Berg V2 axle rear wheel spins slower

[i-5]

Just finished built out the new rig with V2 axle set, issue is the rear wheel spins slower than the front, so creating a drag when driving forward and a push on backward. Below is my setup:

-dual fx-r
-dual battery to supply power individually front & rear
-55t motor (same type) front & rear
-11t pinion grear front & rear

Welcome any idea and advice

[klabeaume]

Could be programming in the radio, or esc's not calibrated properly. Also I haven't seen dual batteries. I wouldn't think that would cause too much of an issue if they are matched batteries.

[Illeagle]

I would bet the esc programming being the issue. Mine did the same thing with dual fxr's and I put the tekin hotwire on them and my front esc had an older version of firmware than my new one and it was causing the same situation you have. Also make sure you calibrate them to your radio after you reprogram them.

[i-5]

Thanks guys.

The radio is Airtronics M11x and I have the front & rear dig setup following the details from one of the posts (the one that describes in details with precise values), so chances is low otherwise other folks will also have the same issue.

I will look into the esc, but need to first get the hotwire cable to do the upgrade via PC. There could be a chance that the front and rear has different version since I bought and installed the front more than a month prior to the rear one.

How about the pinion & mesh gear? Reason I ask because when I install the motor & pinion gear to the rear axle, the wheel rotation was not as smooth as the front, also the gears are noisy when they are running.

[milkyax10]

Make sure the rear pinion is .6 and not normal 48 had a bit of a mix up with one once very noisy though

[i-5]

Thanks Milkyax10.

I feel better now as the pinion is a .6, I put lots of gease and hopefully the gears will become smoother after some run time.

Just ordered the hotwire, will arrive on Friday, hope the fxr version upgrade will resolve this.

[JeremyH]

Originally Posted by i-5

How about the pinion & mesh gear? Reason I ask because when I install the motor & pinion gear to the rear axle, the wheel rotation was not as smooth as the front, also the gears are noisy when they are running.

Yes, pinion mesh will make a difference. Make sure they are both set equally.

[ubbb69]

Pinion mesh will cause a lil bit. I run my rear mesh tight as possible for more drag break. I use a 4pk though so i can dial out any difference. Most likely software related or radio related. I am not familiar with the m11 though.

[WarTrader]

I would think it is one of the following.

Not all motors are created equal. The rear motor might just dog a little compared to the front. Diagnos Swap Motors.

ESC output is different. If your programming your ESC's save the config and Copy and save to the other to ensure they are set exactly the same.

Battery Output is different. Just because two batteries are the same Mah doesn't mean their output is identical. This could be due to internal resistance. Swap batteries. For simplicity and weight savings you may want to use a single battery. I've always run 3s with great success.

You have a connection that isn't soldered so well and is causing added resistance impeding the power to the motor.

[i-5]

Thanks again guys.

These are very useful information. I have some good news, last night I re-calibrated each fxr individually, it seems to fix the unequal wheel speed. Just still have slightly different setting which I will wait for the hotwire to sync them tomorrow. I am now working on fixing the pinion mesh "unsmoothness" in the rear axle ( believing that was caused by motor unalign perfectly onto the mount ). Some more work to do tonight.