Model A with Pm1 upgrade, Pm1 inaccurate

[Hans]

Long time no see;-)

Since a couple of months i am the proud owner of a very rare model A with a Pm1 upgrade

But .. the Pm1 is inaccurate, the pace is never constant. On the 'bikewheel' a round plastic, i asume a magnet,
is mounted with 2 very small screws. The plastic has bent over the years, due to there are just to screws mounted? ,
and that makes that the distance between the round plastic and the sensor varies. I think that's the cause the pace
is never stable ?

My question(s) .. Is the round plastic available somewhere ? .. Anyone an idea how to straighten the plastic or
glue it to a thin metal, round, plate behindd it ?

Thanks for reading!

[Ombrax]

Have you searched the C2 web site for information?

For example, the Model A parts list shows this: MONITOR MAGNET ROTOR/DISC Part # 218.1
That must be for a retrofit, because I don't think the original configuration with the "mechanical" speed display would have required a magnet.

See here for more:

https://www.concept2.com/service/indoor ... schematics

and here:

https://www.concept2.com/indoor-rowers/ ... itting-pm5

If you look at the drawing included in the instructions for retrofitting the PM5 onto a Model A (!!!!) there's a drawing that shows a round magnet disk that appears to be what you're talking about.

See here: https://www.concept2.com/files/pdf/us/m ... lace_A.pdf

I'd give C2 a call and see if they can help.

Good Luck

[Hans]

Thank you.

(after having made my posting i found out about the magnetic disc/ rotor) I'll contact C2 in the Netherlands to ask
for a new one.

Question remains .. can it be straithened.

Regards,
Hans

[c2jonw]

There are three magnets imbedded in the rotor disc. The spacing of these relative to each other (120 degrees) and the pickup are critical. In my experience you may be able to improve the performance by repositioning the disc a bit and changing the tightness of the screws. Spacing of the rotor to the pickup should be about 1/8".

Good luck with it!

[c2jonw]

The disc is plastic- either nylon or abs- and can probably be straightened by removing it and flattening with weight.

[Hans]

Thank you for the advice. I'll go trying too straighten it, and if it doesn't work i'll
contact C2 over here.
Thanks again!