options for very low gears

Great Post!!

I was struggling a little (a lot really :o ) with most of the Hills around here on my Double so I got a smaller (39T) Chainring fitted and it's helped a LOT...it's amazing what difference one tooth can do on the front isn't it??....

Sorry, I didn't mean to interupt.. 🙂

Jaguar27 said:

Great Post!!

I was struggling a little (a lot really :o ) with most of the Hills around here on my Double so I got a smaller (39T) Chainring fitted and it's helped a LOT...it's amazing what difference one tooth can do on the front isn't it??....

Sorry, I didn't mean to interupt.. 🙂

Never mad much of a difference to me. Depending n how it get rounded off,ya got between 1 and 2 gear inches.

el Inglés said:

While the standard system of 52 / 39 is fine for many if you live in more mountainous areas or are not that strong then you may want lower gears than this will provide .

I will use the english system of gear calculation as it´s easier to compare one combination to another with a fast easy calculation : ie 39/27 x 27 = 39 ins
( this system stems from the diameter of the large wheel on a pennyfarthing and we like it so .........

Right back to the plot : the best way is to buy a bike that´s fitted with a triple chain ring system - 30/25 x 27 = 32·5 ins but to retro-fit you need a front mech , bottom bracket and cranks/chainrings ie it costs a fortune .

So ......... what you can do is get one of the new Gran Fondo or compact systems that offer 50 / 36 or 48 / 34 ie 36 ins or 34 ins but new cranks are never cheap .

Now here´s where Shimano owners get lucky , what ever you think about Shimano ( and they have dropped a few clangers over the years ) they are into compatability - ie their MTB rear mechs are compatible with road levers and as the 9 speed mechs can accept a 32 tooth or 34 tooth cassette as standard we are in luck - 39/32 x 27 = 33 ins , 39/34 x 27 = 31 ins ( a triple running 30/27 = 30 ins and that´s low enough to give trouble riding in a straight line your going so slow )

All you need is the mech - the LX seems to offer the best value price / quality wise - and a new casette ( 11-32 or 11-34 ) and possibly a new chain as the cage on the mech will be longer .
As the seperators are the same on all 9 speed systems then it´s just a case of mix and match with pieces from your old casettte with the new to get the best set of ratios for your needs - the LX casette will be held together with allen screws so it´s not a hard job .
It´s been tried , it does work ( cyclo cross ) but there will be a bigger gap between gears than you have now so if starting from scratch a triple is more versitile but this a cheaper option for a retro-fit . 🙂

Mtb casettes on a road bike suck a big one, but if you need that kind of gearing I guess one probably does not care about the finer ponts.I've seen folks around here with 30 granny rings and 32 or 34 big cogs on stuff I ride in the 52 ring with a 23 big cog cassette.

boudreaux said:

Mtb casettes on a road bike suck a big one, but if you need that kind of gearing I guess one probably does not care about the finer ponts.I've seen folks around here with 30 granny rings and 32 or 34 big cogs on stuff I ride in the 52 ring with a 23 big cog cassette.

~70 vs. 24 inches on the same hill (actually 52-23 is ~60 but Georgie'd jump me on cross-chaining an 11/23)? You're a beast or they're incredibly week.

el Inglés said:

Now here´s where Shimano owners get lucky , what ever you think about Shimano ( and they have dropped a few clangers over the years ) they are into compatability - ie their MTB rear mechs are compatible with road levers and as the 9 speed mechs can accept a 32 tooth or 34 tooth cassette as standard we are in luck - 39/32 x 27 = 33 ins , 39/34 x 27 = 31 ins ( a triple running 30/27 = 30 ins and that´s low enough to give trouble riding in a straight line your going so slow )

You guys are too [censored] anal with this compatibility thing! I have a tandem with Campy stuff that has a Shimano hub... I use a 27-12 ten speed ultegra, but also use a 34-12 XTR 9 speed for when we are in the mountains, and I have never had any issues with shifting (you need a long cage derailuer though for the 28+ cassettes)... Even with the mtn bike 9 speed on my campy 10 speed setup, it works and shifts just fine! I agree with Boudroux though, if you are roadie accustomed to close shifts, the Mtn cassettes have some big gaps...but I'll take it to have a 39-34 to climb some steep mtns when I have a 140lb counter weight and a 40lb bike...

wilmar13 said:

(you need a long cage derailuer though for the 28+ cassettes)... ..

Actually, cage length is about wrap capacity. Big cog capability is in the parallelogram.

wilmar13 said:

You guys are too [censored] anal with this compatibility thing! I have a tandem with Campy stuff that has a Shimano hub... I use a 27-12 ten speed ultegra, but also use a 34-12 XTR 9 speed for when we are in the mountains, and I have never had any issues with shifting (you need a long cage derailuer though for the 28+ cassettes)... Even with the mtn bike 9 speed on my campy 10 speed setup, it works and shifts just fine! I agree with Boudroux though, if you are roadie accustomed to close shifts, the Mtn cassettes have some big gaps...but I'll take it to have a 39-34 to climb some steep mtns when I have a 140lb counter weight and a 40lb bike...

Don't forget the triple option if you do a lot of slow climbing but still need all the tight middle and big-ring gears for faster pack riding. By adding a 30 ring, you gain a tight, easy-to-shift set of climbing gears (eg, 19-21-23) and still get to keep all the mid-range and big gears you're used to.

Expensive to change a double to a triple on an existing bike, but certainly a good way to get "very low gears" without sacrificing the tight cassette you need when in the big ring.

boudreaux said:

Actually, cage length is about wrap capacity. Big cog capability is in the parallelogram.

True, no argument there, but Campy short cage lists 26 tooth cassette as max cog size. I know I am a hypocrit because I am saying people don't try stuff just because it says it won't work, and then at the same time I quote some spec that I have never proven to be true or not, but your point about wrap capacity would still require the longer cage with a mtn cassette...

Either way you can mix and match campy and shimano and it will still work within reason. One set-up I think is really great is to use Campy Shifters (light years ahead of Shimano for ergonomics and servicability) with all else Shimano, you just need to change the side the cable is attached at the rear derailer (in effect you are using the cable screw as a cam to alter the cable index to match shimano shifters... I think I learned this at Sheldons site) and it works perfect. I had a bike built like that and couldn't tell a difference between that and pure Campy... except it was cheaper to build and I didn't need to have redneck-pickuptruck-like dual antennas coming out of my shifters and then shift with my brake levers. Of course now that I am a rich expatriate and no longer a poor student I don't need to mess with all that and I go for the bling factor of all Campy 😉

wilmar13 said:

True, no argument there, but Campy short cage lists 26 tooth cassette as max cog size. I know I am a hypocrit because I am saying people don't try stuff just because it says it won't work, and then at the same time I quote some spec that I have never proven to be true or not, but your point about wrap capacity would still require the longer cage with a mtn cassette..

It shifts a 29 just fine..... All mtb RDs don't have long cages. One way around insufficient wrap is to stay out of the small cogs when in the granny. If you need a 32 or 34 it's only a bailout anyway.

dhk said:

Don't forget the triple option if you do a lot of slow climbing but still need all the tight middle and big-ring gears for faster pack riding. By adding a 30 ring, you gain a tight, easy-to-shift set of climbing gears (eg, 19-21-23) and still get to keep all the mid-range and big gears you're used to.

Expensive to change a double to a triple on an existing bike, but certainly a good way to get "very low gears" without sacrificing the tight cassette you need when in the big ring.

I have , and would always reccomend , the triple chain ring set up BUT what I was trying to offer was a CHEAP option for a retro-fit not the best option
ie a new bike . 😎

el Inglés said:

I have , and would always reccomend , the triple chain ring set up BUT what I was trying to offer was a CHEAP option for a retro-fit not the best option
ie a new bike . 😎

Great posts, El.

The retro-fit option is expensive - as I have looked at options on some of my older bikes to get lower gears (getting on now, ya' see and those climbs are getting tougher).

Definite food for thought, El.
Well done.

limerickman said:

Great posts, El.

The retro-fit option is expensive - as I have looked at options on some of my older bikes to get lower gears (getting on now, ya' see and those climbs are getting tougher).

Definite food for thought, El.
Well done.

To be fair the Gran Fondo style of crank / chainring combo is the best retro-fit but cheap it ain´t but you don´t have those MTB gaps between the gears but as always it depends on money .