[Closed] Ive made a boo boo (mech capacity)

Get a different mech?

mech was too much of a bargain, if anything is going its the casette

Maybe run a longer cage r-mech?
I'm using a 50/34 with an 11-32 (on my road bike) with a long-cage XT mech.

You'll be able to push a mech a bit over spec, but 37 on a 31 spec'd mech is too far.

EDIT: Ok, I posted too slow .... 🙄

You'll be able to push a mech a bit over spec, but 37 on a 31 spec'd mech is too far.

what isnt too far then? 33 on a 31? i doubt I would ever go big-big, but you never know, poop happens.

Looks like the cassette is going back then 🙁

anyone tell me how much you can push the capacity of a mech?

organic355 - Member
mech was too much of a bargain, if anything is going its the casette

Sorry - it just seems a bit strange to me to decide your gearing based on some mech you've just bought.

and if I knew what I wanted that would be a starting point.

If the spec on the cassette is Mx sprocket 28t then you need a 28-11 cassette.
The mech will cope with a few teeth more than it's capacity, if you set it up the normal way i.e. put your chain around big chainring and big sprocket without the mech then add 2 links, rather than trashing the mech if you go big-big, you'll be left with some slack chain if you go small-small, although you shouldn't be using this combination anyway.

"if you set it up the normal way i.e. put your chain around big chainring and big sprocket without the mech then add 2 links, rather than trashing the mech if you go big-big, you'll be left with some slack chain if you go small-small "
+1

with the numbers youve put up I think Id be right in saying that would let you run down to 34-17 before the mech went too slack in small-small combos
On an 11-32T 9spd? casette thats in between gears 5 and 6 (where 1 is the 32T)

Having checked it wasnt specced wrong the specialized website archive spec shows a(n '08) Saphire (Stumpjumper FSR 'WSD') is 'correct' in coming supplied with a medium cage sram mech and 3x9 [22-32-44, 11-34T] transmission. Its set up so you can use big-big but means once you're down to about 1-7 the mechs gone slack and the chain runs against itself. For a bike sold to women who are maybe largely 'newer' to MTBing that husbands/sons/friends/parents/etc who introduced them to it, Id have thought big-big and small-small combos (though technically wrong) would be quite likely used, so a long cage mech would make far more sense with 3x9 gearing. Guessing there must be a few more 3x9 (or 3x10) speshs that came with medium cage mechs?

It'll work just maybe no in the full range...either return mech and use full range or accept your vanity and don't use the full range (which may help develop stronger/bigger legs at the same time!)...

organic355 - Member
and if I knew what I wanted that would be a starting point.

FYI, One of my bikes has a 22/32/44 chainset and 11/34 cassette (45 tooth capacity) which I run with a med cage X7 mech (37 tooth capacity, as supplied by Commencal). Chain goes slack if I try to run the 22t chainring with the 4 smallest sprockets so I don't use these combinations !

Don't use all of your gears - as said above. I used to run 105 road mechs on my mountain bike at university because they were super cheap at the time (£11) compared to the mountain bike ones, and I'd gone through a phase of trashing rear mechs. I just made sure I didn't go big / big.

If you're running this on a road bike, what the hell do you want a 32 for anyway? Are you planning on riding up Mont Ventoux? MTFU, man! 😀

Won't the top jockey wheel be too high, so it'll interfere with the big cog? Might be OK with a 30t cog but 32 is a fair bit bigger...

"if you set it up the normal way i.e. put your chain around big chainring and big sprocket without the mech then add 2 links, rather than trashing the mech if you go big-big, you'll be left with some slack chain if you go small-small "

This ^ - I did something similar and found a bit of slack on small small combo is better than too tight on big big.

this is road bike right?

change cassette for a 27/28 top end.

34x32 is a crazy gear on the road, your mates will crash into the back of you and people walking will fly by you like you are stood still.

Suck it up and go compact in't rear. I was in your position and thought I needed the big gear due to my delicate knees but now have 50/34 and a 25/12 or 11 I can't recall...

The smaller block is lighter and the close ratios feel nice and smooth to use. Oh and big-big is a no-no! You shouldn't be crossing the chain that much, the same ratio is achievable without stressing it so much. The small chainring corresponds with the gears 1-5ish and the big with 4-9/10.

Go with the 11-26. A lighter cassette feels great (noticeable acceleration improvement) and offsets the lack of a whopping big gear.

just means that chain might be slack when in little little, but you should not be in that gear

med or long cage mech would be better.. 9speed shimano mtb mechs work fine with shimano road brifters 9 and 10 speed.

34x32 is a crazy gear on the road, your mates will crash into the back of you and people walking will fly by you like you are stood still.

😀

Paints a nice mental image.

Herman Shake - Member
A lighter cassette feels great (noticeable acceleration improvement)

The difference between the cassettes was in the region of 150g, that's a lot of metal shed from the rear wheel. I won't patronise you by explaining rotational weight and it's effects, thanks for my award 😉

My XT 11-32 cassette is 227g. Are you saying if I swapped it for an 11-26, this cassette would weigh 77g ???????

I won't patronise you by explaining rotational weight and it's effects, thanks for my award

Oh go on, I'm dying to hear about the massive centrifugal force exerted by a small chunk of metal very, very close to the centre of the axle.

I second Druid - prize bovine byproduct.