I wondered if there is a consensus as to which mounting style is superior.  My thinking says that in a rear mount situation All of the weight and mass is in front of the firewall.  And in a front mount situation, the motor itself is behind the firewall, but the prop and hub adapter is forward of the firewall. So theoretically there is a better distribution of mass with the front mount.  In a lot of applications it probably doesn't make a difference, but when we get to larger motors and their larger props (read heavier), it may be meaningful. Perhaps flying our square corners and such, may have an undesirable effect due to the cantilever effect, on the motor bearings. Perhaps one style is less affected than the other ?  Just wanted to hear what you guys that have been doing this a while have to say on the subject.  Don't want to cloud the issue with adding additional bearing supports. Just the plain vanilla front or rear firewall mounted motor and nothing else.  OK guys I'm all ears.

purely coincidental information, but I have lost bearings in two electric motors that were rear mounted,, I cannot say without a doubt that it would have made a diffeence to mount them from the front,, but for me and my models,, they will all be front mount from now on,,

I have now converted to the Orbit and the can has a separate bearing to support it. (The motor has 3 bearings.)
Now I don't have any problems anymore with noisy motors etc.

Did you also rear mount the Orbit ?

Yes Allan, I rear mounted the Orbit. 

Looks like a motor mouted front and rear would be the best.   Didn't Bob Hunt have problems in the early vesions of his electric set ups until he put a mount on that held both end of the motor?

I've used both methods myself, and don't have problems either way. I use a lot of E-Max motors, all rear mounted and so far only one has caused problems but this is due to cheaper bearings more than a can flex problem. I found some decent Japanese bearings at a reasonable cost, and this makes a difference. My Electron model has a front mounted MVVS 6,5 motor with a conventional outrunner drum, unlike the ones mentioned by Phil. Percy Attfield is flying his Impact with the same motor but it's rear-mounted. Both of us have plenty of flights on these motors and zero problems. I believe that it's more to do with the quality of the bearings than the way of mounting the motor.

Motors like Plettenberg with the bigger 3rd bearing are obviously the best way to go, but at a price.

Keith R

Can flex or not, it just makes engineering sense to place the mount closest to the where the load is highest.

Front mount seems to be the best if you can only have one type.

Guys,
I think the most important part of the mount is a solid firewall. Some have tried to use thinner 1/8" firewall which seems to work with an external bearing to reduce flexing. I have used 3/16" front mount. On one ship I used some brass mount clips to hold the firewall mount. Unfortunately, the mount clips allowed some flexing of the mount. I added a rear external bearing and that solved the problem. On a second ship I used a solid glued in front 3/16" plywood mount and used a couple small screws through the fuse into the mount and this seems as good as the mount with an external bearing. One thing I do to the plywood mount is once it is cut out and fitted I CA the surface and mount holes to harden the mount.

I think the rear mount will also work provided it is solid.

Best,             DennisT