Corghi Motorcycle Monolever Kit 19mm

Single-sided swingarm wheels are the awkward ones. A conventional motorcycle wheel is held on the balancer by cones pushed into the bearing bores from both sides, and the shaft runs straight through the hub the way an axle would. A monolever wheel does not work like that. It hangs off one side of the bike on a splined or flanged hub, and once it is off the machine there is often nothing in the middle for a cone to centre against. This kit, part 8-21120014, is Corghi's answer to that: a Ø 19 mm centering interface with the sleeves, spacers and fasteners that let a hub-mounted wheel sit true on a balancer built for cars.

It is an accessory for a machine you already own, not a second machine. That is the whole commercial argument for it — a shop with a Corghi balancer on the floor can take on Ducati, BMW, Honda, MV Agusta, Triumph and Aprilia wheels without buying a dedicated motorcycle balancer, finding somewhere to put it, and then watching it stand idle between bike jobs.

Why 19 mm is the number that matters

The Ø 19 mm shaft is the reason this kit works across brands rather than one. Monolever hub bores are not arbitrary — the size recurs across manufacturers, which is why an adapter built to it covers a broad slice of the single-sided market instead of a single model line. Where a hub sits slightly outside that, the sleeves and spacers in the kit take up the difference and keep the wheel square to the shaft.

Everything else follows from getting that dimension right. A balancer resolves an imbalance of a few grams. If the wheel is mounted with any eccentricity at all, the machine faithfully measures the mounting error and reports it as wheel imbalance, and the technician spends the next ten minutes adding, removing and moving weights to correct something that was never wrong with the wheel. Concentric mounting is not a refinement here; it is the difference between a balancing job and a guessing game.

It works with the machine, not around it

The kit fits into the balancer's own clamping and locking arrangement rather than replacing it. The standard centering shaft comes off, the monolever components go on, the locking nut goes back, and the machine's normal routine runs unchanged — same clamp, same spin, same readout, same weight placement logic. Nothing about the balancer's other functions is given up while the kit is fitted, and swapping back for car work is the same operation in reverse.

Because it installs into existing architecture, there is no bench work, no bolting anything to the floor and no reconfiguration. The host balancer's service manual walks through the shaft change; if yours has gone missing, ask us and we will point you at the current version.

Precision that survives the tenth wheel, not just the first

Adapter components live a rough life. They are mounted and pulled off several times a day, they get grease on them, they are stood on end on a steel bench, and they sit in an atmosphere of tyre soap and brake dust. The parts here are machined to hold their fit rather than to look good in a photograph, and the wear surfaces are finished to resist the slow degradation that turns a precise sleeve into a sloppy one after a season.

The load path helps too. Because the kit clamps through the balancer's own interface, the forces acting on the adapter are the ones the machine was designed to apply — they are not concentrated on an improvised joint. Adapters fail when they are asked to do something structural they were never intended to do, and this one is not.

Will it fit your balancer?

Corghi lists this kit against the EM9250/80, EM9550, EM9580 Touch and EM9980C. If your machine is one of those, you are on solid ground. If it is not, send us the model and serial number before ordering — shaft diameter alone does not settle it, because the locking arrangement has to match as well. We would rather answer that question in a two-minute chat than have you return a kit.

If you are also setting the balancer up for conventional motorcycle and scooter wheels, the base motorcycle package and the large-bore upgrade set are separate part numbers. Ask us what a complete bike-capable setup looks like for your specific machine rather than assembling it from part numbers alone.

Perfect For

• Motorcycle dealerships carrying sportbike and adventure brands, where single-sided swingarms are common on the premium end of the range and turning that work away is turning away the profitable jobs.
• Independent bike shops that already run a Corghi balancer for general work and are losing monolever wheels to a competitor down the road for want of one adapter.
• Tyre shops with mixed traffic where a technician needs to move between a car wheel and a bike wheel in the same bay without a machine changeover.
• Race and track-day support operations, where wheels come on and off constantly and a repeatable, concentric mount is worth more than raw speed.

What is in the box

The kit is supplied as a centering set built around the Ø 19 mm shaft interface, with centering sleeves, spacers and the fasteners needed to mount the assembly to the balancer. We have deliberately not published a piece-by-piece parts list on this page, because the itemised contents are not stated in the data we hold for this product and a list we cannot stand behind is worse than none. If you need the exact bill of materials before you order — for a purchase order, or to check one specific hub — ask us and we will get it from the manufacturer in writing.

Specifications

Standards and approvals

We hold no third-party listing or conformity marking for this accessory, and we are not going to imply one. Balancer tooling of this kind is generally covered by the approvals held by the machine it fits, not by its own paperwork. If a fleet policy, an insurer or a workplace inspection asks for documentation covering shop equipment accessories, tell us before you order and we will ask the manufacturer for what exists, so the position is settled before the purchase rather than after it.

Shipping and delivery

Shipped freight to the lower 48 states. Someone needs to be available to receive and unload the shipment, or you can choose to collect it from the carrier's terminal. A residential delivery carries a fee. We do not print a shipping price on this page — it is quoted live at checkout for your address, because carrier rates change and a number typed into a description goes stale. When the shipment arrives, look it over before you sign: any damage to the packaging or the contents must be written on the bill of lading at the point of delivery, because a clean signature makes a claim very difficult afterwards.

Warranty

Covered by the manufacturer's warranty. We have not restated the term length here because it is not stated in the product data we hold, and quoting a number we cannot verify on a page that is supposed to be trustworthy would defeat the point — ask us and we will send the current document. If something does fail, raise the claim before touching it. Stripping a component to diagnose it yourself is the single most common way a valid warranty claim gets refused.