What makes a fixie with a rear freewheel different from other types of fixed-gear bikes?

I have noted the difference between a freewheel and a fixed gear cog in the following table.

A cyclist on a single speed bike with freewheel installed should not have any problem coasting on flat surfaces and cycling uphill.

Without the freewheel mechanism on the fixed gear cog, the cyclist may have to stand on his pedals and strain to pedal uphill. To stop the bicycle from rolling backwards down the slope, the cyclist will have to apply a braking force with his legs and bodyweight to resist the rotation of the cranks.

If your rear wheel is installed with a double-sided or a flip-flop hub, you do not have to remove the freewheel in order to install the fixed gear cog, or vice versa. In fact, some fixies with flip-flop hub on their rear wheels are supplied installed with both the freewheel and fixed gear cog. Cyclists can decide on which of these gears they want their chains to run on. 

You can see what I mean by double-sided hub when you look at the wheel in the following video. From it, you can also learn how a fixed gear cog is installed.

Just send your fixie to the bike shop if you do not have the tools required, to install a fixed gear cog.

Watch this video to see how, when you are cycling on fixed gear cog, you can switch over to cycle on your freewheel or vice versa.

When should I change my gears?

You do not have to zoom down a slope when descending if you put more resistance on the pedals by using the "higher" or "harder" gears.  The lower gears are easy gears are for ascending hills.

Shift down to a lower gear = Ride uphill = ride on lower gears to climb uphill with less effort.

You are cycling on low gear when

1) your chain is on cog of smallest chainring = gear 1
2) your chain is on cog of biggest sprocket at the rear = gear 1

Shift up to a higher gear = Ride downhill = add resistance on the pedals and to reduce cadence (in your own term, heaviest).

You are cycling on highest gear of your bike when
1) your chain is on cog of largest chainring at the front = gear 3
2) chain on cog of smallest sprocket = gear 8 = you are running on 24 speed

This diagram of cogs on a chainring and freewheel of a 24 speed bike gives you an idea on which cog your chain is sitting on when you change your gears.

What this video if you would like a clearer picture of how your chain moves on the chainrings and cogs when you change your gears.

Your rear wheel wobbles when you cycle? Here's why.

One of the questions often asked by cyclists when they noticed this wobbling is, if it will affect the gearing system. No, it does not.



The ball bearings retainer will have to be changed if it is damaged.  If it is still in good condition, the worn out or missing ball bearings can be replaced.

The wobble has to do with the machining on the hub shell. If a hub that is machined off centre is installed on rear wheel the wobble is more obvious when there is a cassette or freewheel on it. This videos explains the reason for wobbling very clearly.