Originally Posted by oldbobcat

In general, undersize chain rings are a crap shoot. The reduced diameter brings the chain closer to the nuts on the inside of the inner ring and the flange of the spider between the ring. This can cause the chain to skate over the teeth (skip) as the chain and teeth wear in. I'd seen this in the shop with 38t rings on a 130 mm BCD. I'd seen this in the shop, and a forum discussion of this a few years ago. You can try it, you can try grinding off some crank arm spider, but this is time and money going into something that might not work and will only show itself after you've been using it for a few months.