Author Topic: Advice for choosing components to reduce gear inches  (Read 10907 times)

0 Members and 1 Guest are viewing this topic.

Offline TransAM2010

Re: Advice for choosing components to reduce gear inches
« Reply #15 on: August 17, 2017, 12:19:36 am »
Russ, isn't 20-22 tooth capacity for a front derailleur pretty standard? You're running a crank set that requires a 24 tooth span and I think mine is 22 - small ring of 24 large ring of 46 in my case. I've seen 20 teeth specced as the range for a bunch of front derailleurs.

Offline RonK

Re: Advice for choosing components to reduce gear inches
« Reply #16 on: August 17, 2017, 05:45:13 am »
Question: If one can achieve the gear-inch target range of 18 - 110 by either changing the chainrings or the cassette (similar cost), is there a preferred option?
Yes, and it's very simple. No lengthy explanation required.

A small cassette has a better progression than a large one, ie. the ratios are closer.

So it is better to use a smaller cassette and change the rings.
Cycle touring blog and tour journals: whispering wheels...

Offline RussSeaton

Re: Advice for choosing components to reduce gear inches
« Reply #17 on: August 17, 2017, 02:00:02 pm »
I've seen 20 teeth specced as the range for a bunch of front derailleurs.

It might be the standard.  Don't know.  Its complete nonsense anyway.  My Campagnolo Veloce bike has a 52-42-24 crankset.  Shifts perfect.  28 tooth difference!!!  My touring bike has a 44-33-20 triple crank.  Shifts perfect.  24 tooth difference!!!  My old touring bike had 50-45-24 rings.  Shifted perfect.  26 tooth difference!!!  Used to be double front derailleurs had a 14 tooth difference.  Just enough to handle the common 53-39 crankset.  Then people started loving these compact cranks with 50-34 rings.  16 teeth difference!!!  Oh no!!!  Shimano, Campagnolo, SRAM did not change the front derailleur.  They magically said it was fine to shift 16 teeth with the front derailleur.  People even use a double front derailleur to shift a triple crankset.  But you say that's impossible?

Offline TransAM2010

Re: Advice for choosing components to reduce gear inches
« Reply #18 on: August 17, 2017, 03:48:20 pm »
I've seen 20 teeth specced as the range for a bunch of front derailleurs.

It might be the standard.  Don't know.  Its complete nonsense anyway.  My Campagnolo Veloce bike has a 52-42-24 crankset.  Shifts perfect.  28 tooth difference!!!  My touring bike has a 44-33-20 triple crank.  Shifts perfect.  24 tooth difference!!!  My old touring bike had 50-45-24 rings.  Shifted perfect.  26 tooth difference!!!  Used to be double front derailleurs had a 14 tooth difference.  Just enough to handle the common 53-39 crankset.  Then people started loving these compact cranks with 50-34 rings.  16 teeth difference!!!  Oh no!!!  Shimano, Campagnolo, SRAM did not change the front derailleur.  They magically said it was fine to shift 16 teeth with the front derailleur.  People even use a double front derailleur to shift a triple crankset.  But you say that's impossible?

Nope not at all - I agree with you, as well as Sheldon Brown who said pretty much the same. I think I just misinterpreted your April Fool's Day comment.

I very rarely have any issue with front derailleurs on any of my 6 bikes all of which have triple crank sets save one. It makes me bristle a bit when I read a comment like the one in the recent issue of the ACA Magazine saying that some manufactures are trying to do away with front derailleurs in favor of single ring cranks with increasingly narrow chains and large cog sets. This is pure and simply an attempt at cost saving on their part yet they frame it as if it is all about "performance".
 

Offline Biggus Duckus

Re: Advice for choosing components to reduce gear inches
« Reply #19 on: August 22, 2017, 12:58:28 pm »
Consider looking at the Wolftooth Goatlink and Tanpan and using those in conjunction with a 40 or 42 tooth cassette. Might be the simplest fix.

Sent from my Pixel using Tapatalk


Offline Bigonabianchi

Re: Advice for choosing components to reduce gear inches
« Reply #20 on: October 13, 2017, 05:33:51 pm »
Not a solution for the OP as set up is different but just as an aside it is possible to use 11 speed Ultegra/105 shifters with an XT8000 11-40 mountain bike 11 speed cassette and keep a 50/34 up front. You have to ignore several you tube videos stating all you need to do that is add a road link to your long cage rear derailer, it's not that simple. Shimanos road and mtb group sets are not compatible, so there is a cable pull differential to be dealt with here that the road link alone does not solve.
The way forward is to use an xt8000 rear long cage derailer but install a wolftooth tanpan inline between your right shifter and the rear derailer. That deals with the cable pull differential. On an 11-40 cassette the long cage derailer can deal with the largest sprocket, even if you cross chain. If you go for say an 11-42 or 11-46 or something then my guess would be you's need the wolftooth road link as well.
The tanpan is a little tricky to install but it does work, giving you a much easier time on the steep climbs without losing the higher gearing on the flats/downhills, all with 11 speed sti road shifters still.
There are many options, this is just one...just in case it's of any help/interest.

Biketouringhobo

  • Guest
Re: Advice for choosing components to reduce gear inches
« Reply #21 on: October 17, 2017, 05:49:15 pm »
I had the same situation with my Burley Hudson.  I replaced the 30 tooth chainring with a 24, and added a N-gear chain keeper to prevent the chain dropping off when coming down off the middle ring (it's a big jump).  Then I replaced the 30 tooth cassette with a 36.  You will need a long cage derailleur to take up all that slack chain, but even a 32 or 34 tooth cassette with that 24 tooth chainring will give you some pretty low gearing.  And relatively cheaply.
I don't know if you can buy the N-Gear Chain Keeper and I have the N-Gear Chain Keeper on my Surly LHT 26 52cm 2008