E-assisting a SWB Recumbent

[Deleted member 4366]

328 rpm will give you about 19 mph in a 20" wheel at nominal voltage. 44v lipos will increase it by 20%.

Don't go over 350w in a front 20" wheel because the torque would rip it out.

Make sure that the torque arms have a slot 12mm x 10mm for the BPM motor. I think the standard Grin ones are 14mm x 10mm which will allow the axle to turn. The BMSB ones are good and cheaper.

 

[Cyclezee]

Torque arms/plates are also available here http://www.ebay.co.uk/itm/261430656364?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1586.l2649

 

[Deleted member 4366]

What's the slot size please, John? Have you got both sizes?

 

[Cyclezee]

What's the slot size please, John? Have you got both sizes?

10mm x 14mm Dave.

 

[Deleted member 4366]

Not good for a BPM. We just wrote off a set of forks when the axle twisted about 45 deg in the torque arm due nothing but torque at 30 amps. The axle was undamaged, but the torque arm slot had distorted, which allowed the axle to turn.

 

[Cyclezee]

You haven't tried our ones Dave.

 

[Aushiker]

328 rpm will give you about 19 mph in a 20" wheel at nominal voltage. 44v lipos will increase it by 20%.

Don't go over 350w in a front 20" wheel because the torque would rip it out.

38 km/h is something I could live with

Ripping the front wheel out does not sound to appealing. I guess swapping out to a steel front fork is a smart move as well Thankfully the LoGo is steel already and I can get a fork for the Bacchetta for US$86 delivered.

Make sure that the torque arms have a slot 12mm x 10mm for the BPM motor. I think the standard Grin ones are 14mm x 10mm which will allow the axle to turn. The BMSB ones are good and cheaper.

Thanks for the heads-up. I liked the Grin ones as they bolt to the eyelets rather than use hose-clamps but if they are not effective then looking better is not going to count for much.

Andrew

 

[Aushiker]

You haven't tried our ones Dave.

Are two required or just one?

Andrew

 

[Deleted member 4366]

For a 350w motor and steel forks, one would torque arm would be enough. I use the BMSB ones. I cut down the clamp arm/tie bar and drill a new hole to fix it to the lower disc caliper fixing point. This gives a very rigid installation.

 

[Aushiker]

A quick update and a thanks for all the input. I feel that somewhere along the way in all my research and "lurching" from one option to the other I lost track of the reason I wanted to "electrify" a bike in the first place which was to provide e-assist, not to end up with a moped so to speak. That is I still wanted to ride my bike but to get some help with that particular on my commute.

With that in mind I have decided to leave my LoGo P-38 as it is, I still want a bike I can ride as a bike and will e-assist the Bacchetta Giro ATT 20 and the key here is e-assist.

It some ways it was a comment that d8veh made about the MAC motors that reminded me I was heading off in a direction towards a moped.

So anyway I have decided to go back to where I started and to get a 36V 350w Bafang BS02 mid-drive mostly likely from Paul at EM3EV. I will marry it up to one of his Samsung 36V batteries, either a 13.8Ah or 16.5Ah which I will mount on a rack (should be able to setup the mounting bracket for the battery on a rack).

This should allow me to pedal and ride as I do but to get assistance or support so that the level of work required into the wind is reduced allowing me to get back and forth in a reasonable state

I will probably add a CA V3 into the mix as well.

The other attraction to me with the Bafang BS02 is I don't need to worry about the hassles that come with a front or rear hub-motor and punctures and I can pretty much keep my drivetrain high-end, just loosing the triple up front. This is my only niggle but I can do ride on the big-chain ring a lot now so hopefully the motor will compensate for the lack of smaller chain rings.

I think going with a Bafang BS02 500W or 750W might be pushing my luck with the local authorities more so given the motors are stamped with the wattage

Any last comments before I pull the pin? I will update later on how this works out ... bad decision or right decision

Regards
Andrew

 

[Deleted member 4366]

I think that you've made a good choice. You only need one chain-ring on an electric bike.

 

[D8ve]

I like your idea. A mid motor to help the smooth running of your bent.
I have a bust BH with good motor and battery.
And am working out how to make a bent with that. Similar thing lots of easy miles even if the wind blows up.

 

[Deleted member 4366]

I like your idea. A mid motor to help the smooth running of your bent.
I have a bust BH with good motor and battery.
And am working out how to make a bent with that. Similar thing lots of easy miles even if the wind blows up.

Isn't it already bent?

 

[D8ve]

Just the head tube bars,rack,fittings and rim.
The Shimano 105 break gear leavers have smashed internals.
So did my left ulna and radius.
Lucky my bike was legal at the time.
I would be well stuffed if it had been a Kilo watt motor.

 

[Aushiker]

Order placed ... now the wait; well spending money on other bits and pieces on the bike in the meantime

Andrew

 

[Aushiker]

Well the build has started; well to be more precise the parts and accessories have been ordered and the first few bits arrived today. Really impressed with the service from JensonUSA with four days delivery from the good ol' USA to my door here in Western Australia.

In the box was ...

K-Edge Gopro Pro Handlebar Mount for mounting my GoPro up front. A requirement for riding around here. Also makes it easy for me to swap my camera between my two main bikes.

A pair of SKS Slidecage Bottle Cages. These allow for the side mounting of the cage which makes accessing the water bottle much easier on the recumbent.

Ergon GP1 Performance Comfort Grips. These are so comfortable, both my recumbents have got them now and I will add them to my mountain bike in the future. Cannot recommend them enough.

Regards
Andrew

 

[Aushiker]

A little more progress on this build, but still no sign of my Bafang BBS01 from EM3EV ... it was promised to be shipped before Easter but alas no update.

In the meantime I have received a Grin DC-DC Convert 6V 10w. Nice bit of kit and so it should be given the price ....



Also received a set of mudguards from Bacchetta. I went with the Bacchetta mudguards over the Planet Bike ones as they come in a 20/26 set for the Giro. Yet to finalise the fit but they look like they fit nicely.

Andrew

 

[Aushiker]

Progress is slowly occurring. I now have the Bafang BBS01 36v 350W motor and all the other bits and pieces I wanted for the conversion (e.g., rack) bar the battery. The battery was coming via FedEx in a separate parcel and FedEx flew it into Perth where I am and then promptly sent it over to the other-side of the country. Hopefully it will turn up next week.

More photos at Google+ Photos if interested.


Regards
Andrew

 

[Aushiker]

Its done, well my Bacchetta Giro 20 ATT with Bafang BBS01 e-Assist (pedelec) had its maiden ride today. Nothing to long, just 30 odd minutes as I am currently restricted to 30 minute rides plus there a still a few niggles to sort out in terms of fine tuning the rider setup and front brakes as well as a couple of bigger issues to resolve.

The main issue to resolve in terms of the conversion is the rear rack. The Topeak MTX Explorer Tubular Rack w/disc rack is simply to tall for this bike so will have to look at other options. Ideally whatever rack I use will take a European rear light but at least it must have a plate on the top to allow mounting of the battery. The search begins.

I am also not happy with the wiring so will look at getting some wire mesh guard to tidy up the wiring once I have the Busch & Muller e-bike light to go on the front in place of the dynamo powered light there now.

Regards
Andrew

 

[D8ve]

I am looking forward to your review.
40k with 250m of climb it should be interesting.
I am predicting a high average speed as uphill shouldn't be slow but down hill you should fly.

Breath bated...