Extremely low gears

[AliK]

My partner and I have just come back from cycle camping in Dorset and Devon and, after struggling on the very steep hills, want to look at having an even lower bottom gear. My bottom gear at the moment is 34 teeth at the back and 22 at the front so pretty low already. However, somebody mentioned to us that on some mountain bike gears you can now get a 50 or 52 tooth at the back for the really steep stuff. My first question is what are these called/ what search term do I need to use?? cos I am struggling to find info on the internet, and in this forum Links to useful articles/ videos would be good too!. My second question has anybody switched to this type of cassette for a touring bike? and what exactly did you use/ have to change? Also, does anybody know of any manufacturers who are using these type of gears on their touring bikes?

Thanks!

[Jdsk]

If you make big changes (!) your other components might not be compatible. Is this something that you might take on yourself, or would you get someone else to do it?

At some point you're going to be asked what you have already: the type of levers and derailers would help, and I suggest adding some photos.

Suppliers who often come up for parts for touring bikes are:
https://www.sjscycles.co.uk
https://spacycles.co.uk

Jonathan

[DevonDamo]

I've got the Shimano 12-speed, 51 tooth cassette on one of my mountain bikes. If you want to search for my one, you're looking for a 'Shimano SLX M7100 Cassette.' One problem you will encounter with this cassette is that it fits Shimano's micro-spline hub, which your bikes are unlikely to have. So you're either looking at a new back wheel, or finding a different large-sprocket cassette which doesn't need the micro-spline hub. One example of such that I'm aware of is the 'SunRace, 12-Speed, 11-51T.' (You'll need to do a bit of Googling to find out whether any of these will fit your hubs.)

Given that the 51 tooth cog is like a dinner plate, and the cassette goes down to a 10 toothed cog, your derailleur will need a lot of forward/backwards movement to take up the slack, so you'll probably want one with a clutch. (Mine is a 'Shimano XT, 12-Speed, SGS.') Then you need 11/12-speed shifters... (Edit: having read Tigerbiten's post below, it looks like it might not even be possible for the derailleur to cope with such a wide range on the rear cog, as well as the range up front with a triple - in which case the whole idea is a non-starter...)

You will be able to get cheaper versions of all the above - e.g. with Shimano, look for 'Deore' equivalents, which will be a bit heavier, but basically the same.

There's a bit more to all this than just fitting the right sized back-end components though - your existing chainrings may be too wide for an 11/12 speed chain, and if you want to get full bangs for your buck, you want to make sure the whole drive train, including chain and chainrings, all work together with the same shifting technology. (11/12 speed systems tend to have all sorts of new ridges and bumps to make the shifting slicker but the whole system wants to match up to get it working right.) So it could be a bit pricey - I'd start by pricing up the cheapest versions you can find of all the above, including chain, chainrings (and cranks, if you can't get 11/12 speed rings for your existing ones.) That should give you a rough starting point to decide whether it's worth all the expense and you could then ask some more specific questions on here about compatibility of the components you've got in mind. The other thing to bear in mind is that 11-speed, and particularly 12-speed, systems may have lower cassette/chain life. I'm not sure whether this will be such a problem in your case, as you're using a triple chainset, so you can have a nicer chainline as opposed to my 1x mountain bike which has the chain contorted at a horrific angle in first gear.

[freeflow]

Depending on your current gearing it may be relatively simple to switch to a cassette with a 40 or 42 tooth chainring. New cassette, new chain and a rear derailleur hanger extender (dog tooth ). However that's not going to get you much. Your current gearing at 34/22 is 17.5 gear inches. Switching to 40/22 will get you to 14.9 gear inches. At this level though, you have to be pedalling with a relatively high cadence to generate sufficient speed to be able to balance on the bike. Consequently, you might already be at the point where it just makes sense to get off the bike and push for a short while. Have a play on the Sheldon Brown gear calculator to see what I mean.

https://sheldonbrown.com/gear-calc.html

[mumbojumbo]

I note you are camping and presumably burdened by tents etc.I would camp in a place accessed by flat routes and take day rides in areas with hills .Otherwise I would dismount and push- many older people have done this over the years.

[simonineaston]

...or go to France! (travel arrangements allowing, obs)

[Tigerbiten]

You've probably got close to the maximum range that's easily possible.
The maximum capacity of a rear derailleur is around 48 teeth.
An 11-42 cassette take up 31 teeth of that range, with around 17 left for the front.
So it may be a bit 50-50 if you can use a 20 tooth difference triple with this cassette.
So you may gain another gear down but with the loss of your top two gears if a triple doesn't work.
And it may be 50-50 to even get a double to work with a 10-52 cassette.

Luck ............

[ossie]

My partner and I have just come back from cycle camping in Dorset and Devon and, after struggling on the very steep hills, want to look at having an even lower bottom gear. My bottom gear at the moment is 34 teeth at the back and 22 at the front so pretty low already. However, somebody mentioned to us that on some mountain bike gears you can now get a 50 or 52 tooth at the back for the really steep stuff. My first question is what are these called/ what search term do I need to use?? cos I am struggling to find info on the internet, and in this forum Links to useful articles/ videos would be good too!. My second question has anybody switched to this type of cassette for a touring bike? and what exactly did you use/ have to change? Also, does anybody know of any manufacturers who are using these type of gears on their touring bikes?

Thanks!

Here's a decent link to understand the gains you will gain from various set ups. As mentioned above - gear Inches

https://www.sheldonbrown.com/gear-calc.html

Whatever you do you'll probably end up pushing at some point in Devon and Dorset. Nothing to be ashamed of,

[horizon]

My partner and I have just come back from cycle camping in Dorset and Devon and, after struggling on the very steep hills, want to look at having an even lower bottom gear.
Thanks!

I wouldn't do it. Your lowest gear as freeflow has pointed out is already 17.5. It's already quite hard to safely balance a loaded bike in that gear as you are at walking speed and any load at the front makes it difficult to "twitch" the handlebars.

I'm just back from a loaded tour of Devon and Somerset and have done plenty of loaded touring in Dorset, so you have my sympathies. But the hills in these counties (Dorset and Devon), are quite extreme - Somerset was a doddle by comparison, even carrying 25 kg in camping gear. Hills are therefore to be walked up: you won't lose much in the way of time and it gives your bottom a rest. It's irksome because you are using different (and possibly less strong) muscles but it's all part of it.

One simple way to get lower gears to to have smaller wheels. My folder has a lowest gear around 15" but at no time on my tour did I wish I was on it - the bigger bike carried the load safely and well.

My tour included part of Cornwall, Devon, Dartmoor, near Exmoor, the Mendips, part of Wiltshire and lots of Somerset: my 17" gear (like yours) did an amazingly good job - moderate hills were lapped up and a (surprising) few were walked up. And that's with 25 kg of gear on a heavy bike.

[Tiggertoo]

You probably have a long arm derailleur anyway, but 22 on the front and 34 on the back is the same as my off-road Marin - and unless you are extremely burdened with a load of luggage, I do wonder what more you can do. You are already spinning in your lowest gear setting, so, to follow up some other suggestions above, maybe walking the steepest hills is the best you can hope for.

[roubaixtuesday]

It would probably be worth posting the exact spec of your current setup (derailleur models, chain ring sizes, cassette range, no of gears).

IIRC rear derailleur has a maximum capacity which is the difference between small+small and large+large. There is also a limit on the maximum rear cog size. The front derailleur has a maximum capacity of (largest-smallest). It's often possible to exceed these limits by a small amount, but you can't be sure until you try it.

It's likely though not certain that a 36 or even 40 cassette is possible on the rear either with existing derailleur or a hanger extender, maybe with some compromise on chain slap in small/small combinations. You may find that worthwhile.

But to echo what others have said, you're unlikely to be able to get a significantly lower gear and still be able to maintain safe balance loaded on hills, so accepting needing to push on the steepest hills might be inevitable.

[Tiggertoo]

that's with 25 kg of gear

I don't have anywhere near as much experience bikepacking as many of you do, but I do have considerable wilderness backpacking and never carry more than 30 lbs on my back - including food for 7 days, do you think there is a tendency to overload whilst bikepacking?
Climbing hills backpacking is a chore made possible by the use of poles, but bikepacking requires the sole use of the legs - and mostly the quads - so wouldn't judicial restriction on weight be as much or more important?
I can't imagine cycling loaded down with 60 lbs - unless I was moving house. It would take all the pleasure out of a trip for me.

[horizon]

I like my comforts! I don't see why I should be less comfortable than someone in a £70,000 motor home. And, AFAICT, I wasn't.

But I was also doing it as an experiment, partly to see just how much I could actually carry on tour and partly to see if I could reasonably carry a greater part of our requirements if accompanied by Mrs H. I carried the same amount on tour last year but that was mainly in the flatter counties north of London. I like to know that if for example I'm going to camp for a period of time in one place I can get there on the bike.

It was actually surprisingly easy and my main problem wasn't the hills but condensation. If I had any worries they were about whether the bike would take the strain. Don't get me wrong, my daily mileages were very low, usually about 25 - 30 miles. But then I also take my time packing in the morning (yes, all that stuff ...). The maximum volume and the maximum weight and my and the bike's abilty to carry it seem to come together at about 25 kg so I don't see my going any heavier.

I'm currently preparing for a couple of short trips with a load of about 12 kg on a lighter bike so that should be interesting. My trips to France last year came in at 15 kg so I think I am going eventually to settle at around that or a bit higher (say 18 kg max) to get optimum weight versus comfort.

[AliK]

Please can somebody clarify why balance may be a problem as presumably it isn't when these 50/52T are used on mountain bikes? or is it?

Or for that matter on a bike with a Rohloff hub (if I've understood various articles correctly)?

I would have thought balance would be easier based on the logic that at the moment if I go one or two gears up from my lowest gear it is then much harder to balance. ie my balance gets worse the higher the gear is. Or am I not understanding exactly what people are meaning by balance??

[Tiggertoo]

"my daily mileages were very low, usually about 25 - 30 miles."

Okay, I see now, rather like the tortoise which is quite happy with its load.

My daily mileage bikepacking is more in the hundred mile range, and it would ride me crazy to lumber along as if I was just going to the shops. If ever I am on the road and I see a ponderous vision on two wheels ahead, I will know it is probably horizon and give a cheery wave - but sorry to admit, not accompanied by any offer of assistance.