E assist for Twin Raven

[Mike Ayling]

The Rear Admiral wants e assist.
Obviously we want to retain the Rohloff so we either go mid drive or front wheel..
I assume that with a mid drive we loose the front ebb so we rely on the rear ebb to tension the timing chain resulting in a problem tensioning the drive chain.
The Rohloff chain tensioner replaces  the derailleur hanger which we don't have a hole for installing one  so what other options are there?
Front drive also has complications with cable removal when using the S&S couplers to didvde the bike for transport.

Any advice please?

Thanks

Mike

[Danneaux]

Mike,

A quick online search brought up a Pinterest link showing a "Thorn Raven Split tandem electric bike conversion" by Electric Bike Conversions in the UK: https://electric-bike-conversions.co.uk/

Attached below is a photo from their Pinterest gallery ( https://www.pinterest.co.uk/electricbikeconversions/_created/ ). It is not the clearest but does show a powered front hub, which would appear to solve many of your potential issues because it leave the eccentrics unencumbered.

I'll keep an eye out for more examples but it might pay to drop a note to the folks who did the conversion to see if they ran into any particular issues.

Best,

Dan.

[Danneaux]

Mike,

These folks also claim a Raven Twin conversion:
https://www.electricbicycleworld.com/electric-conversion-by-brand/

Another here, with photos:
https://www.pedelecs.co.uk/forum/media/ezee-powered-thorn-raven-tandem.401/

Hope this helps.

Best,

Dan.

[rualexander]

https://www.sjscycles.co.uk/ebike/pendix-motor-kit-500w-long-reach-magnet/

[Mike Ayling]

Thanks everyone for the replies.

I am in Melbourne Australia and I will show the pics to my local conversion people.

Mike

[Andre Jute]

The Pendix Thorn sells, already linked above, is a neat solution. But it is expensive.

i've made a couple of installations of bike electrifying kits and one of the problems is routing the wiring unobtrusively. One presumes a kit sold by SJS for named Thorn bikes will have adapted or adaptable wiring. An SS installation much more so!

Even after making two successful electrical installations myself, I really wouldn't like to tackle an S&S installation. Make sure up front that your installers understand that only the neatest installation will be acceptable. Neat wiring will take time and cost money.

Rohloff has a whole bunch of torque reaction methods, not all of which use the fixing socket for the jockey wheel of a derailleur. The image below is a visual summary of the most useful. The original, which I have failed to find on the Rohloff site, was linked to parts lists required for the installation and was a complete selection tree at "Forward" in the bottom right hand corner. If anyone knows where to find the original self-contained app on the Rohloff site, please share.

Good luck.

[percussionken]

Hi!

Just saw this the other day. 
We were in the same situation as you.

Yes, I have installed the Pendix eDrive500 on our Thorn tandem. Bought it November 2020, when they had upgraded it to torque65Nm. Bought it because I don’t want any cables or devices in front of the S&S-couplings. Its essential for us to be able to split the tandem without trouble when using long distance trains, like ICE-trains in Germany.

When we started to use it I was a bit worried if it would work smoothly, read some mixed reviews on the web. It was great! But the real test was last summer on a 10-day credit-card tour. It was mostly flat with a few small hills. We have one Ortlieb XL 35L pannier each. It worked fine. Used it mostly in ECO-mode, the lowest. The battery will manage about 60km with this load At the few hills, I used next mode the Smart-mode and geared down to be possible to use a high cadence without hard pressure on the pedals. If you use to much hard pressure on the pedals it might overheat and then the motor cut of for its own protection. And we are to old for mountains so no long uphills for us anymore.

Regarding the eccentric and chain stretch. Look on one of the pictures which shows the backside of the motor. That side is attached to the eccentric so you just grab this part and move the hole thing so you can stretch the chain. And I bought a new eccentric before the installation, the old one had a lot of dents on it.
Regards, Kenneth

[Mike Ayling]

G'day Ken

We have just ordered a Pendix from our local e-assist place.

Could you share the total weight of crew and two Ortliebs. Ours will be about 135-140kg.

Did you get the largest battery size?

Thanks

Mike

[percussionken]

Hello Mike!

We are about 160 kg with no problem. Read something about max 150 kg in the Pendix instruction, if I remember it right.
The key is to not turn the pedals slowly with heavy pressure on the pedals just because you have a motor, Pendix says around 60-70 per minute. Otherwise the motor can get hot and it might turn of and one has to wait a couple of minutes for it to cool down. Happened once for us, lesson learned for the pilot. But this has been no problem for us with a Rohloff to get low gears, so you can still spin in 60-70 cadence going steeply uphill. Sometimes one can’t avoid some hills, though we prefer nowadays to be on the flat terrain.

We took the biggest battery, 500w. And the 95 cm cable from the motor to the battery stand. The position of the battery on our tandem make it possible, with some care and without stopping, to turn the rotary knob on the battery top for me as a pilot. Handy if there is some hill in front coming and then turn the knob from ECO to SMART or SPORT mode.

For safety I also bought the accu strap for the battery and a protective cover set. Nothing really essential but I wanted to be on the safe side when using the train for transportation and give some protection from dents, mainly for the motor.
Regards

Kenneth

[DavePin]

Kenneth

We are thinking of having the Pendix conversion to our Thorn which has Rolhoff and S&S couplings. My concern was whether the Pendix would make changing gear more difficult and whether we would need to back off on the pedals for longer for a gear change. How have you found it?

Regards
Dave

[percussionken]

Hi Dave

There has not been any difference regarding changing gears and the need to back of the pedals for longer than before.
But I have always been a bit more careful with using the gears on our tandem. If I compare how I am on my single bicycle with Rohloff.

Regards Kenneth

[Mike Ayling]

Hello Mike!

We are about 160 kg with no problem. Read something about max 150 kg in the Pendix instruction, if I remember it right.
The key is to not turn the pedals slowly with heavy pressure on the pedals just because you have a motor, Pendix says around 60-70 per minute. Otherwise the motor can get hot and it might turn of and one has to wait a couple of minutes for it to cool down. Happened once for us, lesson learned for the pilot. But this has been no problem for us with a Rohloff to get low gears, so you can still spin in 60-70 cadence going steeply uphill. Sometimes one can’t avoid some hills, though we prefer nowadays to be on the flat terrain.

We took the biggest battery, 500w. And the 95 cm cable from the motor to the battery stand. The position of the battery on our tandem make it possible, with some care and without stopping, to turn the rotary knob on the battery top for me as a pilot. Handy if there is some hill in front coming and then turn the knob from ECO to SMART or SPORT mode.

For safety I also bought the accu strap for the battery and a protective cover set. Nothing really essential but I wanted to be on the safe side when using the train for transportation and give some protection from dents, mainly for the motor.
Regards

Kenneth

Hi Kenneth

We are collecting our tandem from Rebecca's ebike conversion shop today.
We specified the battery to be accessible to the Chief Engineer so she can go up a notch when the "More power Scotty" call goes out. Of course if already in notch 3 the correct response would be along the lines of "I am giving her all she's got Capt'n.
More detail in a few days.

Mike

Mike

[DavePin]

Kenneth

Can you give any guidance and what distance can expect to get with the Pendix, depending on how hilly and the assistance setting.

Regards
Dave

[percussionken]

Hi Dave!

Sorry for the late answer.

Last summer, on our credit-card tour, the battery was okay for around 60 km. Used mostly the lowest mode ECO and at a hill now and then, I changed to mode SMART.
At a coffee stop I could ask if I could charge it for 30 minutes, just to be on the safe side, and that was okay. No one rejected, I guess its not different than asking for plugging in your mobile phone.

Regards Kenneth