I’m building up my 09 Vigorelli with campy cranks and other parts, and have this cool 144bcd 42t chainring, but it’s 3/32”. I came across this odd Surly 17t/20t two in one threaded fixed cog at my local bike co-op, and I’m curious about using it. Has anyone tried? Does it create issues with chain-line?
by modularwave
9 Comments
haha dinglespeed
I have my freewheel single speed set up like this. It works well, but I rarely ever change the ratio.
Yes I have 2 cogs on my fixed gear. Moving the chain over is easy to do since I have the chainline slightly offset from the chainring. I use bolt on cogs which can be set using different width spacers.
I use 17 & 18 with a 42t chainring. This means I only need to have room on the track end for 1 tooth difference.
Using a 17 & 20 means you need to have room on the track end for 3 teeth difference. Effectively you will need to be slammed all the way in for the 20 and be able to slide the axle all the way out for the 17. The likelihood of this working out is gonna be very low IMO.
Nice find.
Surly sure did make some cool parts
The important thing to think about here is that derailleurs were invented for a reason.
I had a flip flop hub for a while and I never once swapped it around.
The fact is that unless the two gears are quite different – say one that makes climbs much easier and one that allows for high speeds on flats – the likelihood that you ever take the time to get off the bike, pull out your tools, swap the chain to the other cog and then do it again when you need your preferred gear are low.
These cogs are little more than a novelty, best case maybe you come up with a pair of ratios that make a bike trek slightly more manageable.
Personally, I think both dual cogs and flip flop hubs are a waste of money. I’ve never known anyone to seriously use them.
They start to almost make sense when you have a 2x crankset to 1) actually have some significant difference in the two gearings 2) straight chainline 3) keep the axle in the dropout.
Really there’s not much of a gearing gap available and you’re better off just mashing & spinning one gear rather than dismounting and faffing about with a dirty chain on the side of the road and have a geared bike for when you’re gonna ride hills that your back & legs aren’t athletic enough to ride fixed.
I used two cogs and two chainrings with the same chain length ratios on a long-distance bike tour (the bike was a Surly Pugsley). The idea being, if I had a long climb ahead, I could pull over, loosen the QR, slide the wheel up, and swap gears.
In 30 days I swapped once. I ended up just climbing all the hills in the “big” gear.
Tried it? Hell I built one. Mine coasts…
My dropouts allow for 7t of change without breaking the chain so I have a 17/23. Ride to polo and then play bike polo. It’s great. I swap it constantly. Helps that I don’t have to totally remove the wheel.
this aint 1876 bruh