ELI5: Why Preassembled Bikes Are Cheaper Than Custom Builds

written by Danny G.

You’re staring at that shiny preassembled bike, wondering why it costs less than the sum of your dreams (and parts) when you try to build one yourself. I get it.

When it comes to computers, everyone knows: you build it, you save money. Simple as that. But bikes? They don’t follow the same damn rules.

So, what gives? Why is a preassembled bike cheaper than the custom dream machine you’ve been planning for months?

Well, it’s not magic, it’s business—and it’s uglier than you think.

The Real Reason Why Preassembled Bikes Are Cheaper

Here’s the straight dope: preassembled bikes are cheaper than you building one yourself because the guys who make them are getting sweet, juicy deals on parts.

We’re talking bulk, baby. These guys buy parts by the truckload. Shimano and SRAM?

Those companies give them deals that’d make you drool. When you buy parts in bulk, you can save a ton of cash—sometimes as much as 50%. That means they can sell you a bike for less than you’d pay if you tried to buy everything yourself.

You? You’re paying full price for each individual part.

The guys selling preassembled bikes?

They’re getting the components at a steep discount. You might be getting the same parts, but they’ve got an army of middlemen and manufacturers behind the scenes all shoving the cost down your throat while you’re out there struggling to find a deal.

Let’s say you’re eyeing that shiny Shimano SX groupset. If you buy it piece by piece, it’s gonna cost you a small fortune. But bike makers? They’re getting a bulk deal, and they’re using that to sell you a full bike at a much lower price than if you went down the “build it yourself” path.

ELI5: Imagine You’re Building a Lego Set

Alright, let’s break this down to Lego terms. You know how you can buy a Lego set for $50, but if you try to buy the same individual bricks, it’ll cost you $100? Why? Because Lego’s buying thousands of bricks in bulk, and they’re passing on those savings.

You? You’re stuck paying retail price because you’re buying them one at a time. Bikes work the same way. You get the whole set for less when the manufacturer buys in bulk. You try to buy those bricks (parts) yourself? It’s a sucker’s game.

Comparing Costs: Preassembled Bikes vs. Custom Builds

Time for a nice little table.

Factor	Preassembled Bike	Custom Build
Parts Procurement	Bulk buying (big discounts)	Individual purchases (higher cost)
Labor Costs	Bike makers assemble it for you	You (or a mechanic) assemble it yourself
Profit Margin	Spread over the whole bike	High margin on each individual part
Economies of Scale	Mass production = major savings	No bulk discounts available
Total Cost	Lower due to bulk buying and mass assembly	Higher because you’re buying piece by piece

Now, don’t get me wrong, building your own bike has its charm. You get exactly what you want, every piece picked with love. But if you’re working on a budget, or you just want to ride without getting caught up in the pricing nonsense, the preassembled bikes are your ticket (of course you could also go the second-hand route).

The Middlemen’s Grip on the Bike Market

Here’s where things get dirty. The bike industry isn’t just manufacturers and customers. There are middlemen—lots of them. Distributors, wholesalers, bike shops—they all get their cut, and that drives the price up for you. By the time that bike lands in your hands, it’s passed through a lot of greasy palms.

The manufacturers can buy parts for pennies on the dollar, but you, the poor sucker, are left with the bill.

It’s a little like trying to buy a car and realizing the guy selling you the tires is marking them up 500%. Yeah, it’s not great. But that’s the reality of the bike business.

Conclusion

So here’s the deal: if you’re after a custom bike and you’ve got the cash to burn, go ahead and build your dream machine.

But if you’re just trying to get on the road without selling a kidney, preassembled bikes are the way to go. They’re cheaper because of bulk buying, middlemen, and the magical economies of scale that you can’t access.

It’s not rocket science—it’s just business. And that’s the ugly truth.

So, next time you’re standing in a bike shop, don’t feel bad about not building it yourself. You’re just playing the game smarter than the guy who’s drowning in individual part prices.