Cycling UK Forum

Rear over front is an easy choice on a 'bent trike - no one does a stub axle front motor... Amusingly if I get a front wheel motor for the raptobike, that will also be a rear wheel conversion

As for brand. I'm waiting until I've installed to discuss where it's from (since their customer service has been excellent, after initially sending the wrong hub (freewheel not cassette).

Waiting with interest to see how you get on. I'm thinking of converting one of my recumbents for my OH, I've put out a few tentative enquiries which is as much to see how responsive they are as to the specific queries I have! If you're converting a standard bike then it could well be an easy process, add in all that's non standard about a bent and it could be interesting. All the various bits are likely to end up in very different relative positions to on a conventional machine...

Yep, I will update... had another email today telling me that he'd put the longest cables he could in, and had popped both a thumb and a twist throttle in for me to make my choice...

Have to say, it's all seeming positive so far...

Not having a donor bike the jury still out for me, I contacted several suppliers, cyclotricity, woosh, panda, oxicycle, etc, ruled out a couple as having direct drive not a good idea for me, woosh and panda the most helpful so far.

What kind of bikes are you putting the kits on? FH, CST, Crank?

At the moment the kit is going on an ICE sprint 2 RS (2010).

It's replacing my CS-RK3 (3 spd hub with a 9 sod cassette), so I've shifted the schlumpf drive from the raptobike to maintain decent gear range.
The Rapto is looking to get an X-RK8 hub (chosen for having direct drive as bottom gear) to get decent gearing in a sane package. Combined with the triple which I took off the trike that will let me pedal to 45mph at <100rpm, and I can put power out up to about 115-120rpm.

So lots of changes...
Trike - heel shift 30/75 up front, twist shift 9 Spd cassette at the rear.
Maintains dynamo lighting, but adds a twist throttle (probably) in place of the front shifter.

Raptobike - adds a front derailleur, swaps out for an 8spd hub gear. Ends with two twist shifters (though a thumb shifter mounted by the brake levers is tempting, my front mech is an SRAM 1:1 (I could replace it of course)

If I want to later in the year I could get a FWD motor that I can move between the Rapto (at the rear) and a BSO...
I end up with four cycles, all of which have at least one hub/planetary gear set, all with decent ranges for their intended purpose...

Well, It was quite hard to seat the motor in the trike. I'm not quite sure why...
The no turn washers are facing down at the moment.

The nuts are also larger than other wheel nuts I have, so I don't want to have to take it off outside of a workshop (and want a set of spanners for Christmas)
I have a sidewinder spare tube, so shouldn't need to remove the wheel in the event of a visitation from the fairy.

OTOH it's rather nice having a little boost on demand. I'm probably going to switch out the brake levers - I was considering doing so anyway, thinking that the current ones had developed some sideways play, but the power cut off ones are as bad from new ;(. They aren't essential though.

I just need to extend the main power cable from the battery (not a recumbent only problem if I look at the geometry), every other cable is plenty long enough, and well labelled. I think I shall pop the control electronics behind the seat (the display (which does battery power in 20% steps, low voltage protection and power selection) is where the handbrake lever is often found on an ICE (one of the few places the small diameter clamp will hold)

I still need to redish the wheel (or get someone else to) for the ICE offset - but I knew this before buying. It's not rubbing on anything, so it's not an issue. Interestingly I couldn't fit it with the disk brake, I suspect the OLN is just a touch over spec, but I haven't checked, and I'm not likely to check soon)

I also need to look at changing the Rear mech for a shorter cage, since it no longer has to cope with the 24 tooth change at the front.

Right...

First commute done. I reckon this is a winner - particularly whilst I regain some fitness and also any time there is a true winter...

[XAP]Bob wrote:Right...

First commute done. I reckon this is a winner...

Good: please keep us updated on durabiltiy, but where are the photos / info on the hardware

squeaker wrote:

[XAP]Bob wrote:Right...

First commute done. I reckon this is a winner...

Good: please keep us updated on durabiltiy, but where are the photos / info on the hardware

They'll arrive... I've been a bit busy

Cyclotricity Cassette based hub in a 20" wheel from http://www.electric-bike-conversions.co.uk with a Bottle battery. I had to make a small modification to the mounting mechanism to fit it on the frame (drill out the threads on one of the bolt holes used to hold it together to put a longer bolt into the lower bottle boss on the trike, else it didn't fit in front of the cross arm).

As I said earlier, the first wheel I was sent was a freewheel, so that was sent back and a free hub was dispatched instead - all postage paid for by EBC. They have also given me *both* thumb and twist throttles.
Their communication has also been good throughout.

That's good info. Im a bit green here what is the difference between a freewheel and a freehub?

andrewcruzeman wrote:That's good info. Im a bit green here what is the difference between a freewheel and a freehub?

Let Sheldon Brown explain

Thanks for link Nominally 135mm OLN? Any idea what the torque curve looks like? That, and just how 'friction free' the freehub is, are probably my main concerns with rear wheel motors (well, that and durability!).
No rush - enjoy the new ride

Nominally 135, I think my dropouts are a shade narrow after a couple of years with an undersized SA hub in there.

Seems pretty free running when idle, it is internally geared, so it's not fighting the motor.

No idea about the torque curve, but it is soft start - makes main roundabouts easy to negotiate.

On the way home I somewhat bonked - not enough snack/lunch in the office. The support from the motor was brilliant.

Actually not really sure how to measure the torque curve at the moment...

Very interesting.

[XAP]Bob wrote:Seems pretty free running when idle, it is internally geared, so it's not fighting the motor.

Excellent

[XAP]Bob wrote:No idea about the torque curve, but it is soft start - makes main roundabouts easy to negotiate......
Actually not really sure how to measure the torque curve at the moment...

Wasn't expecting you to measure it

Where I'm coming from (and this will prove that I'm not an electrical engineer) is on steep hills a 250W hub motor is essentially operating at a speed well below its rated 15mph. For example, some simple maths shows that on my local, mercifully not too long, 18% grade my ICE trike (all up weight of 90kg) needs about 300W for 4mph (sorry about the units), so I'm curious as to what a hub motor would put out at 25% of rated speed. I've read that some will exceed rated power under such conditions, using temperature sensing to stop internal melting (!) on long hills, but I suspect that's going to be specific to individual designs. (There are likely to be mechanical limits too.) So what I really want to know is how much assistance would I get in practice on said b*st*rd hill, as hill climbing is undoubtedly the area of weakness for my aging legs (and lungs) and the area where much time is 'lost'. If the assistance as such low speeds were 'small' then it's not really worth the hassle / weight (and I'd be better off fitting a Schlumpf MD to get a suitable crawler gear). Will be reading your experiences with interest!

Nice to hear about the soft start - are you just using it in throttle mode or do you have a BB pedal torque sensor for pedalec operation?

I suppose I could try and blag an extended test ride from a local e-bike dealer....