How to track Cadence without a Cadence-meter #Cadencewithoutmeter

How to track Cadence without a Cadence-meter #Cadencewithoutmeter

Can it be done?

Yes, we track it via its derivative - Speed.

We have been told on good authorities that a good cadence should be about 80 -90 at the Gear Ratio that you are comfortable with. When you ride up a slope fall back to about 70 rpm.

Without further ado let’s get into it.

Chain	50	Cogs
Ring		11	12	13	14	15	16	17	18	19	21	23	25	28	30	34
Cadence	65	38	35	32	30	28	26	24	23	22	20	18	17	15	14	12
	70	41	37	34	32	30	28	26	25	23	21	19	18	16	15	13
	75	43	40	37	34	32	30	28	27	25	23	21	19	17	16	14
	80	46	43	39	36	34	32	30	28	27	24	22	20	18	17	15
	85	49	45	42	39	36	34	32	30	29	26	24	22	19	18	16
	90	52	48	44	41	38	36	34	32	30	27	25	23	20	19	17
	95	55	50	47	43	40	38	36	34	32	29	26	24	22	20	18
	100	58	53	49	46	43	40	38	35	34	30	28	26	23	21	19
	105	61	56	51	48	45	42	39	37	35	32	29	27	24	22	20
	110	64	58	54	50	47	44	41	39	37	33	30	28	25	23	21

This table is for a Chainring of 50t.

The numbers in red are the corresponding speed that you have to be riding at in order to achieve cadence of 90 rpm.

It may at first sight look like there are many numbers to remember but in practice you would probably need 1 to at most 3 numbers. From my experience, when you are riding at training pace you would probably be locked into a particular cog and would likely not change cog until you hit a particularly steep hill or meet with high wind.

At that time, you would probably be putting on a big cog and would likely not be paying attention to your cadence - at least during the initial phase. After some time, when you are able to reach a cadence number of about 70+, when ascending a hill, then you should add that number to your memory. Even then, the numbers would not be many at any point of time.

To find out your numbers if you are riding a different size chainring do this:

Speed on chart multiply by your chain ring size then divided by 50. Next Multiply the result obtained 
by your wheel circumference and divide the result by 2125.

Example 1

You ride with a size 53t chainring and a cog of 15t and your wheel circumference is 2110 mm

From the chart, the speed required to hit cadence of 90 rpm with chainring 50t and cog of 15t is 38 kmh

Hence in your case the required speed =   38 x 53 / 50 x 2110/2125

                                                              = 40 kmh

If you find the speed too high then ride with a 16t instead.

The Mathematics is then:  36 x 53 / 50 x 2110/2125

                                            = 38 kmh

Example 2

You ride a mountain bike with chainring size 42t and cog 19t and your wheel circumference is 
1950 mm

From the chart, the speed required to hit cadence of 90 rpm with chainring 50t and cog of 19t is 30 kmh

The Mathematics is then:  30 x 42 / 50 x 1950/2125

                                         = 23 kmh