General Gearing

[griffdowg]

afternoon gents,

Thought I would open a debate on gearing but keeping it simple im not talking SS or 1x9 but I suppose Im talking 2x9! and gearing in general.

As i seem to be the only freak on a 700c I need to move my gearing around as my compact 34/50 (with 12-34? cassette) was too much on the mach N back. At the time I thought I would be ok but fully loaded the lowest gear was not quite enough.

Since then I have bought a triple compact with 28/39/? I plan to only run the 2 rings.

question is should I be altering the lower and middle ring from this ratio? I had a 30t also come with it.

I reckon I will be in the 39 on the road but its a big jump in teeth down to the 28 or even the 30. In reality I will not be spinning through bogs like an MTB but I do want to peddle my way up steep forest tracks.

So what are the rest of you running? standard 22/32/42 MTB? what do 29ers run as standard?

any further suggestions appreciated.

Thanks

G

PS. Will have some 1.75" wide Schwalbe's for the WRT :D

[didnothingfatal]

I'm currently running 34x19 in single speed setup, but have a Middleburn Duo with 27/42 with a 9 speed cassette ready to go for WRT, to be honest, I like to wind it up on the easy bits, and a single speed is just too much compromise for me!

[Ray Young]

22/32/44 with 11/34 9 speed.

[Ian]

I reckon I will be in the 39 on the road but its a big jump in teeth down to the 28 or even the 30

22 to 32 = 10 teeth
28 to 39 = 11 teeth

Not that much of a jump, and no more than the jump up to 50t that the compacts come with?

I think to replicate 26" gear ratios on the 29" wheel, you need to knock 2t off each of the front rings. Middleburn did a 20/30/40 chainset for a while, but I can't find any info on it now.

I like to wind it up on the easy bits, and a single speed is just too much compromise for me!

Sure you don't mean to say you've not got the legs for the hills, DNF?

[Dyffers]

I run 32x18 mostly on my 29er SS.

I have slowly gathered the parts to 1x10 it though. The plan is to leave the 32T ring on the front, and I have a 11-36 cassette to give the widest spread of gears.

Here comes the science, pay attention.
32x11 ~= 44x15
32x36 ~= 22x25

Is that bottom gear is enough? My thoughts are probably for an enduro/24hr race, probably not to avoid walking on WRT- or EWE-type events.

[thomthumb]

the last 2 WRTs have both had me walking for periods on a 29er with 22:36 bottom gear. I'd have no issue with doing it 1x9 with 32:36. there are some bit's i'd be walking whatever bike you had. imo.

what bike you running griffdowg?

the chainring question is interesting; road triples (i assume thats what you got) are normally sensitive to middle and outer chainring sizes but less so to inner c-ring size. http://www.peterwhitecycles.com/chainrings.asp is pretty definitive. the front mech also needs to be considered.

:D

[didnothingfatal]

I like to wind it up on the easy bits, and a single speed is just too much compromise for me!

Sure you don't mean to say you've not got the legs for the hills, DNF?

Haha funny guy

Single speed in Wales means a compromise when it comes to anything downhill or on tarmac, I can't spin 34x19 and make useful power on anything but uphill! That bugs the hell out of me! I'm not pouring miles and hours of weight work into my body, to spin my legs at mind numbing speeds!

[chris n]

I tried 32/20 SS on my 29er and got fed up of walking up hills in Wales, though it's fine for local trails and Cannock. I tried a 4 speed lash up (14/17/21/27T) on a splined SS hub and there wasn't enough of an advantage over SS. So I've fitted a 22T granny ring to give me 2x4 and I'll be trying it out this weekend to see if it works. Other option would be to go to 1x9 which gives a similar range to the 2x4 setup.

[Anthony]

What is all this talk of tarmac on the WRT?

We always plan a route to avoid roads at all cost, there is no shortage of bridleways. It's no race, there is nothing to be gained by hitting every checkpoint :!:

It's about getting isolated that's the appeal for me.

[griffdowg]

the last 2 WRTs have both had me walking for periods on a 29er with 22:36 bottom gear. I'd have no issue with doing it 1x9 with 32:36. there are some bit's i'd be walking whatever bike you had. imo.

what bike you running griffdowg?

the chainring question is interesting; road triples (i assume thats what you got) are normally sensitive to middle and outer chainring sizes but less so to inner c-ring size. http://www.peterwhitecycles.com/chainrings.asp is pretty definitive. the front mech also needs to be considered.

:D

sounds good. Running my Salsa Vaya for bikepacking duties :)

swapped it over tonight, only issue I can see at the moment is the front mech cage is too long. Due to the now top ring being 39 (not 50t), the cage sits on the chainstay and is about 6mm off the chain ring. I seem to recall it needs to be closer to 3mm?

I took it for a quick spin and it shifts really well, the rings are closer than I initially thought. see if the chain skips off on tomorrow's commute.

G

[Guy]

Hi Griffdowg.

Gearing on Slasa Fargo is a 2 x 10 and is 27 - 39 T and 12 - 36 T, this seems really low geared to me but that is without load and we only have short steep hills round here.

But changing on the front is not a problem. SRAM Apex shifters X 7 front De.

[griffdowg]

well the 8 mile commute went well, I can get around nicely on the 39t which I wasn't expecting and I spin uncomfortably above 30mph so Im chuffed with that as I was worried it wouldn't be enough.

The 28t spins nicely to with the lowest gear 28:34.

If there is anything bigger than that on the WRT Im back to walking :D

G

[didnothingfatal]

What is all this talk of tarmac on the WRT?

We always plan a route to avoid roads at all cost, there is no shortage of bridleways. It's no race, there is nothing to be gained by hitting every checkpoint :!:

It's about getting isolated that's the appeal for me.

Agreed but spinning furiously on fire road is miserable, in my world! We all have our own reasons for thinking riding a bike over Wales is a good thing to do :D

[Dyffers]

'Spinning furiously' is a skill to learn, not a penance to be avoided.

Eventually you get to the level at which you are 'spinning smoothly'. 8-)

[thomthumb]

griffdowg any reason why you don't have the outer chainring on?

[griffdowg]

griffdowg any reason why you don't have the outer chainring on?

I only have double STI shifter and mech. Im too tight on £££ to change these. Besides, I think the 2 ring combo is sufficient for bikepacking and commuting needs :)

The other reason is we are leaving the UK next year and the bike is staying while we drive to Australia. Will fly it out to Aus when we are settled.

'Spinning furiously' is a skill to learn, not a penance to be avoided.

Eventually you get to the level at which you are 'spinning smoothly'. 8-)

ai, not pedalling squares!

G

[Ian]

'Spinning furiously' is a skill to learn, not a penance to be avoided.

Eventually you get to the level at which you are 'spinning smoothly'. 8-)

Indeed, a "training" ride around here isn't complete without an 8 mile spin to Talybont at 110 rpm along the canal. And as power = force * veloicity, its definitely a good workout if I can keep the cadence fast and smooth :)

[didnothingfatal]

Alternatively spin a decent cadence on the road bike and train that way, then spin a better gear on the mountain bike.
This isn't about pedalling in squares, it's about efficiency and the fact is a range of gears allows the rider to spin the optimal cadence for the terrain. My fixed gear road bike isn't that much slower than my geared road bike, but the geared bike is less of a workout and better for long rides! So I mix my training, between the two, then chuck in the mountain bike for a bit more work.
It's rider preference, I love my single speed bikes, I love the fact my geared bikes can be wound up that bit faster though and not spin the pedals at 110rpm. 110rpm on 50x11 is a whole faster than a 32x20/?

[thomthumb]

cheers griff. STIs are a bit of a pain - i'm currently speccing* a new build with Drops and mtb rear cassette.

my head is spinning re 1x/double/ triple, 9sp/10sp, sti/bar end shifters. even retro shift is on my radar atm.

* squirrelling parts round the house like an alcoholic hiding miniatures

[gairym]

squirrelling parts round the house like an alcoholic hiding miniatures

good - i'm not the only one who does this!

my future 29er build has already begun (in my head) and so a few bits acquired on the cheap are being put aside here and there for when the time is right (when i can find either a Cotic Solaris or a Pace RC129 for a reasonable price).

fun, fun, fun.