Help! eBike Conversion - but wanting to have a few beers

[lozzer2107]

Hey folks
I'm 45 and have recently (early Jan) had extensive reconstruction surgery on my left leg. Just trying to get back into cycling again and managed to get out out for 8-9 miles last night. The knee is a bit sore today but at least I know I can actually still ride a bike!

I have a 2013 Specialized Cross Trail bike (Hybrid) and want to work up towards getting out to do 10-20 miles 2-3 times a week. Mostly roads but some light off-road through local woods etc.. I also want to be able to cycle to the pub or a mates house, have 5 pints and cycle home. I want to remain legal so I'm not talking about getting totally sh*tfaced and cycling dangerously like a d*ckhead all over the road etc.. A few beers would mean I can't (and don't want to) get behind the wheel but cycling carefully with lights, a helmet etc <1 mile home in a sleepy village seems a better, more ecologic alternative to calling a taxi!

Enter the eBike debate...

I've seen some other threads (thanks very much) and from what I can tell, as long as your ebike is uk road legal, you're on safe grounds to cycle after a few beers.

So I'd like to convert (or have my bike converted) to a Road legal eBike

Questions
1000w motor with 15.5mph cut-out: L1e-A category? Link
Battery size: Can I stick a 48v battery on it? (some of the video's showing people do this on YouTube clearly show the ebike with even a 250W motor going over 15mph?)
Throttle: I'm weary about pedal assist (PA) only as people have said they can be dangerous on small turns etc.. If you have PA & a throttle, you're still legally ok? Is that true?

Possible options:
Motor: Link (I'm uncertain what advantage I would get about going up to a 1000W motor if I'm still limiting myself to 15.5 mph?)
Motor 1000W: Link
Battery: Link (it only just fits in the fame)
Battery alternative: Link (better fit - but no room for control hub) internal frame measurements: 58cm x 47cm x 36cm

Other questions:
Could you fit a 1000W motor that was restricted to 15.5mph with only a throttle thumb-switch and still be deemed legal? Do you need to register them?
Could you fit an on/off-switch that could legally demonstrate on software etc. that whilst using on roads, it was limited to 15.5mph?
Any links to suggestions about a set-up that would work for my requirements much appreciated

 

[StuartsProjects]

Electric bikes: licensing, tax and insurance

Electric bikes meeting the EAPC regulations can be ridden on the road without being taxed, licensed or insured

www.gov.uk

Its electric motor:

• must have a maximum power output of 250 watts
• should not be able to propel the bike when it’s travelling more than 15.5mph

 

[sjpt]

The L1e-A category is not a standard pedalec, and already comes with registration, insurance etc requirements. Also driving-driving laws apply.

I don't know of any cases where standard pedal assist has problems with small turns, as long as they have proper brake cutouts or torque sensing.

Most of the 1000w motors on the market are inefficient direct drive motors. Cheap, and efficient going fast on the flat, but poor on hills and at regular speeds, and need very powerful (expensive) batteries.

For the riding you describe 250w, 15.5mph should be fine. You might want a throttle because of your knee/leg issues. Even then probably not (we don't know exactly what the issues are). You can 'ghost pedal' a cadence sensor bike; just keep the pedals turning but don't apply any effort.

Throttle rules are very confusing. I'll leave that to others to try to explain.

 

[guerney]

Your experience might vary: I've got very bad knees, but a Bafang BBS01b 250W 36V motor with maximum PAS settings - set using the programming cable - is powerful enough for me to ghost pedal with almost no effort at all. No throttle fitted, though of course one would come in handy on hill starts and after sudden stops. The kit works fine without the illegal throttle. As for safe small turns on PAS, there's a setting in the firmware which makes those manageable.

 

[StuartsProjects]

I converted a RockLobster hardtail a year ago, with a 36V 250W rear hub motor.

I use it mainly for on-road and forest paths etc and the 250W is fine. I get up to circa 550W of assistance and since I have kept the 3 speed front gears, I get that level of asssitance even on steep 1:5 roads.

I had originally though that loosing the 9 speed rear cassette gear to a 7 speed freewheel would be restrictive, but in practice with the motor assistance you are changing gear far less often and its turned out fine.

For me the only use for a more powerful motor that I could concieve, would be for steeper off road stuff.

 

[lozzer2107]

I had originally though that loosing the 9 speed rear cassette gear to a 7 speed freewheel would be restrictive, but in practice with the motor assistance you are changing gear far less often and its turned out fine.

I have a 10 speed rear casette - dId you have to replace your deraileur & shifter too?

Helpful reply - thanks very much!

 

[lozzer2107]

For the riding you describe 250w, 15.5mph should be fine. You might want a throttle because of your knee/leg issues. Even then probably not (we don't know exactly what the issues are). You can 'ghost pedal' a cadence sensor bike; just keep the pedals turning but don't apply any effort.

Throttle rules are very confusing. I'll leave that to others to try to explain.

A really helpful reply too, thank you! Some of the kits come with both PAS and a throttle - with a programable switch allowing you to alternate. Do we think that's likely to still be illegal? I guess I could hide a switch in the controller bag if needed - then engage that for off-road only (although I'm not sure that would suffice?)

 

[lozzer2107]

If I'm sticking with 250W, what's the practical different between going 48V or 36V? From what I've read, if I can afford it, then the 48v battery should grant me greater range and/or more power/torque. Or have I misunderstood?

 

[StuartsProjects]

I have a 10 speed rear casette - dId you have to replace your deraileur & shifter too?
Helpful reply - thanks very much!

No, just needed to change the rear shifter.

To save pain on my aging thumbs, I bought a set of adequate twist shifters on ebay, maybe £15 the pair.

Its one to watch for, a lot of kits you might see are for freewheels, up to 7 speed. You can get rear 250W hub motors for cassette, but not so common.

 

[matthewslack]

A 1000W conversion is not a pedelec, and quite possibly risks your driving licence if stopped and prosecuted after 5 pints.

I would be completely beyond safe after that much to drink, so suggest rethinking the premise.

 

[StuartsProjects]

A 1000W conversion is not a pedelec, and quite possibly risks your driving licence if stopped and prosecuted after 5 pints.

Indeed so.

And no matter how well you ride 'after a few' you could get in an accident caused by someone else and if Mr Plod suspects your eBike is not road legal, you could indeed loose a driving licence, and then have to bear significant extra insurance costs in the future.

Just not worth it in my view, road legal 250W eBikes, done well, are well good enough.

 

[cyclebuddy]

The man that sits on my left at the bar in my village pub is someone quite high up in the Metropolitan Police. I asked that very question: "If you're caught pi55ed riding a bike, can you be prosecuted?"

He advised "Technically yes. But so long as the bike is legal, it would be laughed out of Court".

And he later drove home in his Land Rover Defender having drunk at least 3 pints that I counted.

 

[StuartsProjects]

The man that sits on my left at the bar in my village pub is someone quite high up in the Metropolitan Police. I asked that very question: "If you're caught pi55ed riding a bike, can you be prosecuted?"

And he later drove home in his Land Rover Defender having drunk at least 3 pints that I counted.

I guess that "Technically" he is only guilty of an offence if he is convicted.

 

[Bonzo Banana]

The man that sits on my left at the bar in my village pub is someone quite high up in the Metropolitan Police. I asked that very question: "If you're caught pi55ed riding a bike, can you be prosecuted?"

He advised "Technically yes. But so long as the bike is legal, it would be laughed out of Court".

And he later drove home in his Land Rover Defender having drunk at least 3 pints that I counted.

Metropolitan police in recent years aren't particularly highly regarded, so many news stories that puts their competence in question.

I can't see how a drunk cyclist that causes an accident with a non-legal ebike gets to walk away scot free I would of thought they would be prosecuted.

I think if I knew I was a bit over the limit I'd at least play safe with a completely legal ebike.