The Worst Dropouts For a Fixie Conversion 

from Rookie’s keyboard

Hello, friends

Today, I will talk about fixie conversion as I know this is a hot topic in the cycling community. 

One of the most important things to know is to never use a frame with vertical dropouts(VDs) to build your fixie. VDs make it very difficult if not impossible to properly tension the chain. And chain tension is critical for a fixed-gear bike.

Vertical Dropouts

VDs come with a pre-set place for the axle. Ergo, one cannot move the wheel forward or backward to respectively decrease or increase the tension of the chain.

Conversely, dedicated fixed-gear bicycles are equipped with rear-facing-dropoutsallowing you to adjust the bike’s chain tension by changing the wheel’s position.

Some workarounds can help, but most are inconvenient.

< Options >

Below you will find the most common methods to tension a chain when you have VDs:

The“Magic” Gear Ratio

You can manipulate the chain tension by trying different gear combinations.

The bigger the gear, the greater the chain tension for the same chain length. The smaller the gear, the lower the chain tension.

For every chainstay and chain length, there’s a gear ratio that results in satisfactory chain tension. 

The combination is known as the “magic gear ratio“.

This strategy has major downsides:

1. You are limited to 1 or 2 gear combinations that may be sub-optimal for your style of riding.

2. You have to buy more than one rear cog and chainring.

3. As the chain stretches with time, the chain tension will drop, and you will have to rely on a different method to re-tension the chain.

Half-link (pintle) Chain

Standard chains consist of narrow and wide links. To increase or decrease the length of the chain, you have to add or remove two links – one wide and one narrow. 

Since each link is a half-inch long, the user has to work up or down in 1-inch/2.54cm increments.

Half-link a.k.a. pintle chains use identical half-inch links and allow you to add or remove one at a time. You can work in half-inch increments and fine-tune the chain tension with greater precision.

This method sucks because it requires you to periodically remove a chain link to optimize the tension. The process is annoying.

Also, half-links aren’t designed for long mileage because they stretch very quickly and have a tendency to break unexpectedly. 

Normal Chain + Half-link

If you don’t want to use a pintle chain, you can add a half-link to a standard chain. A half-link a.k.a. a cheat link is as long as a regular link but has two sides of different widths. One side is wide, the other is narrow.

The cheat link allows you to make a 1/2-inch change without having to replace the entire chain.

This strategy gives you the strength of a regular chain and the adjustment versatility of a pintle model.

An Eccentric Hub

Eccentric hubs have a mechanism that offsets the rear axle. And that motion allows you to increase/decrease the chain tension.

The pros of this approach are:

  • Clean look
  • Fast adjustment of the chain tension via a wrench
  • You can run multiple gear ratios

But don’t smile yet. Eccentric hubs have major issues:

  • Expensive

A new eccentric hub retails for close to USD 170. You also have to buy a proprietary cog that would fit on the hub as well as the tools needed for assembly.

The rear wheel will have to be rebuilt around that hub too. The expenses add up to:

  • New Hub
  • New Cog
  • Tools
  • Rear-wheel rebuilding

For the same money, you can buy a new frame with rear-facing dropouts.

You may even buy an entire fixed-gear bike on the second-hand market.

This solution makes sense only if you can comfortably afford such a product and adore the geometry of your existing frame.

Аn Eccentric BB

The principle of eccentric bottom brackets is very similar to that of an eccentric hub except that the rotation happens inside the bottom bracket shell.

The pros of this approach are:

  • Discrete, aesthetically pleasing
  • You don’t have to rebuild the wheel or use proprietary cogs and chainrings.

The cons are:

  • Expensive. An eccentric bottom bracket is about USD 160-180. When you add the tools needed to install and set it, the bill goes over USD 200.
  • Inconvenience. Some people may find the installation of the bottom bracket and its adjustment complicated.

Filing The Dropouts Backward

Some riders file the dropouts of the frame backward ever so slightly so that the axle can move a bit.

Obviously, this action is somewhat risky as you are thinning out the dropouts. 

Don’t Use Chain Tensioners

An aftermarket chain tensioner disintegrates when installed on fixed-gear bikes due to high chain tension.

Don’t even try this.

A Ghost Ring

A ghost ring is a free chainring added to the drivetrain to increase chain tension. The ghost ring isn’t connected to the frame. Only the chain is keeping it in place. One can increase or decrease the chain tension by playing with the position of the chainring.

Ghost rings look cool, but they have the following downsides making them a sub-optimal choice:

  • Potential injuries or damages

If the chain wears down without being readjusted, it may become too loose, and the ghost ring may break free.

If the ghost ring jumps out, it can get into the spokes or jam into the cassette and cause major damage to the rear wheel.

  • Tricky Setup

If the chain tension is off or the chain and chainring don’t agree with each other, the ghost ring will keep coming out until you get the set-up “just right”.

Ultimately, it’s best to avoid using a ghost ring, especially as a long-term solution.

Horizontal Dropout Adapters?

Horizontal dropout adapters are an aftermarket product designed to turn frames with vertical dropouts into frames with rear-facing dropouts. The adapters attach to the frame via bolts tightened to the existing dropouts.

The idea may seem great on the surface, but it sucks in practice.

First, a bolt link isn’t as strong as а proper weld. Second, the rear dropouts are under a lot of stress. It makes sense to keep them as strong as possible. Adapters can compromise strength.

Third, horizontal dropout adapters lower the aesthetic points of the bicycle.

You Can’t Run From Reality

A frame with vertical dropouts will always be sub-optimal for а fixed-gear conversion.

This leaves us with three logical alternatives

1. Sell the frame and buy a new one

There are no irreplaceable frames. If you can find one comfortable frame, you can find another. The only exceptions are frames that have sentimental value. In that case, you can keep your existing bike and build a new one with a proper frame.

Below are two viable options:

  • An old frame with semi-horizontal dropouts

Some old road bike frames have semi-horizontal dropouts giving you the option to slide the wheel backward to increase chain tension. The downside is that the dropouts are still forward-facing. As a consequence, you can’t use standard chain tugs to tension the chain.

  • A track frame with rear-facing dropouts

If you’re serious about fixed-gear riding, this is the ideal long-term approach.

Rear-facing dropouts

Until next time

– Rookie





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