35mm swap to 39mm. Stem is longer

[jcorrington]

I'm running a 35mm front end now. I picked up this 39mm setup. I haven't mocked it up yet since I still want to ride out the rest of the summer. But I held it up the other day and noticed that the neck seems about 1" longer on the new setup. What is up with that?

Do I need to use those giant chrome neck cups?

[jcorrington]

I just measured and my neck / distance between trees on my bike is 7”. And this setup is 7-1/4”. So I guess I can shim out the bottom and top with 1/8” washers.

[Salty]

Someone can correct me if im wrong but..... on a 35mm the top nut slides into the tree and the threads sink deeper to the shorter stem. On a 39 the stem slides further out the top tree because the nut design is different.