A cyclists guide to bike pedals and maintenance.

Published: 10th February 2012
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Pedals can often take years of abuse and neglect without ever missing a beat but for many of us this is just not the case. A set of pedals that lasted years for somebody else appear to disintegrate after only a few months. Hopefully after reading what is written below you will have some idea of the warning signs and the preventive measures that can be taken to ensure you get miles of smiles form even the cheapest of bicycle pedals. Think of this not as a comprehensive guide but more of an overview of the sometimes baffling enigma that is the common bicycle pedal.

Overview:

Introduction
Basic Pedal Construction
Types of Pedal
Common Problems and Cures
Pedal Choice & Replacement

When seated on your bicycle there are, arguably, three main points of contact with the vehicle. These are the grips or handlebars, saddle or seating area & the pedals. Many companies in the industry have put lots of time, money and effort into the research and development of these products. As is the case with the first of these two points of contact the blend of comfort and control is the main focus. However, when it comes to pedals not only do you require comfort and control but the mechanics must also play a heavy roll in its design and construction.
There exists a multitude of pedal designs and shapes. There are some that can attach to your shoes in a semi-permanent fashion whilst others can be modified to this purpose using plastic and nylon cages. Both methods equate to a boost in efficiency at the expense of being able to “just step off”. Pedals without these cleated and caged designs are often referred to as “flats” or platform pedals referring to the shape of the pedal body and are the type of pedal that you will find on the majority of complete bicycles available on the retail market today.
As with any other moving part on a bicycle it is put through it's paces every time you head out on your bike. So when is it time to inspect your pedals for wear and if you wish to replace them what do you need to know? It is often found that the majority of people wait until their care free days of pedalling are adversely affected before giving their pedals the attention they require. More often than not this results in the pedals requiring replacement rather than a small adjustment or re-grease and can even lead to further trouble from associated drive parts such as the bottom bracket.

Pedal construction.

The majority of pedals out there work on the same basic mechanical design as each other. A spindle, usually constructed of heat treated steel alloy, is bolted via a section of thread at one end to the crank arm or pedal arm of the bike. On most adult bikes or bikes with a three piece crankset this thread is 9/16”. Most kids bikes or bikes with a one piece forged crank utilise a smaller 1/2” thread. The pedal body then slides onto the spindle with some sort of bearing arrangement on either side. The whole assembly is then held together with another bolt or nut arrangement on the outer end of the pedal spindle. The tension exerted on the bearings is determined by this outer assembly and controls the ease with which the pedal spins upon the axle.
There are various types of bearing construction some are serviceable and some are not. Higher end pedals will tend towards the use of sealed cartridge bearings which although not serviceable still can require small amounts of maintenance to get the most from them. Mid range pedals and some higher end platform pedals are trending towards the use of nylon bush bearings on the outer edge but the majority still use either a cartridge bearing or loose ball assembly for the side closest to the crank arm.
The most serviceable and most commonly used bearing assembly at the time of writing is still of the loose ball arrangement. In this type of assembly a cup, usually made of steel, is pressed into the pedal body. This cup is machined to except an array of ball bearings that are then held into place by the addition of a cone nut. This is a nut forged or machined with a complimentary section, that when tensioned properly will hold the bearings neatly in alignment within the pressed cup section. This is often referred to as simply a “cup-and-cone” assembly and is also used in unsealed hub construction.

Types of pedal.

As you may imagine there are various types of pedal each with a specific aim or purpose. These pedals vary largely in price and often differences within a category are not noticeable to those who are unfamiliar with materials and construction.

Notable and common designs are:

Platform or flat pedals
Caged pedals or toe clips
Clipless

Platform or flat pedals consist of a large platform usually made form moulded plastic or a forged and post machined alloy. They are in all probability the most common type of pedal. The later alloy machined versions rose to fame in the 80's with the release of the Shimano DX pedal. Many alloy platform pedals such as the DMR v8 and v12 still resemble this design up to current day.

Caged pedals or toe clips. Although strictly they are still platform pedals the addition of a cage, commonly made of nylon or alloy, is not always possible on the previously mentioned platform pedals. This is by and large due to the fact they do not have the appropriate shape or mounting holes to accommodate them. However, with the current trend of commuters using fixed gear cycles many have used “hook 'n' loop” toe straps on their plastic platform pedals to achieve the same effect.

Clipless pedals are so called due to them not having toe straps or a cage. Although somewhat humorously people refer to the use of these pedals as being “clipped in”. These pedals have two main categories Road and Mountain Bike (or MTB for short). Essentially the difference being that the Road style clip systems usually only allow the shoe to become detached in a forward and back motion where as the MTB system allows for the shoe to become detached in multiple directions making it easier to remove yourself from harms way in the event of a crash. How hard it is for the rider to unclasp their feet is determined by the amount of spring tension the pedal has. Usually this tension can be set to personal preference with the use of a hex wrench or allen key. Once the shoe is clipped in via the cleat there are minute amounts of movement available to the rider this is often called “float”. Shimano has a proprietary clipless system known as SPD. This acronym has given rise to the erroneous use of the slang term “SPD's” (pronounced “spuds”) in reference to all multi-angle detachment pedal systems.

While being attached to the bike may seem like a nightmare to most of us, advocates of the clipless system claim greater pedalling efficiency. This viewpoint is widely accepted by the majority of cyclists even though it is quite hotly debated amongst others with some scientific research into the topic showing, for the most part, no significant gain over standard flat pedals.
One of the more often overlooked reasons for clipping in is the less measurable effect of feeling as though you are one with the bike and the confidence gained from knowing you will not slip your pedals while tackling rough or uneven ground. Both reasons are debatable and with a complete clipless system including the shoes and pedals designed for use with them usually costing upwards of £100.00 you can see why many people are reluctant to just “give it a try”.

Common problems and cures

So you think there maybe something wrong with your bike and that odd noise is coming from somewhere around your pedals? How can you identify what the problem is and is it too late to cure it? Speaking from experience if your pedals are making noises the damage is already done. The signs that this was occurring were probably evident long before the noises began.

Flat pedals & some clipless models

The number one reason for pedals going wrong is the nut or tension bolt that is holding the pedal to the axle. The easiest way to know if this is the case is to feel for “play” in the pedal body. Bend down to one side of your bike facing the saddle now hold your saddle with your leading hand and grasp the pedal body with your free hand. Firmly pull the pedal body back and forth. If you can feel an unusual amount of give it is likely that the nut or pretension bolt has come loose through vibration or the rigours of regular use. If your pedal is a higher end or sealed bearing type it is likely that the nut or bolt that secures the bearings is easily visible and can be adjusted with the use of a hex wrench or allen key.
If your pedal is of the loose ball nature it is likely that there is some kind of plastic dust shield that caps the outer end of the pedals spindle. You should be able to prise this cap out intact with a sharp flat blade screw driver or something similar. Many of these caps actually have grooves in the edges that are specifically placed for this purpose. Under this cap is a nut most often than not it will be a 13mm one.
Dependent on the design of the pedal you can either use a socket wrench to nip this bolt tight or if it is a tight fit specialist spanners are available from most reputable bike shops. If your in a tight fix and really need to sort this situation out you can use the same flat blade you used to prise the dust cap off. Jam the flat blade against one of the securing nuts flat edges and the body of the pedal. Slowly rotate the body of the pedal. This is not recommended however and if you find yourself in this situation I would strongly suggest that after performing this alteration visit your local bike shop as soon as possible. Explain the situation to them, have them make right to ensure that it cannot occur again and check that no lasting damage has been done.
Usually tightening this bolt requires less than a quarter turn. After each adjustment remove the socket or pedal wrench and spin the pedal. The pedal should roll freely. If it doesn't roll freely or seems hindered in it's movement it maybe that you overtightened the nut. Just back it off a little and try spinning the pedal again. If the pedal is omitting a hissing or gravely sound when spun it is likely that the bearings are dry. Be a dear and treat them to some high quality lubricant.
When working with sealed units as found in higher end pedals (nylon bush or sealed cartridge types) any amount of lubricant applied will not remedy dry bearings. If tightening the pre tension bolt has not removed the play from the pedal the only solution is replacement of the offending cartridge units. Visit your local bike shop who can often order replacement bearings or at least point you in the direction of a decent bearing supplier.
Some mid to higher range pedals will have a “grease port” specifically designed for this job. It will consist of a grub screw that sits flush with the pedal body and will probably be slightly smaller than the grub screws commonly used for grip on many types of platform pedal. Find a suitable hex wrench or allen key and remove this grub screw. They are normally very small so please put it somewhere it won't get lost.
Most pedals of this nature will come with a syringe for applying grease through this port. You did keep it safe didn't you? If not just put down some old rags on the floor and place the nozzle of the lubricant container on top of the grease port. Slowly upend the bottle. After putting in what you feel is a suitable amount spin the pedals and tilt the bike from side to side to spread the grease as thoroughly as possible. You could even take it for a little saunter if you have the time.
Another common problem that can occur is that your pedals work loose from the crank arm. This is extremely easy to fix but for people new to cycling and bike maintenance in general it can be especially puzzling and sometimes even frustrating. The key to performing this repair is to remember that the LEFT hand pedal has a LEFT hand thread. This means simply that to tighten this pedal you must turn the axle counter clockwise. The majority of pedals will require a 15mm pedal wrench. Some will use a 17mm and some clipless types use an 8 or 6mm allen key inserted from the back of the crank arm.
If after all this tightening and adjustment your pedal is omitting a clicking noise it maybe that your pedal axle is bent or cracked. This situation may not seem like the end of the world but it can have serious consequences. As the majority of pedal axles are made from hardened steel they are prone to catastrophic failure. Essentially this means that if a hair line fracture or bend in the axle occurs the next step is not that the pedal will bend or gradually get worse it will literally snap off. The time when this is most likely to occur is when you are pedalling away from a complete stop. This could be just as you set off from your driveway in the morning or it could be right in front of a queue of traffic at the lights. This is a situation that cannot be remedied easily and the direct course of action should be to replace the pedals at the first opportunity.

Clipless specific

When it comes to clipless pedals there is a whole set of problems reserved especially for them. Hopefully I will be able to address, what I feel are, the three most common.
The majority of problems experienced when using clipless pedals are simply down to the cleat itself. That's right the little bit attached to the shoe is causing all that issue. A quick inspection of the cleat is the best place to start. Plastic cleats are the easiest when spotting excessive wear. Chips and worn edges are both good indicators that its time for a replacement. Metal cleats can be a little harder. What your looking for is areas that look well polished or unsymmetrical to its opposing side. A worn cleat will manifest itself in the way you clip in and out. Sometimes it may stick, other times it may appear that the pedal has an excessive amount of float. Which leads me neatly to the next point.
The spring mechanism on clipless pedals will over time become maladjusted it is advisable to check the tension on a regular basis and when appropriate adjust the spring tension accordingly. This is normally achieved by tightening a grub screw normally located on the back or centre of the pedals platform. If the tension is good but the cleat is still sticking a little bit of lubricant can go a long way apply a thin coat of good quality PTFE based lubricant like GT85 to the cleat and the area where the cleat engages with the pedal.
Bolt heads on cleats can often get filled with mud and other debris making it hard to remove the cleat from your shoe during replacement. This is easily remedied with the use of a sharp pointed object perhaps a pin or fine point screw driver.
If your clipless pedals are of the plastic bodied variety you will also want to check the pedal for wear. Clipping in and out all day long can take its toll on these surfaces also.

In general

General good practice when dealing with pedals of any type is to always use a good quality anti-seize compound on the axle thread where the pedal mounts to the crank arm. Remove the pedal wipe the thread clean and apply a nice thin coating of anti seize compound to this section of thread. Then simply reinstall the pedal.

Replacing your pedals

So you've given the pedals a good once over and the problem is still persisting. Perhaps you discovered the axle is bent. It's time to replace those tired dusty old pedals and buy your self a nice shiny new set. What should you look for and what is a suitable budget for that type of pedal?
As previously stated clipless pedals provide little advantage to the majority of casual riders. If you are contemplating taking the plunge and investing in a set of clipless pedals and shoes. A few things to bare in mind is that the majority of people will take a few tumbles before remembering that they are now a part of the bike. Most report that it takes around two weeks and a couple of falls to really get used to this alien feeling of not being able to remove your foot from the pedal.
If your a commuter it is more than likely that you will encounter multiple sets of traffic lights during your commute. Clipping in and out at every stop may become a real chore. You also have the added weight of carrying your second pair of shoes with you for when you reach your destination. If you are truly set on taking the plunge a ball park figure for a decent set of clipless pedals would be around £40.00 with a set of shoes setting you back around a further £60.00. Yes, it may look expensive but if you enjoy the feel of clipless systems with good maintenance these could last you a good few years before they require replacement.
When it comes to flat pedals an alloy platform pedal with a decent set of bearings can be purchased for upwards of £25.00. The more expensive alloy platforms will boast extended features but the majority of what your paying will be spent on the weight savings gained. Plastic platforms can be good for those on a budget and come in a massive range of colours and designs. One point to note is that there are few plastic composite pedals that aren't slippery in the wet and with this in mind may not be the ideal choice for commuters.
If you like the idea of being held to your pedal you could try a nice pair of caged platform pedals and a set of clips or cages. Caged pedals with clips pre-installed can be purchased from around £30.00. Otherwise a pedal and cage bought separately will cost around £15.00 per item.
Hopefully some of this information has been helpful to those of you out there that desired to know more about the humble Pedals. Maybe it was useful in deciding what type of system is suitable for you. So get out there enjoy riding and take good care of your new parts. Who knows the right choice may just last you a lifetime.

This article submission is a sample of the knowledge found in the ASKoo library. ASKoo is a cycling based knowledgebase constructed by Koo Bikes.

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