Stop-and-Go Commuting Gearing: Gear Ratios and Shifting Sequences for Repeated Red Lights (Without Knee Pain)

Repeated red lights force repeated accelerations—exactly where riders tend to mash big gears and irritate their knees. Use a knee-friendly “start gear,” shift early while the chain is moving, and follow simple sequences—

Start in a repeatable “start gear,” and then you can push from a dead stop at a comfortably quick cadence (spinning, not stomping). On derailleur bikes, downshift while you’re still rolling—you can’t shift if you’re already stopped. Aim for a higher, sustainable cadence and lower pedal force during the accelerations—especially if your knees get cranky if you do a lot of stop and go. (A common knee-pain trap is to have your saddle too low and/or too far forward, and then do big-gear mashing at low cadence.) You can use a gear calculator to map your exact gear steps (in gear inches / development) so that your shifts are repeatable at every light. [Informational only, not medical advice. If you have sharp pain or swelling, instability, or pain that lingers for several rides, go to a bike fitter and a clinician (PT/orthopedist) to rule out injury, and diagnose fit.] (cptips.com)

A practical commuter goal: make every start feel like a smooth “spin-up” (quick, light pedal force) instead of a standing squat. That’s primarily a gearing problem, secondarily a shifting-timing problem, and sometimes a bike-fit problem.

The three gearing concepts you actually need (no engineering degree required)

1. Gear ratio (teeth in front ÷ teeth in back)
   If you have a derailleur bike or equivalent, your effective gear is simply determined by the front chainring teeth divided by the back cnog teeth e.g., 34 ÷ 24 = 1.42. The higher the number the “harder” the gear (more distance covered per turn of the pedals), the lower the number the “easier” the gear (less force required to accelerate).
2. Gear inches (a “feel” number you can compare across bikes)
   Gear inches convert your gearing number into a single number which about conveys how hard the gear will be perceived to be (like you could run it through a wind tunnel for actual drag and whatnot): (chainring ÷ cog) × diameter of wheels. Gear Inches have become popular since they allow you to compare setups (700c commuter vs 26″ MTB, and so forth). Here’s a gear calculator that does the wheel calculations taking your exact tire size. (sheldonbrown.com)
3. Cadence (RPM) is the “knee-friendliness” dial
   If we’re commuting it’s relatively highly likely that we’ll be avoiding the combo of low cadences × high pedal force involved in accelerating / climbing. Consumer guidance tell us that we should power the machine use easier gears and higher cadences in order to lay off ourselves and be more efficient in our work. (rei.com)
   Biomechanics work shows that indeed the forces in knee joints rises with increased workloads, and that research in cycling populations (and knee-OA context) suggest that higher cadences × lower power may reduce measures of loading of the knee. Applied to commuting: if your knees hurt, don’t race in big gears from every light—downshift and spin. (pubmed.ncbi.nlm.nih.gov)

Choose a knee-friendly “start gear” for repeated red lights

Your “start gear” is what you willingly downshift into before you come to a stop, so your “restart” is smooth. Trek and Shimano both advise you to shift into an “easier” gear as you come to stops so starting again won’t be a struggle. (trekbikes.com)

• Flat-ish commute, average rider: many riders prefer a “start gear” of roughly ~30-45 gear inches.
• Hilly ride or heavy load/knee issues: consider ~20-35 @ inches.
• If you’re always jumping up on the pedals and “heaving” just to get rolling, your start gear is too hard (or the bottom gear is too big @ inches to be sensible for the route).
• If you instantly spin out with no resistance, your start gear may be too easy—but that isn’t too often bad for knees as being too hard.

Build a plain, simple “gear map” with a calculator (so your seamless and tensionless shifts can become instinct and automatic!)

If you have many lights on your commute you’ll get a lot of benefit from sequential, and predictable, gear steps. Plug your chainring(s), cassette and wheel/tire into calculator; print/save results so you know what each gear “means” (gear inches or meters of development). Sheldon Brown’s is a widely used option for this. (sheldonbrown.com)

1. Count (or read) your chain ring tooth count(s) (eg. 42T, or 50/34)
2. Count (or read) your cassette cogs (eg. 11–36; the biggest cogs are easiest).
3. Enter them with your wheel size/tire into the calculator and print out gear inches.
4. Pick ONE start gear you will use at every light (write it down as chain ring x cog)
5. Pick TWO cruise gears (one slightly easier, one slightly harder) that suit your usual speed and wind conditions.

Shifting sequences for repeated red lights (derailleur bikes: 1x and 2x)

Two rules are critical in traffic (1) shift gently while lightly pedaling (not stomping) on the pedals, and (2) downshift to an easier gear before you stop, so that you can get going easily again when you do stop. (Mainstream shifting guidance systems emphasise both of these points, observed in the wild some of the time; e.g. here, (by Trek :)) (trekbikes.com).

Sequence A: “Full stop, definite red” (best on the knees)

1. As you start braking (still rolling), lighten your foot on the pedals and click down 2–4 cogs on the rear cassette toward easier gears, until you are in your chosen starting gear.
2. If you have 2x:Shift the FRONT to the small ring ONLY if you’re going to need a big drop in difficulty (or expect a slow start up again). Do it well in advance and gently. Start seated, push off, and immediately aim to spin (smooth circles rather than stomp).
3. As cadence rises and you feel ‘too spinny,’ upshift rear 1 click at a time to keep effort steady.

Sequence B: “Stale green / might roll through” (keeps momentum without big torque spikes)

1. As you coast or soft-pedal to time the light, click down just 1–2 easier gears (not all the way to your start gear).
2. If it turns red and you must stop, take the last 1–3 downshifts while you’re still rolling at walking speed (this is the window many commuters miss).
3. If it stays green and you accelerate again, you’ve avoided an unnecessary downshift/upshift cycle.

Shifting sequences for internal-gear hubs (IGH) and e-bikes

Internal-gear hub advantage: you can set the start gear after you stop
With many internal-gear hubs you can shift at (or near) a stop, which is handy for riding in the city. This allows your stop routine to be: stop first, then choose an easy gear you want for restart, then go. (Still, you feel low-load shifting all the time.)

E-bike note: set a comfortable start gear (manual or auto-shift)
Even with all that electric motor help, starting in too hard a gear encourages a slow-cadence grind that your knees may not welcome. Shimano’s rider tips include calls for shifting to an easier gear before stopping at traffic lights and covering cadence ranges for efficient riding. (bike.shimano.com)

• If your e-bike offers a ‘start gear’ setting, set it to the easiest gear you can reliably start in without a big surge
• If you have auto-shift, tune shift timing toward the cadence you prefer so it doesn’t force low-RPM mashing. (bike.shimano.com)

And still practice ‘soft pedal while shifting’—a good habit for smoothness and drivetrain longevity. (trekbikes.com)

Stop-and-go gearing targets: practical ranges (start, accelerate, cruise)

These ranges are intentionally broad because tire size, terrain, load (backpack, panniers, child seat), and personal biomechanics all matter. The point is consistency: pick a start gear you can repeat at every light, then use small rear shifts to keep effort steady. For general shifting technique and cadence guidance, see mainstream resources like Trek and REI. (trekbikes.com)

Examples: simple shifting ‘scripts’ you can copy (adjust to your drivetrain)

Example 1: 1x drivetrain (commuter/gravel) — one ring up front

• Approach light: downshift 2–4 clicks easier while soft-pedaling.
• Start: Stay seated, aim for a nice smooth spin, then shift up 1 click every time your cadence feels ‘too fast’.
• Cruise: Use the shifts up to maintain your cadence, by shifting up 1-click unless you feel the need for a slight change. (You probably want to shift less frequently if you are moving slightly than if you are standing.) (trekbikes.com)

Example 2: 2x drivetrain (road/fitness) — two rings up front

• Use the rear derailleur most of the time for all our stop-and-go adjusting (the small-shifting goes in back). (trekbikes.com)
• Only drop into the little ring if: (a) it’s a real steep and we are stalled; (b) we are carrying a heavy load; or, (c) our starting gear is still too darn hard. (trekbikes.com)
• Avoid extreme cross-chaining, that is, big ring to the biggest in the back or the little ring to the littlest cogs in the back, reduces noise and wear-and-tear on your drive train. (trekbikes.com)

If your knees still hurt: the gearing/technique issues to fix first

Fix #1: Stop doing “big-gear starts”

If you habitually begin a ride in a hard gear, you’re insisting on high pedal forces at low cadence—exactly the pattern many riders report aggravates anterior knee symptoms. REI’s guidance says “gear that’s hard to pedal may affect your knees and easier gears with a higher cadence are usually more efficient”. (rei.com)

Fix #2: Shift earlier (and under lighter pedal pressure)

If you wait until you have almost come to a stop, you may not be able to shift via derailleur, since the chain isn’t moving. And shifting works best when you are pedaling lightly, not under heavy load. This is standard shifting advice from most major brands.

Fix #3: Lower your needed torque (bigger easiest rear cog, smaller front ring, or different cassette)

Do you notice that your easiest gear is still too hard when you start or when riding into a headwind? You can change gear hardware, and/or go with a drivetrain with more range.
Change hardware to a cassette with a bigger biggest cog. Choose a smaller chainring.
Re-map your gears using a calculator to be sure you’ve got an easier start gear. (sheldonbrown.com)

Quick fit checks that matter for knee comfort (especially in stop-and-go)

Gearing and shifting are the first lever for stop-and-go knee comfort, but if pain persists, bike fit becomes the next most likely culprit. Clinical-oriented cycling knee pain guidance often flags a saddle that’s too low and/or too far forward as doing the wrong kind of cycling on the knee (especially anterior knee pain) via increasing patellofemoral loading. (cptips.com)

• Saddle too low: tends to increase knee bend at the top of stroke and can worsen front-of-knee pain for some riders.
• Saddle too high: can aggravate overreaching at the bottom of the stroke and posterior discomfort for some riders.
• Saddle too far forward: can increase knee load and change some tracking out slightly; sometimes shows up as anterior knee symptoms.
• Cleat/foot alignment (clipless): may affect knee tracking; if pain is one-sided or you recently changed shoes/pedals, consider professional help. (cptips.com)

Stop-and-go knee-friendly technique checklist

1. Commit to one start gear and always shift into that before a full stop. (trekbikes.com)
2. Ease off pedal pressure while shifting (soft pedal). (trekbikes.com)
3. Start again while seated, spin up, and shift up in small steps.
4. Rather than trying to will yourself to spin a higher cadence, keep things in a sustainable range where you just ride comfortably instead of grinding away on bigger gears. (rei.com)
5. If you have to accelerate as quickly as possible for safety, shift up while you’re gaining speed—not by starting in a giant gear.

FAQ: Stop-and-go commuting gearing and knee pain