New rower

[James Wright928]

OK, new to the forum and I'm sure someone has encountered this before or asked about it so apologies. Has a rower (model C) for 9-10 years, killed it as kept in garage and rusted away but was used almost every day. I'm a big guy, 18 stone and have rowed for last 30 odd years. Old rower Model D I would row a steady 500m every 2 mins and do 7.1/2 km in 30 mins, I was happily doing 1/2 marathons and marathons and rowed close to 500km in April. Rower dies at end of August and it took three months to get a new one due to lockdown delays etc.

So the thing is, old rower, no issues, new rower, even with drag set identical to old one, I'm rowing a good 300m short over 30 minutes. To row at 2.04 is even a struggle. Its destroying me psychologically and I used to love rowing, now I resent my new Model D and hate it!!

Help.............

[Nomath]

Your call for help reminds me of an earlier topic that didn't get a satisfying answer.
The C2 pundits always answer that you have to believe the latest PM. I think they should also explain why the older PM (PM3?) can be wrong.

[mict450]

I feel your frustration. Seems to me that we've had more than a few threads in the last several months on this same theme. The experts should be here soon & hopefully can provide something helpful.

On a related note...how does a Model D end up dying? If something goes haywire or breaks, parts can be ordered at a relatively modest cost & repaired. Just curious.

[robbiep]

The simple answer might be that you took 3 months 'off' between your old rower dying to the new one arriving, and that's the drop in form.

The difference between 7500m in 30 minutes and 7200m in 30 min is about 22 watts, or 11-12%. If I took 3 months off running or cycling, that's probably what I'd see as my deterioration in time / drop in form for 5k / 5 miles.

However, interestingly, I'm also waiting for a new rower, been on the waiting list since October - current prediction is for late January.

If I see a huge drop in form just from going from a C/PM3 to a D/PM5 with no training break, then I'll be inclined to agree that there is 'something' not right

[James Wright928]

During the 3 months off I was still running and playing squash. Have done probably 50 rows on the new rower now and it just feels very different! Hope your new one turns up soon, waiting is agony!

[Dangerscouse]

I agree with Robbie. Three months off rowing will usually take off a significant amount of performance, at least for a certain amount of time.

However, this is predicated on how long you've been rowing again, and what training sessions you are doing. If it's just longer, slow distances you're not really giving your body much reason to adapt and change. You should do some intervals, and/or faster 5k, 6k, 10k distances as well.

[Ombrax]

I agree with Robbie that it's most likely due to the time off, despite the fact that did to other activities, you weren't rowing. Heck, if one is in tip-top shape, missing just three days can change things, let alone three months.

[Nomath]

In the past decade I have done a handful of cross country bicycle rides in the US that took 2-3 months in which I didn't touch a rowing erg. It usually took me just two weeks, i.e. about 10 runs, to get back to my previous performance level.

I wonder whether it could be the shock cord tension that causes the different feel and also the loss in power on the new erg.
Over the years your old erg might have developed a rather slack cord and the new erg probably has a shock cord tension set to spec. I read here that the tension should be 6-8 lbs, hence 26-36N. Assuming a stroke distance of 1.6 m, that amounts to about 1.6 x 30 Nm per stroke. At a stroke rate of 25 spm, the power expended in pulling the shock cord is 1.6 x 30 x 25/60 = 20W. That agrees roughly to the loss in power from doing 7500 m in 30 mins on the old erg against 7200 m in 30 mins on the new erg (22W). The power for extending the shock cord is not included in what you see on the PM; the PM only measures the power added to the flywheel.
Check the shock cord tension with a luggage scale.

[Ombrax]

I haven't examined the inside of the erg lately, but does the extension of the bungee cord correspond 1:1 to the stroke length? I know there's a pulley system in there that may affect things.

[Nomath]

It doesn't matter. What counts is the static force on the handle. Force x distance = work. Work/time = power.
With a luggage scale you can measure the static force on the handle. The force will increase somewhat from the catch position to the finish position.

[mict450]

This is a very interesting & enlightening thread about bungee tension & a 3 month break without descending into a crap slinging contest. We all remember what used to happen when the subject of bungee cords came up, forcing Dougie to lock the thread. Interested to read what the end result will be.

[Tsnor]

One thing we do know... enough people push to get to the top of ladders that if there were a structural benefit to using a B or C vs model D then people would do it, and it would be documented.

Did your model C have a PM5? And if so was it set to model C vs the default value of D ?

It'll be interesting to see how fast you return to your old times.

(Glad you compared drag factors instead of damper settings. The damper setting on the old model C would be very different than the setting on the new, clean model D. If you meant you set the damper to the same number, then make the D much lower than what you used on the C to get the same drag factor. The D has a clean screen).

Given the average and peak force on the rower handle (given in Ergdata if you use it) is > 100 lbs, I doubt that the tension on the return bungee can be significant enough to give the delta times you are seeing. EDIT: The bungee force is 2 ways. (1) it hurts you as you pull it and (2) it helps you on the recovery stroke - less work to get back to the catch. Not clear to me if this analysis is correct --> "At a stroke rate of 25 spm, the power expended in pulling the shock cord is 1.6 x 30 x 25/60 = 20W." Imagine an 6-8 lb weight hanging from a bungee bouncing up and down 25 times a second. There is no net power gain/loss of 20W. Several people on this forum have replaced their bungee cord - has anyone seen a change in their splits ? Anyone heard of someone getting a new PB by using a weaker bungee -- the time delta from the OP is large. /edit

AFAIK the force curve for the D is the same shape as the force curve on a C...

[Nomath]

.... I doubt that the tension on the return bungee can be significant enough to give the delta times you are seeing.

It does, and quite accurately:
Old erg : Power = 2.8/(1800/7500)³ = 203 W
New erg : Power = 2.8/(1800/7200)³ = 179 W
The estimated power to stretch the new bunjee is 20W (see my above post).

What the bunjee does in the recovery is that helps you to accelerate, but all the kinetic energy must be absorbed by your muscles nearing the catch position. There is no gain from a tense bunjee in the recovery.

[Franklin]

In my opinion I believe it is just a matter of adjusting the new machine. I have two rowing machines, the oldest is from 2004, the original monitor PM3, at the beginning of the year I changed it to a PM5. In May, with the pandemic mess, I bought a new C2, which was manufactured in February 2020. In the first times of use I had the impression that rowing on the new machine was heavier, but now, I row the same thing in both C2, this based on heart rate.

[Franklin]

With time of use, you will get the same results with the new C2.