“Car service intervals [are] getting longer […] whereas the bike industry hasn’t caught up with that,” said Ed Collins, Head of Sales and Marketing for Intradrive. “[The derailleur] is 100-year-old technology, and people have to keep it adjusted. You have to keep it updated, etc, etc.”
To solve this problem, Scottish brand Intradrive has launched an innovative product that combines an e-bike motor and a gearbox into a single unit. Known as the GD8, this 8-speed motor gearbox unit (MGU) delivers 700W of peak power, a 480% gear range, and 0.1-second wireless electronic shifts.
The entire MGU is said to weigh 4.5kg, and it’s specifically designed to shorten the powertrain’s profile (compared to keeping the gearbox and motor separate) without widening the Q-factor at all.
The unique bar-mounted controls are customizable, allowing the bike brand to set up the system however they please. The control paddle features several programmable buttons that can control the power assistance (eco, tour, and boost), the shifting, and even an integrated battery-operated dropper post.
How much time can you save with an MGU?
We’ve been testing gearboxes for years, and the primary benefits of a gearbox drivetrain are extreme durability and minimal maintenance. If you opt for a belt drive instead of a chain, the maintenance intervals are even longer. (Intradrive works with either a chain or a belt.)
“We estimate that your typical derailleur drivetrain takes a half an hour of fettling after a muddy ride. And if you’re in dusty conditions, that’s probably even more important so you prevent chain wear,” said Collins. “We calculate you could get back a week of your life if you’re time crunched. If you want to come back from your ride, stick your bike in your garage, and store it for the next ride, then the half an hour is quite valuable.”
Saving a few minutes per ride is nice — but reducing the amount of money you’re spending on smashed and worn-out derailleurs and cassettes is even better.
Increased weight isn’t an issue on an e-bike
One of the main reasons gearboxes haven’t yet caught on for muscle-powered bikes is the weight penalty. Despite claims that moving the drivetrain weight to the bottom bracket area makes for a better-handling bike, there’s no denying that gearboxes are heavier. But that’s where the ingenuity of the MGU comes in: e-bikes are already heavy, and the motor compensates for that added weight.
So, how much of a weight penalty are you taking with a 4.5kg (9.9lb) MGU from Intradrive?
For comparison, the latest Bosch Performance Line CX-R weighs about 2.7kg (6lb). However, the MGU eliminates the need for a derailleur and cassette. The SRAM XO Transmission derailleur weighs about 472g and the cassette weighs 379g, for a total of 1.9lb.
That means the Intradrive MGU requires a roughly 0.9kg (2lb) penalty over a traditional system, which, again, is pretty minimal when you have a motor doing most of the work.
Production bikes coming soon
From downhill bikes to e-bikes, are gearboxes finally hitting primetime? Intradrive seems to think so.
They plan to have production units of the GD8 available in Q4 of 2026, and they claim to “have bike brands committed to delivering bikes with our system from model year ‘27.” They aren’t yet willing to reveal which brands will be releasing bikes with Intradrive, but Collins did hint that they’ll be brands that “believe in the gearbox system.”
“I think the brands that will survive in the future will be the ones that really innovate, especially around a new form factor like this,” Collins concluded.
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