Dahon Helios SL electric conversion advice

Hi all

 

My first post - pleasure to meet you all! I've just acquired a Dahon Helios SL which I'm very excited about; however I was really on the market for a light electric foldable and so I've taken a punt in the hopes that I can covert this super light bike into a super light electric bike. I know a bit about bikes (little compared to most on this forum) but know next to nothing about conversions. I was wondering if any of you could think, off the top of your heads, of a front wheel kit that might be compatible with the Helios SL? I haven't taken delivery of the bike yet but I'm assuming it will have a <80mm distance between the front forks and so know that I need to be careful about what I choose.

 

Budget is not really an issue - weight and quality is. I won't be doing more than 6 miles per journey, all flat terrain and I weigh about 12.5st. I'm fairly technical so feel I can read my way through this but if people think the contrary, I'd be willing to pay someone with the expertise to make sure it all goes to plan.

 

Any advice is appreciated. Looking forward to getting stuck in! Again, pleasure to be a member of the forum.

 

Cheers

 

Specs of bike:

 

SPEEDS: 8

GEAR INCHES 31" - 91"

DISTANCE: SEAT POST TO HANDLEBAR 670 mm (26.4")

DISTANCE: SADDLE TO PEDAL Min. 710 mm (28"); Max. 950 mm (37.6")

FOLDED SIZE 28 x 56 x 81 cm (11" x 22" x 33")

WEIGHT 7.6 kg. (16.7 lbs) base model w/o options and pedals

FOLDING TIME 15 seconds

SUGGESTED RIDER HEIGHT 142 cm - 193 cm (4'8" - 6'4")

MAX RIDER WEIGHT 105 kg. (230 lbs.)

 

FRAME Y Series, 7005 double-butted aluminum alloy, custom-drawn Sonus tubing, forged Lattice hinge, patented Re-Bar™, EmBed, ViseGrip technology, replaceable derailleur hanger

FORK Dahon SlipStream™, Puro™ U6 aluminum alloy, integrated, Fusion technology

 

STEERING COLUMN Radius ProLite, patented Fusion™ design, forged aluminum, patented InSide™ lock

HANDLEBAR Dahon CarbonLite riser, custom

HEADSET Dahon Fusion XP, Zero stack, machined aluminum cups, ACB cartridge bearings, sealed

GRIPS ProLite foam

SADDLE SDG BelAir FX, I-Flex design

SEAT POST SDG I-Beam Pro, SuperOversize, 2014 aluminum, forged clamp

 

BRAKES Kinetix UltraLite, forged aluminum V-brakes, micro bolts, front Flex stainless noodle, stainless anchor bolt

BRAKE LEVER Avid FR5

CABLES AND HOUSING LiveWire™ K, Kevlar SIS housing, slick cable, LubeTube oil port

 

FRONT WHEEL Rolf® Prima Accel™ - 390 grams

REAR WHEEL Rolf® Prima Accel™ - 640 grams

TIRES Dahon Special Edition Schwalbe Stelvio, Mango/Black, 28-406, 120 psi, foldable Kevlar bead, DualCompound Silica casing, RaceGuard anti-puncture protection

 

SHIFTERS SRAM X.7, 8 spd.

DERAILLEUR SRAM X.7, Dahon custom edition

CASSETTE SRAM, 11-32, 8 spd.

BOTTOM BRACKET American Classic UltraLight

CRANKSET Truvativ Elita, ISIS, forged 6061-T6 aluminum, 6061-AL chainring, alloy chainguard w/ CNC finish

CHAIN KMC Z82

PEDALS MKS Promenade, QR

 

CLIP SYSTEM Magnetix™ system

TOUCH UP PAINT Yes

ACCESSORY Reflective pants clip

Edited September 15, 201411 yr by Sean McGrath

There are front motors that might fit, but they're not very powerful. You can't stretch the forks far because they're alloy, so no standard 100mm motor will fit. You didn't say how fast you want to go. A 36v 328 rpm Q100 rear motor will take you to about 18 mph. If you use 12S lipos as a battery you'll be able to scoot along at about 22 mph. You can just squeeze in a Q100C, which will allow you to keep your gears.

 

On my Dahon, I have a Q100C. I started with a frog battery, and then changed to a bottle battery. The first photo shows it with the frog battery case with two Turnigy 8000mah 6S lipos in, which gave really good performance:

 

http://i451.photobucket.com/albums/qq236/d8veh/Dahon/P1000013.jpg

 

http://i451.photobucket.com/albums/qq236/d8veh/Dahon/20131222_121627_zps2b752ea7.jpg

Wow, it looks awesome - thanks. To be honest, I think I'll be okay going along at the legal 15mph, but if I can squeeze a bit more out of it, I don't mind living dangerously.

 

I'm keen to keep it front wheel so I don't have to screw about with gears. I see a few kits for a Q100 front wheel but no Q100C. Would something like this work http://www.bmsbattery.com/ebike-kits/576-250w350w-q-85100sx-motor-e-bike-kit.html or am I looking at getting a barebones motor and doing it myself (scary!).

The Q100 front wheel won't fit. The Q100c is the Q100 with a cassette spline, so rear only.

 

The motors that fit are the Q85 (maybe), I think Outrider and Keyde do a 80mm motor, and possibly Crystalyte do a 74mm one

http://outrider.en.alibaba.com/

http://www.keyde.com/?do=product&lang=en&event=view&ids=07

http://shop.crystalyte-europe.com/product.php?productid=16513&cat=250&page=1

Thanks mate. Based on the links you have sent, the only one I can see that includes a full kit with the 80mm dropout is http://shop.crystalyte-europe.com/product.php?productid=16235&cat=320&page=1

Are any of these motors better than others? Should I juts man up, get the motor and figure out how to fit it to my existing wheel? How hard is it? I'm assuming it's not straightforward! Thanks again for the advice.

nothing is difficult if you know how. You can get all those motors as a kit.

 

The Crystalyte is a direct drive. It's not everybody's cup of tea because it doesn't free-wheel quite as well.

 

I can't understand why you want to make life difficult for yourself by fitting a front motor. Is there a reason?

1. Most of what I've read suggests that if you want to maintain foldability, it makes life easier.

 

2. I liked the idea of chucking a wheel on rather than messing with the gears.

 

3. I don't want to lose the gears.

 

I am more than happy to be told that rear wheel is the way to go if it is the way to go.

There's no problem with foldability with a rear motor that I've ever heard of.

 

You don't have to lose the gears with a Q100C. The only messing you moght have to do is reset the end-stops, which takes about two minutes.

 

The one thing you will have to sort is getting the rim central. Front wheels are normally OK because they're symmetrical, but on rear wheels, the flanges are off-set and the Chinese always build the rim central to the flanges. Already the Q100C is wider than the drop-outs, so is a bit of a squeeze to get it in. You can make the rim central by spacing it on the left side which will make the hub even wider. I think that's just about feasible, or you can dish the wheel, or a combination of both.

 

None of those front motors have very much power

Okay, sounds good in theory. Thanks. How heavy are these Q100Cs? Will I have any problems stretching aluminium alloy forks? Also, any vendors you recommend for them (that sell with controllers etc.)

 

Really appreciate all your input d8veh.

If you mean your front forks, I doubt that they'll go to 100mm without heat. If you search really hard, there are some replacement 1 1/8"steel forks that you could stretch. IIRC there's another piece you need to convert to them. Do a search for 1 1/18 steel Dahon forks and see what comes up on the various folding bike forums, or search for Dahon 100mm hub.

 

You can get the Q100C from BMSBattery.com, greenbikekit.com and Elifebike.com. They all have a different designation for it. I prefer BMSB because they have a better choice of controllers and batteries, but maybe one of the others has exactly the battery you want, so have a good look at them all.

 

Q100C is about 2.2kg IIRC.

Im just looking on BMSBattery now (like the controllers too) and I don't see a Q100C kit with 328rpm. Only 201. I've emailed them but...whattsup with that? :|

They have the bare motors. at 238 rpm, so I don't see why they can't build a wheel with it.

http://www.bmsbattery.com/rear-driving/618-250w350w-q-85100sx-motor-e-bike-kit.html

Yeah. Will see what they say. Just looking at other sites. Name changes are throwing me off. Is this the badboy I'm after? http://www.greenbikekit.com/gbk-100r-36v-rear-driving-kit-bottle-lithium-battery.html

No. This one:

http://www.greenbikekit.com/100cst-cassette-freewheel-e-bike-kit-36v-250w.html

Got it. One other question (for now). You mentioned in your first post, 12S batteries. What do you mean by 12S.

 

Thanks for helping me find my way.

Lithium-ion batteries are made of cells, which are 3.6v each, so 10 cells in series (10S) makes a 36v battery. You can buy lithium polymer batteries (lipos) in 1S, 2S, 3S, 4S, 5S and 6S packs; so you can put two 6S packs together to male a 44v pack, which gives 20% more torque and speed than a 36v pack. A 36v controller can still work with a 44v pack, so it's an easy way to get a power boost. The other advantage of lipos is that they can give a lot of current for their size, which makes a very light 5ah pack feasible, though you can't go as far, obviously.

Makes sense. I'm just having a think about the tyres and it seems that the Helios SL makes most of its weight savings from the ultra-light Rolf wheels. When every gram counts, it seems a shame to replace one with a clunky heavy thing. I can't find any specs on the wheels offered but I'm assuming they are heavier than 640 grams. Does anyone offer/know of a service, where I could send the wheel (and motor) to have it fitted?

 

Thanks

I doubt that that spoke pattern is strong enough for the torque of a hub-motor. If a spoke goes, you'll be stranded too.

fair enough Any suppliers that give precedence to weight or are they all roughly the same? Is there anything that you'd do different if you were trying to build the lightest e-bike possible?

Power and weight tend to go together. If you want less weight, you can get a lower powered motor. The Keyde is the lightest. After that, it's down to your DIY skills. There's also the Kepler Commuter Booster:

 

http://www.commuterbooster.com/home

Commuter Booster looks interesting. Don't see how the guy is claiming that little thing can take you up to 40km per hour? Think hub is way to go. D8veh, can I ask, how are you so confident that the Q100C will fit my bike. Do the dahons generally have the same configuration? Cheers

It's read the ad carefully.

It can boost his cruse up to 40kph.

That could easily mean I normally cruse at 35kph and with this helping I get 40 but looking at his power rating 500 watts give you 40kph.

That motor can manage that output. Remember most other packages have gearing systems that take up a lot of room.

 

This type of drive has been about for years but will eat tires.

There's a D8ve and a D8veh? Mind...blown. I don't want to be replacing tyres all the time. Think I'm gonna go Q100C. D8veh, you're sure this will fit? As sure as you can be at least?

I have a Q100C in my Dahon Jetstream P8. I think my frame is probably stiffer than yours. It isn't just a question of dropping it in like a new wheel. You'll have to play about with spacers and dishing like most rear motors - normal DIY stuff.

 

The commuter Booster is very powerful. It has an R/C motor in it capable of 2KW. It'll do 40 km'h without pedalling. Kepler is a highly respected member of Endless-Sphere. He doesn't exaggerate his product - unlike other things brought to our attention here.

Interesting. So if this thing can actually get me moving faster than the Q100C and is lighter, why is not at the top of your recommendation list? Is it simply that it burns tyres out? Does it slip in the rain? What are the downsides?