Revel Propulsion Review – This looks like an excellent and powerful mid-drive motor for people looking to convert their bikes into a lighter, more active form of transport for those who can’t or don’t want to use the throttle and have particular needs in MTB, cargo, or city bikes. Revel supply a 10.5ah/378wh battery pack potted for shock/water protection. Grin Tech’s LiGo BMS, who will work in conjunction with a sempu bottom bracket torque pedal assist sensor.
The bike weight increases by 12 pounds due to its large-motor, PAS sensor, and battery system; works with 68, 73, and 100mm threaded BB shell and is available for many different frame designs on the Revel website, and has a BB-threaded torque sensor for pressure. Revel allows the speed to be set in one of two modes, Class 1 and Class 3, and the gear ratio can be changed according to the individual’s preference.
The Revel Propulsion Lightweight 450W Mid Drive Reviews
That being said, Paul is also going for a Class-1 kit. This has its benefits for the various parks where he and Derek are able to tailor it for the rider’s particular location’s allowed max speeds.
Before he was made public, some observers requested an option for a manual gear shift. If there is a large enough demand for this, Paul plans to add that feature to the design in the future. Bear in mind that if you generally use the hand-throttle, you will not get the range the bike is really capable of.
The Motor of Revel Propulsion
The prototype was raced at the Sea Otter Classic in 2017. Racing shows a company’s seriousness. In this way, the designers can get the controller programming perfected so that you will have the best performance and efficiency without worrying about damaging the kit.
You can tell from the picture that the custom motor case is CNC-machined, the aluminum mounting bracket is water-jetted, and the ESC has a cover that was printed on a 3D printer. The three custom production methods are all part of “Computer Aided Design” (click here), which allows a designer to quickly create several improved prototypes rather than having to wait for another company to fabricate your parts.
Based on the pic in the header, the small links in the secondary chain allow the top two sprockets to be closer together. The 2/3 size difference compared to standard bicycle chains keeps the RPMs down and doesn’t take up as much space.
Inside the housing, the primary reduction uses planetary gears. The drive has helical teeth to help keep it quiet. Using a dual-stage gearbox and clever packaging, this lightweight motor can provide surprisingly good torque.
The Freewheel of Revel Propulsion
The benefit of a mid-drive is that the pedals don’t have to work with a constantly rotating chain. It’s unfortunate, but a rider being in this situation becomes an issue if he or she is leaned over when the pedal on the low side of the bike makes contact with the ground. In this situation, it’s likely that the rider and e-bike will fly and end up injured, potentially from falling from their e-bike.
I was surprised when Paul, rather than using one of the several freewheels that are easily found and used, decided to design and develop his own freewheel. He said he wanted to work with the Sempu torque-sensing bottom bracket that none of the other freewheels could attach to.
Still, something seemed out of place to me. As long as you’re designing a completely new wheel and freewheel, the diameter on this one is unusually big. Most bicycle parts are meant to be lightweight and compact; a smaller freewheel would also have less resistance. Though they have proven to be the strongest of the options through trial and error, the freewheels I mentioned are not designed for an electric bike; they are designed for the legs of an athletic bicyclist.
The further away the pawls are located from the center of the hub, the stronger the freewheel will be, while still using the same components found in common hubs. The 3D-printed parts in the picture above are the custom components, but the pawls and springs are off-the-shelf.
The proof is not yet there (I used to work as a tech in the load testing of aircraft parts, both lifetime endurance loading and peak loads until failure). Due to its larger diameter, I suspect this is the strongest mid drive freewheel currently available. Although I play a TV engineer, I am not one.
The Battery of Revel Propulsion
They are making their own battery packs because no one is making one that meets their size and shape requirements. Besides wanting a small, lightweight pack that could fit into a variety of frames, Paul wanted the base-model pack to attach to the common “water bottle” mounts on a framedowntube.
The 36V pack is configured as a handy 10S / 3P pack using the LG-Chem MJ1 cell, which I recommend as one of my top-three cells. This pack will provide 10.5Ah of range at 3500-mAh per cell. Furthermore, the factory rates these at 10A per cell, so you can expect 30A peaks without overheating. the last feature I’d like to mention is that 36V X 30A equals 1,000W…
In this pack, all the components are enclosed in a thermally-conductive polyurethane, which is flame-retardant and has no airspace. Zero motorcycles was the first manufacturer to take this bold design step (at 102V nominal) and they have had great success with it. The Luna Cycles V2 Wolf pack is another example (at 52V). There is one more ebike battery provider that has requested I not mention them.
450W will never cause the battery pack to heat up if it is capable of 1,000W.
In the meantime, they have uploaded step-by-step videos to explain how to use the first Pilot production kits they shipped this week. The video can be found here. Apologies for the poor camera work and sound quality. I would appreciate any feedback you have on these videos.
Revel Propulsion 650W Gen 2
For years, systems and batteries have not been available. This first batch of 650W torque-sensing systems are currently on sale (Class I/Class III). We will have kits with throttles ready in a short time. They have the following changes
From 450W to 650W
an increase of 20% torque
A more stable and powerful torque sensing bottom bracket.
There is no missing link between the two of us.
Aesthetics of cables and batteries have improved
Gen 3 Revel Propulsion
It is the display that has been changed between Gens 2 and 3. The Eggrider display was replaced with the minimalist King Meter display to improve reliability as well as ease of use. We have also added ceramic coating to motors, instead of anodizing. In addition to black with submicron particles, we also have silver Cerakote with submicron particles.
Here is a link to the store: https://www.revelpropulsion.com/store-1
Paul’s first prototype was built to add finesse to technical trails encountered while off-roading and he thinks a light road bike would be another big market for a design like this.
This is why the primary design for it used a Pedal Assist Sensor / PAS (torque-sensing) design, using a new unit from Sempu. Furthermore, if you’re always pedaling, the battery should last you a very long time.