nathand

I've got an Xtracycle Swoop long-tail cargo bike that I use for hauling my kids around. It has a Shimano Steps drive, a 104BCD spider, and a 42T FSA narrow-wide chainring attached to that. I'd like a larger chainring - 46T or 48T - but I don't see any matching ones available with a from known brands. FSA used to have one, it's still listed on their website, but they tell me it was discontinued years ago. I do see several on Amazon from random brands, for example https://www.amazon.com/OHM-Narrow-Ch...3WR/ref=sr_1_7 or https://www.amazon.com/Narrow-Bicycle-Chainring-Machined-Chains/dp/B0BL446H3K/ref=sr_1_3 Can I trust these chainrings? Should I go for steel over alloy for a heavy, and usually heavily-loaded, e-bike? The ones on Amazon are cheap enough that I'm not concerned about the cost to buy and try one, and I realize any sort of sudden chainring failure is unusual, but I also don't want it to break while I'm rushing to take the kids somewhere. I've contacted Xtracycle support; they said they tested 46T and 48T chainrings and found they helped with the cadence at top speed but they didn't recommend a specific one, and they tell me that I should leave the spider in place rather than replacing the entire chainring with a direct-mount one to maintain proper chainline and shifting performance.

veganbikes

I mean I wouldn't. I know Specialized does a 46 or 48t for their Vado line or if you get a 110 bcd spider you can go with Praxis Works E-Road stuff. I am trying to remember other stuff that we tried but my mind is drawing a bit of a blank. You could try asking Gazelle I know we got some 104 BCD stuff from Shimano from them and maybe MIranada as well. We unfortunately did fall down the cheap knockoff amazon crap and they sat till the shop closed they never quite fit well and didn't give us what we were looking for in terms of performance but we got a bit desperate when Specialized was out of stock for a while and people wanted the upgrade to a bigger ring or just needed to replace it.

roadfix

As long as you’re not running a 12 speed chain you should be fine, although I would choose steel over alloy.
I’ve purchased generic 12-sp narrow wide rings in the past and some did not work with my 12-sp chain.

CrimsonEclipse

You have a $4000 bike for heavy duty use. So always go heavy duty. If you're using it with heavy loads all of the time, I'd suggest a quality steel chainring. They generally last longer.

The amazon cheap aluminum cranks are fine for general use, I've used them for MTB with no failures.

grumpus

Carry a spare? They're cheap enough and easy to fit. I had one from Amazon yesterday, 42t branded "Snail", but that's for a RWD trike. I have one on my mid-drive bike too, I think that's 38t - the machining is nice, it's not showing any sign of wear and runs smoothly. Obviously the larger rings may have slightly different operating characteristics, but I wouldn't worry about it unduly.