There are issues!!!!
I spent a good hour on Saturday night trying to run a new gear cable down a friends Sram equipped road bike outers.
Would it hell as like go in!! 😥
I kept turning the inner cable, applying gentle pressure, cutting off the slightly splayed end, (again). It just wasn’t having it.
I tried several spare inner cables, then suddenly one just went straight in, no bother at all! 😮
Just as an experiment I bought two cables the next day, one from the place I’d bought the spare that fitted, the other from another local shop.
Lo and behold, one fitted, one didn’t!
On close examination, one was just slightly thinner than the other, but it made all the difference.
When it came to running new inner cables through her Shimano equipped road outers, anything and everything went straight in, no bother at all.