If you were going to buy a bike to convert....

[scbk]

Hi folks,
I'm sure this has been done to death, but if you were going to buy a good quality bike to convert, what would you go for? Either make/model or just general specs of the bike.
It would probably be a 2nd hand bike, and would probably be converting it with a rear wheel motor.

First thing it would need would be hydraulic disc brakes.

Don't know what wheel size is best, either for riding or converting.
Bike would be used as a typical "hybrid", on roads, occasional dirt tracks, with mudguards and panniers.

 

[Benjahmin]

The best bike is one you feel comfortable riding.

 

[Az.]

I think it is easier to choose conversion kit first and then choose a bike.

There are plenty of bikes to choose from reliable retailers or Ebay while I really struggle to find a well priced conversion kit from reliable source.

 

[Bonzo Banana]

If you went for a cheap kit they are set up for V and mechanical disc brakes out of the box and steel is easier to deal with and denser and stronger plus the cheap kits seem to be mainly 26" wheel based. So if you were going for a low cost ebike, you might end up with a cheap steel 26" mountain bike with rigid forks and either a rear or front hub motor.

I guess the cheapest kits nowadays around £180, a cheap rigid mountain bike perhaps £120 and a battery maybe £150 of good capacity.

Obviously the more you spend the more you can customise and really its down to how much you are willing to pay.

Ebike motors clearly add a few extra stresses and issues to the frame and forks so its good to up the strength. Many bike designs are weight obsessed because many riders will pay more for less so to speak but those bikes are not ideal for ebike conversions you want a bike overly strong with some over-engineering here and there. Mid drive motors put huge stresses on the bottom bracket area, you can see commercial mid-drive bikes are typically massively over-engineered around the bottom bracket with dedicated motor mountings to deal with those additional stresses. Hub motors typically aren't quite as powerful unless you go into the illegal territory but still need some extra strength in a few places.

 

[guerney]

I tried to answer the question of which bike would be best to convert using a Bafang bbs01b kit, but wasn't aware of this forum at the time... After looking high and low, I simply decided to convert the bike I already had. I'm very pleased with how it worked out, and that it still folds. It's not the tidiest looking bike in the world, but here's a 30 second exposure (on "Pro Mode")using a Oneplus phone that I took on a hilltop overlooking the city last night, while eating a kebab (the chip shop owner allowed my bike inside) to recover from hours of digging up the garden. You can just about make out city lights on the left. The only illumination was moonlight, and because it's long exposure, the reflective areas are bright. The green hue on the aluminium frame, is reflected moonlight from the grass. I point the torch on the handlebar backwards to illuminate my hi-viz blouson, to make my myself more hi-viz. The bottle holder is empty, because the kebab was quite spicy.




The sky becomes over exposed, after a 1 minute exposure in moonlight. One can deduce the position of the moon in the sky, by the shadows. The wing mirror appears green - this is due to reflected moonlight, because I stuck reflective tape over them.




Some version of Carrera hardtail has been mentioned on these forums, as a good bike to convert.

 

[Raboa]

The best bike is one that fits, I find that a women's version fits me better due to the shorter top tube.

 

[Az.]

I'm very pleased with how it worked out, and that it still folds. It's not the tidiest looking bike in the world, but here's a 30 second exposure.

Hi Guerney,

As you said your conversion might not be the tidiest one, but as long as it is fun and brings joy to your life it is all that matters, right?
I like your long exposure picture and love your story. I only want to bring your attention to quick release skewers. Can't see well on your picture, but I am under impression your levers are pointing down.

How to use quick release skewer

 

[guerney]

Hi Guerney,

As you said your conversion might not be the tidiest one, but as long as it is fun and brings joy to your life it is all that matters, right?
I like your long exposure picture and love your story. I only want to bring your attention to quick release skewers. Can't see well on your picture, but I am under impression your levers are pointing down.

How to use quick release skewer

@Az. Thanks for pointing that out! I had no idea - this newfangled QR stuff wasn't about in the late 80's when I gave up cycling (after colliding with a black BMW), and I went by Dahon publicity shots where the skewer lever were folded down, yet others showed the levers folded up. I couldn't recall which way they originally pointed, because I had bought this bike from a friend many years ago and it remained in the loft until the pandemic forced me to dust it off for conversion, and at some point I started pointing them down... Very good informative video - I'll flip 'em up! It was well worth the the two or so minutes taking those photos, or I might never have known! This bike magically transforms me into superman... much more than the superman I was in the 80s. I do think any new Superman movie should feature him riding a Dahon.

 

[guerney]

Hi Guerney,

As you said your conversion might not be the tidiest one, but as long as it is fun and brings joy to your life it is all that matters, right?

What didn't bring me joy, was that it couldn't climb the final 100m 45 degree incline to get to the top of that hill! On lowest gear, the motor provided enough power... but the bike's balance was thrown off by the rear rack mounted battery. But there's a "Walk" function for that I hardly ever offroad, therefore it's not a big enough issue to relocate the battery, and a mid-mounted battery would prevent the bike folding.

 

[Woosh]

Hi folks,
I'm sure this has been done to death, but if you were going to buy a good quality bike to convert, what would you go for? Either make/model or just general specs of the bike.
It would probably be a 2nd hand bike, and would probably be converting it with a rear wheel motor.

First thing it would need would be hydraulic disc brakes.

Don't know what wheel size is best, either for riding or converting.
Bike would be used as a typical "hybrid", on roads, occasional dirt tracks, with mudguards and panniers.

if you are going to fit a bottom bracket motor, buy one with hub gear.
If you are going to fit a hub motor, keep in mind that you would not need the smaller chainrings with an electric motor, single ring crankset is fine.
If you are buying a mens bike, look for a downtube with a flat top or wide top, that will give the battery a more stable base and make fitting the battery easier.

 

[scbk]

Just to say this is the current bike, it was a cheap hybrid with V brakes and 26" wheels.
The motor is a yose power 36v 350w but after a year I burnt out the controller, and I fitted a bigger controller, on the display it goes up to about 700w to the motor. That also meant I could fit front and rear lights running off the battery which is handy.

It's now got about 3,800 miles on it.
I had to replace the chain and freewheel/cassette/front sprockets this spring, I wore out the top gear, then wore out the 2nd top gear.
And even more recently, a part of the rear wheel rim was starting to break away, I imagine as a combination of the rim brakes, potholes, and the weight the bike carries.
A local bike shop was able to re-rim the wheel, but it took them a while to find a rim to fit, so the bike was out of action for a month which was kinda annoying.


So hence me being on the hunt for a sturdier bike to do another conversion on, probably with a bigger motor, and the biggest battery I can. The current bike owes me nothing, so it can be a spare runaround

 

[Bonzo Banana]

if you are going to fit a bottom bracket motor, buy one with hub gear.
If you are going to fit a hub motor, keep in mind that you would not need the smaller chainrings with an electric motor, single ring crankset is fine.
If you are buying a mens bike, look for a downtube with a flat top or wide top, that will give the battery a more stable base and make fitting the battery easier.

Why would you want a mid-drive motor and a hub gear as a preference? Bosch typically lower the power output on their mid-drive motors when used with hub gears as they aren't as strong. Nexus 7 is probably one of Shimano's least reliable hub gear mechanisms. I'd give the opposite advice and say if you are using hub gears with the possible exception of the simpler 3 speed mechanisms and strong Rohloff type hub the ideal combination is a front hub motor, that way you share the load between motor and drivetrain that can extend the life of hubs like the Nexus 7 and 8.

 

[Woosh]

Why would you want a mid-drive motor and a hub gear as a preference? Bosch typically lower the power output on their mid-drive motors when used with hub gears as they aren't as strong. Nexus 7 is probably one of Shimano's least reliable hub gear mechanisms. I'd give the opposite advice and say if you are using hub gears with the possible exception of the simpler 3 speed mechanisms and strong Rohloff type hub the ideal combination is a front hub motor, that way you share the load between motor and drivetrain that can extend the life of hubs like the Nexus 7 and 8.

hub gear has perfect chainline, avoiding the dreaded chain noise when you change gear and prolonging the life of the transmission.
I know that Shimano recommend lowering the power when used with their hub gears but it's rare that a hub gear ever fails with a BBS01B, I personally have not seen one fail in years.

 

[jarob10]

Hi folks,
I'm sure this has been done to death, but if you were going to buy a good quality bike to convert, what would you go for? Either make/model or just general specs of the bike.
It would probably be a 2nd hand bike, and would probably be converting it with a rear wheel motor.

First thing it would need would be hydraulic disc brakes.

Don't know what wheel size is best, either for riding or converting.
Bike would be used as a typical "hybrid", on roads, occasional dirt tracks, with mudguards and panniers.

Assuming your legs are long enough, I’d recommend one of those full suspension decathlon bikes in XL size discussed on here recently. then add a Q128c 500w rear hub + hailong battery on the downtube.

 

[Az.]

then add a Q128c 500w rear hub

Which is illegal, isn't it?

The best bike is one you feel comfortable riding.

Don't think it is a good advice. Having a rare opportunity to buy a bike for conversion it is good to plan few steps ahead as DIY conversion is not as straightforward as one might think.

For example Deore 1x11 is much better than Deore 3x10 for mid drive conversions as you will loose front derailer. Steel fork is better than aluminium for wheel conversions. Aluminium better than carbon etc.

I bought a Yose front motor kit and I see now battery base is not designed well as controller is placed where mounting holes should be. It means I will have to work around a problem. Drill holes in frame most likely.

Are you happy to lose gears? Drill holes? Alter balance of your bike? One way or another you will have to make some compromises. Just make sure you are happy with those compromises before you commit to a project.

...and good luck

 

[Bonzo Banana]

hub gear has perfect chainline, avoiding the dreaded chain noise when you change gear and prolonging the life of the transmission.
I know that Shimano recommend lowering the power when used with their hub gears but it's rare that a hub gear ever fails with a BBS01B, I personally have not seen one fail in years.

I totally understand the benefits to the drivetrain compared to a derailleur setup but lifespan of the Nexus 8 has been put at between 8,000-20,000 miles on a standard bike but with a significant percentage of early failures. The Nexus 7 is significantly less than that. I've seen quite a few forum postings in the past where the Nexus or Alfine has failed when paired with a mid-drive motor like a Bosch. Maybe less than 3,000 miles on a Nexus 7. I seem to remember one person had both motor failure and hub gear failure on the same bike outside warranty and the bike was uneconomic to repair despite only being 4 years old. The Nexus 3 is a very simple reliable hub but the Nexus 8 and 7 have significantly less reliability and the Alfine 11 is even worse. All that additional torque going through the hub has to surely significantly reduce its lifespan typically.

Looking at german forums they are stating 20,000 kilometres is good for a Nexus 8 with most failing before that and the Nexus 7 even worse and this is before you add a mid-drive motor to the equation.

However there are reports that adding a front hub motor significantly extends the life of these hubs well beyond normal mileage.

Also how do they work with regards gear changing under load. A significant amount of Nexus wear seems to be those riders who change gear under load how does the mid-drive motor prevent doing that damage? I don't think the earlier Bosch motors or even current motors perhaps had any gear change sensor motor power cut off system. I just wonder if that is something that has been improved on Bosch or implemented on other motor systems.

 

[vidtek]

What I did was to go to my local charity not-for-profit bike shop called "Hope to Cycle". They receive hundreds of perfectly good bikes donated by the general public.
I got chatting to the volunteer bike mechanic who works there and told him I was looking for a lightweight donor bike for a ebike conversion.
At the back of the shop was a very large shed with literally hundreds of donated bikes, he said "pick one and I'll recondition it and make sure it all works for you."

I went through the most likely candidates and picked the lightest alloy one which happened to be a Specialized Crossroads, 1986 vintage. It is a beautifully balanced lightweight bike, ideal for an ebike conversion.
The mechanic cleaned it up, replaced tubes, tyres, brakes all cables, chain and cassette and charged me a grand sum of £240.

I fitted a TSDZ2 mid-drive 2 years ago supplied by Whoosh and have had 2 years of use and about 2500 miles. I am extremely happy with it.

 

[StuartsProjects]

this newfangled QR stuff wasn't about in the late 80's when I gave up cycling

Might not have been 'around' by you, but QRs were released by Campagnolo back in the 30s.

I think I still have a set of Campagnolo small flange QR wheels, 27" of course, from the mid 70s somewhere .......

https://en.wikipedia.org/wiki/Quick_release_skewer

 

[guerney]

Might not have been 'around' by you, but QRs were released by Campagnolo back in the 30s.

I think I still have a set of Campagnolo small flange QR wheels, 27" of course, from the mid 70s somewhere .......

https://en.wikipedia.org/wiki/Quick_release_skewer

I had a nutty Sun racer in the 80s, heavy and built like a bike-shaped tank... I even did a few big jumps with it - deicided to use a long slope ending in a ramp in a park, and flew over my mate's head. On landing, both pedals bent My feet had left the pedals while I was airborne, and my weight upon landing was clearly too much for them. I cycled home on wonky pedals...

 

[scbk]

UPDATE:


I know you're all dying to know.
In the end I got a Giant Escape "City Disc 2".
700c wheels, hydraulic disc brakes, and comes from the factory with a stand, rack, and mudguards.

The tyres it came with were skinny, so I put on the biggest semi knobbly (and puncture proof) tyres it can take, the mudgaurds needed modded.

I got a Bafang rear wheel hub motor kit, 48v 500w, and a 48v 20ah battery. On the display it takes it up to about 900w.


I've got it hooked up with front and back lights, all 48v and running off the main battery.
The display is colour and backlit, and even better the backlight actually dims when you have the lights on. It has a light senor so the lights can come on automatically, or manually.

I've also got a 2nd 48v front light that is very bright and pointing straight out, it's used as a full beam when there's nothing oncoming, it came with it's own little switch for the handlebars, and even has an electronic horn.

Cheap set of panners from aliexpress


I got the bike all put together and on the road towards the end of august, and have done about 850 miles, all going well so far!