Cassette - teeth range - (10 speed tourer with triple chainring)

[Ajax Bay]

The easiest inexpensive way of getting an extra 6+% is to replace your 30t chain ring with a 28t. I do this if I'm attempting a seriously hilly randonnée (eg Valley of the Rocks, or the North Devon coastal line thereof). The FD will handle that no probs, and the RD will wrap the extra. I can combine that with an 11-30 to give me a 25" gear. @Ian H advocates a 24" lowest gear, but I'm still on SPD-SLs.
If only cassette manufacturers produced a 13-30 (or 32) I'm sure it would sell. 50/13 still gives you a top gear of over 100 inches.

 

[ColinJ]

It’ll likely cope with up to 36t , but if you know full model number it can be confirmed.

I put an XT rear mech on my CX bike so I could use a 12-36 cassette...

View attachment 524311

That works really well. I can't check exactly which rear mech it is though because I am not at home.

I agree that 52/11 (4.73:1) is a crazy high gear for most people. I only have 48/12 (4.0:1) on my best bike, 46/12 (3.83:1) on the CX bike, and 42/11 (3.82:1) on the bike that I have in Devon. I can pedal to 50+ kph (31+ mph) on those bikes on descents. If I want to go faster than that on steeper descents I just get into an aero position and freewheel.

As for the low gears on the same bikes... 28/30, 34/36, and 42/42. Those are fine for me to about 17-18%. I would prefer slightly lower gears for (say) 19-23%, and need lower gears for 24+%!

 

[Grant Fondo]

Hi fellow cycle aficionados!
Looking for some advice on upping the range of my rear 10 speed cassette on my touring bike.
currently have a triple chainring with 52/39/30 ratio and a 12-27 cassette.
I’m finding that when fully loaded, I‘m really struggling on the 10% plus hills ( of which there are plenty in Cornwall!)
Can I keep the same chainring setup, but increase the rear cassette to say 11- 32. Would the gears need to be re- indexed?
Thanks Smuggs.

I went 11-34 XT 10sp rear hub, great shifting and worth the extra cash.

 

[Vantage]

Hi fellow cycle aficionados!
Looking for some advice on upping the range of my rear 10 speed cassette on my touring bike.
currently have a triple chainring with 52/39/30 ratio and a 12-27 cassette.
I’m finding that when fully loaded, I‘m really struggling on the 10% plus hills ( of which there are plenty in Cornwall!)
Can I keep the same chainring setup, but increase the rear cassette to say 11- 32. Would the gears need to be re- indexed?
Thanks Smuggs.

An XT rear mech being of mountain bike heritage should accept an 11-32 cassette with ease regardless of part number. It may even stretch an extra couple teeth. My deore is rated to 34t but it's currently running with a 36t. Where you may run into issues is when going bigger than that. One of these these can help in that regard.
You'll almost certainly need a longer chain unless you also switch to a smaller chainset. Even a 48t ring is stupid high. Up till I went electric on my tourer I dropped down to a 24-34-46 chainset.

 

[Ming the Merciless]

That works really well. I can't check exactly which rear mech it is though because I am not at home.

I agree that 52/11 (4.73:1) is a crazy high gear for most people. I only have 48/12 (4.0:1) on my best bike, 46/12 (3.83:1) on the CX bike, and 42/11 (3.82:1) on the bike that I have in Devon. I can pedal to 50+ kph (31+ mph) on those bikes on descents. If I want to go faster than that on steeper descents I just get into an aero position and freewheel.

As for the low gears on the same bikes... 28/30, 34/36, and 42/42. Those are fine for me to about 17-18%. I would prefer slightly lower gears for (say) 19-23%, and need lower gears for 24+%!

My recumbent has a big chain ring of 40t. I hit 73 km/h on a local descent last weekend. You don’t need big chain rings for rapid descents.

 

[DCBassman]

I can combine that with an 11-30 to give me a 25" gear. @Ian H advocates a 24" lowest gear

I obviously am not man enough for all this, my lowest on the Pine Mountain is a fraction below 19", and it's just about low enough!

 

[ColinJ]

My recumbent has a big chain ring of 40t. I hit 73 km/h on a local descent last weekend. You don’t need big chain rings for rapid descents.

Indeed... I have hit 90 km/h on a couple of Yorkshire /Lancashire descents using the chin on stem technique! I can't pedal fast enough, but don't need to.

@Ian H advocates a 24" lowest gear, but I'm still on SPD-SLs.

I used that gear on one steep climb the other day, which was fine because I use the original mountain bike type of SPD on all of my bikes.

 

[slowmotion]

Being hopeless on hills, the first thing I did when I got my ten speed triple was to replace the smallest chainring (30 tooth) with something smaller. I think it was a 28 or maybe a 26. What you need to do is find out the bolt circle diameter of your smallest chainring and then buy a smaller replacement that fits . The Shimano technical documents will give you all sorts of advice about number of teeth allowable but you can push the tooth numbers a bit if you are feeling naughty/desperate.

Spa Cycles usually have good stocks of replacement chainrings. Lookee here.........https://www.spacycles.co.uk/m8b0s0p0/Drivetrain

 

[the snail]

Being hopeless on hills, the first thing I did when I got my ten speed triple was to replace the smallest chainring (30 tooth) with something smaller. I think it was a 28 or maybe a 26.

Yes, that's what I did with my 105 setup, swapped the 30t for 26t, but that may not be an option for the op, eg if it's an ultegra chainset, would need to swap the chainset. Really, I think for loaded touring 20" bottom gear wouldn't be too low

 

[Ajax Bay]

I obviously am not man enough for all this, my lowest on the Pine Mountain is a fraction below 19", and it's just about low enough!

Blimey! What size shoes do you take, Size 3?

 

[DCBassman]

Blimey! What size shoes do you take, Size 3?

Say, what? No. I need low gears because I'm old, unfit, and semi-disabled, so can't rack up big mileages. And, as you're well aware, it's lumpy around here!

 

[roubaixtuesday]

If it were me, I'd get a much lower gear.

11-36 cassette seems to be available:

https://www.wiggle.co.uk/brand-x-10...sfyqftHVDosy7kqoYUhoCWFgQAvD_BwE&gclsrc=aw.ds

It doesn't particularly matter if the rear derailleur can't officially cope, as the worst that will happen is chain slap in the small/ small combinations, which you should be avoiding anyway.

Current 10 speed deore rear dérailleurs seem to have max rear sprocket of at least 36 and up to 41; capacity of 41 or 43 dependent on model, but you do need to check your own model number to be sure:

https://www.wiggle.co.uk/shimano-deore-m6000-shadow-plus-rear-derailleur

"Capacity" is (big +big) minus (little +little) so if you keep the same chain rings you need a capacity of (52 + 36) minus (30 + 11) which is 47, so you'd probably have some slackness in the small sprockets at the rear. Assuming my sums are correct that is...

The golden rule is make absolutely certain the chain is long enough to run big/big, as accidentally engaging that gear with a chain that's too short results in catastrophic damage.

 

[Jameshow]

If it were me, I'd get a much lower gear.

11-36 cassette seems to be available:

https://www.wiggle.co.uk/brand-x-10...sfyqftHVDosy7kqoYUhoCWFgQAvD_BwE&gclsrc=aw.ds

It doesn't particularly matter if the rear derailleur can't officially cope, as the worst that will happen is chain slap in the small/ small combinations, which you should be avoiding anyway.

Current 10 speed deore rear dérailleurs seem to have max rear sprocket of at least 36 and up to 41; capacity of 41 or 43 dependent on model, but you do need to check your own model number to be sure:

https://www.wiggle.co.uk/shimano-deore-m6000-shadow-plus-rear-derailleur

"Capacity" is (big +big) minus (little +little) so if you keep the same chain rings you need a capacity of (52 + 36) minus (30 + 11) which is 47, so you'd probably have some slackness in the small sprockets at the rear. Assuming my sums are correct that is...

The golden rule is make absolutely certain the chain is long enough to run big/big, as accidentally engaging that gear with a chain that's too short results in catastrophic damage.

Yeap run 34 / 36 on my carbon bike runs sweet.

Great for when you have a steep hill at the end of the day!!

 

[HobbesOnTour]

Hi fellow cycle aficionados!
Looking for some advice on upping the range of my rear 10 speed cassette on my touring bike.
currently have a triple chainring with 52/39/30 ratio and a 12-27 cassette.
I’m finding that when fully loaded, I‘m really struggling on the 10% plus hills ( of which there are plenty in Cornwall!)
Can I keep the same chainring setup, but increase the rear cassette to say 11- 32. Would the gears need to be re- indexed?
Thanks Smuggs.

I'm not a gearing expert but have done a bit of heavily loaded touring.
I always think in terms of having the lowest number of teeth on the front and the maximum on the back.
I've never wished for a smaller cog at the rear but would happily sell my soul at times for a bigger one

Due to a recent cassette breakage I had to get one with two less teeth (from 34 to 32) and I can really feel it!

Lots of good advice here as to if your derailleur can cope with the larger cassette.

An indication of the weight you're carrying would be helpful too.

Good luck!

 

[GuyBoden]

The Shimano XT MTB 10 speed RD-M781 SGS (No clutch), has a total capacity of 43T (chain wrap), but this can be exceeded.

If you have a Shimano XT MTB 10 speed RD-M781 SGS.

Your 52T front ring with a 36T rear sprocket should be ok using a long chain that works with both the 52T front and 36T selected.

I have installed many larger cassettes with front triples, with up to 42T rear sprockets.