Bikepacking gear calculator: chainring and cassette for loaded climbs

What you need

On a 10% gravel track at about 160 watts, you'd climb at about 3.0 mph.

26T chainring with the Garbaruk 12-speed MTB 10-50.

In the easiest gear you'd pedal at 66 rpm on that hill. Top gear does 20.4 mph at 90 rpm.

Chainrings go by how they fit your crank. Here are the main ones. If yours isn't here, tell me your crank and I'll find the right ring.

Easiest gear at the top. Each box shows the gear, how far one turn of the pedals takes you, and your speed at 65 rpm. Shaded gears hold that cadence on your steepest hill.
Gear	Your bike
1	32 x 501.50 m3.6 mph
2	32 x 421.78 m4.3 mph
3	32 x 362.08 m5.0 mph
4	32 x 322.34 m5.7 mph
5	32 x 282.67 m6.5 mph
6	32 x 243.12 m7.6 mph
7	32 x 213.56 m8.6 mph
8	32 x 184.16 m10.1 mph
9	32 x 164.67 m11.3 mph
10	32 x 145.34 m12.9 mph
11	32 x 126.23 m15.1 mph
12	32 x 107.48 m18.1 mph

Easiest gear at the top. Each box shows the gear, how far one turn of the pedals takes you, and your speed at 65 rpm. Shaded gears hold that cadence on your steepest hill.

Gear

Your bike

32 x 501.50 m3.6 mph

32 x 421.78 m4.3 mph

32 x 362.08 m5.0 mph

32 x 322.34 m5.7 mph

32 x 282.67 m6.5 mph

32 x 243.12 m7.6 mph

32 x 213.56 m8.6 mph

32 x 184.16 m10.1 mph

32 x 164.67 m11.3 mph

32 x 145.34 m12.9 mph

32 x 126.23 m15.1 mph

32 x 107.48 m18.1 mph

Why I made this

The question I get most from people setting up a bike for a trip is what chainring and cassette to run. A gear that's fine on a day ride feels like a wall at the end of a long day with 20 kg of bags on. Better to find out at home than halfway up a hill in Wales.

How it works

First it works out how fast you'll go up your steepest hill. That comes from the power you can hold, the weight of you and the bike, the gradient, how much the tyres drag on the surface and a little air. Then it finds the gear that lets you turn the pedals at your cadence at that speed. It's physics, so treat it as a good guide. Wind, mud and a long day in the legs all make it harder.

The "how fit are you" choices are about 1.5, 2, 2.5 and 3.2 watts for each kg you weigh. If you have a power meter, put in what you can hold for 20 minutes or more.

Where the gear sizes come from

The cassettes are the Garbaruk ones I sell, with the sprockets Garbaruk list on their own pages. The chainrings are Garbaruk's direct mount sizes, 26T to 42T. Garbaruk have paused their 11-speed cassettes for now, so I've left those out. To compare the bike you have now, there are the common SRAM and Shimano cassettes too, with the sprockets from their own pages. Running something else? Pick "Another cassette" and type its sprockets in. Two chainrings on the front? Type them like 46/30.

Want it fitted?

I fit chainrings and cassettes in the workshop here in Rochford, and I can check your mech will take the bigger sprocket. See the Garbaruk range, the bikepacking page, or book the bike in. Setting up tyres for the trip? The tyre pressure calculator helps there.

Bikepacking gear questions

What chainring size should I use for bikepacking?

Smaller than you'd use unloaded. For an 80 kg rider with 25 kg of bike and kit on 29 x 2.4 tyres, holding 65 rpm up a 10% gravel climb takes about a 26T ring with a 10-50 cassette. Without the bags a 30T does the same job. Put your own numbers in the calculator.

How much slower am I on a climb with bags on?

On a steep hill nearly all your effort goes into lifting weight, so speed drops roughly in line with the extra weight. Add 15 kg to 90 kg of rider and bike and you climb about 14% slower. On the flat you hardly notice it.

What cadence should I aim for on a long climb?

Most people are happy between 60 and 80 rpm. Below about 55 you're pushing hard on every stroke, which tires your legs and knees over a long day. If the calculator shows you grinding below 55 in your easiest gear, go for a smaller ring.

Is a 10-52 cassette worth it over a 10-50?

The 52 is about 4% easier than the 50. That's about half the step from a 28T to a 26T ring. If your ring is already as small as your crank takes, the 52 is the way to get lower.

What's the difference between gear inches and metres of development?

Both tell you how big a gear is. Metres of development is how far the bike goes for one turn of the pedals. Gear inches is the old way: the wheel diameter in inches times the chainring over the sprocket. Lower numbers are easier gears. The calculator shows either.

Does tyre size change my gearing?

Yes. A bigger tyre makes the wheel taller, so every gear gets a bit harder. A 29 x 2.4 is about 5% taller than a 700 x 45, which is the same as going up a tooth or two on the ring.

Will a smaller chainring fit my crank?

It depends on the crank and the frame. Direct mount rings come in different fittings for SRAM, Shimano, Race Face and others, and some frames limit how big a ring fits. Send me your crank model and I'll tell you the smallest and biggest ring that will go on.

Should I walk the steep bits instead?

Sometimes. Once your climbing speed drops to about 3 mph you're no quicker than walking, and pushing rests your legs. The calculator tells you when you're down at walking pace.

Bikepacking gear calculator