The #1 Upgrade for Your Bonnell 775 MX: 5-Speed Kit Saves Nearly 3 lbs
If you own a Bonnell 775 MX and can only make one upgrade, make it the drivetrain. The HPC Bonnell 775 MX 5-Speed Upgrade Kit replaces the stock single-speed rear end with a hand-built wheel, a CYC 5-speed cassette and wireless electronic shifting — and it takes nearly 3 lbs off the bike while doing it.
What is the best upgrade for the Bonnell 775 MX? A multi-speed transmission. The stock 775 MX runs a single fixed gear, which forces a trade-off between climbing torque and top speed. HPC's 5-speed electronic shifting kit removes that trade-off and delivers:
- Nearly 3 lbs of weight savings over the stock setup, right at the rear wheel
- Higher top speed from a taller top gear
- More torque at the rear wheel from a low climbing gear
- Much better throttle control off-road in tight, technical terrain
- More efficiency and range because the motor stays in its best RPM band
Why the Single Speed Holds the 775 MX Back
The Bonnell 775 MX is a great MX-style chassis with a strong mid-drive motor, but it ships with one gear. A mid-drive motor makes its best power and efficiency inside a fairly narrow RPM window. With a single ratio, the motor is only in that window at one speed. Everywhere else, it's either lugging (slow, steep, technical climbs) or spinning out (open fire roads and long straights).
Gear it short and you lose top end. Gear it tall and it struggles on hills and runs hot. Every single-speed 775 MX is sitting somewhere on that compromise. A real transmission is the only way to get both ends at once — which is why we call it the #1 upgrade for this bike.
5 Reasons It's the #1 Bonnell 775 MX Upgrade
Saves Nearly 3 lbs — Where It Matters Most
Most performance upgrades add weight. This one takes it off. Compared to the stock setup, the kit saves nearly 3 lbs, and that weight comes off the rear wheel and drivetrain — the unsprung, rotating mass of the bike.
That's the most valuable weight you can lose on an MX bike. Less unsprung mass lets the rear suspension react faster and keep the tire planted over braking bumps, roots and square edges. Less rotating mass means the wheel spins up quicker, so the bike feels sharper out of every corner.
Higher Top Speed
On a single speed, top speed is capped by one ratio and the motor's max RPM. Shift into 5th and the rear wheel covers more ground per motor revolution, so the bike keeps pulling after a stock 775 MX has run out of gear. Open trails and long straights are where you'll notice it first.
More Torque at the Rear Wheel
Wheel torque is motor torque multiplied by your gear ratio. Drop into a low gear and the same motor puts noticeably more twist to the ground. Steep climbs, ledges and loose, loamy pitches that bog a single speed become easy, and the motor pulls hard without overheating.
Much Better Throttle Control Off-Road
Off-road riders feel this one right away. With a single tall gear, a small throttle input creates a big jump in wheel speed, so tight switchbacks and slow technical sections turn into a fight to keep traction. In a lower gear, the same throttle movement makes a smaller, smoother change at the tire. You get finer control, fewer surprise wheelies and a lot more grip where it counts.
More Efficiency and More Range
When you can pick the right gear, the motor stays in its efficient RPM band instead of lugging or over-revving. Less energy turns into heat and more goes into moving the bike. That means more miles from the same battery, a cooler motor and less strain on the drivetrain. Losing nearly 3 lbs adds to the gain.
Ready to turn your 775 MX into a 5-speed?
Shop the Upgrade KitStock vs. Upgraded: Bonnell 775 MX Side-by-Side
| Feature | Stock 775 MX | With HPC 5-Speed Kit |
|---|---|---|
| Gears | 1 (single speed) | 5-speed CYC CNC cassette |
| Weight | Baseline | Nearly 3 lbs lighter |
| Top speed | Limited by one fixed ratio | Higher, from a taller top gear |
| Climbing torque | Compromised by gearing | Low gear multiplies wheel torque |
| Off-road throttle control | Twitchy at low speed | Smooth and precise in low gears |
| Efficiency and range | Motor often outside its best RPM | Motor kept in its efficient band |
| Shifting | None | Wireless electronic, push-button |
| Rear wheel | Stock wheel | Hand-built WTB i35, Sapim 12g spokes |
What's in the Kit
This is a complete rear-end conversion, not just a cassette swap. Everything is matched and tested together before it leaves our shop.
Hand-Built WTB i35 Rear Wheel
HPC custom 148×12 Boost hub with a steel driver, laced with Sapim 12-gauge spokes we cold-roll and cut in-house.
CYC 5-Speed CNC Cassette
High-strength and made for the torque of the CYC mid-drive system.
Shimano Heavy-Duty E-Bike Chain
9-speed e-bike chain with anti-corrosion treatment and reduced stretch under load.
OX Wireless Shifter & Derailleur
Custom-programmed for 5 speeds, with a strong clutch and no messy cables.
Proven on the HPC Revolution MX
This isn't an experiment. The 5-speed electronic-shift drivetrain is adapted from the setup we've refined and shipped on our own HPC Revolution MX. It was trail-tested before it was ever offered for the 775 MX.
Who Should Get This Upgrade?
- Trail and off-road riders who want smoother throttle control and more traction in technical terrain.
- Riders in hilly areas who need more torque at the wheel without cooking the motor.
- Riders who want more speed on open trails without giving up low-end grunt.
- Range-focused riders who want more miles per charge from their current battery.
- Anyone chasing a lighter, sharper bike. Very few upgrades add performance and take weight off.
Installation and Lead Time
The kit is a complete drivetrain conversion with a hand-built wheel, so we recommend installation by an experienced e-bike mechanic or the HPC service shop. Every wheel is built to order in Simi Valley. Please allow up to 20 business days to build and ship, since we build each wheel by hand and CYC cassettes are in limited supply.
Want more background first? Read our breakdown of Bonnell 775 MX top speed and real-world performance, or our first look at the 5-speed electronic shifting kit.
Upgrade Your Bonnell 775 MX
$1,275Save nearly 3 lbs, and get more top speed, more torque, better throttle control and more range. Everything you need is in one kit.
Get the 5-Speed Kit Ask a QuestionBonnell 775 MX Upgrade FAQ
What is the best upgrade for a Bonnell 775 MX?
A multi-speed transmission is the best upgrade for the Bonnell 775 MX. The HPC 5-Speed Upgrade Kit replaces the stock single speed with a hand-built rear wheel, a CYC 5-speed cassette and wireless electronic shifting. It saves nearly 3 lbs and improves top speed, torque, throttle control and efficiency.
How much weight does the 5-speed kit save?
Compared to the stock setup, the HPC kit saves nearly 3 lbs. Because the savings come from the rear wheel and drivetrain, it is unsprung, rotating weight. That improves suspension response and acceleration.
Will the upgrade make my Bonnell 775 MX faster?
Yes. The taller top gear lets the bike keep pulling after a single-speed 775 MX runs out of gearing, so top speed is higher. The lower gears also help it accelerate harder out of slow corners and up climbs.
Does it add torque?
It adds torque at the rear wheel. Motor output doesn't change, but a lower gear multiplies the torque that reaches the tire. Steep and technical climbs get much easier, and the motor runs cooler.
Does electronic shifting work in mud, dust and rough terrain?
Yes. The OX derailleur is wireless, so there are no cables to stretch, fill with dirt or knock out of adjustment. A strong clutch keeps the chain on over rough terrain.
Can I install the kit myself?
It's a complete drivetrain conversion, so we recommend an experienced e-bike mechanic or the HPC service shop. If you have questions about fitment or installation, email sales@hpcbikes.com. We've installed this kit many times and can walk you through it.
How long does it take to ship?
Each rear wheel is hand-built to order in Simi Valley, California. Please allow up to 20 business days to build and ship.
The HPC Difference
Hi Power Cycles hand-builds wheels in our Simi Valley, California shop. We cold-roll and cut our own spokes, and our US-based team rides what we sell. Questions about your 775 MX? Email sales@hpcbikes.com or contact us.
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