I'm in need of a 38T chainring for my Specialized Turbo Tero X4 and the support staff at Specialized say I need to pull the whole spider and get an 104BCD, 0mm offset spider.

I'm looking at the stock ring and it appears to be specifically made for mounting directly from the front (threaded), directly to the spider that's bolted onto the motor spindle.

1. The motor housing blocks the backside of the spider, so you can’t insert or tighten the chainring nuts from behind like you would on a normal crank spider.
2. If you try to use a standard 104 BCD ring, you’d have to remove the entire spider every time you wanted to swap the chainring… which is not how Specialized designed it, and is a huge pain.

Can somebody clarify any elaborate on this?

Thanks very much for your time and attention!

Are you certain it's not SRAM that designed your crankset or Shimano? The specs for the Spesh' Turbo Tero X4, I looked at said the crankset is SRAM.

Despite the apparent ease of changing just the small ring, SRAM might not sell the rings individually. And the shop might not be willing to put third party rings on your crank for a various number of good business reasons.

You might be able to find something yourself and do it. Or even find a small shop willing to do it. But if there are warranty issues later, your non approved fix might void them.