I don't think I've ever seen a model A in the wild but I've seen plenty of B's still working. I have a 20yo model C that I upgraded with a new monitor and handle and it still works like it was unboxed yesterday.
Depends on where you measure from but yea, 70 might be low. You can talk over two dozen heavies pulling 2ks on air rowers which definitely places it under 100dB.
The standard rowing machines (sit on sliding seat, feet stationary) can actually be pretty abusive to the spine, worse than scull or sweep. I've seen inexperienced people actually hurt themselves. It's mostly an issue of shock at the catch and finish. Dynamic machines such as those made by C2, Row perfect, etc are a bit better in this regard and might be a better fit for this market.
I don't have any stake in C2, I just want to make clear that they are the standard that this will be measured against and that they are said standard for a reason. Anything advertised lesser should be viewed with suspicion, particularly for safety critical products.
All that said, there are opportunities to improve, but those opportunities mainly exist in the software space. Focusing on hardware solely to create a moat isn't innovation, it's making landfill fodder.
Finally, I have significant experience in this area, both as an athlete and a coach. Enough that I would unmask myself very quickly if I mentioned any details. I don't coach anymore and don't have any financial interest in that either. Teaching people to use these devices safely isn't an "instructional videos" and "warm up" ordeal. This will sound silly but people generally don't know what their body is doing without tight feedback loops and their perception breaks down under stress/over the duration of a workout. We frequently had people row in front of mirrors to get things to click (another business opportunity in the computer vision space). It's painfully obvious when you go anywhere that has mixed classically trained and self trained rowers who is who.
I only raise questions because the move-fast-break-things approach is dangerous when you're breaking people. I couldn't care less about the VCs getting fleeced by this.
Just for context, standard is defined on two fronts.
1. Each machine computes effective Watts differently, so pulling your guts out might be 1kW on one machine, and 400W on another. Whichever one everyone has the most experience with wins here.
2. There are a bunch of different designs across about three different resistance modes available A. air B. water and C. hydraulic piston. Air is generally regarded as the best as it doesn't change felt resistance with time, though it can be somewhat noisy, maybe 70dB. Water heats up as all the energy is dumped into it without anywhere else for it to go, so the viscosity changes very noticeably over a long workout. These also tend to have a nylon strap instead of a chain which stretches and can cause an odd sensation. Finally the worst, hydraulic piston, which has the smallest mass to dump energy into, will change resistance dramatically in a short time, and have been known to fail with experienced rowers, sometimes explosively.
There is room for an electrical resistance variant in this lineup, as has been shown with cycling, though it's important to note that thermodynamics specifies the energy has to go somewhere, and you may end up with a dangerously hot resistor bank somewhere on the machine.
It should also be noted that experienced rowers can output a considerable amount of power. Enough to cause piston rowers to overheat and explode/vent. Just because your resident mechanical engineer can't break the prototype doesn't mean you shouldn't find someone who can hit National Team numbers and have them go at it for an hour straight.
That makes sense, the issues I saw were mostly at the post collegiate/open level. There were some issues in U23s but that was somewhat rare, at least compared to alcohol inflicted injuries :)
Why vary resistance? Most athletes learn to handle one resistance setting, the National Team standard being IIRC DF120, though anything between 100 and 120 is fine. Changing it tends to throw people for a loop.
This is going to come down to experience but I'd say the majority of those I trained with had dealt with an injury at one point or another. Most women, particularly the lightweight class experienced broken ribs from strain across the core and most of the guys had lower back issues at one point or another.
I'm not saying these things are death machines or anything, but the concept of adding essentially seated row to a rowing machine is fairly dangerous. Throwing an air damper up to 10 and ripping on it for a couple minutes will leave you quite sore the next morning but adding high weight can start pulling muscles or slipping discs.
This is a kind of thing that needs a lot of direct coaching to achieve...
There are two major rowing postures you'll find people tend to use, hips rotated forward and hips back (spine slightly arched forward/convex). Neither is really wrong but for high resistance you need to be in the hips forward position (back slightly concave) as is the technique for weight lifting in the seated row. IME most people don't actually comprehend which position they're in but using the wrong one can be catastrophic. You typically have to spend a few hours with someone ensuring they stay in the correct orientation before they really get it.
Edited my comment when I saw this. This is exceedingly dangerous. Ask any rower that's worked with people on C2 machines. Everyone will instinctively throw the damper to setting 10, then throw their back due to bad posture.
I see this as an insanely dangerous game. IME most non-rowers won't touch an erg without significant instruction/encouragement as they're technique dependent. Any that do will quickly figure out from anyone who has rowed that C2 is the standard and everything else on the market is flaming garbage.
Add to this that I could recreate this business using the C2 API in a couple weeks and suddenly have a market of everyone who owns a C2 (all the people in this thread complaining that it doesn't support their machine) along with a literal potential customer list available through C2.
Long time high level rower here. Why make a new rowing machine when Concept 2 is the calibration standard all athletes use and has a relatively open USB interface?
For those not in the know, rowing machines all have different calibrations. C2 is the standard because they're very consistent across machines and are by far the best made allowing for many thousands of hours of use without failures. Most experienced rowers won't touch anything other than a C2.
Edit: reading further, the 'moat' here appears to be electrically controlled 100lb high resistance settings. Be VERY careful with this. It's well established that most non-trained athletes will hurt themselves with this feature as it's a common trope on C2 machines. The rowing posture can be rather dangerous for high weight if misused.
And a project config system that will break everything at the slightest provocation! Seriously, setting up even moderately complicated multi-project solutions usually results in days lost to figuring out why x library isn't linking with y project. The editor is great, the build system is somehow worse than make/cmake.