In this 2nd and final blog of our recent trip to Eurobike 2023 we start with what some bill as the holy grail in cycling. That is followed by some supply chain themes, smaller items and interesting tech. Applogies are in order for a brief engineeringly nerdy tangent into novel uses of the differential. We finish off with a look at one of the gold awards from the show and its promise to revolutionise the e-bike market. But let's start with the Holy Grail.
The Holy Grail
We all love the concept of the chainless drive; no chains, rear mechs, cassettes or anything to get filled with mud and grit between pedals and wheels. It sounds just to good to be true and to be honest this exhibit really proves the point.
The chainless drive is a nice idea but the wire is a bit thick and the pedalling is hard even with no load on the wheel! (Note: pedals on the extreme right of the photo on one end of the end of the brown pipe.)
The pipe on the ground in the image above perhaps contains what are truely massive cables? That made me optimistic that the transmission losses, at least, would be minor. But, no doubt, the major efficiency losses are in the generator and motor: energy loss converting pedal motion to electricity and then back again at the wheel.
All said it was really quite hard to operate the pedals just to get the wheel to start to rotate a second or so later.
This particular set up is not going to appear on regular bikes anytime soon. It would be far too heavy and difficult to pedal.
The bike supply chain exhibitors
The supply chain hall was only open during the trade part of the show. Presumeably it would not hold a lot of interest for many visiting cyclists and B2B (Business to Business) exhibitors maybe don't need to talk to the public.
Supply chain companies hall was only open during the week days. (The general public were expected at the weekend when this hall was closed.)
There were a lot of standard size stalls occupied by many companies who had made the trip by air. They were often quite specialised in one or other area of bike component supply. For example there were a lot of companies offering battery packs. I was told that the cost of the cells make up well over half the cost of the battery pack and, despite some considering the cell a commodity, those companies supplying the historically most reliable products are still able to charge a significant premium on their cells.
Another issue facing the battery suppliers was integration of their components with different bikes. Bike companies vary considerably on their attitudes to open source software.
Titanium 3D Printing
I think by any standards this 3D printing looks impressive. These parts have obviously been sand blasted prior to the show but the finish was still impressive.
Impressive titanium 3D printing. You 'just' need a bit of titanium tubing any you could weld this lot into a frame.
The resulting welded titanium frame must have taken ages to grind back and polish but looked great. I also liked the shuttlecock, below, illustrating the fine detail that the 3D printer could achieve. This component was beautifully light and flexible in your hand.
Very impressive: a life size shuttlecock. Titanium feathers can't be easy to print.
Anti Dumping
Another common theme that was advertised on several booths was the offer of organised anti dumping schemes. That is help with strategies to avoid the anti dumping duties of the EC while importing from the far East. These are potentially very high duties set by the EC to protect domestic producers from competition from artifically low prices from the Far East. As the duties can be very high the attraction of circumnavigating them represents very large financial savings and must, therefore, be extremely attractive to some businesses.
Too good to be true
However, I spoke to somebody from a very large comglomerate who had been stung with a massive back dated bill for unpaid duties to the EC as well as a fine. For them the scheme had clearly not worked out as intended and having been burnt, they were now twice shy.
Innovations? a glimpse of cycling in the future?
Tucked away in the show there were more 'far out' inventions or innovations that are, at best, some way off appearing on bikes for sale. These exhibits often appeared stuck on the outer corner of stands almost as an after thought. They were manned by engineers, rather than sales people eulogising the potential benefits.
Of course as a reprentative of KOM the engineering perspective is refreshing. Refreshingly honest sometimes: I happened to end up talking to a friendly group about bearings and questioned some of their marketing comparisons. "Yes, totally unrealistic test they agreed with a smile."
Fish out of water?
One invention that I had not expected to appear at a bike show was the differential. Surely on a single wheel drive vehicle there could be no requirement for a differential? Well I counted at least two appearences at the show.
The first was incorporated in what claimed to be an infinitely adjustable set of gears for an e-bike. This was constructed as two electric motors coupled to a differential. For me that was a novel way of using a differential that I had not seen before. The infinitely adjustable gear concept is not unique but perhaps the use of a differential to illustrate the wider concept in a, 'simple and easy to understand' way is.
This could get nerdy
So how does it work? Well this could get nerdy and skip ahead if you are not interested.
I will have a shot at an explanation.
Imagine the set up on a two wheel drive car. Normally the engine or motor drives both the wheels via the differential. For this example lets assume its an electric motor that is driving and the car wheels are lifted off the ground. If one of the car wheels was held stationary then the other wheel would rotate twice as fast due to how a differential works. So now connect the second electric motor to the held wheel. Assume that you can adjust the speed of the second electric motor. In doing so the effective gearing between the first motor and remaining driven wheel can be adjusted. Eg if you ran the second (control) motor turning the (held) wheel backwards at twice the speed the motor was trying to drive the car forwards then the 'drive' wheel would stop. Slow the contol motor's backwards speed slightly and the drive wheel starts to move forwards but slowly. Adjust the speed of the control motor a bit more and you effectively adjust the gear ratio between main motor and output wheel. This way you can change the ratio smoothly in infinitely small steps. The gear range would still be limited by the performance of the motors but the steps between 'gears' could be infinitely small or effectively eliminated.
How effective or efficient this is remains completely unanswered. I would guess that a great deal of work would be required to take what I saw to a finished product. However a novel and very interesting concept.
Brain Teasers?
It is a bit of a brain teaser: Will this two motor gear system work as an effective torque converter? Will the torque that the drive motor sees vary in the same way as with fixed gears? While you ponder that the rest of us will move on:
Limited Slip Differential
The limited slip differential is something more synonomous with the rally car than the bike, so I was really surprised to see this at the show. With the rise of Ultra Low Emissions Zones in cities, for example London ULEZ, there is a significant increase in use of e-cargo bikes. Apparently there is a common problem with heavily loaded cargo bikes getting stuck. It is possible for one wheel to get stuck, in a pothole for example, with the other rear wheel left spinning. With up to 500kg load, physically lifting the bike out is not really an option for the rider so they are stuck.
E-Cargo bike.
Thus, at least one engineering company is looking at incorporationg the limited slip differential into the drive on these e-bikes so the rider can just use the torque of motor and gears to ride out of a situation where previously one rear wheel was literally left 'hanging in the air.'
Torsen limited slip differentials. Have a look at how stuff works if you are interested.
The Torsen limited slip differential features a clever use of the worm gears in place of bevel gears to give limited slip. When the worm is driven the gears rotate but when the gear tries to drive the worm the friction is too large and the limited slip is applied in the differential thus driving both wheels. A really neat design.
Regional Aisles
Eurobike had all sorts of sub divisions and an interesting one was a short aisle with a distinctive gallic flavour that became extremely popular the moment free food and wine was served. It turns out that the aisle was not funded by France but rather a southern region of France with a strong engineering sector.
One of their exhibits was the limited slip differential but another that caught my eye was a carbon spring.
The carbon spring is a stretch spring and in this test rig it is compared to a coil compression spring. Note the springs are on opposite sides of the fulcrum.
A progressive spring rate combined with no need for a bump stop at a very low weight. (Less convincing is the claimed volume saving and damping is not even mentioned.)
The carbon stretch spring looks really interesting. To incorporate it in rear suspension would require some changes in the way the suspension operates. The issue of suspension damping was not mentioned.
There were a couple of bikes displayed that had forks equiped with this type of carbon spring. However the carbon springs were largely hidden in some very ugly covers that did not improve the look and really called into question the claimed volumetric savings. For me it looked like it might be easier and neater to incorporate the carbon spring into the rear suspension.
Gold Awards
Eurobike actually awards 9 Gold Awards. However there was one seemed to stand out head and shoulders above the others.
There are many awards but one of the 9 gold awards goes to Pinion.
Integrated EMTB Gearbox & Motor
Pinion's new Motor Gearbox unit ditches the traditional derailleur, cassette and even chain. Virtually maintenance free, electronic shifting, auto shift, even when stationary, this is a stunning piece of new technology and must represent enormous investment.
The cutaway shows the electric motor in the top right of the photo and the gearbox seems to make up most of the rest of the package.
Simplify the rear wheel & move the weight to the right place
Getting rid of the rear cassette and mech considerably reduces unsprung mass at the rear wheel and goes a long way to making up for the extra weight of the gear box. All told Pinion claim that their combined gear box and motor adds less than one kg compared to a comparable ebike motor when the savings of rear mech, cassette etc are allowed for not to mention putting the weight in better place on the bike.
Others are working on this combined emotor and gearbox concept but Pinion started from an especially good position already making centre mounted gearboxes. Their new Motor Gearbox Unit (MGU) features up to12 evenly spaced gears with a 600% range.
What happens if you need a new motor?
This product looks great and with a claimed service interval of only once every 10,000km and then just an oil change it looks like it might be the perfect complemetary drive with the superb strength and reliablity of KOM Xeno hubs.
However, the elephant in the room is what happens if you need a new motor. Let's not pretend that E-bike motors have been reliable and long lasting over the last few years. The performance of Pinion's gearboxes is well documented but what happens when the motor fails? It would have been great to see a special port for a quick and easy motor change. Or a couple of T25 Torx screws to replace a cheap and readily available torque sensor.
Let's hope Pinion have really done their homework as replacing these units under warranty could get very expensive indeed!
What about Roholff... do they have something similar?
This does look like a major step forward in ebike drives. I was interested to find out what one of Pinion's major competitors and were up to; Rohloff are perhaps synomous with hub gears and do boast industry leading efficiency for their hubgear units.
Surely this was a great step forwards for ebikes?
Did Rohloff have anything similar in the pipeline?
My questions were met with pretty blank looks. Maybe moving the gears from the hub to the middle of the bike and adding an e-motor is just too much for Rohloff to contemplate? Maybe keeping the gearbox separate from the motor will prove less expensive and easier to repair in the medium term. We'll have to wait and see.
That's it for our reporting of Eurobike 2023 we'll try not to mention it again this year. Thanks for reading.
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