Which bike to convert ? What is important to look at before buying ?

Hi, I am searching a good bike to convert to use to commute 24 miles round trip on road with some hills, and I don't use trottle.
The problem is after searching and searching I don't know what is a good base so I will not have to change a lot of things on the bike.
I see hardtail mtb are good, but is there a recommanded one to buy new (ideally under 1000€) ? For exemple I suppose I will have to put road tires and not use a mtb that have multiple chainring etc.
I am new to bike and I am bit lost. I don't know how to compare the bikes, what characteristics etc.
I have see the motor and how to install it (bafang bbshd), which wasn't easy to understand all but now I get it.
And I am sorry if my english is not perfect.

Kaerio said:

Hi, I am searching a good bike to convert to use to commute 24 miles round trip on road with some hills, and I don't use trottle.
The problem is after searching and searching I don't know what is a good base so I will not have to change a lot of things on the bike.
I see hardtail mtb are good, but is there a recommanded one to buy new (ideally under 1000€) ? For exemple I suppose I will have to put road tires and not use a mtb that have multiple chainring etc.
I am new to bike and I am bit lost. I don't know how to compare the bikes, what characteristics etc.
I have see the motor and how to install it (bafang bbshd), which wasn't easy to understand all but now I get it.
And I am sorry if my english is not perfect.

Click to expand...

Do you need a rack? If so, a hard tail had better support, as opposed to the seat tube type you'd need with full suspension. Front suspension fork is a good idea, and enough seat tube extension to be able to use a suspension seat post now, or later would be a good idea. Other than that, enough room in the triangle for the battery. If you want disc brakes, now or later, a frame that supports disc brakes would be something to look for.

Here is a good place to start:

https://endless-sphere.com/forums/viewtopic.php?f=3&t=111571

Kaerio said:

Hi, I am searching a good bike to convert to use to commute 24 miles round trip on road with some hills, and I don't use trottle.
The problem is after searching and searching I don't know what is a good base so I will not have to change a lot of things on the bike.

Click to expand...

What exactly do you need the bike to do for you? Will you be carrying anything other than yourself? (needing a rack, or panniers, baskets, etc)? Ever need to pull a trailer?

What are the road conditions? Perfectly smooth pavement? Or more typical roads with rough spots, potholes, etc? If so, how bad? Dirt / rock paths? Etc? (determines suspension, tires, wheels)

What are the traffic conditions and riding speed? Stops/starts? etc? (determines braking needs and tires, as well as power necessary to maintain speed).

I am new to bike and I am bit lost. I don't know how to compare the bikes, what characteristics etc.
I have see the motor and how to install it (bafang bbshd), which wasn't easy to understand all but now I get it.

Click to expand...

The primary thing the bike must do, to use the BBSHD, is to have the BB (bottom bracket) area designed so the BBSHD will fit in it without modifying the frame. That includes having the right kind of BB (there are at least several different types, not all of which will fit it), and not having a frame with too thick a tubing for it to fit over. It also includes a frame design around the BB that allows the whole BBSHD to fit under it; some frames are curved or otherwise designed such that parts of them stick out where the BBSHD has to go.

To be certain of a fit, you'd need to look at the drawings of the BBSHD (some in various threads here on ES, should also be on the Bafang site and some sellers of the BBSHD probably have them too) to compare the measurements of clearances needed by the BBSHD and the measurements of the actual bike. Since most bikes don't have drawings with these available, you'd have to actually have access to the frame to measure it yourself, or have the BBSHD in hand and see if it fits.

Alternately, you can check out the various BBSHD build threads here on the forum, and use a bike frame (same model, same year) that's used in one of them, since it fit for them, it should fit for you. (assuming that frame also does everything else you need it to do).

Hi, thanks to all of you for your answers !

Considering your comments, I think I will go for a hardtail mtb with enough seat tube fto be able to add a suspension seat post, and that have disc brakes.

The bike is to commute, 24 miles total, on asphalt road, medium quality (not perfect new smooth road, the asphalt is not new, but no real holes to go in), a few hills (longest is 1km). I need a rear rack but no big weight on it, just food for the day, few clothes, and bike equipment in case of problems. There are 8 possible stops on my way. And I will not use a trottle cause the bike is illegal here in Europe and using a trottle would be too obvious. I will use mostly desert campaign road to avoid big dangerous more direct road and a little part of my city only.
I was thinking about a bike like the Decathlon Rockrider ST540 or a Trek Marlin but the frame seems to have a bit less place in the Marlin. I saw builds with these bikes and the BBSHD.

Thanks I will post the bike before buying. Which size of wheels do you recommand ? I see 26, 27,5 and 29
For tires, I already was thinking of putting tires suited for road and rain, and maybe have second wheels suited to go on woods sometimes on week-end (nothing extreme, just ride in path in nature to change ideas)

Make sure everything fits before buying. Maybe make a box the size of the battery. Or maybe if getting a rear hub have you can get a nut to fit on axle next to derailleur meaning make sure it fits before you buy.

I used to have a BBS02 on my only e-bike. It was fun and effective, but too much maintenance for my liking (on a commuter bike). You would get much better reliability and less service commitment by using a hub motor.

I have seen these 3 bikes I like and have a possibility to test near when I live. My height is 170 cm (5'7 feet) and it would be normally a size M for me as I see on sites :

Trek Marlin
Cannondale Trail
Decathlon ST 540 V2 : https://www.decathlon.fr/p/velo-vtt-st-540-v2-bleu-27-5/_/R-p-335529?mc=8667311&c=BLEU_TURQUOISE

Do you think it need to go high-end range price for these bikes or the entry / mid range are good enough like a Marlin 5, 6 or 7 ?

Chalo, what maintenance do you talk about ? I have see lot of people having lots of miles with the BBS motors and they just speak chains etc
Also a hub is pain to change rear tire if flat as I see. And I have hills to climb. But I am open for advice obviously.

Thanks I will see at the shop.

For the motor, I think I will be fine. A coworker has a cheap Nakamura E-Summit 740 (250w chinese motor), and the motor is just fine in hills when we tried it, so a 750 watts or 1kw must be good enough. I am only 150 pounds and I like sport. And the road I will use have not so much place to ride fast. 25-28 mph for a max speed sometimes is really enough for me. And I can't ride so fast in the city part, cause not allowed and I would be detected as a criminal :lol: (EU shitty rules, seriously I followed a road bike today coming from work that was at +/- 45 km/h on flat at my car board, he must be a beast but electric at 25km/h max no way I pay for that)

E-bulider do you use a shifter intersect. For smooth shifting ?

ebuilder said:

Kaerio said:

Thanks I will see at the shop.

For the motor, I think I will be fine. A coworker has a cheap Nakamura E-Summit 740 (250w chinese motor), and the motor is just fine in hills when we tried it, so a 750 watts or 1kw must be good enough. I am only 150 pounds and I like sport. And the road I will use have not so much place to ride fast. 25-28 mph for a max speed sometimes is really enough for me. And I can't ride so fast in the city part, cause not allowed and I would be detected as a criminal :lol: (EU shitty rules, seriously I followed a road bike today coming from work that was at +/- 45 km/h on flat at my car board, he must be a beast but electric at 25km/h max no way I pay for that)

Click to expand...

Good plan. A BBSHD on pretty much any bike is a magic carpet ride. Dead quiet and plenty of power. It always comes down to the discretion of the rider. I can't tell you how many performance cyclists I approach on my bikes who don't know I have a motor. I am a cyclist first and foremost and look like one. I don't ride bunched up like Mary Poppins. My bikes are a performance fit. The motor to me is an adjunct not the single source of power. I rarely go to maximum power. Almost never. But 30mph with a BBSHD with a bit of pressure on the pedals is a nice thing.
I spend a lot of time in the low 20's with me contributing 100-150 watts and riding in Heart Rate zone 2 which is terrific for endurance development. I do this in power level 1 of the motor which gives the bike good range and combined motor at low level + rider = good speed and decent battery range.
You will really enjoy it I believe.

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That's totally my mindset. I like sport and want to pedal too. I think of even using a real bike sometimes to go to work when i will feel I am ready, like doing the last day of the week and the other days with the electric bike. I am 39 and my life is becoming boring and I need some challenge and fun stuff to do

Gear Sensor for Bafang Ultra and Max Motors
They have these at Luna cycle. Are they needed
"Gear Sensor for Bafang Ultra and Max Motors - Luna Cycle" https://lunacycle.com/gear-sensor-for-bafang-ultra-and-max-motors/

I have another question related to the motor of bafang. Is there a visible label on it that say it is 1000w or another amount ?

I've built 5 ebikes, here's the experiences:

Rigid bike with front hub motor. Direct drive front hub motor was heavy and gave way too much shock up through the handlebars. Gear drive front hub motors (2) were lighter and gave less shock through the handlebars. Lighter hub motor is better.

Full suspension bike with rear gear drive hub motor. Great bike, great ride. Seat post rack held the battery, also tried frame mounted battery. Problems happened when stopped for two reasons. First, rear rack mounted 14S8P battery was heavy and bike was unstable when stopped, especially stopped on an uphill. Second, full suspension bikes place the bottom bracket higher than hard tail bikes, this made touching the feet when stopped difficult.

Front suspension hardtail with suspension seatpost and rear gear drive hub motor. This is my current bike and is close to ideal. Ride on most streets and bike paths is as good as full suspension, but FS is better for going off curbs and taking big hits. Pedal forward frame, Townie, makes stopping a lot easier and safer. This bike has panniers, the battery goes on one side of the rear rack, chain and stuff goes on the other side.

Suspension seatpost: even a cheap one makes a big difference, but longer travel is better.

Suspension fork: cheap is good, a better fork is much better.

Battery mounting: rear panniers place the battery much lower than top of a rear rack. Not much difference when riding, but a big positive difference when stopped, especially stopped on an uphill.

Rear gear drive hub motor: I use three chainrings on the front and 7 or more cogs on the rear. Use a really good torque arm. All the gears are used. A front hub motor allows you to use both front and rear gears.

I've only used a throttle on my bikes but have ridden cadence and torque sensor pedal systems. Throttle is best, especially with cruise control. It's almost impossible for me at least to ride and not pedal hard, throttle is very compatible with pedaling, especially hard pedaling. The cars, trucks, suvs, motorcycles, scooters, powered planes, powerboats, etc. that I've used all have had throttles, so throttle is completely intuitive. Besides being a familiar system, throttle makes starting uphill a lot easier.

Distance: The 14S8P, 52V, 20Ah battery easily gives 50 miles. I don't fully charge it and never discharge it below about 3.7V/cell. Battery weight is about 12 pounds.

A Cycle Analyst V3 is an excellent option, it has lots of information and the very useful cruise control that I use almost all the time.

Hope this is useful, keep is posted on what your plans are, what you get and how it works out.

Kaerio said:

I see hardtail mtb are good, but is there a recommanded one to buy new (ideally under 1000€) ? For exemple I suppose I will have to put road tires and not use a mtb that have multiple chainring etc.
I am new to bike and I am bit lost. I don't know how to compare the bikes, what characteristics etc.

Click to expand...

May I just throw in another consideration - if you are building a dedicated commuter for 40 km/day exclusively on hard road, is there a special reason why you would go for a mtb and not a more purpose-built road bike like a gravel bike or touring hybrid? I would choose a mtb if I wanted to go off road at times, but not for pure asphalt. A mtb is more likely to offer a suspension fork, granted, but for me that would not be a deal breaker on a commuter. Also the gearing on a road(ish) bike may be more appropriate for your 25-28 mph aim.

There may be reasons that I am missing, and I have not the experience from building several ebikes, but I faced very much the same design choice a year ago (27+27 km commute) and building on a mtb never felt like an option to me. I built on a hybrid and really never looked back. General geometry is more suitable imho, rack and fenders were there, rims are right size for the tires I like to use on asphalt. Rigid frame but hey - I ride 100% asphalt. Been considering a suspension seat post though, but that is due to small shocks from the rear rather than front.

I think there is little use for very specific model recommendations as you are limited to your local stock of (used or new) bikes anyway. There is already a lot of good advice in the thread.

Kaerio said:

I have another question related to the motor of bafang. Is there a visible label on it that say it is 1000w or another amount ?

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Do you mean like this? The bottom numbers are engraved into the metal housing. The top numbers are one of the silly stickers that they send out with the motor (I received four). I decided sticking one right above the engraved numbers would be ironic.


FYI: That is on the bottom of the motor.
I am also not certain that printed sticker is printed with UV resistant ink (fade to white).
In the UK and EU one can get a UV resistant clear spray coating.
I have never been able to find anything similar in the US.
One can use Spar Varnish but it has a yellow tint that gets deeper with age.

LewTwo said:

).
In the UK and EU one can get a UV resistant clear spray coating.
I have never been able to find anything similar in the US.
One can use Spar Varnish but it has a yellow tint that gets deeper with age.

Click to expand...

Been a while since I used it but this stuff
https://www.krylon.com/products/uvresistant-clear-coating/
didnt' yellow in the reasonably long time I had it on a few things. (and without thinking about it I also put it over some dayglo paint to try keeping it from fading as fast in the sun, and of course the UV didn't make it thru as well as without it, so the dayglo paint didn't fluoresce as much as before I did that ).

The can looks a lot different now (but so do all their cans), and I have no idea if the formulation ever changed. I think I got it at lowes or home depot at the time, but it shows up even on amazon now .


Just make sure that whatever you put it on isn't dissolvable by xylene or acetone, or similar compounds, as those are the typical solvents Krylon uses in their paints, and it will wrinkle up some plastic surfaces and some paints.

I should have mentioned the 14s8p battery I'm using is from China, a factory build, 18650 cells, with a relatively low price. It's several years old now. Low price went with low energy density and higher weight for a given energy level. The previous battery had higher density cells, it went with the bike it was on when I sold it.

I charge to 4.1 v/cell and try not to discharge below 3.7 v/cell. So, I'm only using about half or less of the total energy in the battery. I have used and worn out a lot of lipos on my RC vehicles, the bike batteries cost more so I'm trying for long life. Short flights with the planes and quadcopters has given me longer battery life on those machines. Using OSD I can see the battery voltage during flight, that helps a lot.

On a full charge and without hurting the battery from too low voltage, my bike could probably do a hundred mile ride, but I do pedal pretty hard. That said the tires are orientated toward no flats and not toward lowest rolling resistance. Worse, I ride sitting up and use a big brim hat that causes air drag. Decades on aero bars took a toll on the neck, so I sit up. Besides, now I see things other than some other guys rear tire in a pace line. Shade on the face is worth some extra air drag.