Difference between reduction kit and regular

[rg12]

Hey Dudes,

The belt reduction kits are more expensive (more complex too), what is the difference between a regular setup and a reduction setup? (reduction has a cool look!)

Also, what is the most affordable kit out there for a high power reduction mid drive kit?


Roy

 

[Joe T.]

Hey Dudes,

The belt reduction kits are more expensive (more complex too), what is the difference between a regular setup and a reduction setup? (reduction has a cool look!)

Also, what is the most affordable kit out there for a high power reduction mid drive kit?


Roy

"Regular" is a bit vague. I have experience with BBSHD, GNG Gen2, and GNG belt reduction. All these systems have reduction of some type. BBSHD has a fixed reduction I believe is 21 to 1. On this you have no way to change it. Very quiet, arguably silent. GNG Gen2 has a planetary reduction as well as the ability to juggle drive gears if desired. Can be heard but not all that loud. The GNG belt reduction is very quiet as well but does have a distinct sound. I upgraded mine with Lightning Rod updates and it was an improvement.

The external reduction I feel gives you some flexibility in both power and reduction choice over a planetary reduction.

 

[rg12]

Why wouldn't I be able to change gears with the bike's shifter on all systems?

Why do some people go for mid drive over hub motor? is it because of performance?

The two reasons that I'm looking into mid drives is for having a lower voltage and higher efficiency to reduce battery size and weight and also to reduce the weight of the bike by having a smaller motor (plus it looks cooler not having a hub in the wheel).

 

[neptronix]

mid drives are typically more efficient up hills, but significantly less efficient on the flats. They also can't do regenerative braking, which is ultimately another efficiency adder.

Mid drives are also more complicated, having multiple reductions and the power must go through a bike chain that was designed with 0-500w of human pedaling power in mind. There are more things to break.

Hubs are simple and have very few things to break, but when you get a flat on a rear tire for example, you get to unbolt a big heavy rear wheel that needs to be secured by torque arms. This is a huge pain in the ass. Also, offroad you have tons of unsprung weight that prevents your suspension from doing it's job effectively.

There is really no winner here.. it just depends on what type of terrain you're looking at. If you don't have multiple miles of >5% grades to climb... i'd go with a hub. If you have crazy hills all over the place, mid drive is the way to go.

As for me, i tried mid drives and got tired of the chain and derailleur issues quickly.. as well as the finnicky internal controllers of the BBS02.. hearing about the the mechanical issues with the GNG and cyclone kits.. i tried em.. but did not feel confident enough in their reliability for the long rides i take. So it's hubs or single speed reduction to the rear wheel for me.

 

[Triketech]

Why wouldn't I be able to change gears with the bike's shifter on all systems?

Why do some people go for mid drive over hub motor? is it because of performance?

The two reasons that I'm looking into mid drives is for having a lower voltage and higher efficiency to reduce battery size and weight and also to reduce the weight of the bike by having a smaller motor (plus it looks cooler not having a hub in the wheel).

In most cases a Mid Drive will be the most efficient option when it can be geared to run closest to the most efficient speeds the motor works at. But not all cases. If you're commuting and pretty much keep a steady speed of maybe 20 MPH and a well matched Direct Drive will be close, possibly better. The more you deviate from that steady speed, the more advantage the mid drive gains.

I've been playing with a handful of power systems on my trike. In many respects the Bafang BBSxx drives are probably the best limited budget option available. A bit annoying to shift even with the cutout switches, but with a good throttle and a free thumb its fabulous ride. Cadence PAS is pretty decent, very ridable, but not so good when trying to keep a pace with others on hills. You'll either go faster or slower as the grade changes even slightly. Some but no all of that can be tuned down a bit with programming. Kepler has done some really nice stuff here.

 

[Joe T.]

Why wouldn't I be able to change gears with the bike's shifter on all systems?

When I decided to build an ebike, mid drive was the only option. My bike is for the woods and trails. I wanted hill climbing power plain and simple. After getting a GNG I started to notice the cadence was a little off. For me to keep up with the motor I had to pedal too fast. Changing gears with the shifter doesn’t solve the cadence issue. After shifting up in gear the bike would go faster but I would still end up pedaling too fast to keep pace. The Lightning Rods update changed the ratio to 35 to 1. This put the motor power right at a comfortable pedal cadence for me. The BBSHD doesn’t give you this option. That is why I personally like mid drives with secondary chain systems. I can get things just like I like.

 

[rg12]

Why wouldn't I be able to change gears with the bike's shifter on all systems?

When I decided to build an ebike, mid drive was the only option. My bike is for the woods and trails. I wanted hill climbing power plain and simple. After getting a GNG I started to notice the cadence was a little off. For me to keep up with the motor I had to pedal too fast. Changing gears with the shifter doesn’t solve the cadence issue. After shifting up in gear the bike would go faster but I would still end up pedaling too fast to keep pace. The Lightning Rods update changed the ratio to 35 to 1. This put the motor power right at a comfortable pedal cadence for me. The BBSHD doesn’t give you this option. That is why I personally like mid drives with secondary chain systems. I can get things just like I like.

I see, I didn't think about the ratio thing...
Guess I will stick with hubs for now as hills are not anywhere around me, just flats, riding in the city...my biggest thing with mid drives is the light weight and cool look...

Thanks alot