[stlburner]

I’m not very good at this forum thing, my last attempt received zero responses. However, I eventually found the info I was looking for.

Anyway, according to Peter at CS there are many folks that are running his CS-197 frame with a Snowshoe 2XL, and no chain rub. I asked about preferred bottom bracket and crank setup to achieve this and he suggested I look here. I can’t find any posts with this setup, so if there’s anyone out there running it could you tell me what bottom bracket and crank you’re running and if the chain rubs? Thank you!

 

[Jayem]

That is generally not a concern IMO, unless you are doing something odd like 2 or 3x. Example: I ran D5s on a 170mm hub bike just fine, but it was 1x, it was close, but close is fine these days with clutch derailleurs that don't let the chain bounce all around. You generally can't get the chainline correct on a 170mm bike to run 2x with those tires. On my CS-197, I'm running Johnny 5 tires on 90mm rims, they are significantly bigger, close to the 2XL, but not quite as big. With a 197 bike, you buy a 190 crankset. From there, you use the spacers that come with it to adjust slightly if necessary. It really doesn't matter what 190 crankset you buy, they all should work relatively fine. The one thing I had to do was I had to move the dropouts to the rearward position to fit the J5 tire, in that position there is plenty of clearance, even for something bigger, but in the forward position the tire would rub/jam against the chainstay yoke.

I have since changed out the tires on the CS-197, but I run next SL with a RF BB. It works for now, but I've already broken the cranks once. It's the only bike I have that still has those terrible cranks on them, so I don't recommend them, since the pedal inserts crack even when riding relatively easy in snow. On my newer fatbike I'm running an XX1 crankset with an E13BB, which I re-greased with low-temp grease. The XX1 cranks (and other SRAM carbon cranks) have a metal skeleton to not run into the same issues as the RF Next.

RF Turbines are good middle-of-the-road cranks though, I have a set for backup and they are hard to go wrong with.

There is a bigger thread with more CS-197 frames and tire combos posted.

 

[Flying_Scotsman]

There is a good thread that Mikesee created and has done extensive testing on the large tyres that you might want to do some reading on.

https://forums.mtbr.com/fat-bikes/testing-one-two-1093684.html

As Jayem outlines above, a 190 chainset running 1 by should clear, most people report not the chain rubbing, but the chainstays/seatstays/bridges giving clearance issues, hence why there are only a few frames that will fit 2XL's in them.

The other way of getting yet more clearance on the chain (but worsening the chainline) is to flip the chainring so the dish is facing outwards if tyre rub becomes an issue.

 

[campykid]

I am running 2XL's on 100mm rims on a CS197. There is an old CS197 and a new CS197 which came out in 2017. I have the old version and there was some rub on the chain stays requiring me to do a little lug trimming which alleviated the problem. The newer CS197 has more clearance and requires no trimming. BTW I use 1x and 190mm BB. Hope that helps.

 

[stlburner]

Oh man, thank you all! This is so helpful!