A bicycle is a relatively simple mechanism. There aren't many components, most of them are on the outside. Standard Allen screws hold the levers and brakes, and the wheels are attached with simple hexagonal nuts or quick-release skewers. Therefore, the prospect of assembling a bike yourself doesn't seem particularly difficult or arduous. There's a lot of truth in this – with basic technical skills and a bit of space, it's possible, though you won't get by without at least a few basic tools. However, if you base your confidence on your uncle's claim that he disassembled and reassembled his bike so many times during the communist era, remember that it might have been possible with a hammer and two wrenches, but most modern bikes are a bit more complicated. Furthermore, your uncle might have had somewhat lower expectations back then, both in terms of bike maintenance and the possibility of play or damage from inappropriate tools .
At Antymateria, we professionally build custom bikes . So I dare say I know what I'm talking about, especially since I've built a wide variety of bikes in other places (including at home). Before we get to the guide, though, let's quickly dispel a myth.
Assemble a Bike or Buy One? A Matter of Cost
If you think you can save money by building a bike, you're mistaken. Manufacturers offer massive discounts on components. Buying all the parts retail will cost you significantly more than buying any bike in the same configuration. How much more? Generally speaking, it's 30%-60%. Even based on used components, it's hard to beat that, and finding everything in good condition won't be easy. Building a bike yourself won't be cost-effective in any case. However, it can be fun, develop technical skills, and ultimately, create a unique bike tailored to your needs.
To assemble a bike yourself, start by designing it
Buying extra parts while you're building is the worst possible idea. If you want the process to go smoothly, write down all (absolutely all) of the parts. This will help you avoid unpleasant surprises with compatibility issues or simply forgetting something. Additionally, with this complete list, you can go to the bike shop where you'll be buying your bike and ask them to check if everything will fit together. I recommend doing this in a spreadsheet. You can also easily calculate the build costs and weight of the bike. Try not to mix groupsets and maintain balance. It's better to have a bike built with average but well-matched components than with a full set of weak parts and a single top-of-the-line derailleur. Seek advice from mechanics rather than online forums.
How to assemble your own bike? The basics
In the following sections, I'll discuss the steps involved, even the trivial ones. I'll also address the proper selection of parts, tools, and common mistakes. The order is dictated by my experience servicing and professionally building bicycles. However, this doesn't mean it's the only or best approach—it's likely partly a result of my habits and preferences. Please also note that I can't cover every existing standard and solution (e.g., bottom brackets and cranks), so generalizations will be made.
Workstation and frame
The frame is where the action will take place. First and foremost, I recommend getting a bike stand. Of course, it's entirely possible to assemble the bike yourself without one, but you should expect to work in an awkward position and have some parts tightened. It's also worth having all your tools and grease within easy reach. For the purposes of this article, I'm assuming you have a simple stand or a makeshift bike rack (a rocking bike will be annoying, but it's better than fiddling around on a desk or floor). So, let's start by installing a seatpost clamp (there are many sizes depending on the seatpost diameter!) and inserting the seatpost. Apply a little grease evenly between the clamp and the frame, as well as between the frame and the seatpost. This will prevent seizing and any squeaking. If you have a stand with a clamp, tighten it onto the seatpost. If you're using a makeshift hanger, you'll also need to install a saddle to hang the whole thing on. In the latter case, you can also attach the saddle to the hanger with cable ties if the whole thing tends to fall off.
We are flying with the front part of the drive
Grease the thread in the bottom bracket shell. A special bottom bracket wrench is essential here. With the most common BSA thread , first screw in the right part counterclockwise. Firmly, firmly, and completely. Then, do the same with the left cup, but tighten it clockwise. It's time to install the cranks – remember to grease them again, and the same goes for the pedals (there are right-hand and left-hand threads). At this stage, I also install the front derailleur. The outer part of the cage should be approximately 2 mm above the tops of the teeth on the large chainring and parallel to them.
Forward
It's time to assemble the fork and cockpit. But before that, we still need the headset. It's easy to make a mistake here, due to the multitude of standards. You can read more about headset selection here . Headsets should be pressed in, but at home, they can be hammered into steel and aluminum frames quite safely. Start by greasing (this will be repeated later) the head tube where it fits. Then, evenly place the upper or lower cup in place, rest the board on it, and... hammer it in. It's important that the cup goes in relatively evenly. If it only clicks in on one side, start over, as it's easy to damage the frame or headset. Gradually "tap" until it's all the way in, and the sound changes slightly. Repeat with the second cup. Clean everything and apply grease to the races (for cartridge bearings, it's worth applying a thin layer to both sides of the bearings – this will protect them from moisture). Next, it's time to assemble all the headset components, in the order they were arranged in the box.
Assembling a bike yourself sometimes requires... cutting.
New forks usually have very long steerer tubes that need to be cut. To find the correct length, tightly assemble all the components, including the stem and spacers. Then mark where the pyramid ends. Subtract about 2-3 mm from this and cut. At home, a saw blade works best, or if you have a steady hand, an angle grinder. Primer to ensure a smooth cut. Then, sand the cut with a file, or in the case of A-head headsets, drive in a star. A makeshift pin resting on the stem and a piece of rubber under the fork will be useful for this. For carbon tubes, a special expander will be necessary. It's also better to leave more tube at the beginning. It's easier to cut later than to glue it on.
To prevent them from scattering around the workshop, we mount the lower elements on the fork. And yes, we still need to press the lower race onto it. Again, grease and a wooden board, but this time we gently tap it on one side and then the other, trying to avoid sharp tilting. If we have a vise, we use two wooden boards on the vise, and we rest the race on them, which we then apply to the fork, which we then tap (also through the protective wood) from above. For standard headsets, we screw the fork to the frame, locking them so there's no play and smooth operation. For A-head headsets, we add washers and a stem, and we try to achieve the same effect using the screw at the top. More on adjustments in a separate article .
Cockpit
Assembling the bike yourself also includes the cockpit. Attach the handlebars to the stem, roughly in their final position for now. Then attach the shifters or levers. That's all for now. Attach the grips to the straight handlebars. If they don't lock, a compressor or brake cleaner will be helpful. Soapy water or dishwashing liquid will also work, but it may take a day or two for the grips to evaporate.
Assembling the bike yourself - brakes and rear derailleur
At this stage, we can attach the rear derailleur (be sure to check which cassettes this version supports first – too little capacity is a common problem). This is easy, but it's worth making sure the hanger is securely screwed on and straight. As for the brakes, there's no big deal. For V-brakes, remember to apply a pinch of grease to the pivots. For disc brakes, attach them so they move freely side to side – about a quarter of a turn from a stationary position.
Wheels
We'll assume you have your wheels ready. If you want to lace them yourself, I invite you to first read our two-part guide , which covers the process in detail. You need to mount the tires on them, then insert the inner tubes, or apply sealant for tubeless wheels . Gluing tubular tires is another topic. For the rear wheels, you might need to screw on a freewheel/sprocket or install a cassette. For a freewheel, you can do it without tools – the key is to screw it on straight, and then pedal to tighten it properly. A cassette or a chainring set for fixed/reverse gears require tools to hold everything securely. Tighten the cassette firmly, but don't rely on a wrench – aluminum freehubs are especially susceptible to damage. Always insert quick-release skewers from the left side. When tightening the brake discs (they usually require a Torx T25 wrench or a cassette wrench for CenterLock systems), try to do it evenly. Time to put the wheels back in place and... remove the bike from the stand.
How to assemble your own bike? Ground setup
First, loosen the wheel clamps or bolts (this does not apply to horizontal dropouts at the rear of fixed gear, single speed, or gear hubs), allowing the axles to engage fully. Only then should you tighten the bolts/lockers. This is also a good time to align the handlebars with the fork and check for play in the headset. Adjust the saddle horizontally to the ground, and adjust the handlebar and lever angles. For most drop handlebars, the top grip should be perfectly flat, and the shift levers should be an extension of it. For straight handlebars, the levers should be angled downward approximately 35-60 degrees, depending on your preference. The shift levers should almost touch them, but it's crucial to leave a minimal gap. Resting the shifter housing against the lever can jam the spring and prevent gear shifting. Back to the stand!
Regulations and cables
At this stage, you can adjust the brake pads on the rim by placing them against the rim. It's time to tackle the housings. They should be as short as possible, but still allow for full handlebar movement and any future adjustments to the handlebar and stem. A good pair of pliers will come in handy for cutting the housings and cables. If you don't want to deal with frayed ends, forget about pliers – something stronger will be useful here. I also recommend applying a drop of chain oil to each housing. Arrange the housings so that, if possible, the last (outermost) one is the one for the front brake. Each housing should be terminated with a suitable end piece (different for derailleur and brake systems).
We start the adjustments with the brakes. Thread the cable through all the housings and into the appropriate spot on the brake. Tension the cable and tighten the retaining bolt. Now squeeze the lever a few times and stretch the cable between the housings with your hand. This will align the entire setup and probably loosen it. Loosen the cable retaining bolt and place it in a more or less working position. Now you can adjust everything using the cable tension and the caliper adjustment bolts. For disc brakes, apply the brake and only then tighten the caliper bolts, which will align the pads parallel to the disc. For derailleurs, proceed similarly. Cut the cables about 2-4 cm from the bolt and tighten the seals on their ends. If you have hydraulic brakes, you will need to shorten the cables and bleed the system. A special kit is required for this. Follow the manufacturer's instructions for your specific model, or measure (with some margin!) the required length and have it done by an experienced repair shop.
We put on the chain
Another essential tool you'll need if you're interested in building your own bike is a chain breaker. With single-speed drivetrains, the length is simple – just enough to tighten (just try it on). With multi-speed drivetrains, things get a little more complicated, but don't worry. Wrap the chain around the largest chainring in front and the largest cog in the rear. Skip the rear derailleur. Grab the chain at the end and find the first link that would allow it to be locked in this position. Add another full link (that's two half-links) and... trim the excess there. For 11- and 12-speed drivetrains without a front derailleur, add two full links. If you have a full-suspension bike, remove the shock and shorten it in the most "tight" position. Now all you need to do is run the chain through the rear derailleur and either crimp it or install a link. Remember that multi-speed chains and links are often unidirectional! Adjust the derailleurs using the tension adjuster and the limiting screws. The B screw on the rear derailleur controls its distance from the cassette. The proper distance can be found in the derailleur manual.
How to tension a bicycle chain?
With single-speed chains, you need to properly tension them by sliding the rear wheel in the dropouts. Do this roughly first, then alternately loosen the bolts and adjust the wheel on both sides in small steps until the chain is taut but can be easily bent with your finger. At the same time, the wheel should be perfectly straight. You'll feel this. Cheaper chainrings can take some time, as they can be crooked and tension the chain differently depending on their position. Try to achieve this effect at the tightest point. Otherwise, you'll experience noise, increased resistance, and faster drivetrain wear. Be sure to tighten the bolts firmly and securely install the coaster brake lever, if your hub has one.
Bullshit
Now it's time for all the bells, kickstands, fenders, and so on. Contrary to appearances, this can also take some time. It can also cause problems. For example, a rear fender often interferes with the front derailleur. For road use, the final step is wrapping the tape – there's no need to rush it. Start at the ends of the handlebars, wrapping from the inside out. It's a real art, and there are many schools of thought. The key is to keep the tape tight. Cut the ends at an angle and secure them securely with electrical tape. Those adhesive strips that come with the kit are usually useless.
Assembling a bike yourself is also riding
It's time for a ride. Remember that many bike components, especially derailleurs and brakes, work differently under load than on a stand. Adjustments are almost always necessary, so take a multitool for a test ride. Pay particular attention to how the derailleurs work under different pedaling forces and in different combinations. Riding in the hardest gear under a heavy load may also surprise you – the frame then works hard, as do the crankset and bottom bracket. As a result, the chain may rub against the front derailleur cage. Adjustments are needed. Also, listen to the brakes under load and in corners. After the ride, check for any play in the headset – this is very common. Finally, return to the stand/hanger and check again that everything is properly tightened.
Congratulations! Your bike is finished! After a few hundred kilometers (and sometimes even sooner), the cables usually stretch a bit and require minor adjustments. If you have any questions or comments, feel free to leave a comment!
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