A review of PedalCell, an impressive new rim dynamo

[IaninSheffield]

Yes, it appears to be more efficient but how much efficiency* do we really need?

This an important point I feel. There's a couple of (promotional, but realistic?) videos of adventure cyclists who have put the Pedalcell to the test. And it clearly suited their high energy, multi-device needs, based on their varied and challenging riding conditions.

Similarly to Hobbes and Ming, I don't need inordinate amounts of energy, but I've found I do need more than a solar panel setup can provide, at least under the UK's less than reliable skies. However, I wonder just how much running a dynamo takes out of your legs? It's easy enough to look at the figures but what does that feel like during a 60 mile, 4000 feet day? Would there be a discernable difference between one system and the other? And how on earth would you measure that if you wanted to?

 

[HobbesOnTour]

However, I wonder just how much running a dynamo takes out of your legs? It's easy enough to look at the figures but what does that feel like during a 60 mile, 4000 feet day? Would there be a discernable difference between one system and the other? And how on earth would you measure that if you wanted to?

They could send one to me!
I'm hardly going to notice any drag and since I have my hub & cycle2charge I can do a direct, simultaneous comparison

You're right of course. How can we measure the drag whether a dynamo, a hub or a tyre? A lot of it is psychology. Oooh! I'm going slow it must be that new hub/dynamo/Schwalbe.
Even the rating on a sleeping bag is subjective. If tired, I'm going to be colder.

There's a big picture in most of these types of decisions and the stats are only a part of it.

 

[IaninSheffield]

I wonder what the long term effects are, if any, of applying a continual(?)/cyclical(?) perpendicular force on one side of the rim of a wheel? On the rim? The spokes? The hub flange?
Guess it depends on the magnitude of the force, amogst other things.

 

[PedalCell]

https://www.spacycles.co.uk/m12b0s208p3515/ADEPT-ELECTRONICS-VeloCharger-for-Hub-Dynamo

https://www.spacycles.co.uk/m10b0s170p3038/SPA-CYCLES-SP-PD-8-Disc-Dynamo-Wheel

In your world maybe, not here in the real world, and no danger of slippage of the O-ring

Thanks for clarifying. Slippage is a non-issue as explained by our user reviews. We've been proven in a multitude of off-road settings.

I got the $450 price via a SON28 hub at a UK retailer. SON is the most efficient/durable hub out there and is used as the primary comparison to PedalCell in 3rd party tests (in which PedalCell is shown to be 3X more powerful). SP dynamos are quite a bit cheaper but aren't an "apples-to-apples" performance comparison to PedalCell (buyers who value charging performance/efficiency). SPs are on the lower end of dynamo hub offerings with more drag and less charging performance than SON.

Even still, PedalCell is the same price as the SP build you mention while offering faster charging and less drag per watt, not to mention the install advantages. If powering lights is your only priority then the SP build I'm sure works great (that's what they're designed for after all). Whatever works best for you!

Now, if @PedalCell were to develop a more slimline adapter thingy between hub and chargepoint I could benefit from the advantages of a hub and their new tech.

It's big, it's bulky, it's got a powerful spring..... if something does go wrong not going into the wheel is unlikely.

Well, not really. A hub dynamo that stops producing electricity is still a hub.

Here's the thing;
Yes, it appears to be more efficient but how much efficiency* do we really need?

* Efficiency of the unit depends on angle of attachment. Can't quite get my head around that one.

Our new tech isn't just electronics and wouldn't offer many advantages to a hub. Every hub dynamo is designed around old German StVZO standards for powering lights. That's why their outputs are all 3W/6V. They work great for powering the lights they were designed for. BUT they were never made to power USB devices (which have higher power requirements). PedalCell is a bottom-up design for USB charging in every part of the system (deep integration between our electronics, software, and custom generator) which is why we have higher power output and better drag efficiency. We made our product because cyclists are using modern devices that are more capable and power-hungry without a power source to keep them topped off.

Efficiency is important when talking about higher power output. More efficiency means there's less power wasted from your legs. BUT the main difference that's easy to measure is PedalCell's higher power output: more charging at slow speeds and 3X more % overall. Efficiency doesn't solely depend on the angle of the Generator but we include that adjustment because different bikes have different geometries. You want the Generator running in line with the wheel to mitigate power loss.

Also FYI our clamp doesn't slip when installed properly onroad offroad etc. All reviews back this claim up. And IF someone didn't follow our directions and it did slip, the Generator puck hits the spokes first and will rotate around them. We tested this fail-safe. We have yet to have anyone crash because of a clamp failure. And a dynamo hub failure can absolutely be catastrophic if the bearings fail (which does happen and will seize your wheel).

It would be nice if this claimed efficiency improvements could be built into a hub.
Maybe I am a luddite, but I would only consider charging battery packs using my bike, I just don’t trust the possibility of spikes ruining my expensive devices. On top of that there is the inherent risk of strapping expensive items, like phones, iPad and kindles to the bike. I would rather charge those in a safer manner.

Again, see the above answer. All hubs are inherently limited in their charging spec due to their German-regulated power output. That will likely never change as long as the laws exist. If you want faster USB charging PedalCell's proprietary system is the only way to go at the moment!

USB charging is quite tricky and dynamo unstable output can destroy devices (as many hub dyno chargers do). We published a whitepaper with cyclingabout.com that goes into detail on how we regulate USB charging in a safe manner. A peek behind the curtain. Highly recommend you read it here.

Similarly to Hobbes and Ming, I don't need inordinate amounts of energy, but I've found I do need more than a solar panel setup can provide, at least under the UK's less than reliable skies. However, I wonder just how much running a dynamo takes out of your legs? It's easy enough to look at the figures but what does that feel like during a 60 mile, 4000 feet day? Would there be a discernable difference between one system and the other? And how on earth would you measure that if you wanted to?

Easy to measure; faster charging at slower speeds! A hub dynamo produces 3-5W of power output and only works well at 15 kmh+. An iPhone 11 pro comes with an 18W charging brick in the box. Modern devices have higher power requirements than hub dynamos are capable of supporting, especially if you're using your devices for GPS, tracking, etc. PedalCell produces 15-20W of power and starts working at ~8 kmh. Big difference at a typical touring pace.

You're right of course. How can we measure the drag whether a dynamo, a hub or a tyre? A lot of it is psychology. Oooh! I'm going slow it must be that new hub/dynamo/Schwalbe.
Even the rating on a sleeping bag is subjective. If tired, I'm going to be colder.

There's a big picture in most of these types of decisions and the stats are only a part of it.

SON engineers already tested our drag here. PedalCell produces less drag per watt than a hub, which means you can charge faster without noticeably more drag. You're right in that when talking about a loaded bike, drag is minimal. In hub or PedalCell, you'll barely notice anything. What you will notice (and what really matters) is the charge rate and at what speed the charge is active (see answers above). PedalCell wipes the floor with all hubs in this area. Most of our riders increase their device usage with more tracking, GPS, taking photos, etc. when having access to PedalCell. Also the value of riding untethered from outlets in a coffee shop or gas station can't be understated!

Happy to keep answering questions!

 

[Milkfloat]

@PedalCell Thanks for all the information, especially where you show more detail than simple marketing. I really appreciate that you have joined the forum to contribute and provide detailed answers. Whilst your product is not for me right now, I will keep you in mind for the future and wish you success. If you can package the entire technology into a decent hub (perhaps in collaboration with SON), then I would be throwing money at you right now, and I expect a lot of other people would do the same.

 

[KnittyNorah]

PedalCell is $299.

Except that it's not $299.

The final cost will be considerably more than the stated '$299'.

There are additional charges for shipping/postage of course, and then on arrival in the UK, there is 20% VAT of both the cost of the item AND the cost of the shipping/postage and insurance. There is a 'handling charge' of anything from £8 upwards which is payable to the delivery service, and there is an additional 2.5% (probably) import tax payable as the total value is greater than £135.

I've found that courier companies are significantly more expensive than Royal Mail with regards to 'handling' fees, and some courier companies are apt to charge fees willy-nilly, even for items on which no clearance, VAT or import duties are chargeable.

So the thing will cost $299 plus a significant percentage more.

 

[Baldy]

That's what's putting me off.

 

[rogerzilla]

If you actually want the additional power this offers over a hub dynamo, it's going to be noticeably draggy. The maximum 20W/68% is getting on for 30W, which is about a third of what a touring cyclist might develop at the end of a long day. Or do you only turn on high power downhill?

The real issue is that something like an iPhone 11 wants more power than can reasonably be delivered by a rider's legs. Better to put the phone into batteey-saving mode, and carry a camera.

 

[Baldy]

View: https://youtu.be/Sq1aj6d1H6o


This chap seemed to cope fairly well.

 

[Richard Fairhurst]

So the thing will cost $299 plus a significant percentage more.

Maybe @PedalCell could set up a UK distributor?

 

[raybo]

The real issue is that something like an iPhone 11 wants more power than can reasonably be delivered by a rider's legs. Better to put the phone into battery-saving mode, and carry a camera.

I have an iPhone 12 and on a 3.5 hour ride fully loaded on my touring bike, I can charge it about 70% using the PedalCell. Though, this with wi-fi and navigation turned off and cell service on, plus audio and Bluetooth. I ride at 10MPH.

 

[PedalCell]

Except that it's not $299.

The final cost will be considerably more than the stated '$299'.

There are additional charges for shipping/postage, of course, and then on arrival in the UK, there is 20% VAT of both the cost of the item AND the cost of the shipping/postage and insurance. There is a 'handling charge' of anything from £8 upwards which is payable to the delivery service, and there is an additional 2.5% (probably) import tax payable as the total value is greater than £135.

I've found that courier companies are significantly more expensive than Royal Mail with regards to 'handling' fees, and some courier companies are apt to charge fees willy-nilly, even for items on which no clearance, VAT or import duties are chargeable.

So the thing will cost $299 plus a significant percentage more.

Maybe @PedalCell could set up a UK distributor?

We do have a UK dealer here. Avoids many of the fees you mention. We clearly disclose on our site's shipping policy that the prices do not include import fees. We are working on opening warehouses closer to our EU and UK customers to help with these fees (we have 0 control over them, are at the will of your government, and can vary from customer to customer). It's worth noting that even when accounting for import fees, PedalCell is still less expensive and higher performing than a comparable hub wheel build. We get close to more orders from the UK than the USA, which should tell you something

 

[KnittyNorah]

We do have a UK dealer here. Avoids many of the fees you mention. We are working on opening warehouses closer to our EU and UK customers to help with these fees (as they are controlled by your government and can vary from customer to customer). It's worth noting that even when accounting for import fees, PedalCell is still less expensive and higher performing than a comparable hub wheel build. We get close more orders from the UK than the USA, which should tell you something

As I said, significantly more than the $299 you have quoted as the cost.

I have no interest in a dynamo of any sort ; it would be overkill for my style of riding. But to see an item's price quoted, more than once, at $299 - instead of the almost $450 which is the actual cost in the UK (around £215 compared to £325), ie more than half as much again - is a bit too much for me to accept without comment.

 

[PedalCell]

If you actually want the additional power this offers over a hub dynamo, it's going to be noticeably draggy. The maximum 20W/68% is getting on for 30W, which is about a third of what a touring cyclist might develop at the end of a long day. Or do you only turn on high power downhill?

The real issue is that something like an iPhone 11 wants more power than can reasonably be delivered by a rider's legs. Better to put the phone into batteey-saving mode, and carry a camera.

Good point, but not entirely true. You'll notice in our reviews that riders don't notice the drag any more than a typical hub dynamo, despite getting faster charging rates at slower speeds.

This is because:

1. Efficiency: PedalCell has 2-3X less drag per watt than most other dynamos, meaning that for a given amount of power, there is 2-3X less drag.​

2. Dynamic output: PedalCell changes its power output based on your speed and device power needs. For example, if your phone is almost fully charged with the screen off, it will output a smaller amount of power. Or, if you're pedaling along at a slow pace (up a hill, touring, etc.), PedalCell will not deliver its peak power output (15-20W).​

3. Mechanical decoupling: Users can completely disconnect PedalCell from the rim when not needed, thus eliminating all mechanical drag.​

4. 3W lock: PedalCell’s Prioritized port locks max output at 3W when used alone for power-conscious rides.​

​

Our product does add 100% drag all of the time. Our firmware is always analyzing device power needs, speed, acceleration etc., and adjusting power output when needed. This intelligence was added to avoid the unnecessary drag you're referencing while taking advantage of our faster charging rates.

 

[FishFright]

Britain today - Whatever you do , whatever you work on , whatever ideal you have half the replies will tell you did it wrong, no one needs one, such and such can do it cheaper and best of all is the near infinite list of Yeah Buts.

Seriously is there any point in trying to work with or sell anything to the UK ?