Gear Range

How fast do you want to be able to go on your bike? What gear ratio do you want to use for climbing steep hills? Choosing the right gear range will give you a fast enough top speed and a comfortable climbing gear. Faster riders and racers need higher gears and will power up hills. Mountain and touring bikes go lower to get over rugged terrain or haul cargo.

Road

A Shimano Dura Ace 2x11 crankset comes with several chainring sizes from 55-42t to 50-34t. Cassettes are available in 11-25t to 12-28t. Here are the gears available in that range:

	30	34	42	50	55
11	2.73	3.09	3.82	4.55	5
12	2.5	2.83	3.5	4.17	4.58
13	2.31	2.62	3.23	3.85	4.23
14	2.14	2.43	3	3.57	3.93
15	2	2.27	2.8	3.33	3.67
16	1.88	2.13	2.63	3.13	3.44
17	1.76	2	2.47	2.94	3.24
18	1.67	1.89	2.33	2.78	3.06
19	1.58	1.79	2.21	2.63	2.89
20	1.5	1.7	2.1	2.5	2.75
21	1.43	1.62	2	2.38	2.62
22	1.36	1.55	1.91	2.27	2.5
23	1.3	1.48	1.83	2.17	2.39
24	1.25	1.42	1.75	2.08	2.29
25	1.2	1.36	1.68	2	2.2
26	1.15	1.31	1.62	1.92	2.12
27	1.11	1.26	1.56	1.85	2.04
28	1.07	1.21	1.5	1.79	1.96

Gravel

GRX 1x cranksets come in 40 or 42t. 2x come in 48-31, 46-30. Sprockets come in various ranges, but the widest is 11-46. The top end with 2x cranks aren't too much lower than a 50t road crank, but the 1x systems will have a noticeably lower top speed on the road. The low end is much lower with a 30x46 cog, which should let you climb hills with ease.

	30	31	40	42	46	48
11	2.73	2.82	3.64	3.82	4.18	4.36
12	2.5	2.58	3.33	3.5	3.83	4
13	2.31	2.38	3.08	3.23	3.54	3.69
14	2.14	2.21	2.86	3	3.29	3.43
15	2	2.07	2.67	2.8	3.07	3.2
16	1.88	1.94	2.5	2.63	2.88	3
17	1.76	1.82	2.35	2.47	2.71	2.82
18	1.67	1.72	2.22	2.33	2.56	2.67
19	1.58	1.63	2.11	2.21	2.42	2.53
20	1.5	1.55	2	2.1	2.3	2.4
21	1.43	1.48	1.9	2	2.19	2.29
22	1.36	1.41	1.82	1.91	2.09	2.18
23	1.3	1.35	1.74	1.83	2	2.09
24	1.25	1.29	1.67	1.75	1.92	2
25	1.2	1.24	1.6	1.68	1.84	1.92
26	1.15	1.19	1.54	1.62	1.77	1.85
27	1.11	1.15	1.48	1.56	1.7	1.78
28	1.07	1.11	1.43	1.5	1.64	1.71
29	1.03	1.07	1.38	1.45	1.59	1.66
30	1	1.03	1.33	1.4	1.53	1.6
31	0.97	1	1.29	1.35	1.48	1.55
32	0.94	0.97	1.25	1.31	1.44	1.5
33	0.91	0.94	1.21	1.27	1.39	1.45
34	0.88	0.91	1.18	1.24	1.35	1.41
35	0.86	0.89	1.14	1.2	1.31	1.37
36	0.83	0.86	1.11	1.17	1.28	1.33
37	0.81	0.84	1.08	1.14	1.24	1.3
38	0.79	0.82	1.05	1.11	1.21	1.26
39	0.77	0.79	1.03	1.08	1.18	1.23
40	0.75	0.78	1	1.05	1.15	1.2
41	0.73	0.76	0.98	1.02	1.12	1.17
42	0.71	0.74	0.95	1	1.1	1.14
43	0.7	0.72	0.93	0.98	1.07	1.12
44	0.68	0.7	0.91	0.95	1.05	1.09
45	0.67	0.69	0.89	0.93	1.02	1.07
46	0.65	0.67	0.87	0.91	1	1.04