
## How to Install and Wire a Dynamo Hub, Start to Finish

Here is how to install and wire a dynamo hub: lace it into a front wheel on correctly calculated spoke lengths, torque the skewer, run a two-conductor cable up the inside of the fork blade to your light, and crimp the connectors properly. Three jobs, three skill levels.

The generator is the part that will not let you down. Schmidt says of its SONdelux that the generator "is optimally protected within the hub and is fully wear and maintenance free as it works without gears or contact," with a five-year guarantee period. What you bolt and solder around it is what breaks.

Rough timings: fitting a prebuilt dynamo wheel and plugging in a light is a 30-minute job. Wiring a light plus a USB charger with heat-shrunk crimps is an evening. Lacing the wheel yourself adds hours. Not sure the approach suits your riding? Start with our [bikepacking power and charging setup](/posts/bikepacking-power-charging-guide) overview and the [dynamo versus power bank comparison](/posts/dynamo-hub-vs-power-bank-bikepacking).

<Highlight label="The short version">

- The hub is maintenance free. The wheel build, the cable run and the connectors are where installs go wrong.
- Dynamo flange geometry differs from your old hub, so spoke lengths change. Park Tool, on measuring both flanges: "Do not assume they are the same."
- Pay a wheelbuilder unless you own a tension meter. Schmidt's instructions say wheel building and wiring "should be done by a competent person."
- Connectors fail, not hubs. Crimp with a proper tool, heat shrink the split, grease the plug lightly, leave a service loop.
- The budget is small. CyclingAbout notes a 3-watt hub "will put out 6 volts at 0.5 amps" in AC, and that below roughly 2 watts a dynamo charger cannot power most devices.

</Highlight>

<SectionDivider variant="rule" />

## Prebuilt Wheel, Shop Build, or Lacing It Yourself

**Buy the wheel prebuilt.** Fastest and safest. You give up some rim and spoke choice, and you must check axle standard, rotor mount and dropout width against your fork.

**Buy the hub, pay a wheelbuilder.** Our default recommendation. You pick the rim and spokes, and someone with a tension meter owns the part that can strand you. If you have not settled on a hub yet, start with [the best dynamo hubs for bikepacking](/posts/best-dynamo-hubs-bikepacking) and come back here once it is on order.

**Lace it yourself.** Fine if you already build wheels, a poor choice for a first build: a badly tensioned front wheel breaks spokes under a loaded bike, usually somewhere inconvenient.

None of this tells you which hub to buy. Choosing the best dynamo hub itself, and which dynamo hubs are worth it for loaded riding, is a separate question from getting one onto the bike.

<SectionDivider variant="rule" />

## The Dynamo Wheel Build: Spoke Length Is Not a Guess

A dynamo wheel build for bikepacking starts with measurements, not with spokes left over from your last wheel.

Park Tool lists what the calculation needs: hole count, effective rim diameter, the "hub flange diameter at the spoke holes, also known as the Spoke Pitch Diameter," the left and right flange spacing relative to hub centre, and your lacing pattern. It warns that "we are not concerned with outside diameter of the flanges."

The trap when swapping a dynamo in is asymmetry. Park Tool says to measure both flanges and "not assume they are the same," and that where the flange-to-centre figures differ you may be offered "differential spoke selections, meaning that different length spokes should ideally be used on left and right sides."

Manufacturers publish these numbers, so use them. Schmidt's SONdelux sheet gives a pitch circle diameter of 54 mm for both versions, with flange-to-hub-centre listed as 25 mm on the non-disc hub and 23 mm one side, 25 mm the other, on the centre-lock disc version. The same sheet says the hub is designed for conventional crossed spoking on "high-quality 2 mm spokes," and that radial lacing "is allowed, yet not recommended (wheels tend to vibrate)."

## Tension, and Why We Pay Someone

Tension is the whole game and the part you cannot eyeball. Park Tool's TM-1 shows a deflection reading on its own scale, which you convert to kilograms-force using the included printed table or Park's Wheel Tension App. Park Tool says the table is organised by spoke material and size, so a raw reading tells you whether a wheel is evenly tensioned, but not the actual figure until you look it up for your gauge.

No meter and no previous builds? Pay a wheelbuilder. Either way, learn to spot a wheel going soft: our guide to [truing a wheel and dealing with broken spokes](/posts/wheel-truing-spoke-repair-bikepacking) covers the roadside version, which you want regardless of who laced it.

<SectionDivider variant="rule" />

## Fitting the Wheel and Torquing the Skewer

Fit the wheel before you cut a single wire, so you can see where the axle contacts sit.

Schmidt specifies a tightening torque of 8 to 10 Nm on the Allen skewer supplied with the hub, and says to "check the tightening torque after 300 km" following installation. Grease the thread and bolt head but **not the shaft** — Schmidt warns that greasing the shaft risks "clogging of the pressure compensation system."

An under-tight skewer is not just a loose wheel. Schmidt notes that if it is tightened insufficiently "the axle might move in the fork slots causing a rattling noise," and an axle that shifts works your connectors loose.

<Info title="Disc clearance">Schmidt says the distance between spokes and brake caliper can be too small on 700c wheels with small rotors, and that its centre-lock disc hubs are made for pavement or limited off-road use. Check that gap with the wheel in the fork.</Info>

## Routing the Wire: Fork Blade, Zip Ties and a Service Loop

Schmidt's instruction for a headlight is simple: "Pass the cable along the inside of the fork blade to the SON and plug it in," then "fasten the cable with zip ties at the fork so that plugs can be easily disconnected before the wheel is removed." That last clause is the design brief for the cable run. If you have to cut a zip tie to fix a flat, you routed it wrong.

- **Inside of the fork blade**, not the leading edge, so the blade shields the cable from spray and from grit thrown by the front tyre.
- **Leave a service loop** at the hub end, long enough that the wheel drops out with the connectors attached and that a damaged end can be cut back and re-crimped.
- **Strain-relieve every bend** with a tie just before and just after it, and add heat shrink wherever the cable enters or leaves a fork port, a guide or the crown.
- **Check clearance at full steering lock**, suspension compressed, bags fitted. The cable must never be able to reach a spoke, a rotor or the tyre.

<Warning title="Keep the cable clear of the spokes, and never work on a live hub">Schmidt warns that a hub dynamo "generates high voltage when lights are switched off and at the very moment of switching it off," that touching it at such a moment "might be painful or even dangerous," and that therefore "careful, contact-free wiring must be ensured." A cable that can reach a rotating spoke will be dragged into the wheel, so tie it clear and test at full lock before you ride.</Warning>

Still choosing the lamp? Our [overnight lighting guide](/posts/best-bike-lights-overnight-bikepacking) covers what a dynamo headlight buys you after dark.

<SectionDivider variant="rule" />

## Connectors: Dynamo Connector Corrosion Is the Real Failure Mode

The generator is sealed inside the hub. The joint between your cable and the axle is two pieces of exposed metal living a hand's width above a wet road, and that is the part that fails.

Schmidt describes SON hub dynamos as having "robust 4.8 mm spade connectors," and says the 4.8 mm size is "more solid and easier to use compared to standard 2.8 mm connectors." Its crimp terminals are listed as tin-plated brass, uninsulated, in 2.8 x 0.5 mm and 4.8 x 0.8 mm. The tin plating buys the corrosion resistance; a scratched or badly crimped terminal loses it.

| Connection | How it goes together | How it fails | Best for |
| --- | --- | --- | --- |
| 4.8 mm spade | Crimped terminal pushed onto the axle contact | Salt works under the plating; the joint greens up and the light flickers over bumps | The hub end, where you must unplug to pull the wheel |
| Coaxial adapter | Replaces the two axle spades with one socket; Peter White Cycles notes coaxial connections require soldering | A poor solder joint | Riders tired of fiddling spades past a dropout |
| Soldered and heat-shrunk | Soldered, then sealed under shrink tube | Rarely, but it is permanent | Mid-cable joins and the light end |
| Piggyback spade | Doubles a second cable onto one axle contact | As a spade, with twice the area to keep clean | A light and a charger on one hub |

Copy Schmidt's assembly sequence exactly: separate the two conductors "over a length of about 4 cm," strip the ends "for about 5 mm," slide the shrink tube over the split, then "crimp the plugs on with a crimping tool or pointed pliers (if in doubt, solder as well)," making sure "the first pair of claws must grip the insulation." Shrink the tube on afterwards.

Then grease it. Schmidt says to "grease the plugs a little, so you can push the contacts onto the SON hub dynamo more easily."

<PullQuote attribution="Schmidt (nabendynamo.de), on crimped spade connections">A well-crimped connection, shrunk over and slightly greased, gives a very reliable connection.</PullQuote>

A thin film on the outside of the joint is the goal — enough to keep water out, not enough to sit between the mating faces. Then make the hub-end plugs the only ones you ever unplug. Peter White Cycles advises the same: pull the piggybacks off the hub and leave the light and charger wires joined, so you never rebuild those connections.

<SectionDivider variant="rule" />

## Wiring a Dynamo Light and Charger on One Hub

You can run both. You are splitting a small budget either way.

Peter White Cycles describes the standard arrangement as a parallel connection: the headlight wires use standard 4.8 mm female spade connectors at the axle, and the charger wires use piggyback connectors stacked on the same contacts. Mount the piggybacks with their male connectors facing the hub shell, which that page notes adds dropout clearance.

Polarity is a non-issue at the hub — Peter White Cycles states that the SON has no polarity, and Schmidt's sheet says the contacts are "arbitrarily interchangeable." Some headlights do care which wire is earth, so read the lamp's instructions.

Now the arithmetic, which is less generous than people expect. CyclingAbout states that "a 3-watt dynamo hub will put out 6 volts at 0.5 amps (3W = 6V x 0.5A)" in AC, and that after rectification the DC output is "more like 5V and 0.5A." Schmidt rates the SONdelux at a nominal 3 watts and says it is "designed to operate a rear light and a headlight" — a rear light, note, not a phone.

Two numbers from CyclingAbout set your expectations:

- Most dynamo chargers "will hit 1w between 7-10kph," the best reach 2 watts at 11 to 13 km/h, and below roughly 2 watts "a dynamo charger will not be able to provide power to most devices."
- Chargers are current-limited. Its example: "Sinewave Revolution is 1A, therefore the maximum power is about 5W (5V x 1A)."

So with the light on, the charger gets what is left. Peter White Cycles is direct: "turn your lights off while charging so as to have all of the hub's power available for charging." Schmidt makes the mirror-image point — run a headlight alone on a SONdelux and "the headlight will take up the higher power."

That split is why the charger matters more than the hub. Our roundup of [dynamo USB chargers](/posts/best-dynamo-usb-chargers-bikepacking) covers which units hold output at low speed, and the [power budget in watt-hours](/posts/bikepacking-power-budget-watt-hours) walkthrough tells you whether a dynamo can fill your daily demand.

The drag is real but small. CyclingAbout puts the efficiency of a good dynamo hub at 10 to 20 km/h at "around 50-60%," so "when making 2.5 watts for USB charging, you're using about 5 watts of your pedalling power" — which it works out, for a 150-watt rider on a flat road, as roughly 0.4 km/h slower, or three minutes over 100 km.

<SectionDivider variant="rule" />

## Corrosion and Winter: What Actually Kills a Dynamo Install

Schmidt is unambiguous about washing: "to prevent water ingress, the hub should never be exposed to strong jets of water (hose, pressure washer) or immersed in water." The bearings are permanently lubricated, with no way to re-grease them.

Testing backs it up. MBR blasted a typical hub with a jet washer "on full power, and at point-blank range," and reports that "when we pulled the hub apart there had been some water ingress," concluding that "overenthusiastic jet-washing can wreck your bearings and remove the grease." MBR calls that experiment completely unscientific, which is fair, but the direction is clear. Stihl's bike-washing guidance says to use a low-pressure setting, ideally 20 bar, and never to aim the jet at bearings and seals.

Our routine after salty or coastal riding:

- Rinse with a bucket or a low-pressure hose, aimed away from the hub seals.
- Unplug the hub-end spades, dry them, look for green or white powder, re-grease lightly, refit.
- Flex the cable along its length, checking for cracked jacket at ties and fork ports.
- Replace any terminal that will not come up clean. A crimp terminal is cheap next to a dark descent.

If you ride through winter, our [cold-weather bikepacking guide](/posts/winter-bikepacking-cold-weather-guide) covers the wider salt-and-grit problem your connectors are only one part of.

## Testing the Install Before You Trust It

Lift the front wheel and spin it by hand. The light should come up as the wheel accelerates, and a standlight-equipped lamp should hold a glow after the wheel stops. Then test it on the road, with the bike loaded:

- **Ride at a steady low speed** and watch for output. CyclingAbout's 7 to 10 km/h figure for 1 watt is a sanity check on a charger that will not start.
- **Ride a rough section and watch for flicker.** A light that pulses over bumps is almost always a connector problem — a loose spade, a crimp gripping insulation instead of copper, or an under-torqued skewer letting the axle move.
- **Charge one device for an hour** and record what you got. That is the number your power plan should use.

One quirk that is not a fault: Schmidt notes that the "pole sensitivity" you feel turning the axle by hand "is a feature of the claw pole generator and has nothing to do with the smooth running of the bearings."

<SectionDivider variant="rule" />

## What We Would Do

Buy the hub, let a wheelbuilder lace it, and spend your own evening on the wiring — that is where the quality of the install lives. Route the cable inside the fork blade, tie it so the plugs come apart before the wheel does, crimp with a real tool, heat shrink the split, grease the plugs lightly, and keep a pressure washer away from the hub.

Then re-check the skewer torque at 300 km, as Schmidt says to, and inspect the spades every time you clean the bike. An install that gets that attention disappears into the bike for years.

For the rest of the system — what to charge, what to carry as backup, and how the numbers add up over a multi-day route — work through [the complete bikepacking power and charging guide](/posts/bikepacking-power-charging-guide).


Installing and Wiring a Dynamo Hub for Bikepacking

Bikepacking Power and Charging: The Complete Guide to Staying Charged Off-Grid


## Dynamo Hub vs Power Bank for Bikepacking: The Short Answer

Ride long days, for many days, away from sockets, and the dynamo hub wins. Ride short days or short trips, and the power bank wins. The crossover sits at roughly **six to seven hours of riding a day** and **about a week between mains outlets**. Below those numbers a dynamo cannot earn back its weight, cost or drag.

That is the whole decision, and it is not about money. It is about how many hours a day you actually turn the cranks. A dynamo is a generator with a fixed cost per hour of riding and effectively infinite range. A power bank is a fuel tank with zero drag and a hard bottom. Everything else in your [bikepacking power and charging setup](/posts/bikepacking-power-charging-guide) follows from which of those two things your route needs.

The uncomfortable version: a dynamo bought for a weekend trip is almost always the wrong purchase, and a dynamo bought for a month-long remote route is almost always the right one. Riders arrive asking which is better. Below a certain daily mileage the honest answer is that a dynamo cannot cover its own charging overhead, and above a certain trip length a power bank big enough to do the job weighs more than the hub.

<Highlight label="The short version">

- A dynamo is regulated to about **3 W at 6 V** on most modern hubs, and Schmidt quotes **65 percent efficiency, but only at 15 km/h**, according to Wikipedia's hub dynamo entry.
- CyclingAbout's lab rig measured a Shimano UR700 producing **4.2 W at 15 km/h** at its maximum power point, but only **2.8 W at the same speed** through a real Forumslader V6 charger.
- The same test found a phone's **2.5 W charging threshold** needs about **13 km/h** with the best hub and charger pairing, and up to **18 km/h** with a worse one.
- Busch+Müller's own USB-Werk documentation says a dynamo supplies about **3 W at 15 km/h** while some phones draw **up to 5 W**, which is why a cache battery is not optional.
- Anker's own arithmetic turns a **10,000 mAh** bank into **37 Wh** and then into about **6,068 mAh at 5 V** once conversion losses are counted. Call it **30 Wh usable**, not 37.
- At a modest **20 Wh a day**, one month off-grid needs roughly **3.8 kg** of power banks. That is the point where the hub stops being a luxury.

</Highlight>

<SectionDivider variant="rule" />

## What Each System Actually Is, and What Each One Costs

A hub dynamo is a small alternator built into your front hub. Most modern hubs are regulated to about 3 W at 6 V, with some reaching 6 W at 12 V, according to [Wikipedia's hub dynamo entry](https://en.wikipedia.org/wiki/Hub_dynamo). On its own it produces wild AC, so a dynamo-to-USB regulator converts and smooths it into something a device will accept.

Its costs are three, and only one is obvious. First, capital: hub, regulator, and usually a cache battery. Second, a wheel rebuild or a new front wheel, because the hub is the wheel. Third, drag — a real, permanent tax on every hour you ride.

That drag has been measured. CyclingAbout's lab test, which spins a dynamo wheel against a motor on a steel plate and subtracts a non-dynamo baseline, found drag with lights and chargers off running from **1.4 W to 1.9 W for a SON 28** across 10 to 30 km/h, against 1.9 W to 5.2 W for an SP PD-8 and 1.4 W to 4.5 W for a Shimano UR700, with the figures accurate to within about 1 W ([CyclingAbout](https://www.cyclingabout.com/dynamo-hub-power-drag-testing-schmidt-son-shutter-precision-shimano/)). Switch a bright light on and the load climbs steeply — the same rig reported 14.5 W at 15 km/h for a UR700 driving a Busch+Müller IQ-X.

A power bank is a sealed lithium cell with a converter on the front. Its costs are simpler: carried weight, a hard capacity limit, and the logistics of finding a socket. Its great virtue is that it adds exactly zero drag. Nothing it does slows you down.

<PullQuote>A dynamo charges you by the hour. A power bank charges you once, in grams.</PullQuote>

<SectionDivider variant="trail" />

## The Dynamo Case: Output at Realistic Touring Speeds

Dynamo output is a function of wheel speed, and the numbers at touring speed are smaller than most riders expect. CyclingAbout's rig measured a Shimano UR700 at its maximum power point producing 1.5 W at 5 km/h, 2.6 W at 10 km/h, **4.2 W at 15 km/h**, 6.0 W at 20 km/h, 7.7 W at 25 km/h and 9.1 W at 30 km/h.

That is the theoretical ceiling. Through an actual charger you get less. The same test put a Forumslader V6 on that hub and measured 2.0 W at 10 km/h, **2.8 W at 15 km/h** and 4.7 W at 20 km/h. The honest planning figure for a loaded bike at a genuine 15 km/h is therefore under 3 W, nowhere near the 9 W you see on a fast descent.

Output also plateaus. Hubs are regulated, so once you are above their rated speed you are not harvesting proportionally more. Retailer listings for the SON 28 state it reaches rated output at about 16 km/h in a 700c wheel, against about 19 km/h for the lighter SONdelux ([SJS Cycles](https://www.sjscycles.co.uk/hubs-front/son-28-centre-lock-disc-dynamo-front-hub-polished-36-hole)). The practical consequence is that a dynamo rewards *duration*, not speed. Eight slow hours beats two fast ones.

<Tip title="Without a cache battery, riders conclude the dynamo does not work">

A dynamo does not charge a phone well directly, and this is the single most common disappointment. Busch+Müller's documentation for the USB-Werk explains the mechanism plainly: the dynamo supplies only about 3 W at around 15 km/h while some phones draw up to 5 W, so a buffer battery charges first and the USB output stays off until it reaches a set level. When the phone pulls the buffer down to its minimum, the output switches off again and the buffer refills, which "leads to interruptions, which some USB devices indicate with the charge start sound" ([bike-components product documentation](https://www.bike-components.de/en/busch-mueller/USB-Werk-Mobile-Charging-Device-p35972/)). The same source notes the buffer needs roughly 20 minutes above 17 km/h with nothing plugged in and the lights off to fill completely. Buy the hub and the regulator and skip the cache battery, and every stop sign undoes your charging.

</Tip>

What the dynamo genuinely buys you is range that does not run out and lights that never die. On a route where resupply is food and water only, that is worth real weight. We will cover the hub choice itself in the best dynamo hubs for bikepacking, and the regulator choice in the best dynamo USB chargers, because the charger matters at least as much as the hub — the measured gap between pairings is the difference between charging a phone at 13 km/h and needing 18 km/h.

<SectionDivider variant="ornamental" />

## The Power Bank Case: Usable Capacity Is Not Rated Capacity

For most trips, the power bank is the correct answer, and it is not close. The tradeoff is that you are carrying every watt-hour you will use, and when it is gone it is gone.

Start by distrusting the number on the case. Anker's own support page works it through: a 10 Ah cell at 3.7 V is 37 Wh, which at 5 V is 7.4 Ah, and after conversion losses at "typically around 82 percent efficiency" the effective capacity a device can use is about 6,068 mAh ([Anker](https://service.anker.com/article-description/Why-Is-the-Rated-Capacity-Marked-on-a-Power-Bank-Lower-Than-Expected)). Converting that back to energy with `Wh = mAh / 1000 x V` gives 6.068 Ah at 5 V, or **about 30 Wh of usable energy from a 10,000 mAh bank** — roughly 60 percent of the headline 10,000 mAh.

Now weigh it. Retailer listings put Anker's PowerCore II 10000, a 37 Wh bank, at **195 g** ([Galaxus](https://galaxus.be/en/s1/product/anker-powercore-10000-mah-18-w-37-wh-powerbanks-10285520)). Against 30 Wh usable, that is about **6.4 g per usable watt-hour**. That single number is the one to carry around in your head, because it converts any power budget directly into grams.

The power bank also wins on every failure mode that matters. It works at 0 km/h, while you sleep, in a tent, on a bus. It has no spokes to true and nothing to short out in the rain. If you are choosing the bank itself, we go through capacities and ports in our guide to [picking a portable charger for your phone and GPS](/posts/navigating-with-power-the-best-portable-charger-for-your-phone-and-gps).

<SectionDivider variant="trail" />

## The Crossover: Show the Sums

Pick a daily draw. We will use **20 Wh a day** as a worked example — a phone topped up, a head unit kept alive, and a light or two. Your real figure may be half or double that, and getting it right is the whole exercise, so start with [how much battery you actually need](/posts/bikepacking-power-budget-watt-hours) and substitute your own number into the sums below. Head units vary enormously in appetite; our round-up of [cycling computers for bikepacking](/posts/best-cycling-computers-bikepacking) is a reasonable place to see the spread.

**Break-even in riding hours.** At the measured 2.8 W a Forumslader V6 delivered from a UR700 at 15 km/h, covering 20 Wh takes `20 / 2.8`, about **7.1 hours of riding a day**. Push to 20 km/h and the measured 4.7 W cuts that to about **4.3 hours**. Drop to 10 km/h and the measured 2.0 W pushes it out to **10 hours**. A three-hour evening ride at 15 km/h yields about 8.4 Wh — under half a day's budget. This is why a dynamo on a weekend trip is a net loss.

**Break-even in grams.** At 6.4 g per usable watt-hour, 20 Wh a day costs you about **128 g of power bank per day**. Schmidt lists the SON 28 hub itself at about 440 g, so on hub mass against bank mass the batteries overtake the hub at roughly `440 / 128`, about **3.4 days**. Be honest about that figure, though: the dynamo system also needs a regulator and a cache battery, and you only pay the *difference* between the dynamo hub and the plain front hub it replaces. Add those back and the real mass crossover lands closer to **a week of genuine off-grid riding**.

| Trip | Energy needed at 20 Wh/day | Power banks, approx. | Our call |
|---|---|---|---|
| Weekend, 2 days | 40 Wh | ~260 g | Power bank, no argument |
| One week, a socket mid-trip | ~60-80 Wh carried | ~400-500 g | Power bank |
| One week, no sockets at all | 140 Wh | ~900 g | Dynamo if you ride 6+ hours daily |
| One month off-grid | 600 Wh | ~3.8 kg | Dynamo |
| Remote and open-ended | unbounded | impossible | Dynamo, only answer |

The bottom row is the real case for a dynamo. It is not that the hub is lighter on a given trip — it is that a dynamo's capacity does not have a bottom, so a route with no known end does not have a battery calculation at all.

<SectionDivider variant="rule" />

## When the Answer Flips Regardless of the Maths

**Cold.** Battery capacity falls in the cold while a generator does not care.

<Warning title="Expect to lose roughly half your capacity in deep cold">

Battery University states that a battery delivering 100 percent capacity at 27 °C typically delivers about 50 percent at -18 °C, and that most batteries sit near 50 percent performance at -20 °C, though the shortfall is temporary and recovers at room temperature ([Battery University](https://batteryuniversity.com/article/bu-502-discharging-at-high-and-low-temperatures)). Plan a winter power budget on your bank's rated capacity and you can be short by a wide margin on the coldest morning of the trip. Sleeping the bank inside your quilt is the standard mitigation, and we go further into cold-weather behaviour in our [winter bikepacking guide](/posts/winter-bikepacking-cold-weather-guide).

</Warning>

**Very slow or technical riding.** Dynamo output tracks wheel speed, and CyclingAbout's test found the 2.5 W smartphone charging threshold requires about 13 km/h with a UR700 and an Igaro D1, rising to about 17 to 18 km/h with other hub and charger pairings. A route averaging 9 km/h on chunky doubletrack may spend most of the day below the threshold entirely.

**Hike-a-bike.** Pushing generates nothing. A route with hours of carrying per day is a power bank route no matter how many days it lasts.

**Electrically hungry setups.** If you are running a bright dynamo light *and* charging, you are splitting a very small budget. For most riders, a rechargeable light plus a bank is simpler than a dynamo trying to do both, and our [overnight bike light round-up](/posts/best-bike-lights-overnight-bikepacking) treats that choice directly.

**The device that must not go flat.** If a [satellite messenger](/posts/best-satellite-messengers-bikepacking) is your emergency plan, it gets its own reserve. Neither system changes that.

**Not wanting to rebuild a wheel.** This is a legitimate reason, not a failure of nerve. A dynamo means a wheel build or a new front wheel, plus a connector that has to survive weather and vibration. Some riders simply do not want another system to maintain, and that preference is worth more than a few grams.

<SectionDivider variant="ornamental" />

## What We Would Do

**Weekends and sub-week trips with any socket access.** A power bank, every time. At about 6.4 g per usable watt-hour, two or three days of autonomy costs a few hundred grams. The tradeoff is that you are rationing from day one, and on a long cold weekend you may ration harder than you expected.

**One to two weeks, mostly rural, occasional cafes.** Still a power bank — one larger bank, charged at every opportunity. The tradeoff is route dependence: your charging plan is now a list of places that have to exist and be open.

**One month or longer off-grid, 6 or more riding hours a day.** The dynamo, decisively. At 20 Wh a day, a month of carried battery is roughly 3.8 kg, and no hub weighs that. The tradeoff is 1.4 W to 1.9 W of permanent drag on [a good hub](/posts/best-dynamo-hubs-bikepacking), plus the capital cost and a wheel build — and you still carry a cache battery.

**Open-ended or expedition routes.** The dynamo, and it is not really a comparison. The tradeoff is complexity in a place where a failed connector is genuinely inconvenient, so carry a small bank as backup regardless.

**Short, slow, technical riding or heavy hike-a-bike.** A power bank, even on long trips. The dynamo simply will not spin fast enough to pay. This is also the one profile where riders most often ask about panels instead — we work through why that rarely helps in [solar charging for bikepacking](/posts/solar-charging-bikepacking).

The useful reframe is that these are not competitors. A dynamo is a slow trickle that never stops; a bank is a fast reserve that does. Most riders who end up with a hub still carry a bank, which tells you what each thing is actually for. For the full system — budgets, device draw, cables and chargers — see [our complete guide to bikepacking power and charging](/posts/bikepacking-power-charging-guide).


dynamo-hub

Installing and Wiring a Dynamo Hub for Bikepacking

Bikepacking Power and Charging: The Complete Guide to Staying Charged Off-Grid

Dynamo Hub vs Power Bank: Which Bikepacking Charging System Suits Your Trip