Condensed Answer: A road bike can readily accept a set of BMX pedals that are 9/16″ x 20 in size.
However, 1/2″ BMX pedals cannot be installed on a road bike as the pedal axles are of the wrong dimensions.
Bike Pedal Compatibility
Whether a pedal can be installed on a bike depends on the following factors:
- The threads on the pedal’s axle
- The threads on the crank arms
The threads on most pedals are 9/16″ x 20.
9/16″ x 20 TPI stands for:
9/16″ (14.3mm) is the diameter of the pedal’s threaded part.
TPI is an acronym for Threads Per Inch and shows the number of threads per 1 inch/2.54cm. In this case, the threads’ density is 20 per inch or 20 per 25.4mm which amounts to 1.27mm between threads.
The vast majority of road bike cranks are designed for 9/16″ x 20 TPI pedal axles.
Therefore, if you have a set of BMX pedals with that kind of threading, you will be able to install them on a road bike via a pedal wrench (or a thin 15mm spanner).
However, there are also 1/2″/12.70mm pedals that have a thinner axle. Those are usually found on the BMX market and are designed for single-piece cranks. If you have a 1/2″ pedal, you won’t be able to mount it to standard cranks unless you replace the axles.
Replacing the axles is not a terribly complicated procedure, but it will require complete disassembly of the pedals and a set of donor 9/16″ pedals from which you can extract the axles. Unless the pedals in question are extremely important to you, it’s simpler to just get a set of 9/16″ pedals.
The Advantages Of Installing BMX Pedals On a Road Bike
Modern road bikes are typically combined with clipless pedals and appropriate shoes with cleats that attach to the pedal.
This retention system increases pedaling efficiency and makes it close to impossible for the rider to slip out of the pedals unintentionally. Pedal slippage is considered dangerous because the rider could lose balance and get hit in the shins by the pedals.
A lot of people experience joint pain (usually at the knees) from clipless systems. With the right fit and equipment, the discomfort can be eliminated, but there’s always a chance for it to come back.
Platform pedals do not lock you in a specific position and thus allow the joints to find a happy place.
- Cornering Control/Slippage Advantage
Flat pedals make it very easy to remove one foot and put it on the ground or near it when moving over sketchy terrain.
BMX pedals are essentially ultra-wide platform models. Many people put BMX pedals on their MTBs and commuters to make the bikes more user-friendly and increase the pedal surface.
Road bikes are designed for speed and efficient pedaling rather than speed. However, some people like to experiment and perform stunts such as bunny hops on road bikes.
If you look closely, you will see that in most cases, the pedals used for the task are platforms.
It’s also worth mentioning that many fixed-gear riders rely on BMX pedals with straps and also perform tricks such as wheelies and bunny hops in freestyle sessions.
Or in other words, if you plan on using a road bike as a stunt bike rather than a speed machine, platform pedals are a friend that makes the execution of those tricks many times easier thanks to their size and grip.
(BMX pedals are usually made of strong nylon composites and have fairly aggressive pins which increase the foot’s grip.)
A set of decent BMX pedals can be acquired for little money. Moreover, unlike clipless pedals, BMX models do not require specific footwear. A basic pair of Vans or Vans-like shoes will do fine.
Also, you can ride with winter boots when the conditions require it. Hence why many touring cyclists continue to rely on platform pedals.
- Compatible with Retentions Straps
BMX pedals are the most common choice to pair with retentions straps. The pedals have many holes making it easier to slide a pair of retention straps through them. (Hence why you see BMX pedals on so many fixies, as already mentioned.)
- Different Look + Style Points
A set of BMX pedals on а road bike will stand out. Cyclists who like to appear different could consider this a positive.
The Downsides Of Using BMX Pedals On a Road Bike
- Incompatibility with clipless pedals
BMX pedals cannot be used with any clipless shoes out there. The lack of a clipless system will result in less efficient pedaling and higher chances of pedal slippage, especially when exerting a lot of effort (usually during uphill riding).
In some cases, the rider may even be prevented from entering a race due to using non-standard road bike equipment.
Dedicated road cyclists are known to be snobbish. Those who move away from the commonly accepted etiquette can face criticism. For example, it’s not uncommon to eat a lot of insults for joining a group ride while wearing ankle socks.
Summary: What You Need To Know
- 9/16″ BMX pedals can be installed on a road bike right away with a basic 15mm spanner.
- 1/2″ BMX pedals found on older and cheaper bikes cannot be installed on a road bike without replacing the pedal axles.
The main advantages of BMX pedals are:
- They do not require special footwear, unlike clipless pedals.
- They can be combined with pedal straps if foot retention is necessary.
- They are the preferred pedal style for performing tricks.
- They are less likely to cause knee pain because the foot is free to move.
- Low price
The main disadvantages of BMX pedals are:
- They do not offer foot retention by default. This property reduces pedaling efficiency and increases the chances of pedal slippage that can result in a shin hit and/or loss of balance.
- BMX pedals on a road bike look out of place and can trigger criticism.