Why are geared motors worse than direct drive for climbing hills?

[DogDipstick]

100% agree.

Minimising stress in the axle is the goal. Minimise stress by maximising the area over which the force is applied => tight fit and maximum surface contact.

You spelled minimize and maximize wrong, friend, but I know you are not native to England so I will give you a break.


I hear your theory: but:

I thought minimizing stress in the tork plate is the goal... so it does not fail? What are we taking about here? An axle break or a hub spinout? Which one is more likely to happen ( on a DD hub motor, on a bicycle, or a geared motor, on a bicycle....)?

I thought it was the latter. I would be mistaken; if we worry about our geared hum botors doin a spinout; but they actually break the axles? Wow did not know that. I thought only a few QS motors and MXUS motors were the ones to break axles. Did not know you had to worry about a broken ax on a geard hub.

You learn something every day.

I care cause I am doing something of the like right now. I was told steel, hardened, tool, over aluminum, the dimensions to make it work, and the forces involved by someone certified and licensed ad insured to give such info.

 

[serious_sam]

Minimising stress in the axle is the goal. Minimise stress by maximising the area over which the force is applied => tight fit and maximum surface contact.

You spelled minimize and maximize wrong, friend, but I know you are not native to England so I will give you a break.

I'm Australian. We use English (s). Not "American" (z). Since you are from USA, I will give you a break, "friend".

I thought minimizing stress in the tork plate is the goal... so it does not fail? What are we taking about here? An axle break or a hub spinout? Which one is more likely to happen ( on a DD hub motor, on a bicycle, or a geared motor, on a bicycle....)?

Stresses in both components should be minimised. I mean, you don't want either part to fail, right ? But since the motor is the expensive component, and the axle material is unknown strength (and generally not as strong as it really should/could be if better materials were used), the smart move is to minimise stress in the axle as much as practical.

I thought minimizing stress in the tork plate is the goal..
...
I was told steel, hardened, tool, over aluminum

It seems like you're confounding stress and strength. Stress is a state that occurs as a result of an applied load, and strength is the ability to withstand an applied load. Making the torque plates strong doesn't reduce the applied stress. The only way to reduce stress is to reduce the force, or increase the area over which that force is applied.

 

[Bullfrog]

Axle spin out or a broken axle...it depends on the combined stress...i.e. torque plus bending where the bending is a combination of the weight on the axle and the impact loading (hitting a bump or landing after a jump).

A MAC running 52v/60A Battery/160A Phase puts out about the same torque as a QS205/Cromo running 72v/200A Battery/200A Phase....my MAC axle has 10 mm flats and I have never had a problem with it breaking and I run 52v/60A Battery/160A Phase and the total weight of me and my bike is about 265 lbs. So I am guessing an axle spin out is more likely.

The strength of the material is a factor as well as its toughness (resistance to crack initiation) and usually stronger means less tough so there is a balancing act that must be followed.

Both an axle spin out or a broken axle are possible and nobody can tell you which is more likely unless you can specify the material properties, the dimensions, and the loading.

Sooo I'd recommend the Civil Engineering approach which is...when in doubt make it stout .

 

[markz]

karen is an internet term for "female" meltdowns you see on yt, basically easily offended snowflake pusssies. A karen would call the cops on a childrens lemonade stand.

For torque arms you just buy the steel from home depot, 1/4" x 2" x 4ft, grab the angle grinder.
If you want free steel, you find some steel bases for temp fences which are usually found near temp fences that have been disarded and just laying around not connected to anything because the owners of the temp fence deemed that steel base defective and littered the ground so you do them a favor by cleaning up their illegal littering. :wink:

For torque arms, it doesn’t give any advantage to ha

You don’t need hard steel to make custom dro

ok Karens.

yall do you, I'll do me. Lol. To each their own, but I just told you a very easy, cheap way to toughen the metal. Might not NEED it.. .. but I also dont "NEED " more than 750w and 20mph according to some, others, that I also consider, ... Dead wrong.

I ride powerful bikes for a decade. The first had a damaged axle because the torque plates were harder than the axle steel. I you believe in hard torque arms, just wait, you will understand some day that you push your motor a tad too hard.

Then, I don’t know Karen but somehow it does sound like an insult. English is not my native language so, for now, you have the benefit of the doubt.

 

[donn]

If you want free steel, you find some steel bases for temp fences which are usually found near temp fences that have been disarded and just laying around not connected to anything because the owners of the temp fence deemed that steel base defective and littered the ground so you do them a favor by cleaning up their illegal littering.

I'll have to keep an eye out, but I expect stuff like that tends to be galvanized?

 

[MadRhino]

I'll have to keep an eye out, but I expect stuff like that tends to be galvanized?

And so?
The scrap piece of angle stock that I have cut custom dropouts off for the last 3 years, is powdercoated green with rusted edges. Who cares, my grinder sure doesn’t. After they are made, nothing is left from the original finish and condition anyway.

 

[donn]

When I have had uses for scrap metal, it has involved some brazing, and no one likes to put a torch to galvanized.

 

[MadRhino]

I agree, but making dropouts or torque plates, even complicated ones with integrated brake mount and mud guard mounts, does not require any welding. I’ve had to weld the bike swing arm sometimes though, to make bolt-on torque plates mounts on bikes that didn’t have enough meat around the through axle to fit them properly.