Building e-bike more expensive than buying one?

[darbas]

After three days of research and calculations, it seems that building an e-bike by purchasing a second-hand quality frame and combining it with a good conversion kit ends up being roughly 30% more expensive than buying a ready-made e-bike from a lesser-known brand with comparable power and features.

Would you agree with this observation, or how would you refine this assessment
?

 

[99t4]

Show your work.

 

[Chalo]

Don't be fooled. Ready to roll e-bikes are divided between gimmicky, overpriced, unserviceable traps for incautious consumers, or cheap horrible non-roadworthy basic bikes that are technically fixable, but often not worth the trouble.

You'll always get a lot more for your money by rolling your own. Simply starting with a bike that fits you properly often gives you something you can't buy in fully assembled form.

 

[gromike]

I have had good luck finding lightly used twenty year-old bicycles for very little money. Converting one gets you to the $1000+ range, and you have a much better machine than a similar priced factory ebike.

For instance, this bike was $125. The hub motor was free, that I laced it into a rim (about $100). The battery will also come from the free donor. The controller was under a $100. New tires and tubes another $100. So, it's a $500 ebike.


The more you know how to build 'em, the less they cost.

 

[slaphappygamer]

It’s true that a conversion kit with a good battery can be anywhere in the $1000 price range, but you will get a lot more. Sure you may not get a complimentary “commuter package” or free shirt, but you will get the satisfaction of creating something you built. The satisfaction that comes with that is something you can’t put a price on…..well you have to buy the kit first so there’s that.

The best thing about converting a bike is that you won’t be limited or locked into whatever the manufacturer set the parameters to. Another nice thing is that now that you’ve built the bike and know where everything goes and what it all does, you’ll be able to repair it yourself. You won’t have to wait days or weeks for a response (if you ever get one) from the manufacturer of the prebuilt bike. Then wait another few weeks or months for warranties parts to arrive. THEN have to take the bike to a shop (if they are willing to work on the bike they didn’t sell to you) and have them install it for whatever labor is involved.

I did buy a prebuilt bike. It’s my first ebike and I knew nothing about them, but fully willing to learn. I only knew the size and type of riding I need to do daily.

For the price of my prebuilt bike, I could’ve got a GMAC conversion kit. Fully featured with a phase runner, cycle analyst, and a legit battery. My next bike might be like that,

@gromike , that’s the same motor I have on my prebuilt bike. Works very well for my commutes.

 

[neptronix]

$2000 built me an ebike on a used dual suspension bike ( bike price included ) that did 60mph and had great range and great quality parts. That was 10 years ago when batteries were more expensive than today.

$2000 will buy you a much slower ebike without full suspension, with lower quality parts, much less battery, much lower speed, and no support for the parts in the future.

$1000 will buy you a prebuilt with really bad parts, and quality, and wimpy power that might last you 2 years or less.

$1250 will build you a basic electric bike on a cheap hardtail with mid tier parts that are at least swappable if they fail.

When the $2000 DIY bike breaks, i can get support for the parts or easily swap in another.
When the less good $2000 ebike breaks, i probably need to re-electrify it because the parts are all locked out and must be replaced. You will never get documentation for the parts and the company that sold it to you doesn't want you servicing. My less good $2000 prebuilt bike becomes an almost as good $2500-$3000 ebike after being converted to partial DIY ( if possible ).

Short version, DIY is still better unless you have specialized needs.

 

[E-HP]

After three days of research and calculations, it seems that building an e-bike by purchasing a second-hand quality frame and combining it with a good conversion kit ends up being roughly 30% more expensive than buying a ready-made e-bike from a lesser-known brand with comparable power and features.

Would you agree with this observation, or how would you refine this assessment
?

You probably won't get what you want when you buy a cheap factory bike. Lot's of folks come to this forum with questions like "I want to be able to go just a little faster" or I just need a little more torque" which with a factory bike, those types of mods may involve replacing just about everything since components are chosen with specs that when combined, just barely meet the bicycle specs you see on the listings. DIY allows you to select components to get exactly what you want and easily upgraded as you want more; and there's no comparison when it comes to performance.
That said, there are some great deals out there now due to so much excess inventory post-lockdown that they are heavily discounted and throwing in freebies to get them off the floor.

 

[JackFlorey]

building an e-bike by purchasing a second-hand quality frame and combining it with a good conversion kit ends up being roughly 30% more expensive than buying a ready-made e-bike from a lesser-known brand with comparable power and features.

Sort of. Yes, it will be more expensive. But the bike you build will tend to have better parts, and so will likely give you more power/range/reliability.

And as others have said - if you are planning on doing this do it NOW before tariff inflation kicks in.

 

[Chalo]

And as others have said - if you are planning on doing this do it NOW before tariff inflation kicks in.

The OP is in Lithuania. I don't know about tariffs there, but the date of onset is probably not the same.

 

[fill]

Totally agree OP.. here in the uk for sure.. a quality conversion kit costs circa £400+ complete with a trusted source battery, while an amazon special ebike can regularly be found for £500 or less ready to ride.

However its not really like for like, while the motors controllers and sensors in the kit and on the cheap bike are probably very comparable.

I would have grave reservations about the cheap bike battery however, as thats where its oh so easy to cut corners and costs...

And the bike.. well its probably what you would expect for £100 or $ waffer thin tyres perhaps?

Comfort in the saddle is even more important on an ebike than it is with an analog cycle. the motor ensures your backside will be in contact with the saddle way more and therefore every bump will be felt.. so dont cheap out on the base/donor bike..

So whats the bike for.. if a daily commute source a comfortable bike with GOOD brakes.. but if its just to fetch the paper on a saturday/sunday morning when its nice out- yeah go for the amazon special..

 

[ebike4healthandfitness]

Of course, the pre-built will be cheaper. It will also almost always be UL2849 certified as well even at the lowest price point.

But price is not the only reason to buy pre-built. Capability is as well. Take for example, narrow q factor mid drives (the only type of mid drive appropriate for a road bike)....you can only get these (TQ*, fazua*, and soon mavic**) a pre-built.

*135mm q factor
**146mm q factor

DIY industry got a lot of work to do to catch up.

 

[neptronix]

I have long legs that like 1990's mountain bike Q factors and my legs like the lightest mid drive's 175mm Q factor.
Bafang BBS02 produced a mild injury because it was way too wide & also had the wrong cadence.. the formal diagnosis was chondromalcia and i spent 6 months doing PT with the grey hairs to re-align my leg muscles after that.

Lightest mid drive, i can pedal all day if i swap the 165mm pedals for 170mm.
My legs start getting angry at 190mm Q factor IE what's typical on fatbikes.

Consider that i'm a physical outlier, was born with tibial and femoral torsion, walk funny to begin with, and have had to have bones cut in half and bolted in the correct rotation.

Only if you have a super narrow stance ( your legs only like road bikes ) or demand absolutely perfect human-pedal transfer ( that would be very few of us ) is the Q factor limiting.

The lightest mid drive is also more power dense per lb than most prebuilt's mid drives.

With hub motors, you can retain the stock Q factor of the bike.

99% of ESers would be happy with these 190mm+ Q factors for cheap mid drives and i am the only person on the forum to report a knee injury from pedals being too wide. it's only an issue for outliers like me.

 

[ebike4healthandfitness]

With hub motors, you can retain the stock Q factor of the bike.

As long as the road bike is thru axle and a person wants to use the GRIN all axle. Outside of that there are lots of people with very nice 11 speed road bikes and 130mm rear spacing (rim brake) and they can't convert those even if they wanted to.

P.S. Q factor for "lightest mid drive" is actually 178mm once a person makes the correction for 3mm offset. The study I am thinking about had the average rider height at 6' and the best q factor for max power on that study was 144mm. Narrow q factor also has other benefits including improved aerodynamics and potential for lower bb which affects handling and braking.

 

[ebike4healthandfitness]

Only if you have a super narrow stance ( your legs only like road bikes ) or demand absolutely perfect human-pedal transfer ( that would be very few of us ) is the Q factor limiting.

The current one hour record holder is Filippo Ganna. He is 6'4" and the q factor on his record setting bike is 134mm.

These wide q factors of 175mm found on analog mountain bikes are not for going fast on the street but rather for allowing easier body weight shifts necessary for balancing the bike in rough terrain (i.e. trails). If not on a trail there is no advantage to having 175mm q factor. Even Bosch is in the process of narrowing q factor to be more relevant via their recently announced SX mid drive which has 160mm q factor.

 

[neptronix]

I've kept the stock Q factor on 10 bikes i've converted using all kinds of motors that weren't the Grin all axle.

Few people would convert a roadbike on this forum ( not a good platform for high speed ) so such advice should be reserved for someone doing that specifically.

Okay, i stand corrected. Then my legs that like narrow pedals like 178mm. But again, few people see sub-optimal pedaling force as a negative, most ebikers here don't pedal. I'd suggest reserving that advice for people who state they care.

I like narrow Q factor for optimal power transfer and joint happiness, but don't require it. Losing 10 watts of human power isn't a big deal when you're adding 1000w of electric power.

These are not most people's requirements.

The current one hour record holder is Filippo Ganna He is 6'4" and the q factor on his record setting bike is 134mm.

These wide q factors of 175mm found on analog mountain bikes are not for going fast but rather for allowing easier body weight shifts necessary for balancing the bike in rough terrain (i.e. trails).

That would be a concern of a road cyclist doing competitive riding and not of any interest to 99.9999% of the population of this ebike forum.

 

[BiggKidd]

After three days of research and calculations, it seems that building an e-bike by purchasing a second-hand quality frame and combining it with a good conversion kit ends up being roughly 30% more expensive than buying a ready-made e-bike from a lesser-known brand with comparable power and features.

Would you agree with this observation, or how would you refine this assessment
?

I'm new to E-bikes myself and came to the same conclusion. I ended up buying one and I am very happy with so far. It does leave me wanting more and sort of wishing I had built one but in hind sight I'm pretty glad I didn't. I will likely build exactly what I want at some point in the future.

 

[neptronix]

Re: --^

Most people new to here start with a prebuilt bike, discover how crappy they are, see the cool stuff others are building here, and eventually become EV diehards with little exceptions.

I'm saying you can skip the first step

 

[ebike4healthandfitness]

Few people would convert a roadbike on this forum ( not a good platform for high speed ) so such advice should be reserved for someone doing that specifically.

A road bike is a great platform for high speed. They are made for it. They descend at over 60 mph and sprinters in the tour de France are known to go over 45 mph on flat ground with just their legs, of course.

The reason for people with 130mm rear spacing and 11 speed road cassette not converting their bike is because they cannot. You can't advise them on how to do the conversion because their is no hub motor that fits that criteria.

 

[neptronix]

..but not for things that ebikes need, like traction, comfort ( some form of suspension ), frame strength, strong dropouts, strong brakes... that's why almost everything on here is a MTB.

Good advice to dispense to someone looking to convert a road bike but that's an edge case on this forum and probably not relevant here.

 

[ebike4healthandfitness]

..but not for things that ebikes need, like traction, comfort ( some form of suspension ), frame strength, strong dropouts, strong brakes... that's why almost everything on here is a MTB.

Good advice to dispense to someone looking to convert a road bike but that's an edge case on this forum and probably not relevant here.

Nobody in the road bike world is complaining about comfort. Even in the gravel bike world suspension forks never caught on. However, If someone was really bothered though they could also add a short travel suspension fork. Frame is strong enough and so is drop outs especially if using a clamping torque arm. Brakes are a zero issue in dry weather and even in the rain performance can be acceptable with the right pads. In fact, the only reason road bikes switched to discs has nothing to do with the braking performance but rather aerodynamics. Carbon fiber aero rims can't take high heat from rim brakes due to the resin going soft from the heat and while there such a thing as high temperature resin it makes the carbon too brittle. So with much protest disc brakes came. With that noted, Regen via a hub motor solves the heat issue that would happen on long descents with rim brakes and carbon. But nobody makes such a hub for a 11 speed rim brake road bike (130mm rear spacing). That is the real reason why almost every bike on here is a mtb bike.

Edit: forgot to mention traction. I see no problem with traction in a street setting. These bikes are set up to be agile and take turns fast on pavement.


P.S. Rim brake wheel sets are known to descend faster on a twisty road than disc brake wheelset due to wider spoke flange spacing.

 

[neptronix]

One last time. Let's see if OP is building a roadbike before dispensing more roadbiker related advice. You're cluttering up this thread and interfering w/OP getting help at this point. Bad signal to noise ratio.

 

[maiz]

With hub motors, you can retain the stock Q factor of the bike.

BikeOn is another solution allowing undisturbed q factor

 

[Chalo]

Road bikes are unsuitable for electric conversions for the same reasons that they're good at being race bikes. They have their structural margins shaved down as low as the budget allows, to make them light and limber (both undesirable qualities in an e-bike). They lack luggage mountings, they have abbreviated weight limits, and they usually sharply limit the sizes of tires that can be used.

They're basically poser bikes for posers.

 

[ebike4healthandfitness]

Road bikes are unsuitable for electric conversions for the same reasons that they're good at being race bikes. They have their structural margins shaved down as low as the budget allows, to make them light and limber (both undesirable qualities in an e-bike). They lack luggage mountings, they have abbreviated weight limits, and they usually sharply limit the sizes of tires that can be used.

They're basically poser bikes for posers.

Even the Lightest road frame can handle over 1900 watts of pure human sprinting power through the cranks to the tire (which about 50% more power than what a BBSHD puts to the tire)....and keep on going race and race. Engineering is amazing my friend.

 

[docw009]

Cheaper to buy a cheap ebike than to build one if you start as a newbie builder., If you get the building bug, like me and build a dozen or more, you accumulate enough batteries so that isn;t a new expense, and you might have found some good deals on both motors and batteries too. or you learn how to build safe batteries with good cells. Then it's a hobby, and economics don;t matter as much.

I can buy this basic Hoverfly ebike for $467. It has disk brakes, suspension fork and cost less than the $480 I spend on my first ebike. Sure, it might have cheap shifters a base derailleur, weak brakes, but those are easily upgraded for less than $100 ,
.