Hello,

So I currently ride a bike with a 30-42-52 by 11-28. I don't tour on this setup but I do ride long distances.

I have a 26-36-48 by 11-34 drivetrain on the shelf (with the appropriate derailleur and a separate chain), that I have never installed but bought for doing loaded touring.

If I were to switch back and forth between the two, installing the touring setup for my weekenders and switching back to the other setup for road rides and commuting, what do I need to be concerned about? Do I need to change the derailleur each time or could I just leave the long cage derailleur on all the time? If I need to change derailleurs, do I need to change the cable each time?

Thanks.

If you are using a MTB rear derailleur, you should be ok at the rear. The chain wrap required is 2 units greater on the touring drivetrain, but should work. Check the chain on the big-big combination to see if the chain is long enough.

The front derailleur will need to repositioned and adjusted. Changing over will take some time and effort.

Assuming that these are 3x9 or 3x8 drivetrains, I would use one crank. A Shimano Tiagra 4503 can take a 26 or even a 24 small chainring. This will provide a 50, 39 & 26 (or 24) chainring set. You could sell the two cranksets and the extra derailleur and be $$ ahead.

https://www.google.com/products/catal...d=0CGcQ8gIwBA#

and

https://www.google.com/products/catal...d=0CDQQ8wIwBA#

or

https://www.google.com/search?tbm=sho...l0l77l77l1l1l0

I'm thinking that before I started changing drivetrains out for different types of riding I'd seriously consider just having two bikes. Or just run a compromise, say 26-39-52 with an 11-34. That's what I run on my 520.

This is what I would do myself, too... another bike (even a used one for commuting) or find a compromise with my drivetrain. No concerns other than it's too much of a PITA to be messing around changing cranksets, cassettes, chain twice a week.

I'm not crazy enough to change the drivetrain two times a week. I get to go on weekend tours 6 times a year if I'm lucky.

The suggestion to build two bikes is a good one, and that's exactly what I'm doing. But the second bike won't be ready for quite some time. I'm still missing some parts and it may be a while before I have the time to restore what's there and the money to buy what is needed. I still need a rear wheel, pedals, brake levers or butterfly bars, and shifters. Plus cables, tape, tires, etc.

matthewpetty, There's a couple of ways to simplify this. First and easiest is to swap the cassettes and ride for evaluation. The second easiest is the crankset swap (my choice) and use the closer ratio cassette for weekends and the wider range cassette when loaded. You may find that you don't miss the original crankset too much.

Brad

That sounds like a winner to me, too. Maybe it`s just me, but messing with a front derailler always leaves me frustrated, so I try to avoid it whenever possible. Much easier (for me) to do ANYTHING with the rear. Will your current RD handle the mtb cassette? Even if it doesn`t, any derailler compatible with that one will certainly work with your 11-28, so you could just change it one time and swap wheels at will (with a chain long enough for the big cassette).

I see front derailleur issues between the crankset swap; having to buy new cables quite often. It just looks like a pain and putting the long cage RD, 11-34 and 30-42-52 would be the lesser of all the evils, but your buddies on the group ride are going to make fun of the pie plate on your rear wheel. I also don't like to take bottom brackets in and out, but that may just be me. Good luck

My choice has been two bikes. It saves me the frustrations of getting the drive train dialed in every time I changed it.

I have 6 bikes and I still chose the compromise method. Once I figured out my riding style was better suited to a wider spaced cassette regardless of touring or town riding. I tried a bunch of gearing changes and came to the conclusion I needed a small granny gear in the front and a range of larger gears in the back to climb loaded. That range also worked fine as town gears as long as I left the center ring road gear sized. And the big ring is what a big ring does, moves you down the road fast when not loaded. I found my town riding now just staying on the center ring and using all 9 gears in the back sequentially for 90% of my riding. I personally don’t miss the double shifts.

If your town riding is less leisurely and more race oriented then I say two bikes and a tighter cluster. The other reason I say two bikes is touring bikes tend to take on weight with racks and fenders etc. and a good touring bike has heavier built wheels and frame and maybe a little more relaxed geometry.

What I found is all the nice features in a touring setup made me happy when town riding also. I have a very light road bike but most of the time I grab the tour setup bike.

Just for comparison I run 26-42-52 by 12-36 (9sp) with 700 wheels.

11t top cassette cog, even the 48t is over-geared.. 4:1,= 11:44, 12:48.. 13:52..

I could live with a 14-38and not have to alter the chain rings.

I have four bikes that use three distinct drivetrains.

All of my bikes have triple cranksets. Two of the bikes have Shimano 105 triple cranksets with ten speed cassettes. The other two bikes use Deore triple cranksets with nine speed cassettes.

Touring and trail riding with a 48, 36 & 22t cranksets and a 12-27 or 11-32 cassettes;



Touring only with the same 48, 36 & 22t crankset and a 12-27 or the 11-32 cassettes;



Fitness road-riding, faster gravel tow-path, century events and commuting with a 50, 39 & 26t crankset and a 12-30 cassette;



Fitness road-riding, group rides and century rides with 50, 39 & 26t crankset and an 11-23 cassette;



The 3x10 drivetrains with 50, 39 & 26t and an 11-23 or the 12-30 cassettes have very tight gear spacing and very small changes in cadence with each shift.
The 3x9 drivetrains 48, 36 & 22t and a 12-27 or the 11-32 cassettes have moderately tight gear spacing but the 22t provides improved climbing with a heavier tour.

Loaded touring thru several western European countries several trips,
the top gear at 95" a 14:50, 700c-35 tires was fine..

low was a 24:34 ..
as always, YMMV..