I love threads like this - all perfectly valid answers covering about every possible setup.
+1 on hydraulic disk brakes though.
What is your budget?
+1 on hydraulic disk brakes though.
What is your budget?
Donor bikes - what to look for?
- Thread starter Egon
- Start date
A pedelec is a bicycle not a motorbike. DD motors are too heavy, that weight will also break spokes. I think the Q128H is about the best pedelec rear hub motor compromise power/weight ratio wise.
A point that I think has been missed up until now, is that a mid-drive will feel most "bike like". The bike will retain an even front/rear balance with the motor mounted at the crank and the battery in the centre of the frame.
You will also be forced to think about gear selection like with a regular bike. I personally find this aspect is not as relaxing as a hub motor though.
Another point not covered is that the mechanical advantage of a hub motor can be altered by lacing in a smaller wheel to make them more efficient. IMO, 26" is the largest you'd want to go.
You will also be forced to think about gear selection like with a regular bike. I personally find this aspect is not as relaxing as a hub motor though.
Another point not covered is that the mechanical advantage of a hub motor can be altered by lacing in a smaller wheel to make them more efficient. IMO, 26" is the largest you'd want to go.
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From my one off experience.. things to consider
To get the wheel in the correct position, a rear hub motor may need to go further back in the frame than the rear drop outs offer.. this means you may need to cut the hole back so check if you need to and if it can be enlarged easily and safely. ( My rockrider 8.1 worked fine with no cutting.)
The type of bottom bracket on your bike and the amount of room around your front gears may necessitate a specific pedal sensor . the more basic your bike the less worry this is..
hydraulic brakes are great . hydraulic brake cut off switches are not so cheap /easy to get. To save rapid brake pad wear a cut off is a good idea, mechanical disc brakes would make life simpler. Having hydraulic brakes I opted for a thumb kill switch like this .
On another thread I mentioned I didn't like the firmness of the seating of the battery on the frame. You should consider the thickness / cross section of the downtube if you are planning on placing your battery there , also you may have to consider drilling some extra bottle holder screw rivnut holes. I got away without doing that so far.
As I understand it, the smaller wheels are better for uphills.
I have an oxydrive cst kit they seem to be on offer here
and at 27.5inches .. mine is 26 and those seem to be all gone.
however, I dont know why they now sell options of road legal 250w and off road only 350w since I understood the difference to be in the settings.( It could be the hub markings ?) This may have been discussed elsewhere, I havent been here in a while.
That kit makes my rear end heavy. I imagine larger ones must be noticably worse. I weigh 17.5 stone and it has plenty of power to ride up muddy hills It is not a motorbike though and I still pedal about the same as a normal bike on the flat..obviously harder if I want to go faster. It is proper fun exercise.
Personally, I now prefer an All Mountain / enduro geometry so if I were to do it again I would look for a hardtail AM host bike. but you have to be sure the battery will fit where you want it. and I would still go with larger tyres for rear cushioning rather than rear suspension but thats just personal opinion..
To get the wheel in the correct position, a rear hub motor may need to go further back in the frame than the rear drop outs offer.. this means you may need to cut the hole back so check if you need to and if it can be enlarged easily and safely. ( My rockrider 8.1 worked fine with no cutting.)
The type of bottom bracket on your bike and the amount of room around your front gears may necessitate a specific pedal sensor . the more basic your bike the less worry this is..
hydraulic brakes are great . hydraulic brake cut off switches are not so cheap /easy to get. To save rapid brake pad wear a cut off is a good idea, mechanical disc brakes would make life simpler. Having hydraulic brakes I opted for a thumb kill switch like this .
On another thread I mentioned I didn't like the firmness of the seating of the battery on the frame. You should consider the thickness / cross section of the downtube if you are planning on placing your battery there , also you may have to consider drilling some extra bottle holder screw rivnut holes. I got away without doing that so far.
As I understand it, the smaller wheels are better for uphills.
I have an oxydrive cst kit they seem to be on offer here
and at 27.5inches .. mine is 26 and those seem to be all gone.
however, I dont know why they now sell options of road legal 250w and off road only 350w since I understood the difference to be in the settings.( It could be the hub markings ?) This may have been discussed elsewhere, I havent been here in a while.
That kit makes my rear end heavy. I imagine larger ones must be noticably worse. I weigh 17.5 stone and it has plenty of power to ride up muddy hills It is not a motorbike though and I still pedal about the same as a normal bike on the flat..obviously harder if I want to go faster. It is proper fun exercise.
Personally, I now prefer an All Mountain / enduro geometry so if I were to do it again I would look for a hardtail AM host bike. but you have to be sure the battery will fit where you want it. and I would still go with larger tyres for rear cushioning rather than rear suspension but thats just personal opinion..
Thanks for all the feedback guys.
To answer some questions:
I think I weigh around 12 1/2 stone. It's been a while since I checked.
My budget can probably stretch to around 2 grand, for a bike and kit.
To add a question. Is there a list of kit / parts retailers, hopefully ones that forum members had good experiences with? And, when it comes to batteries is it best to order from the UK to avoid and postage issues?
To answer some questions:
I think I weigh around 12 1/2 stone. It's been a while since I checked.
My budget can probably stretch to around 2 grand, for a bike and kit.
To add a question. Is there a list of kit / parts retailers, hopefully ones that forum members had good experiences with? And, when it comes to batteries is it best to order from the UK to avoid and postage issues?
Are you looking to build a pedelec (legal) or something with more power (unregistered motorbike)?
£2,000 is a nice budget for a DIY build. If the answer to the above question is the latter and you do have that sort of money at your disposal, my recommendation would be to look at either of the following as a basis for the heart of your ebike:
Cycle Analyst based system:
http://www.ebikes.ca/product-info/cycle-analyst-3.html
or
Adapto based system:
http://adaptto.com/Products/Controllers/
I'm not so interested in *legal* builds, so someone else would be able to provide better practical advice than I on the matter.
I live on a farm in the middle of nowhere, so road legal is not a concern. I'm not particularly interested in speed, but I do want as much power as possible as there are some pretty hefty hills surrounding me.
"I do want as much power as possible"
Are you sure about this? You might be surprised at what is possible:
Is this your first build? You certainly don't need super high levels of power to climb hills at a leisurely pace.
Ha. I guess I meant, within reason and price.
It is my first build. I don't want to build a full on mini motorbike, I'd still want it to pass for a bike. I don't think it's a great idea to go overly powerful for my first bike. And probably the more technical side of things would be wasted on me at first as well. But I would like the right kind of power to climb steep hills and hopefully not too slowly.
It is my first build. I don't want to build a full on mini motorbike, I'd still want it to pass for a bike. I don't think it's a great idea to go overly powerful for my first bike. And probably the more technical side of things would be wasted on me at first as well. But I would like the right kind of power to climb steep hills and hopefully not too slowly.
You might want to try some off-the-shelf pedelecs before committing to build your own. So you can get a feel for how a hub drive and crank drive feels to ride. You might be surprised as even my KTM eRace P while legal (hub drive 250W > 600W peak) and limited to an assisted 15mph climbs hills like a billy goat with the available torque.
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That's a low powered hub motor (Bafang SWX I think) and its running at legal power levels, around 15 amps peak.
With a CST/BPM at 30 amps it would be a very different thing.
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