Skarper

The offer

What Skarper actually is

Skarper is one configuration from Skarper, made in United Kingdom, filed here as a disk drive. The family is Disk, generation Catalogue. British disk drive. The motor sits on the chainstay and drives the rear disc, not the tyre and not the bottom bracket. 250 W, about 240 Wh.

In the box, as this record has it: Disk drive unit, Pack, Charger, Chainstay mount. Still required before the bike moves under its own assist: Disc-brake rear wheel, Chainstay clearance. A cheaper advert for the same family name is not this list. If the battery, the charger or the throttle differs, it is a different configuration and it gets a different page.

250 W class. The fit engine treats it as a specialist friction-class install because it is not a hub or a BSA motor.

The price on the card is the maker’s published figure in GBP, or Maker list when no figure was published. Allowances for a missing pack, a charger and workshop time sit in the complete-cost band. They are not a second product and they are not a promise that a random pack will talk to this controller.

The bicycle

The frame this motor is asking for

Skarper lists Skarper against Road, Hybrid bicycles, for Commuting, Leisure. Wheel sizes on the card: 700c, 26, 27.5. The mechanical interface is Uses the existing rear wheel. Brakes are disc.

This architecture does not replace the axle or the bottom bracket. The question is whether the mount — roller, rotor, seat stay or hitch — has a flat, strong place to live, and whether the tyre, the disc or the seat post is the one the maker designed for.

Pedals stay. This configuration is a bicycle with assistance, not a motorcycle conversion. Sensor on the card: torque. Cut-off on the card: 15.5 mph. Throttle: not fitted.

The numbers

250 W is not the whole story

Continuous rated power for Skarper is 250 W. Claimed peak is not stated separately from the continuous rating. Torque is not published as a crank or hub figure. Manufacturer stated. Motor mass is not published. System mass, once the named parts are on the bike, is Disk drive unit, Pack, Charger, Chainstay mount.

Peak is a short claim. Street rules, including the Great Britain check on this site, use continuous rated power and the speed at which assistance stops. A controller that can be unlocked does not change the record of the motor as sold. Skarper is filed in the 25 km/h class: 250 W pedelec class used across the EU, Great Britain and Australia.

In this class the useful comparison is torque and mass, not a bigger watt sticker. A 250 W torque-sensing mid-drive and a 250 W cadence hub do not feel alike, and neither of them becomes legal somewhere else just because the sticker matches.

Pack and charger

The pack is part of the kit

Skarper pack is 240 Wh at 36 V. Lithium-ion The charger is Included charger.

Nominal watt-hours are voltage times amp-hours when both are known. That is stored energy on the label, not usable energy, and not a mileage promise. Cold, load, hills and how full you dare to run the pack all move the distance. Any range sketch on this page shows the watt-hours per kilometre it assumed.

Charge this pack with the charger named for it. The same plug on a higher-voltage brick is the wrong part. A swollen, hot, hissing or sharp-smelling pack is a stop: do not open it and do not keep charging it.

Disk drive

How Skarper uses this layout

Disk drive. Skarper drives the brake rotor, or sits beside it, instead of replacing the hub or the bracket. The wheel you already trust can stay, which is the reason people with a good wheelset look at this architecture.

The mount needs a chainstay or a caliper area that is round, reachable and strong enough. A rear disc is required. Rim-brake bikes are a different problem and are not solved with a wish.

Heat in the rotor is shared with the brake. The workshop looks at pad clearance and whether the drive puck and the caliper argue. That is a specialist fit on this record when the card says so.

The workshop

Specialist, even if a shop is doing it

Skarper is marked specialist. An online fit is a brief. The stand still has to see the frame. Cargo, long chainstays, unusual dropouts and this architecture are why the automated check stops.

Warranty as published: Maker warranty. Term is on the invoice.. Labour in the cost band is separate from the offer. A brake service the bike already needed, a new chain, or a hanger alignment is not folded into Skarper’s price to make the total look neat.

The sensible order is measure, then mount, then connect, then the first assisted roll in the stand. Connectors are keyed for a reason. The torque arm, the axle nuts and the connector boots are one inspection at the end, not three trips.

After it is on

The first month, and the parts that wear

Spoke tension on a motor wheel is part of the service, especially in the first few hundred kilometres while the wheel beds in. A ticking torque arm is a loose bolt, not a personality. Check axle nuts after the first week.

Keep Included charger with Skarper pack. Store the pack cool, part-charged if it will sit, and not in a hallway that is your only exit. Skarper’s display, if one is included, is paired to this controller generation. A screen from the next family is not a spare.

My Garage on this device can hold the configuration, who fitted it, and what was still open. That note is for you and for the next workshop. It is not a certificate. If a later notice lands on this configuration, the record is where it should show.

Read next to it

• Bimotal ElevateBimotal · Disk drive · 20 mph

From the library

• What a conversion kit actually includesA motor wheel and a complete system are not the same product. The page should say which one you are looking at.
• Watts, torque, and the sticker that does not mean rangeContinuous watts, peak watts and newton-metres describe different moments. Mixing them is how a listing looks twice as strong as the motor you will live with.
• Speed classes, from 25 km/h to off-roadThe class is a property of the kit as sold. The road you may use it on is a property of the country, and sometimes of the state or the canton.
• Disk drives and seat-stay motorsTwo ways to add a motor without rebuilding the wheel or pulling the bottom bracket.