True brake pedal mod / load cell braking - strength and techinque

[ace-tacer]

Hi all,

I just ordered the TrueBrake pedal mod for my G29, can't wait for it to get here. I have a question on strength and power needed to operate this, I guess it goes for all load cell brakes:

I have been racing G27/G29 for over a decade, literally, since they came out, and use the clutch for left foot braking. I like the pedal soft and with range to modulate. I realise the difference to the mod will be huge, I don't mind that as I trust all the great reviews it's been getting and the advantage of load cell over rotation/travel, I've been meaning to learn to use it for a long time now.

However, I'm a little reluctant as to the force I need to use. I ordered the softest and second softest springs, but even 13kg for the softest to reach 100% brake power is quite a bit of pressure to be applied. I often do do 3 or 4 hour sessions. I wonder if I will have the power in my leg to press down 13kg ever 15 secs for 4 hours straight!

I can't even imagine how guys do it with the hard springs!!

I do race in an office chair, but it doesn't move and the pedals are raised and bolted to a support. Still they are not as high as they would be in a race car, I still push down a little, not just forward.

As it is I'm at the fisio once a week, at the moment my right leg gives me grief as holding down the accelerator for hours, over consecutive days/weeks starts to tense up my right calf over time, as well as the rest of the leg. I guess now he'll also have to work on my left side .... he thinks I'm nuts by the way

Any thoughts/experiences/tips?

Cheers

 

[blekenbleu]

Any thoughts/experiences/tips

I use a load cell with office chair and no issues.
Keep in mind that you are under absolutely no obligation to apply any more force
than that with which you are comfortable; the only question is
how much pedal movement one cares to associate with their chosen maximum force.
Maximum force is set using Windows' joy.cpl or other software options, some included in games.

Right calf discomfort probably has more to do with holding some constant position,
probably other than ideal, rather than the amount of force being applied,
which for a G29 throttle is negligible.
FWIW, the rear of my G29 pedals was elevated about 30mm from horizontal.

 

[ace-tacer]

That makes sense @blekenbleu , thanks for that! If I decide to configure the input to only use half the force I guess I'll be left with 50% of the range, since it's only a potentiometer in the end, not a real load cell. That will be milimetrical, let's see how that goes

I plan to build it into the actual brake pedal, so I'll have the new mod on the brake but clutch remains as an optional axis fallback if I can't get it sorted

Good tip on the pedal elevation, I'll play around with that. And yes, it's definitely a position thing rathe than force on the leg, and some of it comes from the lumbar region, too. Sitting all day writing code and then all night racing cars isn't good for any part of your body

Anyone suffering from similar problems: I actually had to stop simracing for 2 - 3 years because my body couldn't take it anymore. Keyboard/Guitar/Wheel every day did my forarms and neck region in, sitting for prolonged period of time harmed my lower back and eventually legs. I'm over 50 What I do now is to work out almost every day, all body functional/Crossfit workouts and strengthen the parts I need for racing. And I go to the fisio once a week to sort out contractions. Since I do this I can race as much as I like again!

Thanks man!

 

[stigs2cousin]

I concure with @blekenbleu with regard to the pain by bad leg position.

I myself, ( well over 50 and to lazy to workout, but at least not a keyboard perpetrator) got rid of the pain by changinging my rig.
The accelerator foot is leaning to the right and resting against the profile that carries the shifters and the handbrake. Accelerator is from Heusinkveld sprints on the stiffest possible setting.

When left foot braking the brake ( HSV Sprint, max 65kg´s) is directly in front of my foot, the leg is straight and the knee is resting aginst a little kneepad I fixed to the left upright.
In this position the clutch is far away to the left and awkward to reach.
but I need it only once for the start of the sequential cars.
Both legs don´t "fall away" when they are completely relaxed, so I don´t need any muscle tension to keep them in place.

For H-Pattern cars clutch and brake on their mounting plate geht shoved to the middle, clutch is comfortably in reach, brake is used with the right foot. Because of constant movement no problems with the muscles.



I guess that this "necessary muscle tension" to keep the legs in position causes you leg problems, especially when your races are longer.

If it is impossible for you to swap to a dedicated rig with "leg rests" to safe on muscle work, maybe you can fabricate "knee pads" that you fix to your desk when racing and take of when "working" at your computer??

MFG Carsten

 

[blekenbleu]

After a July back injury, an Aeron desk chair
was one of only 2 places I could tolerate,
other than standing in crutches.
I often spend over 8 hours daily in it,
e.g. programming or doom scrolling.
Since that chair was already also being used with a wheel stand,
by swiveling 90 degrees and strapping,
it is only a question of exactly where to position pedals,
which turns out for me to be barely raised above the floor,
at a distance where heels rest on pedal base
immediately in front of throttle and dead pedal.
G29 pedal base was tilted slightly forward;
ProtoSimTech PT2 base works better for me tilted slightly back.

 

[ace-tacer]

Thanks for those tips guys!

My pedals are screwed to a baking tray which is 7.5cm high. I sit comfortably but I do (at least partly) use my calf to press the pedals, not the entire leg as I guess I would do in a real racing car. So holding the throttle for hours is a bit like like standing on your toes at a rock concert to get a better view. And doing it for hours almost every day adds up. Maybe I should raise it more to get more of a leg action and reduce the stress on the calf.

But what about the actual strength needed to press a brake pedal with 23kg resistance at every brake point for hours? I can imagine that can get quite tiring!

I also wonder about DD wheels for the same reason. They often get rated be the strenght/resistance they generate. And I always think: I don't even want it that strong, I wouldn't last more than 20 mins! I even have my G29 at 85%. Guy doing endurance with upper tier DD wheels must be athletes to battle that thing for hours!

Cheers

Chris

 

[blekenbleu]

My pedal deck is near 5 than 7.5cm.

But what about the actual strength needed to press a brake pedal with 23kg resistance at every brake point for hours? I can imagine that can get quite tiring!

I suppose that you mass more than 46kg; how long can you stand?
With proper leg and seating position, braking should not be much more uncomfortable,
and even with trail braking, a hairpin lasts only a few seconds.
Holding any position for long periods with muscles tensed constrains blood flow, not recommended.
Adjust throttle angle so that ankle is relaxed with throttle applied.

I even have my G29 at 85%

I did as well; higher was unpleasant, but not because of strength (~1.5 N.m?) required.
My (13 N.m) AccuForce is set at about 75%;
time exerting more than 5 or so N.m is brief.

 

[stigs2cousin]

As @blekenbleu wrote it´s probably more the muscle work to keep position than the force to depress the pedals.

Try to find a position that is relaxed in the state you need most often.

MFG Carsten