Bmp2 + S12s + Lcd3 build into offroad bouncer

jackhandy

Esteemed Pedelecer
May 20, 2012
1,820
323
the Cornish Alps
Thought I'd submit a short resume of my E-Bouncer build...

03 09 2014 – Ordered Bpm2 (200rpm) built into a 26” wheel; S-12s controller; Lcd3 display etc. from BmsB.

12 09 2014 – Order shipped through Fedex.

18 09 2014 09:50 – Order delivered :eek:)

On unpacking, it was obvious the box was open at one end, but nothing was missing (Maybe customs, but not resealed).
Everything was in good order, but the wheel, although true & round, played a polyphonic little tinkling tune when bumped: Half the spokes on one side were less than finger-tight, so it's just as well it needed dishing to sit centrally in the frame. This is a first-time job for me, but a couple of hours diddling with a spoke key did the job OK & the wheel seems to have stood up to the rigours of its first day on the trails.

The swinging arm of this bike is all steel with 5.0mm thick dropouts, so I haven't fitted a torque stay.

Now it was time to rethink the placement of the controller:
I had intended to bung it in a Wedge bag, under the saddle & had ordered a Topeak wedgie ( small) for the purpose; Unfortunately, I was totally unprepared for the sheer ginormosity of said controller – It's truly hooge!
The only other place, really, was in the small frame triangle, but even this would only accommodate the Hulk on its flat; so that's where it jolly well sits.

Cabling to the motor & from the pas sensor & throttle were of manageable length, but the umbilical from the handlebar display needed coiling under the controller, out of sight; And the lead on the brake sensor I had lying about, needed extending.
The motor cable runs down the main tube & under the swingarm pivot, but is a tad unsightly there, so I'll re-route it inboard if I can be arsed to ferniggle the connectors out from their snug hideaway between the rear damper braces: Should be done really – spoils the look of the thing.

The Ezee 14ah flatpack battery goes in a backpack, surrounded by 1/2” thick, high-density closed-cell polyethelene packing & connects, via an umbilical of 2.5mm cable, about a metre long, to the Anderson-equipped short cable seen wrapped round the seatpost.
The Andersons disconnect without any undue tugging (as proven todayboth when I fell orf & when I forgot to disconnect before walking away!).

One thing worth a mention, is that I route the umbilical down the right side of the backpack, then across my crotch, to connect in front of the seatpost: This way, I can mount & dismount by swinging my leg over the saddle without pulling apart the connectors. Any slack cable is tucked under the waist strap of the pack.
It works well & is perfectly comfortable & very practical in use.

I've set-up the Display parameters so that I have throttle control even when pas assistance is off: This enables me to use fine throttle control when negotiating tricky sections, although I'm finding that level 1 pas is very usable on many tracks, 2 gets me up pretty steep climbs, and I haven't even tried the higher settings in earnest yet – The grunt this thing produces inspires serious respect.

For now, I'm running it in Torque-simulation mode, but will try speed-mode once I feel comfortable with it; and as for Cruise Control... You can stick that where the sun don't shine – It has No place on singletrack! It frightened the bejaysus out of me when it kicked-in on my first test-run around the block.

The only thing left to do now is to sort out some means of hiding the controller & wires from view:
My first thought was to use some thin stainles-steel sheet, from domestic boiler trunking, that I have somewhere in the black 'ole I call my shed; but maybe I can fabricate something from a battered pannier bag that came second in a contratemps with a gatepost, lined with some 3 or 4mm closed-cell polyethylene or neoprene – like a kind of sleeve that goes over the top tube & controller.
I think I'll leave the red/yellow power connector exposed, as an indicator the bike's 'lectric, in case of accident.

Anyone struck by inspiration?

I guess I could always chop orf a leg of my old wetsuit – a bit of velcro...IMG_20140919_Saracen 1.jpg IMG_20140919_Saracen 2.jpgIMG_20140919_Saracen 3.jpg
 
Last edited:

derf

Esteemed Pedelecer
Aug 4, 2014
1,007
766
53
Thought I'd submit a short resume of my E-Bouncer build...

03 09 2014 – Ordered Bpm2 (200rpm) built into a 26” wheel; S-12s controller; Lcd3 display etc. from BmsB.

12 09 2014 – Order shipped through Fedex.

18 09 2014 09:50 – Order delivered :eek:)

On unpacking, it was obvious the box was open at one end, but nothing was missing (Maybe customs, but not resealed).
Everything was in good order, but the wheel, although true & round, played a polyphonic little tinkling tune when bumped: Half the spokes on one side were less than finger-tight, so it's just as well it needed dishing to sit centrally in the frame. This is a first-time job for me, but a couple of hours diddling with a spoke key did the job OK & the wheel seems to have stood up to the rigours of its first day on the trails.

The swinging arm of this bike is all steel with 5.0mm thick dropouts, so I haven't fitted a torque stay.

Now it was time to rethink the placement of the controller:
I had intended to bung it in a Wedge bag, under the saddle & had ordered a Topeak wedgie ( small) for the purpose; Unfortunately, I was totally unprepared for the sheer ginormosity of said controller – It's truly hooge!
The only other place, really, was in the small frame triangle, but even this would only accommodate the Hulk on its flat; so that's where it jolly well sits.

Cabling to the motor & from the pas sensor & throttle were of manageable length, but the umbilical from the handlebar display needed coiling under the controller, out of sight; And the lead on the brake sensor I had lying about, needed extending.
The motor cable runs down the main tube & under the swingarm pivot, but is a tad unsightly there, so I'll re-route it inboard if I can be arsed to ferniggle the connectors out from their snug hideaway between the rear damper braces: Should be done really – spoils the look of the thing.

The Ezee 14ah flatpack battery goes in a backpack, surrounded by 1/2” thick, high-density closed-cell polyethelene packing & connects, via an umbilical of 2.5mm cable, about a metre long, to the Anderson-equipped short cable seen wrapped round the seatpost.
The Andersons disconnect without any undue tugging (as proven todayboth when I fell orf & when I forgot to disconnect before walking away!).

One thing worth a mention, is that I route the umbilical down the right side of the backpack, then across my crotch, to connect in front of the seatpost: This way, I can mount & dismount by swinging my leg over the saddle without pulling apart the connectors. Any slack cable is tucked under the waist strap of the pack.
It works well & is perfectly comfortable & very practical in use.

I've set-up the Display parameters so that I have throttle control even when pas assistance is off: This enables me to use fine throttle control when negotiating tricky sections, although I'm finding that level 1 pas is very usable on many tracks, 2 gets me up pretty steep climbs, and I haven't even tried the higher settings in earnest yet – The grunt this thing produces inspires serious respect.

For now, I'm running it in Torque-simulation mode, but will try speed-mode once I feel comfortable with it; and as for Cruise Control... You can stick that where the sun don't shine – It has No place on singletrack! It frightened the bejaysus out of me when it kicked-in on my first test-run around the block.

The only thing left to do now is to sort out some means of hiding the controller & wires from view:
My first thought was to use some thin stainles-steel sheet, from domestic boiler trunking, that I have somewhere in the black 'ole I call my shed; but maybe I can fabricate something from a battered pannier bag that came second in a contratemps with a gatepost, lined with some 3 or 4mm closed-cell polyethylene or neoprene – like a kind of sleeve that goes over the top tube & controller.
I think I'll leave the red/yellow power connector exposed, as an indicator the bike's 'lectric, in case of accident.

Anyone struck by inspiration?

I guess I could always chop orf a leg of my old wetsuit – a bit of velcro...View attachment 9608 View attachment 9607View attachment 9609
great write up and pics = how is the torque? will it do steep hills OK? I just received two 8000mAH 22V Lipos from hobbyking - I have not done this before - and, for what its worth, was truly astonished at how small they are - were talking two tiny little bricks same size as an average (small) controller, that could be one alternative for the battery (its also cheap and 30C)
 

jackhandy

Esteemed Pedelecer
May 20, 2012
1,820
323
the Cornish Alps
Sounds ideal for a backpack, Derf; or secreting about the bike if they are that small.

I can only describe the grunt as awesome ☺
Even more so than my Ezee motor which is 250rpm in a 29" wheel, whereas the bpm is 200rpm in a 26", so probably about the same, like 4 like.
I found level 1 was ideal for giving me fresh legs on tiring singletrack, while level 2 got me easily up some slopes I have real trouble with on the vanilla bike.
Haven't really tried high levels of assist yet, as that's not the way I like to ride, but a judicious thumbful of throttle now & then made me smile ☺
 
D

Deleted member 4366

Guest
I just received two 8000mAH 22V Lipos from hobbyking - I have not done this before - and, for what its worth, was truly astonished at how small they are - were talking two tiny little bricks same size as an average (small) controller, that could be one alternative for the battery (its also cheap and 30C)
If you need any help with them, just ask. A couple of things in case you don't know:

never have positive and negative wires exposed at the same time. If you fit a new connector, do one side first, then insulate it before doing the other wire.

Always use female connectors so that there's no bare pins exposed.

Be careful when you fit a serial harness. As soon as you connect one pack the connector for the other one becomes live. I was connecting four packs in series one time. The connectors for the other three were dangling, and one touched my belt buckle. I was lucky, I guess, I only lost my belt and a connector. It was close enough that I could have lost something more valuable.
 
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derf

Esteemed Pedelecer
Aug 4, 2014
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If you need any help with them, just ask. A couple of things in case you don't know:

never have positive and negative wires exposed at the same time. If you fit a new connector, do one side first, then insulate it before doing the other wire.

Always use female connectors so that there's no bare pins exposed.

Be careful when you fit a serial harness. As soon as you connect one pack the connector for the other one becomes live. I was connecting four packs in series one time. The connectors for the other three were dangling, and one touched my belt buckle. I was lucky, I guess, I only lost my belt and a connector. It was close enough that I could have lost something more valuable.
many thanks, will be very careful and hold all of that in mind, easy to forget how many amps one is actually dealing with while handling two little bricks
 

jackhandy

Esteemed Pedelecer
May 20, 2012
1,820
323
the Cornish Alps
Had a great run at the Beast yesterday _ Went round on the vanilla bike in seconds under an hour, followed 1/2 an hour later with a run on the cheat bike in 53 minutes, which is slower than my 1st try last week; Mainly because I came a cropper, over the bars on the exit from a fairly steep downhill switchback :(
Wrenched my shoulder & slid ignominiously don the gravelly track. Stiff & sore today, but all Will be well for another adrenalin fix later in the week. :)

Anyway _ Reason for the update _ Photo attatched of the finished bike.
1 kids' wetsuit, £3 from a charity shop, middle section chopped out & Robert's yer mother's brother.
http://


Left in the zip up the back, which now lies along the top of the crossbar, making for easy acces to the mare's nest beneath:)
 

falmouthtony

Esteemed Pedelecer
Impressive Bodmin Beastie speed machine you've got there now JH. Certainly looks the business !
Fancy some company for a circuit or two in a couple of weeks?
Up country for a week tomorrow. Contact you on return??....
 

jackhandy

Esteemed Pedelecer
May 20, 2012
1,820
323
the Cornish Alps
Hi Tony,
I was just thinking, today, that I must get in touch now that I've got me an offroad machine to give your Cube a run for it's money ☺

Fancy making a day out of it?
Beast in the a.m. & Lanhydrock p.m.
Last man down the Timber trail buys the ice creams

Anyone else fancy joining us? As the teeshirt says "Old Guys Rule".
Thought I was going doolahlie for a while there _ Knew I'd suggested just that, then realised it was in Tin Kitten's thread...

Yuss - Week after next sounds good ☺
 

jackhandy

Esteemed Pedelecer
May 20, 2012
1,820
323
the Cornish Alps
Just a quick update on my build...

Getting kit from BmsB really is a lucky dip _ I ordered a 201 rpm motor in a 26" wheel, for maximum grunt at low speeds & I've just checked, to find I have a code 12, which is 250 rpm

It's not quite as controllable as I'd hoped, but still does the job very well.
 
D

Deleted member 4366

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Code 12 is my favourite. A bit of solder on your shunt should make it a bit more controllable.;)
 
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