Dr1Gonzo

Was thinking of getting a fixie for the commute to work. Most of it would be on the flat in Montreal, but occasionally there are some hills.
Wondering if I could somehow have a flip flop hub with one side a bigger gear than the other?

acidfast7

yup.

i have one of these and usually ride SS but it's easy to flip the wheel on the street with a spanner

Dr1Gonzo

So, can I have a bigger cog on one side, like a freewheel cog?

acidfast7

i don't know all about the FGSS offerings, but it seems that the most common is one FG and one SS on the rear hub.

i run a 16t FG and a 16t SS but to be honest, i don't change flip it often.

i don't see why you couldn't run a 18t and a 14t if you wanted

the tugs have to take up the extra chain slack though

Mr IGH

Good luck flipping the hub in January. Have you looked at the Sturmey 3 speed fixed hub?

Sturmey Archer

Dr1Gonzo

Won't a hub increase the costs?
How would I take up the slack?
I was probably thinking of the freewheel on downhill sections and the fixie on the up but I guess most would have the fixie with less teeth, harder to pedal.
I guess I don;t really see the point in having a flip flop if both gears are the same size.

Mr IGH

The hub I linked to is a fixed gear hub with three gears/speeds. The gear mechanism is inside the hub. No getting off the bike and removing the wheel. Just use the shifter to change gears, use the lower gear up the hill and the higher gear going down.

acidfast7

not that i'm an expert, but with tugs and two spanners ... it seems like a 30 sec job maximum.

fwiw, my bike is preconfigd for a Nexus 3, which would be quite nice when I start riding across the country.

Mr IGH

OP lives in Montreal, it's very cold in winter, 0*F and lower is very common. Maybe it's just me, it doesn't seem as if one would want to remove the rear wheel in those conditions when there are other good options. Your 3 speed is a good example, OP mentioned fixie and I thought of the Sturmey 3 speed fixie....

Dr1Gonzo

Makes sense, I guess I could just take the flat route in winter (if even cycling then).
The 3 speed hub looks good but do I have to buy a wheel with it already installed or can you put them on yourself?
I've only ever had freewheels before so this is a new venture...I ideally want a light bike with not too many components on it...and cheap.

cplager

Maybe this would gain more traction in one of the FG/SS forums?

tarwheel 

Flip-flop hubs work great and don't cost much more than without. IMHO, the biggest problem with riding a fixie on hills is not climbing but going downhill. You can simply stand to climb most hills if necessary, but it is very hard to spin fast enough going down long or steep hills on a fixie without hitting the brakes a lot. My commute route has a lot of hills, and I had one of my bikes set up as a single-speed with flip-flop rear hub for a while. I ended up leaving it on the freewheel side because I didn't like having to ride the brakes on many of the hills. I've got a pretty good pedal stroke but spinning at 130+ rpm is a challenge for most cyclists. I eventually went back to having multi gears on that bike because the single-speed was doing a number on my knees.

tsl

For the record, until Campagnolo invented the derailleur in the 1930, racing bikes used in the Tour de France (among others) had flip-flop hubs with one side for the flats and the other side for the hills. So it's not a new idea at all and works just fine.

Chain slack for a fairly small difference in the cog sizes can be taken up in the sliding dropouts. Too big a difference and you'll need a chain tensioner in there.

MichaelW

Mos flip-flop hubs have one stepped-thread for fixed (ie lockring) and one freewheel type thread.
You need 2x stepped-thread flip-flop hubs :
philwood
also
Goldtec
Formula

Chain tension is by horizonal dropout or track ends. Sliding vertical dropouts require re-setting each time you change gear so are better suited to hub gears.
You cannot use a spring tensioner for fixed.

Mr IGH

In the book "The Dancing Chain" they claim Tulio's inspiration for inventing the precursor to derailleurs was exactly this circumstance, stopping at the bottom of the hill in a spring snow storm to flip the wheel. You're in Upstate NY, would you ride a flip-flop in the winter?

Mr IGH

Yes, you'll need a new wheel or at least have someone change the hub in your rear wheel (rebuild the rear wheel). And it's not cheap.

I road a fixed gear bike for several years when I was young (15-25) and I just manned up and grunted up the hill and slowed my cadence down the hill (you're working all the time on a fixie). I didn't even have a front brake until I was in my 20's, yet I could lock up the rear wheel no problem. If I remember correctly. Montreal isn't too hilly, you should be able to pick out a gear that'll work for you.

azgreg

Look in this thread from thirdgenbird. https://www.bikeforums.net/classic-vi...city-bike.html
A little more info in this one as well. https://www.bikeforums.net/singlespee...unctional.html

Andy_K 

Another option is the Surly Dingle: Universal Cycles -- Surly Dingle Dual Fixed Gear Cogs

tjspiel

You can have them be different sizes but I think the point of the flip-flop hub is not so much to be able to change cog size as to being able to switch between fixed and single speed.

I'm currently riding a fixed gear (with a flip flop hub) and have never used the single speed side. I'd think you'd get tired of changing it during your ride every day even it didn't take all that long. I would choose a cog and chainring that represents the best compromise in terms of gearing and go with that. You can certainly put a different cog on the single speed side that you might want for longer rides on hillier terrain or just when you're tired.

Remember that as young kids most of us rode single speeds everywhere using bikes that weren't particularly light and with our legs that weren't particularly strong. We managed.

IAmSam

You cannot use a chain tensioner on a fixed gear

The S3X hub suggested by MR IGH is an excellent solution to OP's dilemma if he won't mind the weight & cost involved

fietsbob

Now Florian Schlumpf is saying his 2 speed planetary crank will work with a fixed gear

with the 110 BCD chainring option and a 34t chainring , when kicked into its overdrive 1.6X that 34t acts like it is a 54t..

no flipping involved , OK it is Swiss, so not cheap , and the installation requires chamfering the BB shell edge

to engage the conic grip washers that resist the torque in the overdrive range, and it's not light ,,


just a mechanic and I like the reduction gear version I fit on my folding bike.. there a 50t chainring acts like a 20t chainring when
kicked into the low reduction gear [there I get to use my AW3 hub twice in high and low range, for 6 ratios over a wide range]

the other fixed gear 2 speed drivetrain He makes is a Unicycle Hub , so a 24" wheel for highway riding acts like it's 36" in diameter ..

happy to help you spend more than you wished ..

wolfchild

Yes you can have two different sizes. But no more then 2 teeth difference on most frames. It really depends on how long your rear drop-outs are, how much tire clearance your frame has and the size of the tire. For example most Surly frames have tons of clearance so it's easy to have 2 different gear ratios on the same frame...But if it's track bike or a road bike then you will have a problem sliding the wheel back or forward because of very tight clearance, the tires may rub the frame.

wolfchild

Never ever use chain tensioner with fixed gear drivetrain, it's dangerous and it will get ripped off.