Two Chainrings on a Rear Wheel

Hi, can anyone tell me?

If I buy a rear wheel with one gear, can I purchase another cog and fit it to the other side? What tools would I need - thx.

Alternatively, I could just place them next to eachother.

You will need a flip-flop hub on the rear if you wanna put a sprocket on each side.
You'll need a chainwhip and a lockring wrench to do it.

When you buy a track hub it will be described as fixed/fixed, fixed/free or single fixed.

Fixed/fixed means that you can run a fixed sprocket on either side, fixed/free means a fixed sprocket on one side and a freewheel on the other, and single fixed means one fixed sprocket.

As overdrive mentions you would need a chainwhip to do the sprocket up nice and tight, and a lockring tool to tighten the lockring down to keep the sprocket on.

You cannot run two sprockets side by side on the same side of the hub.

If you want to use both side fixed then make sure you get a fixed-fixed flip flop hub, as they also come with one side fixed and one side freewheel. The you can turn the rear wheel around to run a different gear.

Not that I want to over-complicate things...but...

I'll get my coat.

Yes, I'm trying to work out whether to go for fixed/fixed, which would mean having to take the wheel off and turn it around to use the other cog.

Obviously, jonlubi's suggestion is probably best because the wheel wouldn't have to be removed.

Yes, I'm trying to work out whether to go for fixed/fixed, which would mean having to take the wheel off and turn it around to use the other cog.

Obviously, jonlubi's suggestion is probably best because the wheel wouldn't have to be removed.

Why not get a geared bike then?

Not that I want to over-complicate things...but...

but then what about the tension to the chain when you change the gearing?

I'd be more worried about my chainline...

I'm worried about your chainline too. I've been reading chainlines for a few years now and I'm worried about what your said to me last time I saw. I see problems ahead for you.

There has been some tension...

I sensed that. I felt there had been some friction at some point too.

I'm going to side with Mr. Slain on this one (unless it involves divorce proceedings, then I'm out)

but then what about the tension to the chain when you change the gearing?

Doesn't this come with some sort of strange chain ring (or cranks) for dealing with the chain difference issue?

Yes, I'm trying to work out whether to go for fixed/fixed, which would mean having to take the wheel off and turn it around to use the other cog.

Can you please explain your thinking behind this? Why would you need to flip your wheel so often ?

Doesn't this come with some sort of strange chain ring (or cranks) for dealing with the chain difference issue?

not a clue....
didnt even know they existed
but youd prob need some sought of spring tensioner
i have wondered if they were possible to find tho....

Can you please explain your thinking behind this? Why would you need to flip your wheel so often ?

depends on his location i.e how many hills he has to climb... or if hes cycling on flat roads... :/

whilst a double fixed cog does seem like a good idea in theory, its pretty pointless.

you would end up with two cogs with dodgy chainlines, they may not be out by enough to cause a 'problem' it would almost certainly create a noisy drivetrain, and secondly with a double fixed hub you can flip the wheel round just as easily. you'll need to carry the tool to remove your rear wheel anyway to repair punctures, and you'd have to handle the chain eitherway so your hands will get dirty.

go for double fixed as well, as it's possible to run a freewheel on threads for a fixed cog but not the other way round!

depends on his location i.e how many hills he has to climb... or if hes cycling on flat roads... :/

HTFU solves this.

either gear down so you can make it up the hills and havbe to learn to spin on the flat or go with a more comfortable gear on the flat and build your leg strength on the hills.

I'd personally go for the first and suspect the majority of people on here would agree but there are bound to be a few who think they cant learn to spin.

only real need to have two cogs on a bike is for going to the tarck where you have far enough to ride that its easier to change gears than ride very slowly and carefully.

From Sheldon Brown (of course):
Bruce Ingle, a fellow member of the Charles River Wheelmen, has gone me one better, and made a triple-fixed mountain bike. He used a Shimano cassette hub, which he immobilized by brazing the ratchet mechanism together. I am a bit nervous as to the long-term prospects for this hub, in particular the connection between the freehub body and the hub shell, but I think I will have to copy his setup. He's got:

        Gain    Inches    Meters    
48/20    Fixed    4.65    62.4    4.99
42/26    Fixed    3.13    42    3.36
36/32    Fixed    2.18    29.3    2.3

(http://sheldonbrown.com/singlespeed.html)

Triple front ring, triple rear, but always with the same overall number of teeth for each ratio, so same chain length.

not a clue....
didnt even know they existed
but youd prob need some sought of spring tensioner
i have wondered if they were possible to find tho....

I was thinking of > White Industries DOS Dual Single Speed Freewheel
at top of page here > http://www.charliethebikemonger.com/userimages/procart5.htm

Two sprockets together and two chainrings that equal same length chain but different rations, similar to Sheldon's calculations.