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Need lower drag factor

Posted: November 24th, 2020, 4:11 pm
by drop40
Long time lurker, first time poster here. I am wondering if there is an easy way to set the drag factor lower than the minimum damper setting? My son likes to ride the BikeErg but his cadence is low, even on a damper setting of 1. I would like to make the sessions more natural for him. He's ten years old. Thank you for any ideas. This BikeErg is used by the whole family so I am looking for modifications that can be added/removed quickly.

Re: Need lower drag factor

Posted: November 24th, 2020, 10:45 pm
by Cyclist2
In general, drag factor is determined by how much air the fan is moving as it turns. Reduce the amount of air and the DF will go down. There are a myriad of DIY modifications to reduce drag factor and they all involve putting cardboard, roofing paper, tape, or other handy material over all the holes in the fan enclosure. I don't know how much you can affect a model D fan (I have a model B and C erg) by this method but it's easy to try.

Re: Need lower drag factor

Posted: November 25th, 2020, 1:17 am
by jamesg
No idea what will happen with a bike, but as the sole user of a rower I have an aircon filter over the inlet. Drag is 97 with the damper wide open. The idea was to keep the dust out, which it does about 90%, but the low drag level is fine too. Can be reduced further, but there may be a limit to drag level where the maths can operate. I'm at about 200m asl.

Re: Need lower drag factor

Posted: November 25th, 2020, 5:22 am
by mict450
Just drape a towel over the fan assembly. Cheap, easy & on/off quicker than a New York second.

Re: Need lower drag factor

Posted: November 25th, 2020, 5:36 am
by hjs
mict450 wrote:
November 25th, 2020, 5:22 am
Just drape a towel over the fan assembly. Cheap, easy & on/off quicker than a New York second.
Or a piece of paper, or cardboard.

Re: Need lower drag factor

Posted: November 25th, 2020, 2:08 pm
by CaseyClarke
Yeah, lowest drag on the newer models is Df 33 but best and easiest way to reduce it further is with a towel covering all of the flywheel to block off all airflow into it. This’ll distort the readings you see on the PM5 and make them super fast but allow you to ride against virtually no resistance.

Re: Need lower drag factor

Posted: December 4th, 2020, 3:25 pm
by drop40
Thank you everyone for the responses. We've now experimented with a towel and figured out something that works. He is highly motivated as the BikeErg is one of the only times I let him watch Pat and Jen on YouTube. :lol:

Re: Need lower drag factor

Posted: May 19th, 2024, 8:16 am
by Eemil
jamesg wrote:
November 25th, 2020, 1:17 am
No idea what will happen with a bike, but as the sole user of a rower I have an aircon filter over the inlet. Drag is 97 with the damper wide open. The idea was to keep the dust out, which it does about 90%, but the low drag level is fine too. Can be reduced further, but there may be a limit to drag level where the maths can operate. I'm at about 200m asl.
@jamesg Could you show a picture, how did you attach an aircon filter over the inlet?

Re: Need lower drag factor

Posted: May 20th, 2024, 12:04 am
by jamesg
I cut out a disc from an AC filter and fastened it over the air inlet with a long shoelace and three screws in the peripheral grille on my C.