Reference

Rad Power Bikes RadMini 4 and RadMini Step-Thru 2: parts and specs

Replacement parts for the RadMini 4 and RadMini Step-Thru 2: the 20 inch fat tires that fit them, 20 x 4 Schrader tubes, Tektro E10.11 pads, mechanical levers and cables, charger and battery upgrade, with Rad's links and prices.

Last edited Nov 9, 2026 by Pedalwise team Edit History Add a subpage

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Tools

Parts

This page lists the common replacement parts for the Rad Power Bikes RadMini 4 (high-step) and RadMini Step-Thru 2 folding fat tire bikes. Specs are for the stock bikes as sold. Check the markings on your tires and brakes, and your owner's manual, before ordering.

Photo needed: A RadMini 4 folded, showing the 20 x 4 tires and the mechanical disc brake caliper.. Add one

Electrical parts on this list must match this exact model, and they are fitted at the external plugs or by a pro. Never open the battery, controller, motor or display. For battery and charger trouble, start with battery won't charge and e-bike battery care.

Parts list

Tire: three 20 inch tires from Rad fit the RadMini. The RadExpand Replacement Tire, a CST BFT 20" x 4", fits the RadMini 1 to 4 high-step and RadMini Step-Thru 1 to 2, $55, out of stock. The Kenda Krusade 20" x 4" fits the RadMini and RadMini Step-Thru, $67.95, out of stock. The Kenda K-Rad 20" x 3.3" fits all RadMini model years, $65, out of stock. All read Nov 9, 2026. Match the size on your sidewall.
Inner tube: Rad's 20" x 4" inner tube fits the RadMini 1 to 4 high-step and the RadMini Step-Thru 2. Schrader valve, 5 to 30 PSI, $22, shown as shipping within 2 business days, read Nov 9, 2026.
Disc brake pads: Rad's Tektro E10.11 organic pads fit all RadMini models and Tektro Aries calipers, which take rectangular pads, $25 per set for one wheel, back order, read Nov 9, 2026.
Brake lever: Rad's Tektro mechanical brake lever fits all RadMini models, $25, shown as shipping within 2 business days, read Nov 9, 2026.
Brake cable: Rad's Brake Cable Kit fits any model with mechanical brakes, cut to length, $15, shown as shipping within 2 business days, read Nov 9, 2026.
E-bike charger: Rad's Rad Battery Charger (MY2025) fits all Rad bikes except the 2016 to 2017 RadMini 1 and the RadKick, $65, out of stock, read Nov 9, 2026.
E-bike battery: Rad's Safe Shield Advanced External Battery (15 Ah) is an upgrade for the RadMini 4 high-step and does not fit the 2020 RadMini 2 Step-Thru, $599, out of stock, read Nov 9, 2026. It needs the updated 2025 Rad charger. Step-thru owners should confirm with Rad support before buying a battery.

Tools for common jobs

Hex keys: brake caliper and lever bolts, and checking the fold hinge and stem.
Tire levers: changing the 20 inch fat tire or tube.
Floor pump with gauge: Rad's 20 x 4 tube is rated 5 to 30 PSI; pump to the range on your tire sidewall.
Axle nut wrench: removing the rear hub motor wheel to fix a flat.
Torque wrench: tightening axle nuts and brake bolts to your manual's values.
Cable cutters: trimming a new brake cable on the mechanical brakes.
Chain checker: checking chain wear.
Chain lube: regular chain care.

Where to buy

Rad's spare parts store: tires, tubes and brakes. Much was out of stock on Nov 9, 2026. For a controller, motor or display, ask Rad support.
Independent sellers: our parts suppliers page. A local shop can order and fit parts: find a shop.

Common repairs

Sources

Stuck after these checks? Find a shop near you.

Need a pro?

If these steps didn't fix it, find a shop near you in our partner network. For battery or wiring trouble, look for shops marked Battery and electrical.

Talk

Questions, things that worked for you, or something that looks wrong on this page.

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