Dahon Roo El or motorize a Downtube mini?

[elmergeorge]

Hi, after reading the Downtube thread I bought a VIIIFS in May off Ebay. I love it. Now I have been considering an electric pedal assist to commute with. I have tried the Dahon Roo El, I really like how light it is, and it looks good, but I really like the way my Downtube fits and feels. After travelling twice with it, I would like to have a bike easier to pack and lug. After reading the DTmini threads, I think it would be more fun than a Brompton and for a comparable amount of $ to purchase a Dahon Roo El. I could add a good motor. Any thoughts? My priorities are: 1- folded size, 2-performance/fun, 3 -weight , though I have a bad back so 2 and 3 are tied.
Any recommendations for the motor? I've looked at Cyclone and Bionx and a couple others that I lost the links to. Any suggestions would be appreciated. Thanks.

[Wavshrdr]

I can't speak for mounting a Cyclone I can't speak for mounting a Cyclone on a Mini. I can say that on your FS it is not a problem. The Mini may be a bit too compact depending on some of the mounting choices. Problem with BionX is that you would have to ditch your internal hub to use it and then use a derailleur with their cluster.

Best option would be some sort of internal hub motor that you could use on the front wheel. Unfortunately the 16” wheel size makes this a challenge AND with the small wheel size top speed is limited vs. larger size but climbing capability will be increased.

One plus though to the Mini is its gearing would be great for an electric assist especially with how the SA hub’s gearing is setup. The VIIIH would be probably one of the best candidates from a gearing perspective IF you use a motor that will go in series with your current chain. The downside there is weight and folded size vs. an electric Mini.

[woofman]

Problem with BionX is that you would have to ditch your internal hub to use it and then use a derailleur with their cluster.

According to Yan, you needn't ditch that hub, as there's a new Capreo mini about to be introduced. Yan says they "are in the warehouse and will be stocked in the shop in 5-7 days." Price will probably be about $150 more than the hub mini.

woof

[dalmore]

According to Yan, you needn't ditch that hub, as there's a new Capreo mini about to be introduced. Yan says they "are in the warehouse and will be stocked in the shop in 5-7 days." Price will probably be about $150 more than the hub mini.

woof


That's interesting news aside from the point of this thread.

Getting back to topic. I suspect Capreo cassettes won't fit the Bionx either so he'd be better perhaps to dicth the internal hub and since the OP can probably source a derailer and shifter more cheaply than $150 upcharge for the capreo that would be ditched.

[Wavshrdr]

Or, if you buy a Mini and go with a motor, I'd be interested in the wheel and hub. :-)

A Capreo would give some tall gearing options with the Mini and a choice if you don't want an internal hub and it might shave a pound. I love the stealth look with the internal hub. People shocked as you just keep shifting up through the gears. Many have never seen a "modern" internal hub that doesn't have an indicator chain.

[elmergeorge]

So no one is mentioning the Dahon...which is going with my natural instinct that the mini would be the best bet if I can figure out the hub. the front hub idea is interesting, is that really doable? I am still on a steep learning curve, what difference would the capreo mini make?

[elmergeorge]

sorry I missed this before writing my last question, I think one of the main attractions to the mini is the internal hub, so I'd like to figure out a way to keep it.

[spambait11]

No one mentions the Dahon because they took the Roo out of the US market AFTER they supposedly improved the battery and performance. Plus regular Dahon front hubs are the funky 74mm size which is not common stock, though this might not apply to the Roo; most standardized hubs are 100mm.

Hub motors from Crystalite (http://www.evsolutions.net/kits.html), for example, can be fit in 16" rims for the front wheel, but I'm pretty sure the hub axles are 100mm. The biggest issue will be the weight of the battery, and then where and how to mount the batteries esp. on the Mini.

[Wavshrdr]

You could mount the battery pack inside the frame on the Mini if you custom build a pack. Some of the pre-built NiMH packs would easily fit on a clamp-on seatpost rack. I still don't know about the clearance under the bike and the motor. It mike work but I haven't had a chance to loook yet.

I would have been seriously interested in the Roo IF they didn't pull it from the US market. That is why I'll likely never buy another Dahon product. You NEVER know how long any of their bikes will stay in your market. I really don't want to get stuck with an orphan'd bike. Parts can become a PITA. The upgraded Roo caught my eye and then they decied not to sell it here. I often wonder who is awake at the helm of Dahon when it comes to the US market.

[wubrew]

I talk to Yan awhile back on possibilty of BionX on an internal hub Gear DT. He pooh phooh the BionX sysytem and gave me the run around with a system called ICS?? or something like that. I do not have a clue what he was referring to. I googled his description, spent a couple of hour and came up with nothing. Wavshrdr your cyclone idea makes the most sense. Front wheel driven sysem is not reccommended for greater than 15mph. I will try to find the Knowlege base web page that show the physics behind the claim later

[DeltaMike]

The issue with front hubs is generally too much torque on the fork, and finding an appropriate method of attaching the hub to the fork even if it can take the forces.

[elmergeorge]

I was wondering if you could clarify; in the DT mini thread Wavshrdr said that the gearing was perfect. Personally I would rather have the low gearing for getting up the hills and sacrifice speed. With the capreo hub is it win-win?, do you get both or is it better for speed?

[spambait11]

The issue with front hubs is generally too much torque on the fork, and finding an appropriate method of attaching the hub to the fork even if it can take the forces.
How much torque is usually generated, or what force is acting on the fork such that it's in danger of failure? I'd think a cromo fork could take it. Most electric front hubs I've seen require some kind of pedal assist before they kick in; I've seen very few that kick in at 0 mph.


Capreo systems are a step backwards IMO: 1. Capreo hubs are proprietary; 2. they're derailleur-based if you care about such things; 3. they require their own exclusive cassettes and/or cogs; 4. they're pricey. Their plus is that they can give you the gear range of full-sized uprights. But folders have been coping for years without them.

[Wavshrdr]

The SA hub on the Mini has a great gear range for most people. This is the one advantage of the SA hub. It STARTS at a 1:1 ratio. So instead of having both underdriven and overdriven gears, all gears are overdriven. What this means is that you aren't hampered too much (or at all) in having a decent gear range even with a small rear wheel and not having to do anything wild with the gearing like a huge front chainring to get tall enough gears.

One issue with most hub drive motors is that on small wheels, they have are just plain limited on top speed because there is a most efficient RPM the motors will turn and for a given wheel revolution smaller wheels travel less. So if the hub motor can only turn 280 rpm (max) then for a given wheel, the larger wheel will have a higher top speed assuming there are enough watts in the motor. A 500W motor could push most people easily in the low 20mph range on flat ground with appropriate gearing.

I like systems like the Cyclone because I can use the advantage of the bike's gearing to help out the motor and to improve hill climbing performance as well as top speed. It doesn't look quite a clean if you do it as an aftermarket system compared to a factory one.

I personally wish that Dahon had continued to bring in the Roo especially after the upgraded the system. I rode a Giant LaFree and it was quite a nice electric assisted bike.

[Wavshrdr]

Here are some photos of a Cyclone kit on a DT. It should give you a better idea of what you are looking at if you want to try and mount it on most folders.

http://public.wavshrdr.airpost.net/DT/ElectricDTLeft.jpg
http://public.wavshrdr.airpost.net/DT/ElectricDTRight.jpg

[bookishboy]

Does the unit get in the way of the seatpost as it collapses down through the tube? If so, just curious how much higher (approximately) it sticks out with the Cyclone motor installed.

Also, if you use the Cyclone with an internal hub, does it mean that you're stuck using a derailleur, just to keep the chain tensioned?

[Wavshrdr]

Several ways you can do this. Easiest way is I am working on a telescopic seat tube ala Dahon's accessory one. My seat sticks up about 3-4" extra. You can mount the motor many different ways.

If you have the right chain length you don't need a tensioner with an internal hub. If you want to take the motor on and off easily than you would need one. If you leave it permanently attached then cut the chaing to fit. My current project is to fit it on a VIIIH interna hub or the Mini. Mini might be too tight for the clearance below but I haven't had time to play with it yet.

[foldingmagic]

You may take a look Dahon Yeah Bike as well.
Make by Dahon using Brand name Yeah! Same quality but cheaper price.

North American agent, web site: Dahon Yeah! Bike (http://www.civagroup.com)

[elmergeorge]

Here are some photos of a Cyclone kit on a DT. It should give you a better idea of what you are looking at if you want to try and mount it on most folders.

http://public.wavshrdr.airpost.net/DT/ElectricDTLeft.jpg
http://public.wavshrdr.airpost.net/DT/ElectricDTRight.jpg

Reading your posts have made me think maybe I should add the motor to my VIIIFS and get the Mini just to travel and keep it light. How heavy is your FS w/ the Cyclone? Did you add the 360 or 500watt system and which batteries? Is it a DIY bracket adapter? it's still pretty clean.

is there a good reason why Yan pooh poohed the Bionx?
has anybody looked into the Crystalyte or Wilderness energy kits?

[elmergeorge]

Here are some photos of a Cyclone kit on a DT. It should give you a better idea of what you are looking at if you want to try and mount it on most folders.

http://public.wavshrdr.airpost.net/DT/ElectricDTLeft.jpg
http://public.wavshrdr.airpost.net/DT/ElectricDTRight.jpg

again, I should look at the other threads before asking, as your DT mini thread talks about the batteries etc. But what is your actual motorised DTFS weight? I would probably try to go with the NiMH batteries.

[JDELUNA]

Hi Wavshrdr,


Are you able to re-post the pictures that you have of the Cyclone unit on a Downtube bike ?? Thanks and God Bless :)

[fireworkz]

Would be nice to see DT Mini with the electric kit.. how about this one on youtube - nano motor
http://www.youtube.com/watch?v=lAM-Oh-gfrM

Silent too but weighs 5kg or so..

and here is the guys site http://www.mr-motorvator.co.uk/

[Wavshrdr]

I'll see if I still have the photos of the DT FS with the motor. I had a hard drive die and some of my less important photos weren't backed up. This might be one of them but I'll check in the next few days.