2015 Specialized Diverge Comp Smartweld won’t fit the Zwift Hub

Also I guess make sure the hanger is straight. Would be funny and something I’d def do to figure out a complicated solution and then find out my hanger was just bent :slight_smile:

Hi @Mark_Gauding welcome to Zwift forums.
I agree with Colin’s suggestion to see your local Specialized dealer to find out if a better derailleur hanger is available.

Looking at your photos, two things stick out to me. First of all, I agree that your derailleur hanger bulging inward is the root of this problem.

  1. The ~5 mm gap you measured between your smallest cog on the wheel and the inside face of the dropout is wider than normal. Like, enormous to my eye. That extra long axle end may have been spec’ed to accommodate the unusual hanger design.

You can verify this hypothesis when you take it to a Specialized dealer. Ask if they would put an aftermarket QR wheel with an 11 speed cassette into your frame. Assuming that wheel didn’t come off of another Specialized bike from that era, that smallest cog should sit much closer to the inside face of that dropout. That ~2 mm gap in your other photo is what’s normal.

Why would they do that? ~2015 was around the time that Specialized made proprietary design choices like the OSBB bottom bracket standard that no other bike company used. It’s possible that they used proprietary wheel specs that nobody else used. :man_shrugging: And If that’s true - then you’ll have this chain clearance problem with other brands of trainers, and wheels with more standard axle end specs.

#2 thing that stands out to me is the hanger that bulges inward.

Wheels Manufacturing is a US company that makes aftermarket replacement derailleur hangers that most times are better quality than the OEM ones that came on your bike.

This hanger is what Wheels Mfg’s search tool came up with for your bike. Your photos don’t show the profile view of your hanger. Does this look like it would fit? If it looks like it might, the bulgy part is on the correct side and should solve your problem.

Since the bulgy part is on the outside of the frame, it will change how your derailleur pulleys line up underneath the cogs, so you’ll have to adjust the derailleur after this hanger is installed and aligned. It’s important that the shop use a hanger alignment tool. If they tell you it’s not important on a brand new hanger - find another mechanic.


Well I had our local machine shop modify the drive side QR adapter and it works perfect!

Instead of making a whole new adapter the machinist suggested cutting off the 5 mm piece the bike drop out rest on along with drilling it out of the main body. He made a 3 mm spacer with the drop out rest and a piece that pressed into the hole on the main body.

All my gears shift perfectly now!



Great solution :smiley: