Building a bike for heavy hill climbing on country roads.

[Cyclezee]

strictly for what its worth - I genuinely know nothing about pedelecs, but I have a friend

Join the club.....sorry, you have already and what's more you have a friend

 

[JamesW]

I find it interesting that no one has mentioned one of the big advantages of a hub drive over a crank drive yet. With a front hub motor, the bike is 2wheel drive when you peddle. This gives better traction on slippy surfaces like mud, wet tarmac and ice and thus better handling in poor conditions with less chance of spinning out. It also makes tyre wear more even than if all of the drive is coming through the rear wheel. (For this reason alone I will not consider anything but front hub drive.)
Puncture proof tyres make changing a tyre so rare that the requirement for a spanner is not an issue either.

James

 

[Deleted member 4366]

I find it interesting that no one has mentioned one of the big advantages of a hub drive over a crank drive yet. With a front hub motor, the bike is 2wheel drive when you peddle. This gives better traction on slippy surfaces like mud, wet tarmac and ice and thus better handling in poor conditions with less chance of spinning out. It also makes tyre wear more even than if all of the drive is coming through the rear wheel. (For this reason alone I will not consider anything but front hub drive.)
Puncture proof tyres make changing a tyre so rare that the requirement for a spanner is not an issue either.

James

You're absolutely right for motors like Q100, Bafang SWX and other motors up to 120mm in diameter, but you can't get enough traction for a high-torque motor like a BPM with 25 or 30 amps, especially when going up hill. On a 25% hill, it'll spin all the way up. I draw the line for a front motor at 350w or about 20A. You get the other problem too above that power, that it's not easy to mount one securely in aluminium forks. I've seen one spin out of the drop-outs that had two well-mounted torque arms. We had to change the forks to steel.

 

[Ash21014]

So err, any recommendations on frames?...

 

[Deleted member 4366]

Too much choice, but the Rocky Mountain Element is my favourite because it has nice air suspension on the back and a big triangle for the battery. Plus, it still looks like a traditional bike. They're not easy to find, but they turn up from time to time. I paid about £150 for a bare frame (used) and £500 for a whole bike (also used).

 

[Cyclezee]

I find it interesting that no one has mentioned one of the big advantages of a hub drive over a crank drive yet. With a front hub motor, the bike is 2wheel drive when you peddle. This gives better traction on slippy surfaces like mud, wet tarmac and ice and thus better handling in poor conditions with less chance of spinning out. It also makes tyre wear more even than if all of the drive is coming through the rear wheel. (For this reason alone I will not consider anything but front hub drive.)
Puncture proof tyres make changing a tyre so rare that the requirement for a spanner is not an issue either.

James

I entirely agree James and have said as much many times

So why do I ride this on a daily basis

 

[JamesW]

... But you're all about max speed and power Dave and most people don't need to go that far. Besides a road legal bike has a limit of 250W so what is the issue. (If you are non legal and have a collision, you can probably expect to lose everything as who will insure those who knowingly break the law?)

James

 

[Deleted member 4366]

... But you're all about max speed and power Dave and most people don't need to go that far.

Who's that addressed to and what does it mean?

 

[JamesW]

Who's that addressed to and what does it mean?

It means (tongue in cheek) d8veh, that you seem to use all of your vast technical knowhow to build formula 1 style ebikes from the ground up at a budget (at least that is how many of your posts can read.) It was not meant to offend, but as a kind of backhanded compliment whilst reminding the OP of the wording of the law. (I am equally aware of your interpretation of that wording and how it differs from some others and had not been tested yet!)

James

(But hitting a child on a bike or being hit by a car will get the wording of the legality tested VERY quickly indeed!)

 

[Alan Quay]

Here we go again, yawn.

 

[RobF]

At least it's near bed time.

 

[Nealh]

From reading alot of d8veh's posts he for sure does not advocate being a tear ass, much the opp and more of a touring cycle plodder. The ampage is more for climbing ability and range rather than speed.

 

[trex]

...

(But hitting a child on a bike or being hit by a car will get the wording of the legality tested VERY quickly indeed!)

I agree totally. While the UK have not officially adopted EN15194, all those big hubs including those laser marked to 250W may not be legal after all. Some smart lawyers may insist to measure their output power the old fashion way.

 

[selrahc1992]

I agree totally. While the UK have not officially adopted EN15194, all those big hubs including those laser marked to 250W may not be legal after all. Some smart lawyers may insist to measure their output power the old fashion way.

"old fashioned way" sounds intriguing, it should, at the very least, involve a few prostitutes and a good whipping..

 

[Deleted member 4366]

It means (tongue in cheek) d8veh, that you seem to use all of your vast technical knowhow to build formula 1 style ebikes from the ground up at a budget (at least that is how many of your posts can read.) It was not meant to offend, but as a kind of backhanded compliment whilst reminding the OP of the wording of the law. (I am equally aware of your interpretation of that wording and how it differs from some others and had not been tested yet!)

James

(But hitting a child on a bike or being hit by a car will get the wording of the legality tested VERY quickly indeed!)

That's not quite right. I build every type of bike I can, but I've never built one with a motor rated at more than 500w except, the one that was specifically built for the World Championship race on a closed road. I don't use it on the road. Those bikes above have small low-powered motors and are probbly no faster than yours.The top one, which is restricted to 15.5 mph and bears a 250w label will be my main bike until I find a better one (which will be difficult). I only travel at 12 to 14 mph except downhill.or with the wind behind me. The reason I build a lot of different bikes is mainly to explore the technology and possibilities.

 

[Deleted member 4366]

I agree totally. While the UK have not officially adopted EN15194, all those big hubs including those laser marked to 250W may not be legal after all. Some smart lawyers may insist to measure their output power the old fashion way.

They can measure them how they like. EN15194 does not restrict the maximum power.

 

[Alan Quay]

At least it's near bed time.

Don't you go foisting your interpretation of 'bedtime' upon me!

I'm a responsible adult, I know the risks, and I'm not harming anyone else. I'll choose what 'bedtime' is right for me.

Also, while I'm in bed I think it's my right to choose between front or rear wheel drive, so long as my partner consents. (although I'm pretty sure she won't be up for CD).

 

[selrahc1992]

At least it's near bed time.

have a look at http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&sqi=2&ved=0CDsQFjAE&url=http://www.gopedelec.eu/cms/dmdocuments/legalAspectsOfPedelecs.pdf&ei=sc2lVOHCEaev7AaOjIHYDg&usg=AFQjCNHBFmc9ZKMfCzTaohGrPggUlQ0GVg
couldn't figure out if I felt more like self harm or sleeping after a few paragraphs..

 

[JamesW]

Ok my misunderstanding. I'll leave it at that. Happy new year !

 

[Geebee]

So err, any recommendations on frames?...

I think the issue here is there is so many to pick from, your best bet is to troll the bike forums for the bikes/frames you like and see what opinion says.
I would recommend some but my style/type of bikes/trikes don't suit most and trikes can be expensive.

Having said that unless I was off roading seriously, I like hard tails and for road use no front suspension either as it makes for a lighter, stronger more reliable bike.

Good luck in the hunt.

p.s. Its a good forum but suffers more thread drift than most