replacing the car with an electric cargo bike fantasy

[mitty]

Hello all, great stuff on the forum as always. I nearly went electric before but hung on as I thought the bikes were going to improve, my problem is getting heavier every year !
I was wondering what you thought about these bikes, Kona UTE, yuba mondo, and the xtracycle add on.
Basically my wife or myself haul 2 kids (6 and 4 years old) in a trailer in beautiful but hilly cornwall with an old school mountain bike. I would like to add an electrical motor for going up the hills. so I was wondering if it would be possible to add the xtracycle attachment to the kalkhoff bikes ? the other option could be to add a hub motor to the Kona ute or the yuba mondo, or just stick with the trailer and swap the bike pulling it for an electric assist. The kids are getting a bit big for the trailer. We do get them to cycle but we still have a few years to go before they could keep up for most of our bike journeys.

Any thoughts appreciated mitty

 

[mitty]

links

here are a few pix of what i am thinking about

http://www.bikefix.co.uk/index.php?unique=16bac1592b38be82afad23a4a8414378&get_ol_id=7&get_gl_id=37&get_sgl_id=214#a37

http://homepage.mac.com/awcg/.Pictures/XtraLite/XL1.jpg

http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=3514

 

[burncycle]

here are a few pix of what i am thinking about

Bikefix - the bike shop on your desktop

http://homepage.mac.com/awcg/.Pictures/XtraLite/XL1.jpg

Endless-sphere.com • View topic - Oatnet's current Tidalforce X5tracycle protoype

Would't it be cheaper, easier and more adaptable to buy a ebike and a trailer mitty?

 

[flecc]

I don't know those two models, but the Koga Miyata if that's the same thing uses the Sparta direct drive motor which is very poor on hills and would be a very poor choice in Cornwall. The Xtracycle attachment has been used many times on the Lafree, so it should fit on the Kalkhoffs ok. One question mark is on the derailleur gears used with it. The Panasonic unit's sprockets are for 1/8th chain which is no good for most derailleurs which use 3/32" or less, so the chainwheel and sprocket might have to be machined down to width.

Personally I prefer trailer solutions, and perhaps a trailerbike on an electric for the 6 year old to pedal as well would be ok, but that could only work if you were both out together with the other bike towing a child trailer with the 4 year old.

Maybe a bigger trailer like mine?
.

 

[andyh2]

Hi Mitty,

Been having the same fantasy myself and have got as far as getting a Yuba and selling one of our cars. Though in our case it's one (nearly) 4 year old and I doubt I'll persuade my wife to let go of our remaining car.

I tried the mtb + Xtracycle and personally found it had more flex than I wanted with an occasional adult passenger. I wanted a Big Dummy, but not available over here until late in the year. So plumped for a Yuba. It is a meaty beast weighing 65lb, now I've added wooden footboards and seat to sit on. On the other hand it will carry 2 x 14 stone passengers without feeling like spaghetti. Great fun on the flat, but the slightest incline with that sort of load kills the will to live, well at least to ride. It would take a 4 and 6 yr old no problem, but a big advantage with a trailer for kids is the weather protection. The Yuba is a nicer ride, and no heavier, than bike and trailer combo, but the weight is always there.

For big loads assist through the gears is the received wisdom, though there are folk very happy with both BionX and Ezee hub kits on their Xtracycles. The Stoke Monkey system (not currently available, but supposed to be quite soon) is specifically designed for X'cycles and I estimate that it'll be £1,000+ to import, compared to Ezee hub system £900ish.

I considered Xtracycle and Kalkhoff and, as Flecc notes, you either have to machine parts on Kalkhoff for it to accept derailleurs or move X'cycle in frame to tension chain or use a chain tensioner. The latter is probably best way to go as less complicated than machining for derailleurs and maintains ability to change gear at a standstill. Another complication in the Kalkhoff / X mix is wheel size. The very smallest Agattu has 26" wheels, but all other models have 700 size. The 700 X can only take up to 35mm tyres. 26" wheels with 2" + tyres proabably better. You can put a 26" X on a Kalkhoff and run a rear 26" fat tyre, but you'd have to stick with 700 front or replace forks. So it all starts to get a bit complicated. But I've read of Lafree / X owner who's very happy with his 10,000 miles in the past 3 years.

The Kalkhoff has a longer than standard wheelbase to accommodate battery and in earlier posts Flecc noted to me that it would be fine with a child seat on the back. So you could go for Kalkhoff with 4 yr old in Bobike maxi or Junior seat with 6 yr old on trailerbike and have the option of your trailer when the weather's less good.

I actually like the look of the Bakfiets bikes, where the littluns can sit in front of you, with or without weather protection. Heavier than Yuba though and there seems to be some concern about braking ability if you use assist to get up hills you couldn't normally ride up. Though I'm not really clear as to why it should be any worse than any other loaded cargo bike.

If you've not already found it there's lots of enthusiastic Xtracycle owners on Rootsradicals list (Xtracycle site under community) and Clever Cycles has lots of info about X'cycke conversions, bakfiets, stokemonkey assist system.

Happy hunting and fantasising.

Andy

 

[andyh2]

Sorry I meant to add that I think a really good car replacement would be a Bakfiets with a Panasonic motor system. They have done an SRAM SPARC version, but I understand it's pretty underpowered.

Maybe one day.

 

[mitty]

Thanks for the replies, I may go for the trailer bike plus child seat option. I still feel that this is a important problem to solve as I am sure people would make less local car trips if there was a safe painless way of moving kids around town. I like the idea of the yuba with 2 bobike junior folding seats combined with an electric assist for the hills. ideally through the gears but maybe a hub motor geared for the hills. is the puma motor that team hybrid used to offer still available ? or which other hub motors might work under such a load ? if I can succeed in replacing the car for alot of journeys then the bike would pay for itself pretty quickly. also I read on another forum that the guy who put the xtracyle on the giant lafree (i posted the picture of ) now thinks that th nu vinci hub is the best hub gear solution under heavy loads ( i know that they are not gears in the normal sense ) he thinks it is more robust than the nexus and sram internal hubs which is interesting. lastly has anyone used the mountain drive system where you tap a button on the crank to change the gearing ?

thanks again mitty

 

[flecc]

I'm not sure about the Puma, but I think the very powerful Crystalyte is still available, though Team Hybrid's page on it has disappeared.

The Schlumpff mountain drive and high speed crank drives apparently work ok but are universally reported as inefficient, adding quite a lot of drag, so those may not be a good idea for high loadings.

The claims on the NuVinci are that's it's stronger, but it's early days yet and I don't know of any commercial load application proving it over any length of time The hub gear that's been most successful with very high commercial loads is the SRAM 7 speed, people like York Couriers using them to haul very high weights, and they've been used on extremely heavy trikes and quad cycles. It's slow gear changing is the disadvantage though.
.

 

[john]

I have an extra bicycle seat attached to the crossbar and footrests on the front wheel axle. Works well for kids up to 13 years or so and I don't think I could have got rid of the car without it.

 

[carpetbagger]

i had a similar set up to John with a seat on the cross bar and folding footrests on the....whatever you call the angled bit between cross bar and pedals..what a tech description !

 

[flecc]

i had a similar set up to John with a seat on the cross bar and folding footrests on the....whatever you call the angled bit between cross bar and pedals..what a tech description !

The name is even less high tech, Down Tube.
.