CYC vs Bafang: Which Mid-Drive Conversion Kit Should You Buy?
CYC and Bafang both make bolt-on mid-drive kits that replace a bike's bottom bracket. CYC kits ship with a torque sensor and publish more torque per kilogram (Photon 2: 135 Nm, 3.5 kg). Bafang's BBS02 and BBSHD cost less, use cadence-based assist, and are the most widely installed DIY mid-drives. Choose CYC for pedal feel and tuning. Choose Bafang for lowest cost.
Specs verified on October 9, 2026. Every Bafang figure links to its source at the end of the article.
The CYC kits in this comparison
Each CYC kit is matched against its closest Bafang rival below. Prices are current on cycmotor.com.
CYC Photon 2
Street-legal commuting, gravel and Class 1 trails
750W nominal, 2000W peak, 135 Nm, 3.5 kg
Kit $950 · Photon 2 + A-52 battery $1,338
CYC Photon Pro
Steep off-road climbs, cargo and private land
3000W rated, 4000W peak, 180 Nm, 4.5 kg
Kit $1,098 · Photon Pro + A-52L battery $1,636
CYC X1 Pro Gen 4
Maximum power off-road builds
6000W peak, dual-stage reduction, X12 controller
Kit $1,250 · X1 Pro 4 + A-65 battery $2,246
How we compared
This is a spec and cost comparison, not a ride test. Here is the method, so you can check our work.
- CYC figures come from the live product pages on cycmotor.com and CYC's engineering posts. Where CYC's own pages disagree, we use the product page value and flag the conflict.
- Bafang figures come from Bafang's official M-series pages (bafang-e.com) first. We use retailer figures only where Bafang publishes nothing, and we label them as retailer figures.
- Prices are list prices in USD on the access date. Bafang prices come from third-party sellers because Bafang does not sell kits direct.
- Owner reports from Electric Bike Review and Endless Sphere forums are labeled as anecdotal.
- What we did not do: no back-to-back dyno runs, range tests or speed tests. We make no top-speed claims for any motor.
A note on names. Bafang sells the same motors under two names. The BBS02 is the M315, the BBSHD is the M615, and the "Ultra" is the M620 [B2][B4]. We use both names below.
CYC vs Bafang at a glance
| Model | Rated power (W) | Peak power (W) | Max torque (Nm) | Weight (kg) | Voltage (V) | Sensor | Kit price (USD) |
|---|---|---|---|---|---|---|---|
| CYC Photon 2 [C1] | 250 / 750 | 2,000 | 135 | 3.5 | 36 to 72 | Torque | $950 |
| Bafang M315 / BBS02 [B1][B2] | 500 (Bafang); 750W version sold by retailers | Not published | 100 | 4.3 | Not stated by Bafang | Cadence (forum consensus) | $499 for BBS02B [B8] |
| CYC Photon Pro [C2] | 3,000 | 4,000 | 180 | 4.5 | 36 to 72 | Torque | $1,098 |
| Bafang M615 / BBSHD [B3][B5] | 750 or 1,000 | Not published | 160 | 5.6 (Bafang); 4.8 (retailer) | 48/52 (retailer) | Cadence (forum consensus) | $695 [B8] |
| CYC X1 Pro Gen 4 [C3] | 5,000 | 6,000 | 280 | 5.6 | 36 to 72 | Torque | $1,250 |
| Bafang M620 / Ultra [B6][B7] | 1,000 | 1,500 (retailer) | 170 (Bafang); 160 (retailer) | 6.7 | Not stated in our sources | Dual (torque + cadence) | Not sourced |
Weight figures are as published. Makers do not always state whether cranks or controllers are included, so treat small weight gaps with caution.
Model-by-model matchups
Photon 2 vs Bafang BBS02 (M315)
These are the entry points of each brand. Both target street and trail riders who want a pedal bike with assist, not a motorcycle.
| Spec | CYC Photon 2 | Bafang M315 / BBS02 |
|---|---|---|
| Rated power | 250 / 750W [C1] | 500W official; 750W version at retail [B1][B2] |
| Peak power | 2,000W [C1] | Not published by Bafang |
| Max torque | 135 Nm [C1] | 100 Nm [B1] |
| Weight | 3.5 kg [C1] | 4.3 kg [B1] |
| Bottom bracket | BSA 68 to 83mm, BB92, BSA 100mm, BSA 120mm [C1] | 68mm [B1] |
| Sensor | Torque [C1] | Cadence (forum consensus) |
| Kit price | $950 | $499 (BBS02B) [B8] |
On published numbers, the Photon 2 makes 35 Nm more torque and weighs 0.8 kg less. That works out to about 39 Nm per kg for the Photon 2 and about 23 Nm per kg for the M315.
The BBS02 costs roughly half as much. You often see a 120 Nm figure quoted for the 750W BBS02. Bafang's own page does not list it, so we do not use it.
The Photon 2 can also be set to US Class 1, 2 or 3 limits in the Ride Control app [C6].
Best for: The Photon 2 suits riders who want a light, street-legal setup with natural pedal feel. The BBS02 suits riders on a tight budget with a standard 68mm bottom bracket.
Want torque sensing at the BBS02 class of power? Start with the Photon 2.
Photon Pro vs Bafang BBSHD (M615)
This is the matchup most forum threads argue about. The Electric Bike Review thread "A BBSHD Killer? Here comes the CYC Photon" runs to about 200 posts [F1].
| Spec | CYC Photon Pro | Bafang M615 / BBSHD |
|---|---|---|
| Rated power | 3,000W [C2] | 750 or 1,000W [B3] |
| Peak power | 4,000W [C2] | Not published by Bafang |
| Max torque | 180 Nm [C2] | 160 Nm [B3] |
| Weight | 4.5 kg [C2] | 5.6 kg (Bafang) [B3]; 4.8 kg (retailer) [B5] |
| Bottom bracket | BSA 68 to 83mm, BB92, BSA 100mm, BSA 120mm [C2] | 68 to 120mm [B3] |
| Controller | VTON Gen 2 [C2] | 30A max (retailer) [B5] |
| Sensor | Torque [C2] | Cadence (forum consensus) |
| Kit price | $1,098 | $695 [B8] |
Be clear about one thing: these are not equal power classes. The Photon Pro is rated at three times the BBSHD's 1,000W. That puts it outside US e-bike Class limits, and CYC positions it for private land and off-road use [C6].
The torque gap is smaller: 180 Nm vs 160 Nm. The weight gap depends on which BBSHD figure you trust. Against Bafang's official 5.6 kg, the Photon Pro is 1.1 kg lighter. Against the 4.8 kg retailer figure, it is 0.3 kg lighter.
Best for: The Photon Pro suits riders who want much more power than a BBSHD without a heavier motor. The BBSHD suits riders who want a proven 1,000W unit at a lower price.
Looking for a lighter BBSHD alternative with a torque sensor? Compare the Photon Pro.
X1 Pro Gen 4 vs Bafang M620 Ultra (and why they are different classes)
Bafang has no direct rival to the X1 Pro Gen 4. The M620 Ultra is the closest Bafang mid-drive by torque, so we compare them. They are built for different jobs.
| Spec | CYC X1 Pro Gen 4 | Bafang M620 / Ultra |
|---|---|---|
| Rated power | 5,000W [C3] | 1,000W [B6] |
| Peak power | 6,000W [C3] | 1,500W (retailer) [B7] |
| Max torque | 280 Nm [C3] | 170 Nm (Bafang) [B6]; 160 Nm (retailer) [B7] |
| Weight | 5.6 kg [C3] | 6.7 kg [B6] |
| Sensor | Torque [C3] | Dual: torque + cadence [B6] |
| Kit price | $1,250 | Not sourced |
The M620 is a high-torque motor at 1,000W rated. The X1 Pro Gen 4 is an off-road platform. Its X12 controller runs at up to 84V (72V nominal) and 120A input. CYC limits the system to 6 kW and 180 phase amps in software [C5].
The X1 Pro Gen 4 drives the chain through a dual-stage reduction with a separate motor chainring: 32T with 53T, 38T with 63T, or 40T with 72T [C3][C8].
Note that the M620 also has torque sensing. If torque sensing is your main reason to pick CYC, the Ultra is the Bafang option that matches it.
Best for: The X1 Pro Gen 4 suits off-road builds that need very high power and torque. The M620 suits riders who want strong torque with dual sensing at a far lower power level.
For the most power CYC makes, see the X1 Pro Gen 4 and its Heavy-Duty Drivetrain.
Torque sensor vs cadence sensor: the real difference in ride feel
A torque sensor measures how hard you push on the pedals. The motor adds power in proportion to that force.
A cadence sensor detects that the cranks are turning. The motor then delivers a set level of power, whatever your effort.
In practice, torque sensing feels like stronger legs. Cadence sensing feels more like a switch. CYC's FAQ describes cadence-only assist as "abrupt, scooter-like" [C6]. That is CYC's view. Forum riders who prefer cadence systems say they like the predictable output, especially when riding mostly on throttle [F3].
Every CYC Photon and X1 kit uses torque sensing [C6]. Bafang's official M315 and M615 pages do not state the sensor type. Forum consensus and CYC's FAQ both describe BBS02 and BBSHD as cadence-based. The M620 Ultra is officially dual sensor [B6].
Weight and frame fit
A mid-drive must fit your bottom bracket shell. This is often the deciding factor.
| Bottom bracket | CYC Photon 2 / Photon Pro / X1 Pro Gen 4 | Bafang M315 / BBS02 | Bafang M615 / BBSHD |
|---|---|---|---|
| BSA 68 to 73mm | Yes [C1][C2][C3] | 68mm [B1] | Yes [B3][B5] |
| BSA 83mm | Yes | Not listed | Within 68 to 120mm range [B3] |
| BB92 press-fit | Yes | Not listed | Not listed |
| 100mm / 120mm fat bike | Yes | Not listed | Yes, separate fat versions (retailer) [B5] |
| PF30, BB30, T47 | With press-to-thread sleeve [C6] | Not listed | Not listed |
| Trek BB90 / BB95 | No [C6] | Not listed | Not listed |
"Not listed" means our sources do not state it. It does not mean the motor will not fit. Check with the seller before you buy.
CYC claims its kits suit "over 95%" of bike frames. That is a marketing claim, not a measured figure [C1].
Controller, display and app tuning
CYC kits use CANBUS electronics. The Intuition display is a 2.1-inch color screen rated IP65 for 36 to 72V systems [C2]. It connects over Bluetooth to the Ride Control app.
In the app you can adjust torque sensitivity, power ramp, assist factor and cadence start for pedal assist. For throttle, you can set deadband, ramp times and soft start. Separate Street and Race modes switch from the phone or display [C7].
Bafang's strength here is community knowledge. Years of BBS02 and BBSHD builds mean forum guides exist for most programming questions [F3]. We have not verified the interface details of each Bafang model, so we do not compare protocols here.
Total build cost compared
Kit prices alone mislead. What matters is the price of a finished, ridable build.
| Build | Motor kit | With battery | Source |
|---|---|---|---|
| CYC Photon 2 | $950 | $1,338 (A-52, 520Wh) / $1,488 (A-52L, 780Wh) / $1,946 (A-65, 1,300Wh) | [C9] |
| CYC Photon Pro | $1,098 | $1,486 / $1,636 / $2,094 | [C9] |
| CYC X1 Pro Gen 4 | $1,250 | $1,638 / $1,788 / $2,246 | [C9] |
| Bafang BBS02B | $499 | Battery not included; price not sourced | [B8] |
| Bafang BBSHD | $695; about $500 bare (forum) | Battery not included; price not sourced | [B8][F1] |
| Bafang M620 Ultra | Not sourced | Not sourced | n/a |
CYC also sells parts separately. Prices include the Intuition display at $196, a Photon chainring at $70, a bash guard at $28 and a brake sensor set at $30 [C9]. The HD Drivetrain is $368 to $388 for high-torque builds. We have not confirmed which of these ship in each kit.
The forum math is worth knowing. In the EBR thread, one rider priced a bare BBSHD at about $500, about $780 with basic upgrades, and about $1,020 with more parts. They argued that at that point it is "essentially the same" cost as an all-in CYC kit [F1]. That is one owner's estimate from the Gen 1 era, but the logic holds: compare finished builds, not motor boxes.
Browse CYC batteries and the full drive system range to price your own build.
Reliability and serviceability
Bafang's case is track record. Forum consensus describes the BBS motors as proven at 30 to 35A over many years and a very large installed base [F3]. Spare parts and repair knowledge are easy to find.
CYC's first Photon had real problems. CYC itself calls the sprag clutch the Gen 1's "most reported" pain point [C4]. One EBR owner logged 180°F motor temperatures and power cuts on long climbs [F1]. Another reported heat derating to 700 to 800W on sustained climbs above 25 mph [F2].
The Photon 2 redesign targets those issues [C4]:
- Inrunner motor (Gen 1 was an outrunner), flat-wire windings, epoxy-potted core for heat transfer.
- Sprag clutch enlarged from 12x20mm to 20x28mm, which CYC says triples torque capacity.
- Drive unit opens with four M5 bolts. Controller, torque sensor, motor module and first stage are each replaceable.
These are CYC's engineering claims. Independent long-term data on the Photon 2 is still limited, so weigh them that way. For the X1 Pro Gen 4 changes, see CYC's Gen 4 breakdown [C5].
When Bafang is the better choice
Bafang is the right call in several common cases.
- Lowest upfront cost. A BBS02B at $499 or a BBSHD at $695 [B8] costs hundreds less than any CYC kit.
- Throttle-first riding. If you mostly ride on throttle, the pedal-feel advantage of a torque sensor matters less.
- Parts everywhere. Bafang's installed base means more sellers, more used parts and more local shops that have fitted one.
- Community knowledge. Years of forum threads cover nearly every BBS02 and BBSHD install and programming question.
- You want torque sensing at moderate power. The M620 Ultra offers dual sensing and 170 Nm at 1,000W rated [B6].
When CYC is the better choice
- Natural pedal feel matters. Torque sensing is standard on every CYC kit [C6].
- Weight matters. On CYC's published figures, each CYC motor is lighter than its Bafang counterpart.
- Unusual bottom brackets. CYC lists BB92, 83mm and fat widths across the range, plus PF30, BB30 and T47 with a sleeve [C6].
- You want to tune the ride. The Ride Control app exposes assist and throttle settings in detail [C7].
- You need more power than a BBSHD. The Photon Pro and X1 Pro Gen 4 are rated well above 1,000W, for off-road use.
Riders have noticed the install difference too. The Radavist described the Photon install as "even easier than the Bafang platform" [T1].
FAQ
Is CYC better than Bafang?
Neither is better for everyone. CYC kits offer torque sensing, lower published weight and more power per tier. Bafang kits cost less and have a larger support base. Choose by budget, riding style and frame fit.
Is the CYC Photon a BBSHD killer?
Not on price. The BBSHD lists at $695 [B8] vs $950 for the Photon 2 and $1,098 for the Photon Pro. On torque per kilogram and pedal feel, the CYC units lead on published specs. Forum owners remain split [F1].
Does Bafang BBSHD have a torque sensor?
Forum consensus says no: the BBSHD uses cadence-based assist. Bafang's official M615 page does not state the sensor type [B3]. Bafang's M620 Ultra does use a torque sensor, alongside cadence [B6].
Which is lighter, CYC Photon or Bafang BBSHD?
The Photon 2 is listed at 3.5 kg [C1] and the Photon Pro at 4.5 kg [C2]. Bafang lists the M615 (BBSHD) at 5.6 kg [B3]; one retailer lists 4.8 kg [B5]. On CYC's published figures, both Photons are lighter than either BBSHD figure.
Can I use Bafang chainrings on a CYC motor?
CYC does not list Bafang chainrings as compatible. The Photon 2 and Photon Pro use direct-mount CYC rings from 32T to 50T [C8]. The X1 Pro Gen 4 uses matched pairs of front and motor chainrings [C3]. Check with CYC support before you fit any other ring. See CYC chainring options explained.
Why is CYC more expensive than Bafang?
The kits are built to a different specification. Every CYC kit includes a torque sensor, CANBUS electronics and app tuning [C6]. The Photon 2 adds a larger sprag clutch and modular service design [C4]. The higher CYC tiers also carry far higher power ratings than the BBSHD.
Which mid-drive is better for steep hills and cargo?
For climbing and loads, torque and heat handling matter most. Among the six units here, the X1 Pro Gen 4 lists the most torque at 280 Nm [C3], and the Photon Pro lists 180 Nm [C2]. For a road-legal cargo bike, the Photon 2 (135 Nm) and Bafang M620 (170 Nm) are the relevant choices. A smaller chainring adds climbing torque at the wheel [C8].
Still deciding? Our conversion kit FAQ covers fit, legality and batteries.
Sources
CYC (accessed October 9, 2026):
- [C1] CYC Photon 2 product page: https://cycmotor.com/products/photon-2
- [C2] CYC Photon Pro product page: https://cycmotor.com/products/photon-pro
- [C3] CYC X1 Pro Gen 4 product page: https://cycmotor.com/products/x1-pro-4
- [C4] Photon 2: Power, Reliability and Smarter Engineering: https://cycmotor.com/blogs/news/photon-gen-2-power-reliability-and-smarter-engineering
- [C5] X1 Pro Gen 4 Upgrades Explained: https://cycmotor.com/blogs/news/x1-pro-gen-4-upgrades-explained
- [C6] Ebike Conversion Kit FAQ: https://cycmotor.com/blogs/news/ebike-conversion-kit-faq
- [C7] Mastering Pedal Assist and Throttle: https://cycmotor.com/blogs/news/control-app-mastering-pedal-assist-throttle
- [C8] CYC Chainring Options Explained: https://cycmotor.com/blogs/news/cyc-chainring-options-explained
- [C9] CYC store prices: https://cycmotor.com/collections/drive-system
Bafang and retailers (accessed October 9, 2026):
- [B1] Bafang M315 official page: https://www.bafang-e.com/en/products/motors/m-series/m315
- [B2] Retailer listing, BBS02B as M315 (500W and 750W): https://nstem.org/item/48v750w68mm-bafang-mid-drive-motor-bbs02/
- [B3] Bafang M615 official page: https://www.bafang-e.com/en/products/motors/m-series/m615
- [B4] Retailer listing, BBSHD as M615: https://ozo-electric.com/en/composant-ki/990568-1692487-bafang-central-motor-bbshd-48v-1000w-m615.html
- [B5] Retailer BBSHD specs (Golden Motor): https://goldenmotor.bike/products/bafang-bbshd-48-volt-1000-watt-68mmm-mid-drive-kit
- [B6] Bafang M620 official page: https://www.bafang-e.com/en/products/motors/m-series/m620
- [B7] Retailer M620 figures (Biktrix): https://www.biktrix.ca/products/ultra-motor-uart
- [B8] Third-party price comparison (frontdeskreview.com): https://frontdeskreview.com/product/ebike-conversion-kits/cyc-photon-gen-2/
Owner reports and reviews (anecdotal):
- [F1] EBR forum, "A BBSHD Killer? Here comes the CYC Photon": https://forums.electricbikereview.com/threads/a-bbshd-killer-here-comes-the-cyc-photon.51035/
- [F2] EBR forum, owner build thread: https://forums.electricbikereview.com/threads/my-diy-buids-gmac-bbshd-9c-rh212-and-cyc-photon.38385/page-16
- [F3] Endless Sphere, CYC Photon Gen 2 thread: https://endless-sphere.com/sphere/threads/cyc-photon-gen-2.127832/
- [T1] The Radavist, Surly Big Dummy with CYC Photon: https://theradavist.com/surly-e-big-dummy-with-cyc-photon-motor-review
