Originally Posted by
Iride01
You might still have an issue with how far down on the tapers the cranks sit, but as this is a very modern bike with the current for today type of square tapers, then you should be good. Just be a little leery if their description starts talking about it fitting old bikes.
There are two tapers, JIS and ISO. ISO is for vintage Campagnolo and possibly other obscure European cranks. Ask your bike shop for any 73x125.5 JIS BSA-threaded bottom bracket.
It looks like Shimano is replacing their BB-UN26 and BBUN-55 with a new model, BB-UN300. Unfortunately, it looks like nobody has these in stock yet. You might have to shop around and consider off-brands.