Rear 26" 1000w hub motor, is a 31mm external width rim preferrable or mandatory vs a 25mm wide rim?

[Planet Indigo]

My original 26" 1000w rear hub motor rim was 31mm of external width. It recently got damaged by a pothole, so I'm looking to replace just the rim itself, and looking at replacements, I'm finding way more rims that are 25mm of external width than 31mm.

Is 31mm recommended for sturdiness in a rear hub 1000w rim or can I safely go with 25mm with no adverse effect at all?

 

[ebike4healthandfitness]

The rim width has nothing to do with the motor.

Rim width (often referenced to inner width) is about tire width.....and if running rim brakes external width can also matter there as far as compatibility goes

 

[Planet Indigo]

I have disc brakes so I'm not concerned about that. I was mainly wondering if having a wider rim provides more sturdiness? (all other things being equal). Maybe more impact resistance? More weight is on the back, so I was wondering if having a wider rim would be preferrable.

 

[neptronix]

How big of a tire do you want ( or what's stock? ) and are you OK with getting the spokes recut/relaced? that's what will be involved in replacing the rim.

A wider rim is more sturdy but with a 1000w motor you don't need the sturdiness, 24mm would be fine for most bikes with 2.0"-ish tires.

I ran 24mm rims on a bike with 6000w of power, no issues.

If you had a pothole mess up your previous wheel then you need to run more pressure in that tire next time.

 

[ebike4healthandfitness]

I was mainly wondering if having a wider rim provides more sturdiness? (all other things being equal). Maybe more impact resistance? More weight is on the back, so I was wondering if having a wider rim would be preferrable.

If you need more weight bearing capability....that usually means a wider tire and thus a wider rim.

See this chart for guidance on how to choose the proper internal rim width for X tire width:

Tire & Rim Fit Chart

The WTB Tire & Rim Compatibility Chart is used to determine what tire and rim width combinations provide optimal performance and compatibility. By matching your tire section width to your rim width you can determine optimal, compatible, or not optimal fitting options to ensure the best tire &...

www.wtb.com

P.S. As far as sturdiness goes....yes a wider rim (all other things equal) should be more sturdy but often this is often not the case as, for example, the Andra 29 Disc - Ryde and Andra 29 - Ryde (and to a lesser extent the Andra 40 - Ryde) are considered by many to be the strongest rims yet they are not even close to being the widest. In contrast, super wide rims (for fat bike tires) are typically pretty flimsy (in a relative sense) being almost always single wall construction. However, because they are protected from shock and impact by giant marshmallow tires the designers apparently believe they can get away with a less robust construction.

 

[Papa]

Try this link. It goes into much greater detail....

http://www.schwalbetires.com/technology-faq/tire-dimensions/

 

[Planet Indigo]

How big of a tire do you want ( or what's stock? ) and are you OK with getting the spokes recut/relaced? that's what will be involved in replacing the rim.

A wider rim is more sturdy but with a 1000w motor you don't need the sturdiness, 24mm would be fine for most bikes with 2.0"-ish tires.

I ran 24mm rims on a bike with 6000w of power, no issues.

If you had a pothole mess up your previous wheel then you need to run more pressure in that tire next time.

I use tires that would range between 1.75" and 2.3".
I hit the pothole (which was pretty big) at around 25mph and I was running about 40psi at the time, it bottomed out my rear shock.
Just curious, did you use 12g spokes on that 6000w bike with a 24mm rim?

Thanks for the charts guys, useful info. Are you supposed to run same rim width on front and back? Up until now, my rear was 31mm because that's what my kit came with but my front was the default wheel that is 25mm (both referring to external width, internal being about 6mm narrower)

 

[ebike4healthandfitness]

Are you supposed to run same rim width on front and back?

You don't have to run the same width rim and tire front and back. It would be perfectly acceptable and in some cases even ideal to run a narrower tire and rim up front and a wider tire and rim out back. Just remember when braking very hard (i.e. your rear wheel comes off the ground) all of your weight gets loaded onto the front tire. Therefore size your front rim and tire accordingly (just keep in mind the front tire obviously doesn't need to have lowish rolling resistance when this load shift during braking occurs. The tire and rim just needs to be wide enough and with enough pressure to adequately support the bike's braking when the load shift to the front occurs).

 

[E-HP]

I ran 2.4" tires on the cheap crappy narrow Chinese rim that came on my kit motor and they did fine on and offroad, the only downside was the tires have a rounder profile and are narrower on a narrow rim than on a wide rim.

My front rim was wider then, and is wider on my current setup. I think it's more important to have the front stable.