I thought moving from geared bikes would be simple, but my feeble brain has not been able to figure this out despite several days of reading.

Here's what I want to do:

• Sram Omnium
• 1/8 chain
• WI 16t fw 3/32 (I thought you can use a 1/8 chain on 3/32 but not the other way around) - Also interested in a Halo Clickster or Excess
• Rolf Vigor FX (not flip/flop but website says it can accept a threaded freewheel - shop says it is fixed only and they won't warranty using a fw)
• Sram Rival brakes (Rolf has a machined brake track)

I keep getting conflicting information and the more I read about thread sizes, fw not threading in properly and chain lines the more confused I get as to which products will work together.

Thanks for your help.

Should work fine for the most part. Phil Wood says they won't warranty their hubs using a FW on fixed threading but I have 2,000 miles on this setup with zero issues. Your chainline may be slightly off due to the WI FW, in which case using square taper cranks would give you BB options to dial in your chainline. Scrod may be able to weigh in here.

EDIT:

Also, this page here is an amazing reference:
https://sheldonbrown.com/chainline-single.html

Thanks for your reply. WI says no way their 16t FW can be used with a 1/8 chain so that is out. Omnium comes on the bike so I have to use a 1/8 chain and I'd prefer to keep it for simplicity and no new tools to buy. Rolf told me they recommend using the Excess FW. Can't buy one in this country, but Retrogression sells them for $30 including shipping so I guess my problem is solved - except I don't know about the chain line until I get everything set up. Probably will be fine. What's the worst case? Noisy chain? Parts wear out a little quicker? The FW and brakes give away the fact I won't be doing anything super cool on it...

The number that most closely corresponds with the amount of sense that makes is zero.

You can use a 1/8" chain on any 3/32" single-cog freewheel you choose, regardless of the manufacturer.

Lame shop. Rolf says it's freewheel compatible, and I assume they warranty the product, not the shop.

^ Yup.

WI is full of sh**! I've put several hundred miles on my WI 16t freewheel using a 1/8 chain and chainring with ZERO issues.

Thanks for letting me know your real world experience. I just ordered an Excess FW from some dude's shop in San Diego, but I may still try a WI if the Excess isn't noisy enough.

I did get an email from WI saying: "We had to shrink everything down to allow enough room for the teeth. We have had to engineer a channel for the chain to nestle down in to allow enough room for the chain to seat on the teeth and we use a smaller bearing with the 16t size. Unfortunately, with the adjustments we need to make with the 16t, there isn’t enough room for the 1/8” chain."

That makes perfect sense, and I'm glad the manufacturer took the time to explain this to you. Sometimes anecdotal reports from internet users are incorrect.