[Shinkers]

Is there anybody that makes a really big ss cog? Like 30+?

Before I'm berated for being a *****, I do have an idea I'd like to try. I currently spend a lot of time climbing in my 22x36 combo. A dingle set up with 22/36 front and 36/22 rear would be the cats pajamas IMO.

Just wondering if it's even doable.

Thanks.

 

[kevhogaz]

I'm sure you get creative with a cassette, and build something like that. Probably not a lot of market for a cog bigger than 22t.

 

[blkangel]

The largest Endless makes is 25t. That is probably the biggest you can get. Thinking if Endless does not make a larger you are out of luck.

 

[Shinkers]

Figured as much but it never hurts to ask.

Actually considered pulling a cassette apart. My concern would be digging into the freehub unless I could maybe find something with a carrier that would work...

 

[Velobike]

I had the same problem and did not want to use a cog from a cassette because that guarantees the chain will come off.

I found an adapter. It's actually intended for Pinion bottom bracket gearbox bikes. To keep them light they do the torque multiplication at the rear end, so they need a large rear cog.

The adapter takes a normal 4 bolt chainring.



I needed it so I could have a singlespeed ratio for deep snow or when I'm bog hopping.

My standard trail ratio on my fatbike is 32/22, and for my ultra low I run a granny ring of 22 and a rear chainring of 32. Thus I can change over and because the chain length need remains the same, I don't have to readjust the disk calliper position.

Adapter is available on eBay Pinion Spider Hinterrad - Spider Rear Wheel - P8200 | eBay

 

[Slash5]

I tried using a cassette cog but found it would fold and crack. I had to poprivet a smaller cog to the large cog to reinforce it.

 

[Shinkers]

Velo, dude that is exactly what I'm looking for. Awesome!

 

[Shinkers]

Just bought one. Bcd looks like 104?

Did you have to do anything funky with your chainline? And can you change cogs without loosening the rear wheel?

Thanks so much!

 

[Velobike]

Just bought one. Bcd looks like 104?

Did you have to do anything funky with your chainline? And can you change cogs without loosening the rear wheel?

Thanks so much!

Yes, 104mm.

The rear wheel would have to come off to remove/replace the cog. Nothing to stop you putting 2 cogs on it though - it's just like putting them on a crank - so if you want to play around with ratios it will be a bit easier.

 

[Shinkers]

Sorry, I worded that poorly.

I mean, can you push the chain over from the 22/32 to the 32/22 without loosening the rear wheel?

 

[Shinkers]

Okay a few more questions now...

So I'm committed to doing this. I had originally intended to get Surly's sliding MDS dropouts to make this easy, but Surly's kind of in the tank right now as far as parts availability goes and probably won't have those for quite some time.

So I'm considering using an old road derailleur I have as a tensioner, and using the tension adjuster to switch between cogs in the back. This would be super easy to do with the head end of a piece of shift cable pulled into the cable stop and maybe a ferrule.

My question is, the derailleur had a capacity of a 28t cog back in the day. If I run my chain relatively tight, can I still clear that 36t in the rear?

And Velobike, what ring are you using on the back?

Thanks!

 

[Velobike]

Okay a few more questions now...
...And Velobike, what ring are you using on the back?..

Ah, sorry I missed this earlier.

The chainring I'm using is a stainless steel On-One ring, but Surly also make stainless chainrings.

My setup is not intended to provide quick gear changes, I have to slacken the wheel and move the chain over by hand.