" groups were introduced, indexing Shimano rear derailleurs from 7-speed through 10-speed road were compatible with any speed road or MTB rear shifter (with the sole exception of pre 9-speed Dura Ace).  Dyna-Sys 10-speed MTB rear derailleurs only work with their matching MTB shifters. 

Offline dkoloko

Re: Tour Bike Gearing
« Reply #7 on: July 04, 2012, 10:08:30 am »
Gearing: I would keep 20 gear inches as target low for you. That is 24x32. Lower can be good. New bike I am currently building will have lower.

Front Derailleur: Probably over concern. I have used racing double derailleurs on triples with  range 53-24T with no problem. If derailleur has sufficient snuggle factor (my term), it will probably work. Snuggle factor: ability to get close enough to seat tube to drop onto small chainring of triple setup.

Shifters: I am taking brifters off my new touring bike and replacing them with bar ends. Too many stories of being unable to repair brifters on road.

Tires: I have toured on tires from 20 to 35mm. I suggest 32mm as target.

Spokes: Stick with 36 spokes. Much easier to get parts if need repairs on road, and should be adequate for your needs. What I use. Certainly 28mm tires and  40 or 48 spoke wheels is a mismatch.

Offline driftlessregion

Re: Tour Bike Gearing
« Reply #8 on: July 04, 2012, 10:58:52 pm »
Good choice of a Wisconsin made bike. I'm from La Crosse and Madison and love those hills in the Mississippi River Valley. I agree that touring in the Driftless Region of Wisconsin you can't get too low with your gearing.
In September I toured halfway around Lake Michigan  from Manitowoc north then across the UP, across the bridge [you can't ride across actually] and along the lake down to Luddington and then took the ferry back to our car in Manitowoc. 95% of that route won't require extremely low gearing but that 5% did.
It's a great route. Lots of great retaurants and fresh fish. Have fun.

Offline HWP

Re: Tour Bike Gearing
« Reply #9 on: July 05, 2012, 10:30:46 am »
Thanks for all the helpful advice.  I am leaning towards 24/36/46 with 11-34 for gearing.

I did want STI shifters as I like them on my Madone, however I am finding that to be problematic as the new 10sp Dyna-Sys isn't compatible with STI....although the Co Motion Americano offers this as an option!!  I have seen that the older 9sp RD works...so that could be an option.

Another alternative could be SRAM as their shifters work their MB RD, however they do not offer a triple. One suggestion has been to use bar end, downtube or MB shifters for the FD as SRAM does not support triple cranks...seems a little funky but could work!

I am coming to the conclusion that it may not be worth the hassle and that bar end shifters may be best for reliability/simplicity.

Appreciate your thoughts.

Offline RussSeaton

Re: Tour Bike Gearing
« Reply #10 on: July 05, 2012, 12:28:24 pm »
Tires:  I like big fat wide tires on my touring bike.  35mm Specialized currently.  Have used 32 and 38 at times.  But a friend uses 28 tires.  So about anything will work I suppose.

Low gearing:  Lower the better.  Smallest inner chainring possible.  Biggest rear cassette cog possible.  Your crankset seems to be 74mm bcd inner.  So 24 is the smallest.  Mountain bikes seem to use 22 teeth as the smallest.  Not much difference.  A 34 tooth rear cog is good.

Front derailleur:  For whatever reason people seem to imagine all sorts of problems for this.  People are enamored with fiction.  I use a Shimano STI 5703 10 speed triple shifter with a 9 speed Tiagra front derailleur and 10 speed cassette and chain.  Shifts perfectly.  I'm pretty sure most other combinations work fine too.  Don't invent problems.

Spokes:  36 spokes per wheel works fine.  Loaded or unloaded.  No need for tandem spoke wheels.

Offline dkoloko

Re: Tour Bike Gearing
« Reply #11 on: July 05, 2012, 12:35:00 pm »
"Low gearing:  Lower the better.  Smallest inner chainring possible.  Biggest rear cassette cog possible.  Your crankset seems to be 74mm bcd inner.  So 24 is the smallest.  Mountain bikes seem to use 22 teeth as the smallest.  Not much difference."

A difference that can make a difference. Not much difference in number of teeth, significant difference in percentage, 8 percent. Would you say dropping from 52 teeth to 48 teeth for large chainwheel is not much difference? Same 8 percent.

Offline Pat Lamb

Re: Tour Bike Gearing
« Reply #12 on: July 05, 2012, 02:08:09 pm »
"Low gearing:  Lower the better.  Smallest inner chainring possible.  Biggest rear cassette cog possible.  Your crankset seems to be 74mm bcd inner.  So 24 is the smallest.  Mountain bikes seem to use 22 teeth as the smallest.  Not much difference."

A difference that can make a difference. Not much difference in number of teeth, significant difference in percentage, 8 percent. Would you say dropping from 52 teeth to 48 teeth for large chainwheel is not much difference? Same 8 percent.

Sorry, I've got to agree with Russ on this one.  Using www.sheldonbrown.com/gears and assuming a "standard" 11-34 cassette, and calculating the speed at 60 rpm (slower than I'd like to climb, but sometimes necessary), I fly up the hill at 3.4 mph using the 24 tooth chainring.  Compare that to crawling up the same hill with a 22.  (/sarcasm off)  Yes, you're talking about one extra gear.  But I'd give up that lower gear before I'd compromise shifting.  I don't know of a way to reliably shift to a 22 chainring using STI shifters, and it's critically important to be certain you can use that lowest gear when you hit the nasty hills.  Besides, we're approaching the speed at which I can walk a loaded touring bike uphill (2.7 mph, verified more times than I want to admit!).

Offline RussSeaton

Re: Tour Bike Gearing
« Reply #13 on: July 05, 2012, 03:05:07 pm »
"Low gearing:  Lower the better.  Smallest inner chainring possible.  Biggest rear cassette cog possible.  Your crankset seems to be 74mm bcd inner.  So 24 is the smallest.  Mountain bikes seem to use 22 teeth as the smallest.  Not much difference."

A difference that can make a difference. Not much difference in number of teeth, significant difference in percentage, 8 percent. Would you say dropping from 52 teeth to 48 teeth for large chainwheel is not much difference? Same 8 percent.

As already stated, percentage changes lose their significance when you are talking about small gears.  For small gears you need to look at the difference in gear inches between gears.  Percentage difference is OK at the large gears.  For instance, take gears of 1 inch and 2 inches.  50% or 100% difference.  The 2 inch gear is TWICE as hard to pedal as the 1 inch gear.  In reality, you could not tell the difference on a bike.  Same logic applies for low bike gears around 20 gear inches.  You can tell the difference between a 25, 20, and 15 gear inch gear.  But in reality, there isn't much differene.  All will work just about the same climbing a hill.  It would be nice to have the 15, but the 20 is perfectly fine too.  And the 25 does not put you at much of a disadvantage.  All three gears would be equal enough.  Huge percentage difference though.

In another post it was commented that STI would not reliably shift to a 22 chainring.  ??????????  My Shimano STI 5703 triple 105 shifters shift a 44-33-20 crankset perfectly well.  STI shifts all cranksets fine.  There can be difficulties in getting the front derailleur set up properly.  But the STI shifter will shift between any and all chainrings fine.  Size is irrelevant.

Offline dkoloko

Re: Tour Bike Gearing
« Reply #14 on: July 06, 2012, 11:01:16 am »
"Sorry, I've got to agree with Russ on this one.  Using www.sheldonbrown.com/gears and assuming a "standard" 11-34 cassette, and calculating the speed at 60 rpm (slower than I'd like to climb, but sometimes necessary), I fly up the hill at 3.4 mph using the 24 tooth chainring.  Compare that to crawling up the same hill with a 22.  (/sarcasm off)  Yes, you're talking about one extra gear.  But I'd give up that lower gear before I'd compromise shifting.  I don't know of a way to reliably shift to a 22 chainring using STI shifters, and it's critically important to be certain you can use that lowest gear when you hit the nasty hills.  Besides, we're approaching the speed at which I can walk a loaded touring bike uphill (2.7 mph, verified more times than I want to admit!)."

Compromising shifting is not true, with well planned gear ratios. As mentioned, I do not use or recommend STI shifters for touring (reason given). Walking a hill for me would be very rare (maybe you need lower gears). As I stated, I think 24T is fine for a target, but as I also stated, lower is better, particularly for someone with limited experience as the person who started this thread.  Percentage makes a difference, and it is not to palmed off with comment couple of teeth difference doesn't make a difference for lowest gear. I have experienced the difference using 24T low and 22T low over many thousands of miles.
That experience caused me to remove crank with 24T low on new bike I am building to substitute a crank with 22T low at significant expense.