PedalCell dynamo for charging phone etc

[DGG1941]

I’ve read some excellent reviews of this product but am struggling to figure out if it can be fixed to my ICE Adventure. Anyone experience of fixing this to a trike?

https://pedalcell.com/

Ideally it would work off the 26” rear wheel to give higher output but the lower of the two horizontal chain stays does not have enough space above it and the one above it has a bracket inconveniently welded in place and there’s a mudguard support in the way. And I can’t make use of the luggage rack as I have rear suspension.

[Psamathe]

No suggestions to question but it does look quite large. Have you considered https://www.velogical-engineering.com/d ... n/?lang=en. I've not checked power outputs, charging mechanisms, etc. but Velogical have a range of fitting options (and they mention recumbents). But it's (Velogical) less of a package and you'd need something else to get to the USB power outputs. Just a thought if you are having problems finding something that will fit.

If Velogical's offering was of interest you could contact them re what you'd need to e.g. charge a battery pack.

Using my solar panels which have 2x USB outputs they charge some stuff fine but would never charge my iPhone X - the phone screen kept switching on which meant screen drawing loads of power which limited charging a lot. How successful direct charging devices from a dynamo would be (where your speed varies and you stop at junctions) would depend on the buffering in the regulator circuits ... and I'm already talking beyond my technical experience/knowledge.

Edit: Just found a review of Velological's offering (not the device the OP was asking about - sorry) https://www.bikeradar.com/features/so-i ... k-anymore/ and for device charging the suggest using with Busch + Müller E-Werk + cache battery.

Ian

[Carlton green]

“Ideally it would work off the 26” rear wheel to give higher output ... ” .

I’m a bit puzzled by that comment, for Dynamos that work off of a rim or side wall the wheel size isn’t a factor that has much to do with performance. Road speed, tyre surface speed and rim surface speed are all closely linked and vary similar in value (measured in linear distance per unit of time). The Dynamo wheel rotates against those surfaces which are being driven along at pretty much road speed.

I like and use bottle Dynamos for lighting, but if I needed power during the day (daylight hours) for other stuff then I’d be using a hub Dynamo. Price wise rim Dynamos are darned expensive, to me they make hub Dynamos look like excellent value.

[DGG1941]

Thanks for the input about Velogical, a really neat piece of engineering, although I’m still leaning towards the PedalCell - if I can fit it as it is specifically aimed at charging devices directly.

“I’m a bit puzzled by that comment, for Dynamos that work off of a rim or side wall the wheel size isn’t a factor”

My simple maths suggests that a 26” wheel rim will travel 30% further per revolution than a 20” wheel, therefore providing 30% more input to the dynamo at low speeds; and low speeds is a given for this old cyclist (the clue is in my username!). However, it seems that I may have to resort to running it off the front wheel, which given there are no forks will be an interesting challenge.

[Jdsk]

“I’m a bit puzzled by that comment, for Dynamos that work off of a rim or side wall the wheel size isn’t a factor”

My simple maths suggests that a 26” wheel rim will travel 30% further per revolution than a 20” wheel, therefore providing 30% more input to the dynamo at low speeds; and low speeds is a given for this old cyclist (the clue is in my username!). However, it seems that I may have to resort to running it off the front wheel, which given there are no forks will be an interesting challenge.

What are you keeping constant in the comparisons?

If it's road speed then the wheel size doesn't matter. If it's number of rotations then it does.

Jonathan

[Carlton green]

Thanks for the input about Velogical, a really neat piece of engineering, although I’m still leaning towards the PedalCell - if I can fit it as it is specifically aimed at charging devices directly.

“I’m a bit puzzled by that comment, for Dynamos that work off of a rim or side wall the wheel size isn’t a factor”

My simple maths suggests that a 26” wheel rim will travel 30% further per revolution than a 20” wheel, therefore providing 30% more input to the dynamo at low speeds; and low speeds is a given for this old cyclist (the clue is in my username!). However, it seems that I may have to resort to running it off the front wheel, which given there are no forks will be an interesting challenge.

I’m sorry that I somehow didn’t make this clear enough. For a rim Dynamo the wheel size is (effectively) irrelevant, for a hub Dynamo the wheel size is relevant. A rim Dynamo’s rotational speed is a function of linear road speed and Dynamo pulley diameter, a hub Dynamo’s rotational speed is a function of both wheel size and linear road speed.

[crossy]

I’ve read somewhere that the the velo Dynamo has to be upright to prevent water getting in. On a trike on the rear chain stay the Dynamo will be on its side.

[axel_knutt]

My simple maths suggests that a 26” wheel rim will travel 30% further per revolution than a 20” wheel, therefore providing 30% more input to the dynamo at low speeds; and low speeds is a given for this old cyclist (the clue is in my username!).

The periphery of the dynamo pulley is always travelling at road speed regardless of the wheel size, because the rim is (near enough) at the periphery of the wheel. There is some small benefit to a larger wheel, because the distance from rim to periphery is a smaller fraction of the diameter of a large wheel than a small one, but it's only about 4%. (For a pulley that runs on the tyre rather than the rim, the difference is even smaller.)

[DGG1941]

You are quite right, in my rush to do the maths about wheel size and circumferences, I had forgotten that a smaller wheel has to turn faster than a larger.
Thanks for the lessons in geometry!

[rogerzilla]

https://youtu.be/o7xfGuRaq94

Suggests it's badly designed and made

[[XAP]Bob]

Are you on disc brakes?
The SON dynamo for trikes is fantastic... you you then need an e-werk or similar, but it's a very good setup.


I don't know if the SA stub axle hub brake/dynamo model ever materialised.

[RecumbentRide]

I've looking at Pedalcell as well.

It seems hub dynamos are designed to output limited power due I believe German law you have this restriction and it's probably got to do with the engineering side of things which bottle dynamos don't fall under. I know the Pedalcell can output way more hence will charge up larger devices during the day.