Weight limits for really hilly commute

[chris667]

Hello

I am looking at getting a new job. It is in the centre of Derby, and I am not driving there in rush hour.

I am thinking about getting an ebike for my commute, which would be 8 miles each way but has a 16% hill at one point.

I'm pretty big, 20ish stone. I would be taking panniers with my work clothes.

What sort of kit should I buy? I have had a look at a few articles about the Bafang BBS02 and I have a few bikes that would appear to fit it. I think it would fit my 1980s Giant MTB, subtly modified with strengthened wheels and better brakes.

I wanted to buy one from Woosh, but they're out of stock till February.

Would I get away with one of the hub kits instead? And what size battery do I need to get there and back?

 

[guerney]

How about staying on the legal side by getting something like the 250W BBS01b, and increasing the amps drawn by the controller to 20? You could do that using a programming cable. Others on here know what battery would be suitable for you.

 

[soundwave]

How about staying on the legal side by getting somthing like the 250W BBS01b, and increasing the amps drawn by the controller to 20? You could do that using a programming cable. Others on here know what battery would be suitable for you.

Derestriction, ‘off-road’ switches or modes and dongles

The Department of Transport say that electric bikes fitted with off-road switches or modes, that enable a bike’s motor to continue assisting to speeds beyond 15.5mph, do not comply with UK EAPC law. The term ‘off-road’ suggests that these bikes can be ridden on parkland, forests or other places away from main roads, which isn’t accurate. E-bikes with increased motor power (continuous rated power above 250w) or increased speed (with motor assistance not cutting out at 15.5mph) cannot be used legally as bicycles anywhere on land accessible by the public; when riding on private land you would need permission from the landowner.

so if you can change the power settings it is classed as a of road switch or same as using a dongle, the fact you can change the power settings means it is not road legal in the uk.

yet you try buy a kit where it wont let you change anything pmsl

 

[soundwave]

 

[guerney]

Yes, it's appears a little grey increasing the amps, but black using a BBS02. A roadside inspection by cop would reveal a limited speed and 250W engraving - any deeper look, say, after a serious accident, would reveal the truth.

With a very low gear, I think that a 36V BBS01b would haul a bike ridden by a 20 stone someone up most hills. My 15A and speed limited BBS01b manages to haul me (12 stones [now, after losing three stones]), plus 62kg of pumpkins (don't ask) up all of the hills, between me and my pumpkin patch.

 

[Nealh]

Brighton ebikes for the BBS01 25a etm.

 

[soundwave]

 

[chris667]

Ah, sorry guys. I meant the BBS01, I just got the descriptions mixed up. I don't want to go faster than a normal bike, just get a little help up the hills when I'm tired.

So this is everything I need? 46t seems like very tall gearing. Or am I underestimating what it can do?

Bafang BBS01B-ETM (MM G430.250) 36V 250W motor kit

Bafang BBS01B-ETM 36V 250W mid-drive complete conversion kit including LG MH1 cell battery

www.brightonebikes.co.uk

Or could I use something with a hub motor, or look at any other mid drive kits?

 

[guerney]

46t seems like very tall gearing. Or am I underestimating what it can do?

I've got 52T on a standard BBS01B, and up "Steep" hills it manages a very slow 6 to 7 mph (32T rear) - going any slower would be make my bike very twitchy. I tried the 44T and was even slower, was almost too twitchy. In both cases, pedalling was mostly easy - no standing on pedals required.

 

[chris667]

I'm not worried about my legs so much, it's damaging the motor!

If it is unlikely to give me any trouble, I'll do it.

 

[sjpt]

Derestriction, ‘off-road’ switches or modes and dongles

The Department of Transport say that electric bikes fitted with off-road switches or modes, that enable a bike’s motor to continue assisting to speeds beyond 15.5mph, do not comply with UK EAPC law. The term ‘off-road’ suggests that these bikes can be ridden on parkland, forests or other places away from main roads, which isn’t accurate. E-bikes with increased motor power (continuous rated power above 250w) or increased speed (with motor assistance not cutting out at 15.5mph) cannot be used legally as bicycles anywhere on land accessible by the public; when riding on private land you would need permission from the landowner.

so if you can change the power settings it is classed as a of road switch or same as using a dongle, the fact you can change the power settings means it is not road legal in the uk.

yet you try buy a kit where it wont let you change anything pmsl

It's certainly very confusing; the regulations are not at all clear about what constitutes a 'switch'.

My understanding (not at all guaranteed correct) is that a switch is something that can easily be changed while out riding; eg a physical switch, or controls via the display buttons.

If something can by changed but only by intervention while the bike is not in use (eg by firmware changing with the bike connected to a computer), and if that change has not been made, then this change does not constitute a switch and the bike remains legal.

Even if that is correct it still leaves a grey area in between.

 

[Nealh]

Good luck trying to change parameters on a BBS whilst riding.

 

[Nealh]

The BBS likes to be spun up so low gearing is better.
One can try the 48v tongsheng tsdz2 or go for bust BBSHD.

A 36v 250w hub might be a tall order for 20st and 16%, how long is the 16%.
For such a hill if a hub is used 48v at 201rpm will be the specs to look for at 25 or 30a.

 

[chris667]

A 36v 250w hub might be a tall order for 20st and 16%, how long is the 16%.
For such a hill if a hub is used 48v at 201rpm will be the specs to look for at 25 or 30a.

The climb is very short - about 200ft. I am not too proud to walk that bit.
There's a longer gradual climb after that, then the rest of it is fairly undulating.

 

[guerney]

The climb is very short - about 200ft. I am not too proud to walk that bit.
There's a longer gradual climb after that, then the rest of it is fairly undulating.

My BBS01B manages a hill as steep, longer than that, but I'm fairly lightweight (unless carrying 24l of spring water to grow pumpkins with, long story). I did worry about burning out the controller with hills, but after killing one accidentally and replacing it (easy replacement), I simply don't worry, maintain as high a cadence as possible. And an easy high cadence is very possible on my local steepest hills, with the 15A standard BBS01B. New controller cost me $97-ish delivered untaxed (somehow) by greenbikekit.com (thanks @peter.c)

 

[chris667]

I simply don't worry, maintain as high a cadence as possible. )

That seems doable.

I understand some people have fitted doubles to these. I have got lots of chainrings, I could make something like a 36/46. Walking speed is fine, as is getting off and walking speed.

 

[Nealh]

Fitting a double isn't too troublesome, the chain line may not work for all the gears but one will certainly get at least 5 or 6 gears high gears from the large chain ring and likely the 5 or 6 low gears with the small chain ring. You might be ok and get all gears just depends on the chain line.
I have used alfine 8 with a double on a bbs.

 

[Andy230262]

I am an older and heavy guy. I have a BBS02 750w motor and a 840w 17.5 amp Battery. It’s perfect for me. It will pull up any hill. Have had a few issues with my old wheels but sorted now. When you get the bike kit it’s programmed to limit the speed to about 15mph. I have changed that up to it’s max . If you keep it at the 15mph you will have no trouble with the law as there is no way of knowing the power. The good thing is there is enough power to move you a long and up any hill.

 

[Greg Burrows]

Hello

I am looking at getting a new job. It is in the centre of Derby, and I am not driving there in rush hour.

I am thinking about getting an ebike for my commute, which would be 8 miles each way but has a 16% hill at one point.

I'm pretty big, 20ish stone. I would be taking panniers with my work clothes.

What sort of kit should I buy? I have had a look at a few articles about the Bafang BBS02 and I have a few bikes that would appear to fit it. I think it would fit my 1980s Giant MTB, subtly modified with strengthened wheels and better brakes.

I wanted to buy one from Woosh, but they're out of stock till February.

Would I get away with one of the hub kits instead? And what size battery do I need to get there and back?

Hi I have been running Heinzmann hub motors for 10 years or more, and live in the Pennines, hills everywhere I have found these to be the most powerful motors on torque, you would need the low geared cargo type Classic power RN 120 though 162 RPM max 60 NM is the one you would need probably looking at there specs, I have never bought a new one, they are probably around £400 or £500 now though, these are a geared brushed motors, I run 170 rpm 200w 36v ones, I run at 48v though so get even more out of them and gives me a couple of miles an hour more speed, on long hills around here I found they overheat, so I put a vacuum pump on my bike, with an air pipe to it for cooling also drilled and put one way valves in the hub to let the air out, ( you will not have this problem as your hill does not sound anything like for it to overheat, these motors pull up to 1200 watts at 36 v, I run with a 48v 1000 watt controller, at 48v it is pulling around 26 amps, at 36 v would be pulling around 30A, reckon a 12 amp hour battery would be Ok for your journey.

 

[Greg Burrows]

Derestriction, ‘off-road’ switches or modes and dongles

The Department of Transport say that electric bikes fitted with off-road switches or modes, that enable a bike’s motor to continue assisting to speeds beyond 15.5mph, do not comply with UK EAPC law. The term ‘off-road’ suggests that these bikes can be ridden on parkland, forests or other places away from main roads, which isn’t accurate. E-bikes with increased motor power (continuous rated power above 250w) or increased speed (with motor assistance not cutting out at 15.5mph) cannot be used legally as bicycles anywhere on land accessible by the public; when riding on private land you would need permission from the landowner.

so if you can change the power settings it is classed as a of road switch or same as using a dongle, the fact you can change the power settings means it is not road legal in the uk.

yet you try buy a kit where it wont let you change anything pmsl

Hi does any one know if what the Department of Transport has said, has ever been tested in a court of law, as saying this does not mean it would stand up in law, if there has been a case, yes it may, but still would only be in the, circumstances of that case.
If I put a spare hub motor on my bike, so that I could have two wheel drive and only use that extra drive on private land, I can not see how that would constitute breaking the law. That is as long as I was not operating it on a public highway.
This looks a very grey area to me, I am sure what has been said, would have to be tested in a court of law, it may have been.
Probably the Department of transport mean a bike that is new and has been imported having this facility as then it would have been made and or imported without compliance to UK law.