PedalPower+

Charge your mobile phone while riding your bicycle

PedalPower+ Frequently Asked Questions

With a revolutionary product like the PedalPower+ there are a number of questions that are consistently asked by our customers prior to purchasing.

Below are the most frequently asked questions and we trust our answers will give you much clearer picture of the overall product and the available accessories

 

                 “Everyone (who doesn't use one) complains that dynamos slow you down. Well okay, of course they do, but I suggest that the slowing down has more to do with psychology than the actual power required to turn it. It takes energy to make a noise, your energy. Add the lowering tone (eee becomes urrr) as speed drops on a hill and it becomes hard not to believe this morale sapping device is responsible blame for the pain in your legs and the sweat on your brow!

                 There have been some crude and nasty ones, but the drag of any decent modern generator is rather insignificant. This is especially so at low speed and compared to the resistance afforded by any recognisable hill. But no one wants to work any harder than they have to. This makes Generator Drag an interesting subject. And striking differences in power input make this a much more interesting graph. Take a look at it now. You'll see that I've also plotted the amount of extra effort for a 75kg person to ride a 15kg bicycle up hills of various gradients, over and above that required on a flat road.

                 I wrote hills but you can hardly call them that. All of the generators were easier to turn than riding up a 1 in 300 slope. Another way of putting that is a rise of 18 feet per mile; and there's quite a cluster of sidewall and hub-driven models around the 1/500 line, or 10 ft per mile. If that's a hill I'm a Dutchman! Let's put this into another context. Our 90kg (total) cyclist must produce about 70W to maintain 20 km/h on the flat. If he turns on his dynamo he needs another 6W minimum, 14W maximum. He can work a bit harder or slow to 19 km/h, 18 minimum. Now that's not too bad is it?

                 For those who simply must have the least drag possible: 1/1000 (6 fpm) is achieved by the two best hub generators. Both of these, and one other hub-mounted model, are of the fixed type. This means that the generator cannot be disengaged and always turns with the wheel. So there is always some extra drag - relative to that of a normal wheel - even when the lights are switched off. This residual drag is also shown by dashed lines on the graph. It's generally much less than when electricity is flowing in the generator (for if it's doing no work it should take less work to turn it) and in Schmidt's Original the residual drag amounts to less than one foot of climbing per mile. Feel that and it is you who must be the Dutchman!

                 Residual drag is not so well controlled by Shimano and Pioneer. Indeed: above a certain speed (23 and 37 km/h respectively) their generators become easier to turn with the lights switched on again! (I can only speculate that this may be due to inefficient eddy currents in their armatures, which are perhaps not laminated.) But note nevertheless, that they demand less effort than to climb 7 feet per mile.”

http://www.myra-simon.com/bike/dynotest.html:

HOW MUCH DRAG IS THERE
WITH A HUB GENERATOR?

 

This is a question we are very often asked and while there are a many criteria to meet to establish this,
we have found that the following article does a real good job of answering it.

             The article is written by Chris Juden, based upon data from tests performed at Wilfried Schmidt Maschinenbau, Tübingen, Germany.
             The tests were independently audited by a professional engineer (and Munich cycle dealer): Thomas Metzmacher. And by the time you read this, articles based on the same data will also have appeared in
VeloPlus (Switzerland) and Radwelt (magazine of the ADFC - German CTC equivalent