Single Speed Questions
 

I'm slowly working on a commute-ish/ gravel bike that will run fat tires tubeless and see plenty of dirt and crushed limestone .... and have been going back and forth regarding setting it up SS.

I currently have or will have a set of Bontrager wheels (9/10/11) and a SRAM Rival AXS crank 1X and 8 bolt spider which is of course 12 speed. I know Surly and Wheels Manufacturing make SS spacer kits but curious what other option are out there. It's been a long long time since building a SS bike so what do those of you who run single speed have to suggest?

- Chain and cog issues with wide/narrow ring on the crank? Can I just run a 9 speed chain? Does a rear cog exist for a narrower chain. My research has been spotty.

- No real hills here in Chicago but will take this thing to local single track for kicks. Crank has a 40T on it but what do I want for a cog? I was thinking 16 or 17T

Thanks for the knowledge and advice.

I run a DT Swiss 240S singlespeed hub laced to a 330g carbon hoop, hub flanges are 100% symmetric so you have equal spoke tension across, which makes it dead simple to build and bombproof.

Cog is SS specific, it is 3-5x wider at the splines to avoid digging into the freehub (spoiler alert, it still did), I run an 8 speed chain iirc. Narrow/wide and whatever doesn't make a difference if you're not shifting.


I swap between 32x16 and 32x18.

Which cog do you use?

Absolute Black and Wolf Tooth make nice looking SS cogs, but i really like the design of the Problem Solvers one with a built in carrier to ease the freehub bite.

https://www.jensonusa.com/globalasse...s/cs237b01.jpg

Looking at receipts, it's a stainless Chris King. Not sure they're available anymore.

https://i.ebayimg.com/images/g/0YgAA...O9j/s-l400.jpg

That one Angry posted doesn't look like a bad solution either.

I saw those Problem Solvers and they look like a solid solution.

Thanks

I don't believe they exist @ Chris King any longer.

I do like the idea but maybe utilitarian is better in keeping with the scope of this bike and it's intended use.

Thanks

2:1 is the starting ratio for SSCX, but for road and gravel, I would go a bit harder. 40/18 or 40/17 sound like a good place to start.

The spacer kits on a regular wheel will be totally fine. I've been thrashing the ***** out of my SSCX all year and it's an old set of CK Iso hubs with spacers.

I don't THINK you'll have any issues with 9spd chain on a 12spd crank. the fit won't be AS precise as a narrower chain, but with good tension and a good chainline, there's nothing the chain can actually do but be straight.

I have an aluminum Niner 17t that seems more narrow than the steel Surly cogs. But the steel Surly's are basically a lifetime purchase, they're the go-to for a reason.

EDIT: What are you doing for chain tension? Sliding dropouts? EBB? External spring tensioner?

Thanks for that info Brad

https://omniumcargo.dk/shop/product/...le-or-11-speed

Oooohhh.. Sweet. Swinging dropouts and thruaxles. :banana:

Might be fun, right!

I've used Surly cogs in the past. They have a wider edge at the free hub, similar to the CK shown above. Appears that it'll work with 6-9 speed chains.

For spacers, it doesn't really matter - all the kits are pretty much the same. As long as it has a few different width spaces so you can fine-tune the chainline, any of them will work.

Gear ratio - I've used 40x18 and 40x20 for SSCX (700x33 cx tire) and 44x16 on pavement (700x32 slick). My mountain bike (29x2.3) was 32x16 or 32x18. I'd guess for a gravel/commuter, you'd want somewhere around 40x18 or 40x20, depending on hills.

32x16 = 40x20. :)

I have various cogs but my favorite is Endless Cogs. Cool shop out of NC. Whatever you get, don’t get those stamped cogs with thin base. It will mar up the fh body.

For chains, SRAM 8 or 9 Speed works well. But if you want the lightest, I really like KMC x9sl.

Spacers: if you’re just trying this out and want to keep it cheap, PVC pipe works really well for spacers. I used it when getting into singlespeeding. Currently, I run Velosolo spacers.

https://www.ebay.com/itm/VeloSolo-UK...-127635-2958-0

Gearing: I always say start around 70 gear inches.

I should have an extra 16 or 17t cog. I think a Surly or King or something like that. PM me your address and I can get it sent your way.

Endless cogs.....now you've done it ;-)