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Bimotal

Paul Skilbeck

Thursday 04 May 2023

The Bimotal Elevate: A convenient ebike solution for custom builders

A small group of former Tesla engineers in California have made a game-changing ebike system. Bimotal is the company, Elevate is the product: a removable system standing at the forefront in weight, versatility and power.

The Bimotal Elevate: A convenient ebike solution for custom builders
We would love to see this system on a custom frame. Photo: Paul Skilbeck

Hands up if you've been considering an ebike but haven't yet found a system that suits you? Until 2020 that would have been me, but in February that year, right before the Covid lockdown, I was introduced to Bimotal's 'Elevate', a system that checked enough boxes to tip me over the edge. I was so impressed that in 2022, as soon as the first consumer Beta models were ready, I handed over $2200, full retail plus tax, for a prototype system. Having test-ridden several other high-end eMTB systems, before and since, for me the Elevate remains the best value at the upper end of the market, and for custom frame builders it looks like an elegant and easy offering to customers looking for electric assist.

The Bimotal Elevate is described by the company as "A removable, lightweight, powerful ebike drive system that cleverly mounts to your bike's disk brakes." I couldn't have put it better myself. In fact, I wrote that description myself! Bimotal hired me from 2020 - 2023 to help with outbound communications. I know the company well, and I support its overarching philosophy of working to achieve climate goals. I don't think it's fair to say I'm biased, though. If it weren't an excellent product, the Bimotal Elevate wouldn't have made it into HBG.

The company was founded by Toby Ricco, a mountain biking enthusiast who was a rising star at Tesla Motors. His staff includes several high level engineers with experience at successful and innovative companies such as Tesla, Ferrari, and Impossible Aerospace. A vast amount of engineering work has gone into the Elevate system, in which almost everything beyond the screws and bolts is custom designed. They have considered a wide range of factors in its design, such as not discarding an entire bike when the system becomes obsolete, using less material, maximizing system efficiency and thus energy consumption.

The Bimotal Elevate system they started trickling out to customers in the second half of 2023 comprises four main parts in a neat package that converts an acoustic bike to an electric bike and back in under one minute.

The main part in the Elevate system is a 3.5lb (1.6kg) drive unit that houses a 750-watt motor which mounts using quick connects on a lightweight bracket above the rear brake. This bracket shares the existing brake mounts (post mount or ISO).. Bimotal removes your existing brake rotor and replaces it with one that has a helical gear attached to the inside, which drives the rear wheel. From this section, neatly enclosed cables run to the battery tray that attaches to the water bottle cage mounts; and a handlebar-mounted throttle. A 350W/h lithium battery pack comes with the Elevate system, which securely straps into the tray.

The total system weight is about 6.5lb (3kg), which means you can have the most powerful legal, fully-suspended eMTB for around 33-35lb (15-16kg) total bike weight.

For extended range, riders simply carry an extra battery pack, which when riding with e-power is not an issue if you’re okay riding with a medium/large hydration backpack. The farthest I've ridden off-road with two batteries is 35 miles with 5500 feet climbing. I weighed about 220lb on that ride. I did a road ride on the same fully suspended MTB. The first battery died at 27 miles/2400 ft climbing. Conserving battery energy requires a conscious approach with Bimotal's throttle-controlled system. A fully computerized system makes it more brainless, but requires more anticipation should you need a burst of maximum energy.

Bimotal has set the controller software to keep the Elevate system within the US Class II ebike specifications, which allow for throttle control on vehicles with top speed of 20mph.

The Elevate system delivers optimum performance in a rear-wheel drive configuration, a choice underscored by the inherent deficiencies of front-wheel drive setups in ebikes, particularly in rugged off-road environments. Front-wheel drive ebikes have greater traction issues on loose and slippery surfaces, and adding weight to the front end makes it more difficult to lift the wheel when needed. However, the current iteration of the rear-mounted Elevate system faces a spatial challenge: it cannot be accommodated within the rear triangle of the frame. Bimotal, the innovative force behind Elevate, has conceptualized a drive unit adaptable to a flat-mount configuration, yet this design remains in the theoretical phase, with a tangible prototype still forthcoming.

One of the most frequently asked questions by mountain bikers before they’ve tried the Elevate system is how it affects the bike’s balance and suspension performance. Afterall, it’s adding unsprung mass and it’s mounted on the non-drive side. Theoretically it’s untrue to state that there’s no difference, but empirically, when riding the bike, there’s no appreciable difference.

To the side-to-side balance:  There’s already an imbalance on most bikes, which nobody seems to complain about. Think of the combined weight of the chainset, gear cluster and derailleur on the drive side, which is more than the combined weight of the disc brake systems. Sure, the Elevate system changes that slight imbalance to the other side, but it's so close to the center of the saggital (lateral) plane, even riders performing aerial maneuvers say they cannot feel any difference.

As for the unsprung mass, again the difference looks a lot greater on paper than it feels out on the trail. I’ve ridden the same bike on the same downhill runs with and without the Elevate system attached and I’ve not noticed a difference.

What you will feel, very noticeably, is when you have to lift the bike onto a rack or whatever. For a start, we’re talking about a total bike weight of under 35lb in my case, which compares to several eMTBs in this performance category that are over 40lb. But if you take 20 seconds to remove the battery and drive unit, you’re talking about lifting a 27lb (12kg) bike versus 40lb+ (18kg). Unless you’re lifting in the gym regularly, you’re going to feel that.

This brings us to arguably the greatest intangible value of the Bimotal Elevate system: When your riding buddy picks up your eMTB at the trailhead and realizes that it’s lighter than his, when he spent 12k or more and needed to reorganize his garage to fit an extra bike, while you spent 2k adding it to a bike you already have and love, made no garage adjustments, and your eMTB did everything his could. It’s one of those times when you don’t need to say anything.

Let’s talk about throttle control vs pedal assist. Bimotal is shipping Elevate systems with throttle control only. A torque based pedal-assist system is in the works, and they aren’t going to offer an rpm based system. A lot of riders say pedal-assist is the way to go. Personally I prefer the throttle. The Elevate throttle software has excellent modulation, meaning on technical steep climbs, for example on a loose surface, if I want to add an exact amount of power I can do this without spinning the wheel and losing my momentum. Is it more sensitive than a high-end PAS such as the Bosch CX models? Hard to say, but having the option to use my brain to choose between Economy and Power modes by simply pressing my thumb on the lever, and to have the instant access to Burst mode, and so on, these are the reasons I won’t be installing Bimotal’s PAS when it’s released. I just prefer the throttle.

A couple more things about throttle control, sometimes you want to add a quick burst on a descent without pedaling, and in some super-technical slow sections sometimes you want to just balance on the pedals and inch forward with small throttle pulses.

As well as that, one frame builder I spoke to while working for Bimotal said he had elderly customers and those recovering from surgery ask for throttle power to help get them started from standstill, because even pedal-assist systems put too much stress on their knee joints.

One thing about setup though: Bimotal will set up your bike with an over-bar throttle on the right. For me that’s a no-no. I like to have at least partial thumb-wrap on the bars while using the throttle, and to this end I’ve mounted my throttle control under the bar. This meant moving it to the left side and putting my seat post dropper on the right, above the bar. Not a big deal for me.

In my mind, the Bimotal Elevate presents a simple solution for custom frame builders who’ve been asked to make an ebike. There is no need to change anything in the bike’s design, as long as the rear brake is post-mount or ISO. Aesthetically, having an appendage above the rear brake caliper rather spoils the lines of the bike, but the rider won’t notice this and so in the majority of cases it won’t be an issue. Also, for beauty shots just unclip it.

Finally, readers will notice that bikes photographed are not custom-built. I don’t have a custom full-suspension mountain bike. I would love to install an Elevate system on my Naked gravel/adventure bike, but for that I will have to wait for the flat-mount version.