Advice on Lower Gearing

[mkmiller91]

Was looking into upgrading my cassette and rear derailleur to get some lower gears. I have very minimal knowledge of this and was looking for some advice. My current setup is a Cannondale Caad 8 with a Shimano 105 5700 rear derailleur and a Shimano Tiagra 4600 12-28 10 speed cassette. My crankset is an FSA 50/34. Was looking into getting a cassette with about a 32T max and wanted to know if a rear derailleur that has a recommended max cog of 30T would still be ok. I read somewhere that you can go over the max recommendations but I just wanted to be sure. I found a Shimano Tiagra 4601 RD with a max 30T cog. Thank you for any help or info!

[RussSeaton]

You can usually exceed the maximum cog on a rear derailleur by 1 or 2 teeth.  Usually.  But the only way to know for certain is to install the cog and rear derailleur on the bike and shift it.  Only way to know for certain.  I'd suggest finding a long cage rear derailleur.  Shimano 105 or Tiagra should work fine with your shifters.  That long cage rear derailleur will handle a 32 or maybe a 34 tooth cassette.  Maybe on the 34 cog.  Try it to be certain.  Maybe you could put a 33 tooth inner chainring on the crankset if it is a 110mm bcd crank with five arms like "old" cranks used to be.  Not sure what your FSA compact crank looks like.  Try to find a 12-32 or 12-34 cassette.  But you may be forced to use a 11-32 or 11-34 cassette.  Not sure anyone makes a 12-32 or 12-34 ten speed cassette.  With a 50 tooth outer chainring, a high gear of 50x12 is plenty high.  Despite the internet being filled with countless people who need a higher gear than 53x11 because they spin out so easily.  Size your chain so it just fits the big-big combination.  50x32 or 50x34.  Don't worry if the chain hangs loose when in the small-small combination.  Never use that gear anyway.  And using it won't break your rear derailleur off the hanger.  Like a too short chain on a big-big combination will.

[Pat Lamb]

What kind of riding are you planning to do?  You're playing around with a 27-30 gear inch "low."  I'd find it difficult to go for a ride in the mountains, loaded or unloaded, with a gear like that.  But there are lots of people younger or in better shape than I am.  And for those people, especially if they're carrying a minimal load, a 27" low may be enough.  (See http://www.sheldonbrown.com/gear-calc.html for a a good gear calculator)

I usually aim for about 20 gear inch low, especially if I'm carrying a load.  You're going to have to change out the crank to get down there, which probably means a new front derailer as well.  Add in a 34 or 36 cassette in the back, which will probably require a long cage derailer as well.

[mkmiller91]

Thank you for the advice! Yes I have been reading a lot on sheldonbrown.com to learn about gear inches. I usually ride around 150 miles per week when the weather finally warms up here in the Northeast lol. But this summer I am planning to do some weekend rides that include some steep hills but not mountains, for the first time with as little load carrying as possible. I was going to for this summer at least try out an 11-32 cassette for a 34-32 low combination. Then to start off I would just be getting the new rear derailleur and cassette to try and not complicate it too much in the beginning.

[Pat Lamb]

Try it and see how it goes.  All gearing has the really low combination available -- two feet on the ground pushing the bike up the hill.  Make sure you've got cleat covers if you're using road pedals.

[RussSeaton]

two feet on the ground pushing the bike up the hill.  Make sure you've got cleat covers if you're using road pedals.

Eeeek!!!!  I HOPE every bicyclist tourer with clipless pedals is using SPD or Frog or Bebop pedals/cleats.  NOT road pedals.  A concealed, small cleat on the bottom of shoes that is unobtrusive and easy to walk in.  I can walk miles and miles on almost any terrain with my SPD shoes and sandals.  I could easily survive and thrive with no other shoes except maybe flip flops on any tour of any length from one week to one year.

[Pat Lamb]

Russ, I actually agree with you on using some kind of MTB pedal and cleat system. Although it's possible to wear out the rubber cleats on the shoes, that takes a lot more walking than the flimsy metal cleats.   That said, I've seen a few tourists using road bike pedals, ergo the warning was specific to those.

[great_egret]

The article, "A Big Shift" in the April 2016 issue of Adventure Cyclist is a good primer on the confusing world of drive trains for touring bikes.  The blog Cycling About has some very specific solutions to getting down to the desired 20 gear inches.  Check out the post here:

http://www.cyclingabout.com/wider-gear-range-road-shifters-gears-for-easier-hill-climbing/

The biggest issue is your crank.  Depending on your wheel size, with your 34t inner ring, it won't be possible to get below 29-ish gear inches with a 32t rear cog and 27-ish gear inches with a 34t rear cog. 

Compatibility is confusing and hopefully the Adventure Cyclist article and the Cycling About blog post clarify things.  There are good solutions.  They become easier and more expensive the more willing you are to swap out drive train components.

[BikeFreak]

two feet on the ground pushing the bike up the hill.  Make sure you've got cleat covers if you're using road pedals.

Eeeek!!!!  I HOPE every bicyclist tourer with clipless pedals is using SPD or Frog or Bebop pedals/cleats.  NOT road pedals. 

I bicycled 4 times across USA and circled Australia with normal leather boat shoes. I even did the continental divide trail with my boat shoes. And no they are not special ones fitted with a SPD system. And I average at 125 mi/day. And my next tour will be with my boat shoes again. And yes, I have had 2 pairs of SPD shoes and I quickly dumped them because I dont like them at all.

Lucas

[RussSeaton]

I bicycled 4 times across USA and circled Australia with normal leather boat shoes.

You will have to provide a better description of what "boat shoes" are.  Maybe a web link.  As for preferring your "boat shoes" over SPD shoes and clipless pedals, I would guess there are one or two million times more people who use SPD shoes than use "boat shoes".

[BikeFreak]

Boat shoe: https://s-media-cache-ak0.pinimg.com/originals/9d/1d/46/9d1d460862751889381a30459f9645a7.jpg

I once met a guy who raced the German Continental Divide Trail (Grenzsteintrophy) with clogs: http://media.demo.all4coding.com/magento/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/c/n/cn-clogs-beach-garden-clog.jpg

Lucas

[RussSeaton]

I remember those shoes from 30 years ago.  Have not seen anyone wearing them in recent decades.  Down tube, stem, and bar end shifters were the only way to shift a 5 or 6 or 7 speed freewheel back when those shoes were popular.