If you are an avid rider, you probably have an unused, multispeed bike that is gathering dust in your garage. If you have been considering dropping the mountain bike at the dump or selling it for scrap, resist the urge – you can do much better by converting the bike into a single-speed ride.
Single speed conversion brings a lot of benefits. In addition to helping you get your old ride on the road, it helps you create a low maintenance machine that allows fun urban jungle riding, improved pedaling technique, and low gear winter training. In this guide, we will show you how to make a single speed convert.
Multi-Speed to Single Speed Conversion Guide
1. Measure the Steerer Length
The space occupied by the headset is known as “stack height”. For the majority of the headsets, the stack height is usually 42mm. However, if you are building the single speed convert for your kid or someone shorter, you can get headset models featuring a stack height of 32mm.
After measuring your frame’s headtube, let say you get about 132mm. Add 42mm for the standard headset, and just in case, a couple of spacers (say, four 5-millimeter washers). Next, measure the total length – 194 millimeters in this case – onto your fork column starting at the crown race seat upwards and mark.
Thread an adjustable cup – preferably, made of steel – down past your mark and cut, using the cup as a guide. Using a file, tidy up the edges, then back off your cup, cleaning your threads in the process. A locknut and blue thread lock on the top threads should prevent loosening.
2. Assemble the Fork and Headset
If you intend to use a threaded fork on your budget road bike, check to make sure it is long enough to fit in your frame’s headtube while allowing threads on your headset. When using a threadless steerer, you will also have to check for similar length requirements.
Assuming you have a threadless fork whose diameter matches that of the headtube, simply push it into the bike frame and slide your headset together, using the stem, spacers, and bearings to figure out the needed length. Mark above the bike’s stem and use a sharp hacksaw to cut.
If you cut a bit longer, you don’t have to worry – this can be dealt with by adding a washer. Grease, assemble, and then adjust to make sure there is no play. Check to make sure the assembly allows free rotation.
3. Check the Brake Reach
This is a crucial measurement, especially if your goal is to get an old frame on the bikepacking trails. Make sure that the MTB brake pads can reach the rim braking surfaces without touching the mountain bike tire – if the pads wear through your tire, they can lead to an unexpected blowout.
When performing the single speed conversion, you will need to measure from the center of your brake bolt hole to the middle of your rim’s braking surface. If your bike features an old frame made for 27-inch road bike wheels, you may need to invest in longer reach brakes – Shimano brakes do feature designs that can offer enough reach and modern levels of braking power.
Longer reach dimensions are usually 47mm – 57mm or more when you measure from the brake pivot bolt to the center of the pad bolt while at its lowest position.
4. Add the Handlebar
The right type of handlebar will make your single speed convert look cool. You can get a road bike handlebar featuring a round criterium bar and a big drop to maximize your comfort on the road.
If you get a “quill”-type unit, you will simply need to use a special wedge and bolt to fix it on your ride. Grease the mating surfaces and threads along with the inside of your steerer and the outside stem.
When purchasing your handlebar, ensure it’s compatible with the headtube and steerer. This will make the installation process painless.
5. Add the Brake Levers
Install the brake levers in an ergonomic and appropriate position on the handlebar. While you can run only the front brake, two brakes may be essential for a freewheeling single speed convert.
Size and then cut the brake cable housing to the right length, ensuring that there is enough to accommodate turning handlebars.
Where possible, use ferrules and apply a medium oil or light grease to the inners before you string them through. Turn your barrel adjusters all the way, anchor the cable firmly, and then put a crimp on any exposed end.
6. Modify Your Drivetrain’s Cog and Chainring
One of the important parts of your bike, the drivetrain deserves special attention. A three-to-one ratio between your chainring and cog is the most ideal option for single speed rides. It allows enough top speed that lets you keep up with traffic while allowing mild climbing capability and decent acceleration.
If you choose a 48-tooth chainring and a 16-tooth cog, you get an 81-inch gear. Both the shorter bolts and rings required are fairly common.
When installing your chainring and cog, be sure to grease generously to avoid annoying ticks and creaks during the rainy season. Also, be sure to tighten firmly.
Which Kit Should You Use?
The bike market is saturated with a wide range of single speed kits. This makes selecting the perfect kit extremely difficult. To help you transition your multi-speed ride to a single-speed bike without experiencing issues, we have done the necessary research to find a single speed kit that offers value for your money.
7. Add the Spacers
If you Invest in a new single speed cog, it should come with its spacers. You can also purchase the spacers separately. If you are on a budget, you can take advantage of your old spacers.
You can use the nylon spacers between your cogs to fill any gaps existing between the freehub. In most cases, an additional spacer or two may be necessary.
8. Adjust Your Chain Length
If you are extra lucky, you may end up with a chain length that works without the need for a tensioner. This is, however, possible if you have a semi-horizontal or slightly longer drop out slots common on steel – and in some cases, alloy – frames.
See if you can locate a link that matches up with your wheel in the most forward position. An SRAM Powerlink is generally safe to use and can make your work much easier during installation and bike maintenance. However, the whole process can be quite tricky and it may involve a lot of trials and errors.
Grease your threads and don’t forget to install a tensioner in place of the touring bike’s old derailleur. Two tensioners are available – no spring and spring tensioners. The spring-tensioned version is more ideal – it allows you to enjoy the peace of a single jockey wheel.
If you are using an old chain, be sure to clean the chain before installation. Also, use a chain lube to lubricate the chain – this will protect it from extra friction that might end up damaging it.
9. Check Your Chain Line
Check your chain line again to make sure that it is reasonably straight. It is possible to get away with a light right or left variation, especially if you are using the 3/32” (derailleur type) chain. They are generally more flexible than the 1/2″ x 1/8” pitch chain and will also run smoothly when you are climbing your chainring from a slight angle.
However, it is always a good idea to get the chain right. Swap the spacers as needed, then lightly grease the spacers, your cog, and the freehub lockring. Next, tighten firmly without overdoing it – the serrations available on the lockring will keep it from working its way loose.
Placing a metal washer against the inside edge of your freehub body as a first spacer is always a good idea. This will keep your cog running true. Keep in mind that the nylon spacer can get distorted if you overtighten the locking.
10. Make the Final Tweaks
Install any final parts, including bike pedals, a cool bike seat, a bell, some eco-splash guards, and zip ties. Once you finish assembling everything, take your bike for a ride. Check for pedal overlap, perfect brake lever placement, and adequate braking power. Be sure to assess the handling – a small variation in your fork offset shouldn’t affecting the bike’s behavior significantly.
The headset adjustment is extremely important. Make sure that it is not too tight since it can indent your headset, interfering with the bike’s balance. After going for several rides, re-check your chain and the tensioner.
If you can, keep your bike clean. Also, make a habit of checking the critical components for any signs of failure.
Q: How Do You Convert to Single Speed?
To convert a multi-speed bike to single speed, you will need to install the following:
- Something to run the rear bike wheel with a single gear – you can use a single-speed conversion kit.
- Something to allow the cranks to run just one chainring – a dedicated single-speed chainset is ideal.
- If your bike frame features vertical dropouts, you will need something to help you tension the chain – spring chain tensioners are an ideal option.
This guide has the steps you need to follow to install the above components. Once everything is installed on your bike perfectly, take it for a ride to figure out whether there are problems you need to address.
Q: Can Any Bike Be Converted to Single Speed?
Most bike frames can be adapted to run a single speed setup. However, the difficulty of adapting the bike does vary. If you have the option to choose an old bike to convert, look for one featuring horizontal dropouts as this will be the easiest to convert.
Q: What Is the Best Single Speed Gear Ratio?
A three-to-one ratio between your chainring and cog is the most ideal for single speed bikes. Offering a high enough top speed, it allows you to keep up with the traffic. It also allows mild climbing and decent acceleration.
Globo Surf Overview
Riding a single-speed bike can bring back the unfettered joy you experienced while riding a bike as a kid. You don’t recognize the amount of mental energy you devote to gear shifting until you ride a single speed bike and realize that a whole corner of your brain that was formerly wondering when to shift is now free to enjoy the surroundings and your sensations.
This guide makes multi-speed to single speed conversion easy for both beginning and expert riders. With the right components, you can complete the conversion process at home.