Pedal assist on recumbent trikes

[UpWrong]

I'm contemplating getting a 'bent trike again, but with pedal assist this time. I'd definitely be wanting suspension and am tempted to experience full suspension having not had it before. So I costed up an ICE Sprint X and it comes to £8900. Without the pedal assist it's £5500. That's a big difference. Having had two eBikes with rear hub motors, I think I would be happy with fitting a conversion kit and this could be done for something like £1000, mounting the battery with a Terracyle holder. ICE trike wheels are undished of course but a dished wheel will still work. Or I could consider an HPV Scorpion or AZUB Ti-Fly, assuming QR drop-outs rather than thru axles can be fitted to the latter. A concern is the dropout width of hub motors. I have the 48v Shengyi DWG22C in mind which measures 138mm across the locknuts, and the offering from Yose Power is the same. Should be OK but all these trikes have aluminium swing arms, steel would be better for a hub motor.

[[XAP]Bob]

Took me a while to find a cassette (rather than freewheel) hub motor of 135mm dimension, but after that I just extended a few of the cables and it worked well.

I seem to recall some give in the rear triangle, or you might be able to lose a washer?
The removing the wheel was always a challenge, so I carried a linear inner tube as a replacement.

[UpWrong]

Took me a while to find a cassette (rather than freewheel) hub motor of 135mm dimension, but after that I just extended a few of the cables and it worked well.

I seem to recall some give in the rear triangle, or you might be able to lose a washer?
The removing the wheel was always a challenge, so I carried a linear inner tube as a replacement.

Yes, spreading the rear triangle by 3mm should be possible but some might say the extra stress could cause fatigue over time. Linear tubes are good. A torque arm might be a good idea to reduce stress on the dropouts from the anti-turn washers.

Stein trikes still use steel frames.

[Psamathe]

When I was looking for my tadpole (early in pandemic) I was considering HPV but shortage of dealers in UK was an issue, worse because I was told (by a cyclist NOT a competitor) that to maintain warranty on HPV you have to get the cycle services by a dealer!

I've never double checked ('cos I don't need to know) but I think I may have gathered from somewhere that the ICE rear is setup strangely to keep it on the centreline. I may be completely wrong on this but might be worth double checking.

When looking and talking to other riders one person who test rode both ICE and HPV (Scorpion) commented "my thighs hit the crossbar on the Scorpion so that was Game Over instantly".

Whilst I've never ridden a trike with a "suspended"/fabric slung seat, I got mine with a hardshell seat. Expensive but I love it and with what I know now would spend the money on one again. I appreciate you are not asking about the ICE options but from your historic recumbent posts I have the feeling that such aspects could be important to you and it would affect the costs a lot.

Ian

[UpWrong]

When I was looking for my tadpole (early in pandemic) I was considering HPV but shortage of dealers in UK was an issue, worse because I was told (by a cyclist NOT a competitor) that to maintain warranty on HPV you have to get the cycle services by a dealer!

I've never double checked ('cos I don't need to know) but I think I may have gathered from somewhere that the ICE rear is setup strangely to keep it on the centreline. I may be completely wrong on this but might be worth double checking.

When looking and talking to other riders one person who test rode both ICE and HPV (Scorpion) commented "my thighs hit the crossbar on the Scorpion so that was Game Over instantly".

Whilst I've never ridden a trike with a "suspended"/fabric slung seat, I got mine with a hardshell seat. Expensive but I love it and with what I know now would spend the money on one again. I appreciate you are not asking about the ICE options but from your historic recumbent posts I have the feeling that such aspects could be important to you and it would affect the costs a lot.

Ian

Freetrike in Exeter are an HPV dealer. I'd do my own servicing but could go back there if something major needed doing so probably ok for the warranty.

Yes, ICE use asymmetric swing arms with undished wheels. Installing a dished wheel shouldn't be a problem.

The Scorpion main tube is probably 60mm diameter, not good if you are knock-kneed.

I costed the ICE Sprint X with AirPro hardshell seats. Mesh seats are cooler (and less expensive) but need to be more upright. (My neck suffered when I converted a Sprint to 3 x 26 because the seat support was inadequate for the increased recline.) On balance I want to get low, reduce drag and improve range and efficiency.

[UpWrong]

The conversion will probably invalidate the warranties on any of the trikes of course.

[UpWrong]

Took me a while to find a cassette (rather than freewheel) hub motor of 135mm dimension, but after that I just extended a few of the cables and it worked well.

Was that an Aikema motor?

[[XAP]Bob]

Can’t remember offhand - I’ll have to trawl emails to find out.

Crikey that was easier than expected… Inised sales@electric-bike-conversions.co.uk who were very good, though the initially sent me a freewheel they swapped it without question.
I then had the tension adjusted to move the rim a little way over…


The ICE rear end is offset so that the rim is built centrally to the flanges, but remains on the centreline.
As the wind cheetah shows the obsession with centreline is probably misplaced, but it does mean that it’s equally stable turning left and right.

[UpWrong]

Can’t remember offhand - I’ll have to trawl emails to find out.

Crikey that was easier than expected… Inised sales@electric-bike-conversions.co.uk who were very good, though the initially sent me a freewheel they swapped it without question.
I then had the tension adjusted to move the rim a little way over…


The ICE rear end is offset so that the rim is built centrally to the flanges, but remains on the centreline.
As the wind cheetah shows the obsession with centreline is probably misplaced, but it does mean that it’s equally stable turning left and right.

Thanks, I'll take a look at them.

[squeaker]

I'm contemplating getting a 'bent trike again, but with pedal assist this time. I'd definitely be wanting suspension and am tempted to experience full suspension having not had it before. So I costed up an ICE Sprint X and it comes to £8900. Without the pedal assist it's £5500. That's a big difference. Having had two eBikes with rear hub motors, I think I would be happy with fitting a conversion kit and this could be done for something like £1000, mounting the battery with a Terracyle holder. ICE trike wheels are undished of course but a dished wheel will still work. Or I could consider an HPV Scorpion or AZUB Ti-Fly, assuming QR drop-outs rather than thru axles can be fitted to the latter. A concern is the dropout width of hub motors. I have the 48v Shengyi DWG22C in mind which measures 138mm across the locknuts, and the offering from Yose Power is the same. Should be OK but all these trikes have aluminium swing arms, steel would be better for a hub motor.

Agree with you wrt to OLN of some of the rear hub kits, but another worry might be the distance between the hubs spoke flanges? For example, on non-power hubs this is of the order of 55mm, but on the Geeko (which I fancy due to its simplicity) it's 42mm, which might result in a less stiff (laterally) wheel: not an issue on a bike, but on at trike? (The XS08FC - attached - is a bit better at 45mm.)

[UpWrong]

Agree with you wrt to OLN of some of the rear hub kits, but another worry might be the distance between the hubs spoke flanges? For example, on non-power hubs this is of the order of 55mm, but on the Geeko (scroll down( (which I fancy due to its simplicity) it's 42mm, which might result in a less stiff (laterally) wheel: not an issue on a bike, but on at trike? (The XS08FC - attached - is a bit better at 45mm.)

I hadn't thought about hub flange spacing. Food for thought. The Shengyi hub spacing is also 42mm. I guess a mitigation is the 13G spoke guages used, and the spoke length is reduced by having a large hub diameter. If for an ICE trike then undishing a wheel should make it stronger.

Good find on the Geeko conversion kits . Very neat. I didn't see anything about limiting the top speed to 15.5 mph to keep them legal though. For UK use, you'd want a motor which is most efficient at 15 mph, so potential loaded max speed of 20 mph needs to be limited. They state an RPM of 290 for the 250W motor, and a max speed of 29 km/h in a 26" wheel. I calculate 35 km/h at that RPM so max efficiency (at around 75% of unloaded RPM) would be at around 17 mph. So pretty ideal , if the top speed can be limited to keep it legal.

[Marc]

Yes, spreading the rear triangle by 3mm should be possible but some might say the extra stress could cause fatigue over time. Linear tubes are good. A torque arm might be a good idea to reduce stress on the dropouts from the anti-turn washers.

Spreading the frame is no problem. I've spread my rigid 26" ICE rear frames some millimeters and they have 25000km under their belt. Even with 2-3kW hub motors...

High quality torque arms are a must! Especially with aluminium dropouts, but also steel dropouts aren't strong enough to resist the force
of the anti-turn washers. Don't ask me how I know...
In my not so humble opinion, the best torque arms come from grin Tech:
https://ebikes.ca/product-info/grin-pro ... -arms.html

Stein trikes still use steel frames.

Mild steel frames. I'm not 100% sure, but IIRC they build their frames from cheap St60/E355/1.0060.

[Marc]

I've clocked some 85000km with hub motors since 2010 and tried the whole range. I think I've got 13 or 14 of them. I like hub motors!
Here is what I found out:
-avoid hub motors with screw-on free-wheels! (the are cheap, but you pay in way more hassle down the line)
-avoid hub motors with cable through the axle! (killed several hub motors, that fell on the side and cut a few wires)
-small (2.5kg) geared hub motors are very nice!
-bigger (3.5kg) geared hub motors are way more sturdy and have more torque.
-big direct drive hub motors (5.5-6kg) are the sturdies (think daily commuter) but have a lot of drag when the battery is empty.
-install good torque arms!

If you want to build the electric assist system yourself (it ain't rocket science) and like to know exactly whats going on while your drive around, consider the Cycle Analyst v3.

Anyway, you find most informations you want to know at Grin Tech:
https://ebikes.ca

[UpWrong]

I've clocked some 85000km with hub motors since 2010 and tried the whole range. I think I've got 13 or 14 of them. I like hub motors!
Here is what I found out:
-avoid hub motors with screw-on free-wheels! (the are cheap, but you pay in way more hassle down the line)
-avoid hub motors with cable through the axle! (killed several hub motors, that fell on the side and cut a few wires)
-small (2.5kg) geared hub motors are very nice!
-bigger (3.5kg) geared hub motors are way more sturdy and have more torque.
-big direct drive hub motors (5.5-6kg) are the sturdies (think daily commuter) but have a lot of drag when the battery is empty.
-install good torque arms!

If you want to build the electric assist system yourself (it ain't rocket science) and like to know exactly whats going on while your drive around, consider the Cycle Analyst v3.

Anyway, you find most informations you want to know at Grin Tech:
https://ebikes.ca

Doesn't the motor cable exit through the axle on all hub motors? How else can power get to the motor?

[squeaker]

Doesn't the motor cable exit through the axle on all hub motors? How else can power get to the motor?

Copenhagen wheel?