Hi! Dumb question - can anyone tell me the standard crank arm length on the schwinn jc3? I’m using that with assioma uno and have a feeling my power output is too high because I measured wrong. Have not been able to find the part measurement anywhere. Thank you!!!
Hi Lauren,
I’ve never used one of those, but was surprised that the info you’re looking for isn’t more easily available. Either my Google-fu is wonky, or they don’t publish it anywhere.
Regarding crank length measurement, it’s very straightforward to do accurately: you are looking for the distance between the centre of the pedal thread to the centre of the crank rotation point.
By the way, I found the following on Schwinn’s own FAQ page which is almost certainly wrong, since 208mm cranks are for giants. (Most real bikes use 165mm to 175mm):
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The FAQ is definitely wrong, I used to have a IC3 and used with Assioma pedals. If I recall correctly the length was around 170, but you definitely measure.
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@Lauren_Longley
When you’ve measured your crank arm, it would be nice to put it in this thread so that it might help future users searching for the same information.
They probably measured the crank arm end to end rather than center to center…
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It is center to center.
Yeah, I know, it’s not like drop bars or frame seat tubes where some measure c-c and others end to end or center to top or center to virtual whatever. The presumptive 38 mm error just sounds about right for an end to end measurement…
Thank you! I had measured myself around 172.5 but the crank is not a straight line (has a curve in it) so I wasn’t sure if that mattered. I do still think my FTP and power is way off, I’ve got an FTP on Zwift of 326 using the pedals on my schwinn, and I don’t think I’m in comparable shape to other women at that level by any means. Is there any way to validate that somehow? Alternative way to test?
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You wouldn’t by any chance happen to have a single-sided power meter (Assioma Uno) with the double power option turned on? Use the Assioma app to check your settings.