Help needed, lots of questions

[cogs]

Hello.

i'm a disabled cyclist who currently uses a modified Thorn Raven bike with a Rohloff hubgear. The modification is the addition of a 'hinged crank' on the right side, because my right knee will only bend to about 45 degrees. i cycle to keep fit (and for pleasure!), and i wish to keep doing so. However, i find that advancing years are slowing me down a bit, rendering me somewhat unstable on hills or into winds (lots of wind where i live on the Moray Firth). It has occurred to me that an electric solution is the obvious one. i'm desirous of keeping the existing bike, and it is essential for me to keep costs on a very tight rein, so i'm thinking a kit will offer a way forward.

Looked at ePay, and i've seen a few 'all in one' offers from 'Alien', but they include a few unecessaries like brake levers with cut outs, a built wheel with a poor quality (presumably) rim and tyre etc, so i'm hoping that i can economise by using my existing Rhino rim and magura rim brakes.

Can anyone offer any advice/guidance on the best route to take please - sources for kit, type of hub, will it work in conjunction with my Rohloff etc.

Sorry for such a complicated first post..

 

[MaryinScotland]

Hi Cogs,

Given that your bike is so set up for your needs, it sounds like you should put a hub motor in your front wheel. Some years ago, I did that, as I wanted to motorise the bike I was then using. I went the Heinzmann route, expensive but good quality. At that time the main Heinzmann dealer was Kinetics in Glasgow. They supplied me with the conversion kit, including a new front wheel with the motor built in. The forks had to be spread a little, less than a centimetre I think, to accommodate the motor width. I got the local bike shop to do the fitting for me. It wasn't a problem with plain steel forks. If you have suspension or alloy forks, get more info to see if it will work.

The rest of the conversion consisted of fitting a twist-grip throttle, and the custom rack with the battery mount. The throttle did interfere a bit with my gearshift (I had them on both sides). With a Rohloff, I expect you only have a shifter on one side, so you could probably have the throttle on the other side.

Heinzmann may well be out of your price range, but try searching on "hub motor conversion kits" and see what comes up. Getting a motor ready-built into a wheel will add to the cost, but will save you a tricky wheel-build. Someone else on this forum (sorry, I forget who) described having a problem getting a hub motor to fit into the forks, so check dimensions before you buy.

Mary

 

[Nick]

Hello Cogs

I'm afraid I can't really help with any information - I ride a Bionx which although excellent doesn't keep costs on a tight rein. I can confirm, thought, that an electric bike makes a huge difference as it more than compensates for the lost power on the stiff leg.

Would you be able to post some photos of your crank setup please? My right knee bends to about 95 degrees and you can see my setup at Nick and Jo - A Long Split Second. I'd be interested to see if yours is similar or maybe you have found a better way of doing this.

Many thanks
Nick

 

[cogs]

Mary, i appreciate the response.

i have more or less arrived at the conclusion you have kindly suggested, i supose i'm just a bit nervous, probably due to my total inexperience of electric bikes. Reading round the subject helps, but also confuses a bit!

The main area i'm having difficulty with is the pedal assisted drive, (which i understand to mean pedalling most of the time but with less effort up hills, with the additional reward of greater mileage in prospect before the battery collapses), versus having the rotary thumb control to regulate speed.

Surely either method will give a similar result in terms of mileage before battery exhaustion?

The 'Alien' product i mentioned looks to be my best bet, but i've even considered acquiring a second hand powabyke and plundering it for the necessary bits, but the awful large battery is off putting.

Anyway, thanks again for your input.

 

[cogs]

Hello Cogs

I'm afraid I can't really help with any information - I ride a Bionx which although excellent doesn't keep costs on a tight rein. I can confirm, thought, that an electric bike makes a huge difference as it more than compensates for the lost power on the stiff leg.

Would you be able to post some photos of your crank setup please? My right knee bends to about 95 degrees and you can see my setup at Nick and Jo - A Long Split Second. I'd be interested to see if yours is similar or maybe you have found a better way of doing this.

Many thanks
Nick

Nick, i'm trying to get a photo on for your interest, but its proving a little challenging. i'll stick with it though, and i'll offer a bit more detail later if that is ok? Cheers.

 

[cogs]

Hi Nick. This may work. Sorry it isn't close up, but you may be able to work out that my crank isn't disimilar to your own, just executed differently.

Longstaffs made it (Stoke on Trent?). Not that cheap, and i've had to replace the bearing a couple of times. Yours looks as though it may be more robust.

 

[cogs]

Incidentally Nick, having seen and read the description of your injuries, they are remarkably similar to my own, even down to a motor cycle being centrally involved. Perhaps one difference may be that my injuries stem from 1967 and surgical techniques then were quite basic by comparison to the 'bionics' that your surgeon appears to have executed?

Sympathy and respect mate - and thanks for the advice.

 

[Nick]

Hi Cogs

Thanks for that information, and it's interesting to see a variation of what I'm using. Incidentally, Hipath Engineering also make cranks along these lines. A local cycle engineer made mine which was originally due to be just a prototype but I've been using it for a few years now. One day I must get round to getting a new one made! The bearings are the originals - a bit stiffer than the were but not noticeable through your foot, only when rotating by hand. I can give you the engineer's contact details if you want, and I know he's made 2 or 3 for other people since doing mine.

I'm sorry to hear about your tale. I was very fortunate indeed in the people who treated me, culminating in Professor Michael Saleh who is widely regarded as the world's leading authority on limb reconstruction. I can give you his contact details too if you want! He continues to pioneer new developments in this field - he takes great care of his patients, working with them very closely for the best overall outcome for them. I was very happy for him to go to the limits of his knowledge and am reaping the rewards as people do not notice any disability now - even when I spent three days with a bunch of physiotherapists. Mind you, none of them asked me to run or bend my leg far!

All the best with your endeavours, and I hope you get to enjoy the freedom and mobility of an electric bike as much as I do. There are some very knowledgeable people on this site who should be able to help with the information you need.

Cheers
Nick