How We Assess Tongsheng Motors

Most sites that compare mid-drive motors copy figures from a marketplace listing without checking their origin — or worse, without saying which one. In a market where the same Tongsheng motor gets credited with 90, 120, or 140 N·m depending on which reseller you ask, that lack of rigor produces an unreadable lineup. We'd rather tell you what we actually do.

What we do

We verify specs first against the manufacturer's official spec sheet. For the TSDZ8 and TSDZ2B, every figure in our reviews comes directly from Suzhou Tongsheng Electrical Appliance Co., Ltd.'s manufacturer site (tongsheng-e.com), checked and dated. Not a reseller press release copied over, not another site that itself copied it.

When no official sheet exists, we say so. The TSDZ16 and the original TSDZ2 don't appear in any manufacturer catalog we could find. Their specs come from specialist resellers, systematically flagged as such — never presented with the same authority as an official figure.

We apply an identical grid to every model. The same standard spec sheet, the same rating criteria, from the historical motor to the most recent. That's what makes the comparison honest: without a shared grid, comparing two motors amounts to comparing two marketing pitches.

We check prices regularly. A Tongsheng kit's price depends on a configuration (model, power, display, battery), not a fixed per-model rate — which makes tracking it more complex than for a finished product, and all the more necessary to document clearly.

What we don't do

We don't claim to have tested every motor in real-world conditions. We also don't claim otherwise: our work is documented analysis, not a test bench. A site that claims to have "tested" conversion kits it never bolted onto a bike is lying to you.

We don't fill in data gaps. A "Not disclosed" field on a spec sheet is information in itself — a signal that no sufficiently reliable source lets us state that figure, not an oversight on our part.

Why this method beats a single quoted figure

A torque figure copied from a single listing tells you nothing about its reliability. Our value isn't in having taken a motor apart: it's in the systematic cross-checking of sources, which reveals that an official "140 Nm" and an unconfirmed reseller "140 Nm" don't carry the same evidentiary weight, even displaying the identical number.

That's the work that reveals a motor absent from the official catalog (TSDZ16) can claim more torque than a fully documented motor (TSDZ8) — without either necessarily being better. No single figure reveals that nuance; only cross-checking sources does.

Our independence

We have no commercial relationship with Tongsheng or with the resellers cited on this site. Our conclusions show, whenever the figures demand it, that a cheaper or less powerful motor on paper remains the more rational choice for most use cases — that's the only test of independence worth anything.

→ Our rating system, criterion by criterion