Online queries about C2 rowerg vs magnetic rowers - a fair few lately is there a consensus on this?

[JoeChaos]

I have seen a fair fewe online queries about C2 rowerg vs magnetic rowers lately is there a consensus on the differences between them and any advantages of C2 rowerg?

IMHO I think the C2 rowerg is significantly better but I have seen questions asking about resistance training on C2 after doing it on mag rower, how can the C2 work my back or other part of the body and comments about being at a high resistance on the mag rower and will C2 work my back more. My view on the kind of answers to these sorts of queries it so make the comment that the air resistance of the rowerg is better with it giving more resistance the more you put into the stroke and the damper setting is not about making it harder/better workout. I would explain about drag factor. I would say that if you need strength training then you should be doing a strength training exercise on top like weights (seek pro advice if you need it). All things like this.

I guess here I am wondering if there is kind of an agreed set of comments the more experienced rowerg users (not me) would give in answer to people who might have bought a cheap mag rower but think the C2 is better for them or indeed anyone new to using the C2 rowerg?? TBH I have learnt a lot but I think I could do with learning more so whilst I have only used a C2 rower I do not profess to be an expert or even close.

PS I do find it interesting how people who are used to resistance rowers all seem to ask questions about resistance setting to get a harder workout. It is like they have reached a point the mag rower can not give more so they are looking around for something a bit more demanding. I think if used right the C2 rower is such a piece of kit.

[Citroen]

We don't discuss magnetic rowers on here.

[gvcormac]

I don't like magnetic resistance, whether on a rower, bike, or elliptical.

For me, the following are non-negotiable requirements:

1. Substantial inertia [moving mass]
2. Increasing resistance with speed
3. Calibrated measure of effort (i.e. erg).

I suppose it would be possible to provide 1 and 3 with magnetic, but it isn't often.

It is not really possible to provide 2 with any fidelity. The computer can try to adjust the resistance with speed, but the feel is all wrong.

[JaapvanE]

For me, the following are non-negotiable requirements:
1. Substantial inertia [moving mass]
2. Increasing resistance with speed
3. Calibrated measure of effort (i.e. erg).
I suppose it would be possible to provide 1 and 3 with magnetic, but it isn't often.

As lead developper and package maintainer of OpenRowingMonitor (basically an Open Source alternative to the PM5) I can attest to these, especially the last one. We see a lot of people with magnetic rowers come to ORM as their metrics are complete BS (as is with many non-established rower brands). In all honesty, I never encountered a magnetic rower where the metrics made sense. Making it work isn't difficult (hey, even we manage to do it quite reasonably), but the manufacturers consider metrics an afterthought.

Point 2 is a big one. To elaborate on this for the novice reader: in essence the handle force is determined by two things, the flywheel's inertia (resistence to velocity changes) and the dragforce. Inertia is a given based on the physical size of the flywheel, so once the flywheel is constructed it remains fixed for eternity. The dragforce is the thing you indeed feel. On an air braked machine's dragforce is dependent on the flywheel's angular velocity. On a statically magneticly braked system, the dragforce is a constant, regardless of flywheel angular velocity. Although magnetic resistence is dependent on a determined distance between the magnets, similar to air inlet for an air rower, it will not change in a stroke. So indeed the resistance of a magnetic rower is completely fixed, where an air-braked system will vary throughout its angular velocity and thus rowing position. For me, air braked feels much more gentle. But I realize some conditioning has taken place over the last decennia, but having to deal with the full force of a magnetic rower never pleased me.

Please note that mechanically, some of these machines are often completely insane. We recently had an issue where the flywheel stopped completely before our pause time-out (i.e. 6 seconds after the start of the last drive, similar to the PM5) had passed. This is a full hard stop, within about five seconds after completing the last drive. Imagine the dragforce there. A C2 flywheel spins for over two minutes. Some users removed the magnets and added fins, just to get some decent behaviour. We really had to change ORM's behaviour to accomodate that insane mechanical weirdness.

To be honest, I encountered several magnetic systems where the dragforces seem to be intended for horses and elephants. They maxed out on way too high resistance. Even on hybrid systems (NordicTrack) the highest settings are absurd (DF450 to DF600...). It is extremely easy to overshoot the magnetic resistance on these machines in design. I don't think these manufacturers had any industry experience on board when designing these things, and it shows.

It is not really possible to provide 2 with any fidelity. The computer can try to adjust the resistance with speed, but the feel is all wrong.

Theoretically, it can be done, and practically it has been done as well by Hydrow. Admittingly their implementation is still a bit crude, but it is quite a decent approach (albeit a lot more expensive than a C2). In the end it is about high frequency measurement and response, which can be done even on cheap hardware like a Raspberry Pi. It is more about being able to have a decent actuator circuit that responds quickly enough to stimuli but doesn't have a tendency to overshoot (as that can actually create huge loads on the handle instantly, hurting the user). I'm convinced it is the way eventually, but I don't know if manufaturers are risking it when flywheel based machines work well and are a lot less expensive.

[jamesg]

differences between them and any advantages of C2 rowerg?

Using an air braked flywheel is similar to rowing on water, since air and water exhibit a cube law for speed/power. So inertia and resistance conditions are satisfied.

Also it's possible to measure flywheel speeds at release, catch and next release, so Work done by the flywheel on air can be calculated, knowing its inertia; and so Power, knowing the times.

Other brake systems are possible no doubt, but if the speed/resistance characteristic differs from the cube law, results shown will differ too. This does not imply that a user will be wasting his time. Just that the C2 machines make it all too clear if we are.

With Inertia, there's some satisfaction in knowing we are using a fundamental characteristic of Mass in our Universe, studied by such as Newton and Einstein.

[JaapvanE]

Also it's possible to measure flywheel speeds at release, catch and next release, so Work done by the flywheel on air can be calculated, knowing its inertia; and so Power, knowing the times.

With anything that rotates, this is true (and yes, with ORM we try them all ). But you don't need that to calculate work. A simple load-cell and directional acceleration sensor in the handle (like SmartRow is fieldtesting now) can do the same, and to some degree even more accurate.

Other brake systems are possible no doubt, but if the speed/resistance characteristic differs from the cube law, results shown will differ too. This does not imply that a user will be wasting his time. Just that the C2 machines make it all too clear if we are.

With Inertia, there's some satisfaction in knowing we are using a fundamental characteristic of Mass in our Universe, studied by such as Newton and Einstein.

Please do not exclude changes in inertia. Waterbased rowers exhibit behaviour consistent with inertia changes (as the watermass essentially is the flywheel, but changes shape due to rotational velocity). In my experience, this has pretty interesting effects on lower linear velocities as the catch is extremely gentle.

[nick rockliff]

We don't discuss magnetic rowers on here.

Too late

[Ombrax]

A simple load-cell and directional acceleration sensor in the handle (like SmartRow is fieldtesting now) can do the same

It's interesting that they're also adding an accelerometer to the handle (measuring the force is clearly required for this approach). Do they integrate that (once or twice) to calculate what the handle is doing, or is it simply to identify the beginning and end of the drive?

[JaapvanE]

It's interesting that they're also adding an accelerometer to the handle (measuring the force is clearly required for this approach). Do they integrate that (once or twice) to calculate what the handle is doing, or is it simply to identify the beginning and end of the drive?

They seem to be integrating it twice to get to the usual metrics. At least, that is the only way I can think of that gets to the usual metrics. It is an interesting approach as handle movement measurement is quite complex in that way, thus power calculation is tricky. With OpenRowingMonitor we helped a guy building an identical product, but he couldn't get position measurement reliable, which was a nightmare. Small measurement errors propagate too quickly into calculations, making them unstable.

But SmartRow even retrofitted it on a C2 (that was one of their fieldtests). I even spoke to one of their beta-testers, who was quite positive. Please note, SmartRow has a similar commercial product already: a pulley with a loadcell that can be fitted to WaterRowers (where distance travelled can easily be calculated via pulley rotations).