Heavy-duty steel road bike conversion - Advice needed

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Bobbincon   1 µW

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Heavy-duty steel road bike conversion - Advice needed

Post by Bobbincon » Feb 21 2016 9:58am

Hello,

I'm hoping to get some advice from some knowledgeable people about an e-bike conversion.

As per the post about getting good advice here's some info.

Desired Max Speed: 25 kmph (Legal Max)
Desired Max Range+CrusingSPeed: Long Range maybe 100km, again 25 kmph (Legal Max)
Bike wheels: 700c
Brakes: not Disc, rubber calliper pads
Rider weight: Max 210 pounds or 95.25 kilos
Terrain: Flat and Hilly to Mountainy if possible. Roads only
Budget: I'd hope under 1000 €/$ . Could go over 1000 by a hundred or so if it's worth it.

It should be pedal assist, another legal requirement for Ireland/Europe. I will be performing the conversion myself. I'm experienced at regular bicycle maintenance/mechanics.

Here's a picture of the Bicycle in question (As attachment, I don't know how to post it here).

I hope some one might have some advice for me, such as which type of motor I should consider, mid drive or back wheel etc. and what make, power. I'm finding it quite difficult to decide.

Thanks for your time :D
Attachments
(scaled)DSC01256.JPG
"When I see an adult on a bicycle, I do not despair for the human race."
-H.G.Wells

Simonvtr   100 W

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Re: Heavy-duty steel road bike conversion - Advice needed

Post by Simonvtr » Feb 21 2016 10:09am

Hello Mr.Bob

Reading your requirements/needs and to me it screams mid drive kit.
With a mid drive kite you can keep the same wheels and the same braking system. You will be able to tackle most hills/mountain paved roads (depending on the kit wattage limit/ gearing options).

This article is dated back from 2014 but It does seem to have some of the newer mid drive system on there. If anything you might give you a better idea what you might want to look for in a mid drive kit.

https://www.electricbike.com/mid-drive-kits/

Bobbincon   1 µW

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Re: Heavy-duty steel road bike conversion - Advice needed

Post by Bobbincon » Feb 21 2016 11:28am

Simonvtr wrote:Hello Mr.Bob

Reading your requirements/needs and to me it screams mid drive kit.
With a mid drive kite you can keep the same wheels and the same braking system. You will be able to tackle most hills/mountain paved roads (depending on the kit wattage limit/ gearing options).

This article is dated back from 2014 but It does seem to have some of the newer mid drive system on there. If anything you might give you a better idea what you might want to look for in a mid drive kit.

https://www.electricbike.com/mid-drive-kits/
That article was enlightening reading, thank you Simonvtr. Mid-drive it is!

The BafangHD sounds very interesting. Much more power than I need, but it sounds like it is well built and long-lasting. Perhaps best value because of that. I wonder how it works with the gears already on the bike, what battery to get with it, and if it's pedal assist...
"When I see an adult on a bicycle, I do not despair for the human race."
-H.G.Wells

Raged   1 kW

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Re: Heavy-duty steel road bike conversion - Advice needed

Post by Raged » Feb 21 2016 6:23pm

Bobbincon wrote:
That article was enlightening reading, thank you Simonvtr. Mid-drive it is!

The BafangHD sounds very interesting. Much more power than I need, but it sounds like it is well built and long-lasting. Perhaps best value because of that. I wonder how it works with the gears already on the bike, what battery to get with it, and if it's pedal assist...
Better to have more power than to be left stranded climbing a hill. A mid-drive BBS02 750 or BBSHD (1kw) replaces your bottom bracket and crank. The standard size for BBS drives are usually BSA English Thread 68mm, so check what bottom bracket you have to ensure it fits. As it replaces your crank, you lose the front shifting mech. so if you have a 18 speed ( 2 crank x 9 rear ) it becomes a 9 speed ( 1 crank x 9 rear ). I find that I never use granny gears on a road bike anyway... with a motor, you definitely wont. They come with pedal assist and the max speed is 50km/h. If you get the programming cable, you can set it to whatever you want.

Items to take note
- standard chainring is 44t which might be too small for a road bike. I went up to 48t on my cyclocross.
- under bike cable routing on road bikes... You might need to fabricate some rubber padding ( 2 peices of rubber either side of the cable to ensure the motor doesnt interfere with the cable movement.
Focus Black Forest 29er - MAC10T 14S Lipo - 50km/h, 50km range. (dead)http://endless-sphere.com/forums/viewto ... 91&start=0
Cube Reaction 29er Cyclocross BBS02 http://endless-sphere.com/forums/viewto ... =6&t=70549

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Ykick   100 GW

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Re: Heavy-duty steel road bike conversion - Advice needed

Post by Ykick » Feb 21 2016 7:15pm

If you’re able to maintain and build wheels a small rear hub motor like Q128H has been good to me on a similar bike. Check the last page of my signature link, there’s a heavy steel bike using that drivetrain. I even have the steel crank, haha!

I do like BB drives too (finally got 750W Bafang) but it’s quite different. Can’t quite put my finger on it yet? I like it, I really do but I also like the smooth simplicity and lower purchase price of a powerful little hub motor.

Lotsa options!
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dogman dan   100 GW

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Re: Heavy-duty steel road bike conversion - Advice needed

Post by dogman dan » Feb 22 2016 6:49am

Steel road bikes may be old enough to have exotic bottom brackets. But yeah, in a way, any road bike screams mid drive me. Really. Then you keep those original, again quite possibly odd size wheels.

But if the wheels are 700c, easy to get a rear kit in that size rim. And it can be pretty low power, only about 200w needed to cruise at 25 kph on the flat.

If you don't mind cheating the law a bit though, give the motor a bit more power, say 500w. 36v 15 amps controller would do.

Your back end may not be the full 135mm wide, to take a standard rear bike motor. But a steel frame can safely be bent out to 135mm, with no worries at all. Likely not that narrow, but if yours is 5 gears, it will likely be 125-130mm wide.

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