Design Parameters for 280lb'er with hills

[Aaron DenHerder]

I am new to this group. Currently own a 48V electric boat and recently became aware of hub motor electric bicycles. I have been researching everything I can find and would like input from the group on motor/controller/battery choice. My design parameters are as follows:

1.) I am 280lbs.
2.) I live in a hilly area. Not mountains but 40%uphill, 40%downhill, and 20% flat.
3.) I would like to carry my son on the bike (approx. 40 lbs) sometimes be it in a child seat or a trailer.
4.) Bike is for recreational use only. 12 mile range would be sufficient. Likely to stay at pedalable speeds. I cannot see going more than 25 mph on a bike. With my son along, probably no more than 20 mph. My thought is that if I could pedal as fast as we motor along, then it is safe for him to be with me.
5.) Light pedal assist is OK. I need the exersize

I am considering the 5305 (Brute) or the 5304(Cruiser). Cruiser only because it seems to be the more popular choice I think the torque (Brute)to get up the hills would be better for me considering my weight. Don't let my thought process bias your recommendation.

Efficient cruising in the 15 - 25 mph range is important.

Which battery set-up do you recommend? 48V or larger. Electric Rider is appealing because of the complete package they offer but seems to stop at 48V. Are the SLA's acceptable or do I need to look towards NiCd, NiMH, or Lithium? Has anyone tried Electric Riders Eon yet?

Thanks for all your help.

 

[CGameProgrammer]

The Eon isn't out yet (chargers were defective/incorrect; the next shipment is due at the end of June and hopefully those will work) but it's basically like any other lithium-ion polymer ("LiPo") battery. In the case of the Eon, it's 22 lbs compared to 34 lbs for the lead-acid, yet it has over twice the range. It also lasts longer.

Anyway, the Brute (5305) will be strong enough that you won't need to pedal at all on level ground or slight hills, though given the payload of 320 lbs, pedaling will probably still be very useful on uphills. And it will help acceleration a lot, which would be slow otherwise.

 

[mvadventure]

At 220 with a Cruiser (5304) on a 26" bike, slick tire to 70 lbs and 48 volts of SLA I can reach 32 MPH which is too fast, a comfortable 25 - 27 sitting up is just fine. Range however at that speed makes 12 miles iffy but quite easily at 18 MPH or so which is still a comfortable speed.

Here in N FL our hills are bridges and the 5304 has yet to find one it doesn't like. Some suppliers offer wire baskets for the SLA's and that is the supplier you want to go with. The nylon panniers will rip out under the SLA weight if left unsupported plus the balance of the bike can be effected.

IMHO a "watts up" and the ability to read it makes for an ideal companion along with a good mileage/speedo computer. The extra hundred bucks is not only worth it but essential for peace of mind when you're ten miles into the trip and wondering how much battery you have left.

LIPO, NIMH or any of those other letters combined in various ways to present expensive battery packs are undoubtedly better than the SLA's but I would still recommend the SLA's to start with. They are cheap enough so that if you dump them in a month or two it's no big deal. I'm fixing to dump mine but I just can't seem to decide on the replacements.

Good luck but beware, this can get a little consuming. I don't know why but the EV grin is pretty powerful.
Mike

 

[xyster]

If you buy one of the 530x models, feed the beast at least 48 volts and 35 or 40 amps (buy the 35 or the 40 amp controller), else it's not worth having the much heavier 530x -- the 12lb lighter 400-series would do just as well. IMO, the hills and your weight demand the 5304 or 5305. The 5305 will be a little more efficient for the relatively low speed you're interested in (meaning you can go farther on a charge), and climb the hills a little better than the 5304.

My requirements are a little different than yours'. But if I had your requirements and was just starting out, here's what I'd choose knowing what I know now after almost a year with my 5304 at 80 volts 35 amps:

1) Rear 5305 (brute) in a 26" double-walled wheel (or a 24" DW wheel if your rear brakes will allow it). Definitely rear wheel -- too much risk of a front 5305 ripping itself out of the dropouts even with electricrider's torque arm.
http://www.electricrider.com/crystalyte/phoenix.htm
http://www.poweridestore.com/Hub-Motor-Kits/X-5-Hub-Motor-Kit/X-5-750W-Rear-Hub-Motor-Kit
The 505 is the same as the 5305.

2) 72 volt 40 amp controller. Could go with electricrider's 48 volt 40 amp controller, but the 72 volt gives you headroom in case you wish to increase the voltage later for more power.
http://www.poweridestore.com/Hub-Motor-Acces/Series-500-Controllers

3)48 volt 10ah or 12 ah SLA batteries. Can upgrade to something lighter later if you want. If riding more than a couple times per week, better batteries will save money in the long run as the SLA's will need to be replaced annually, and NiMH/Nicad/lithium every 5 years approximately.

4)Drainbrain bike computer to tell you how much battery you've used -- it's better than the Watts-Up meter and either is better than the notoriously unhelpful LED battery meters that come on the throttle with most kits:
http://www.ebikes.ca/drainbrain.shtml

5) If riding in the rain, a non-LED throttle because the LED meter throttles have a bad habit of shorting out, causing a dangerous throttle full-on situation.
http://www.poweridestore.com/Throttles/Half-Twist-Grip-Throttle

The 530x with a 3 speed freewheel fits inside standard 135mm width rear mountain bike dropouts without too much wheel "dishing". 5 speed or 7 speed freewheels require extreme dishing which can weaken the spokes. So be prepared to lose some gears. I find nine (3 crank + 3 freewheel) is plenty, still allowing me to pedal comfortably if I don't feel like using the motor for some reason, like I'm exercising.

 

[gwsaltspring]

Xyster;

Could you explain what "wheel dishing" is please?

Greg

 

[xyster]

Xyster;

Could you explain what "wheel dishing" is please?

Greg

I'm too lazy to reinvent the wheel, so how 'bout some links, pics, and quotes instead...

Pic:

Dish:
http://www.sheldonbrown.com/gloss_da-o.html

A bicycle wheel should have the rim centered directly in line with the frame. The fork ends are symmetrical with respect to the frame, and the hub axle locknuts (or equivalent surfaces) press against the insides of the dropouts.

Wheels should be built so that the rim is centered exactly between the axle ends on the hub. In the case of rear wheels, the spokes attach to flanges which are not symmetrical...the right flange is usually closer to the centerline than the left flange, to make room for the sprocket(s).

When rear wheels are built properly, the spokes on the right side are made tighter than those on the left side. This pulls the rim to the right, so that it is centered with respect to the axle (and to the frame.) Viewed edgewise, a rear wheel built this way resembles a dish, or bowl, since the left spokes form a broad cone, while the right spokes are nearly flat.

By extension, the term "dish" is used as a general synonym for accurate centering, even in the case of symmetrical wheels.

On general wheel building and truing:
http://www.sheldonbrown.com/wheelbuild.html
There are 4 different things that you need to bring under control to complete the job: lateral truing, vertical truing, dishing, and tensioning. As you proceed, keep checking all 4 of these factors, and keep working on whichever is worse at the moment.

 

[mvadventure]

Generally I defer to he xyster because of more time in the field and a much greater interest in the subject but on the single point of rear wheel motor I tend to present an argument.

280 Lb Rider
48 Lbs of batteries
24 Lbs of Hub motor
3 pounds of controller, wires, switches and bag
355 pounds on the rear wheel plus the potential for a small child will make, IMHO squirrelly handling and a lot of strain on a bicycle tire. These figures are also for a 0 weight bicycle and nothing has been added.

We recently had a member from New Hampshire put a rear motor on with SLA's and he reported some unusual and perhaps unpleasant handling characteristics.

However as my dear departed mother used to say "to each his own". The issue of the torque arm ripping out could be an issue in the 5305, I have no idea, but on the 5304 with steel forks I have not had an issue of having to re tighten anything except for spokes. The bike is well balanced and performs well. The most important upgrade I need to make is brakes because the regular rim brakes I use when combined with all this weight make an emergency stop a long one. As of yet I haven't figured out how to resolve this issue.

Good luck,
Mike

 

[Aaron DenHerder]

Thanks for all the input so far. Sounds like the Brute is the motor for me and good to hear people support the SLA's.

I am interested in more feed back on the wheel placement.

Rear placement -
1.) I have an aluminum frame comfort bike right now. Is this OK to mount the rear motor or would it need to be steel frame?
2.) Existing bike has 7 speed cassette. Are any shifter/deurailer changes required to use the 3 speed cassette xyster suggests? With the hills I use almost all the gears besides the granny however I guess with the electric assist the nine gears would be sufficient.
3.) Anyone besides mvadventure concerned about all the weight? I know I am. Realistically the SLA on the back would require my son to go in a trailer. When he is with me the battery bag could live in the trailer as well. However, when alone I do not want the trailer.
4.) What about the balance? One of the things that appeals to me is that most people will not recognize it as an electric bike with the batteries in rear panniers. I want to stand out as little as possible. Taping SLA's inside of the frame certainly makes it more noticeable.

Front placement -
1.) I realize I will need to get a steel fork for my bike or a new steel bike.
2.) Are you concerned about ripping the dropouts out even at 48V? Electric rider seems to support the front location but they run the Racer and not the Brute. My instinct is telling me to go front but if the experienced members are insistent on rear for my use it would seem foolish to ignore.

Buy from who?
I see three likely sources:
1.) Electric Rider - I like their "everything comes in the package" approach. They seem to have a better webiste than Power Ride Store so I assume their customer service is better. The downsides I see is their controllers peak at 48V (I think I can live with that), they don't readily offer a 3-spd rear hub (need more input to decide front vs rear), their motor cases are black (looks more noticeable than the grey). Do I really need the cruise control and e-brakes?
2.) Power Ride Store - The reasons I see to go with them would be the 72V controller and the 3spd rear. What about customer service?
3.) Ebikes - His controller comes pre-wired for the DrainBrain and offers 72V. His motors have the grey case. Downside is that it looks like I need to purchase each component individually.

I should mention that I am in Maryland so none of these are close. Can anyone push me in a direction?

 

[xyster]

...
I am interested in more feed back on the wheel placement.

Rear placement -

1.) I have an aluminum frame comfort bike right now. Is this OK to mount the rear motor or would it need to be steel frame?

My 5304 is on the rear of my aluminum comfort bike too. No problems so far. My dropouts are 9mm; the hubmotor axle is 10mm; I had to carefully grind 1mm off the axle. No matter what the instructions with the kits say, Do Not Grind Your Dropouts! Cracks can develop. Grind the axle if you have to.

2.) Existing bike has 7 speed cassette. Are any shifter/deurailer changes required to use the 3 speed cassette xyster suggests? With the hills I use almost all the gears besides the granny however I guess with the electric assist the nine gears would be sufficient.

Mine was 3 speeds front, 7 rear. I did not have to adjust the derailleur. I just have to skip over a shift to engage each of the three rear gears (7, 5, 4 on my index shifter).

3.) Anyone besides mvadventure concerned about all the weight? I know I am. Realistically the SLA on the back would require my son to go in a trailer. When he is with me the battery bag could live in the trailer as well. However, when alone I do not want the trailer.

Definitely concerned. I agree with all that weight on the back your bike's handling would get dangerously squirrelly at higher speeds. I had to remount my 30lbs of batteries, formerly all the rear, because speeds over 28mph would put my bike into the dreaded "death wobble" scenario. However, I don't think a front 5305 is the answer. It's not just a hypothetical risk, there's been a number of cases recounted on these forums of all types of hubmotors tearing out of front dropouts (or ripping the front dropouts and then tearing out) when run at 48 volts 35 amps or more. It's a torque thing....

To correct balance, I'd suggest mounting at least 2 of the 4 SLA's in the triangle -- 3 or all 4 in the triangle would be better if you can fit them all in there. 12ah SLA's are not too wide (3.5" if I remember right) 10ah SLA's are a little thinner still.

4.) What about the balance? One of the things that appeals to me is that most people will not recognize it as an electric bike with the batteries in rear panniers. I want to stand out as little as possible. Taping SLA's inside of the frame certainly makes it more noticeable.

There are special triangle-fitting bike bags too -- few people will suspect you've got batteries in there

Front placement -
1.) I realize I will need to get a steel fork for my bike or a new steel bike.
2.) Are you concerned about ripping the dropouts out even at 48V? Electric rider seems to support the front location but they run the Racer and not the Brute. My instinct is telling me to go front but if the experienced members are insistent on rear for my use it would seem foolish to ignore.

I would not do it, even at 48 volts, even with the electricrider torque arm which some people have had trouble fitting properly, and/or felt it was too flimsy. If you are serious about running >1000 watts in a front hubmotor, I'd advise having torque arms specially fabricated.

Buy from who?
I see three likely sources:
1.) Electric Rider - I like their "everything comes in the package" approach. They seem to have a better webiste than Power Ride Store so I assume their customer service is better. The downsides I see is their controllers peak at 48V (I think I can live with that), they don't readily offer a 3-spd rear hub (need more input to decide front vs rear), their motor cases are black (looks more noticeable than the grey). Do I really need the cruise control and e-brakes?
2.) Power Ride Store - The reasons I see to go with them would be the 72V controller and the 3spd rear. What about customer service?
3.) Ebikes - His controller comes pre-wired for the DrainBrain and offers 72V. His motors have the grey case. Downside is that it looks like I need to purchase each component individually.

I should mention that I am in Maryland so none of these are close. Can anyone push me in a direction?

A la carte kit?

I bought my motor from ebikes.ca (there was a $54 import duty). Justin is very helpful, and does fine work -- he specially dished my wheel and installed the 3 speed freewheel I wanted.

I bought my controller and throttle from the poweridestore. Earl was conscientious and prompt.

I used 4, 10ah SLA's from my scooter on my bike until I finished soldering the 300 lithium-ion laptop batteries I bought from all-battery.com

 

[Aaron DenHerder]

Can someone provide a link for these triangle bike bags? I see the one on e-bikes but will it fit a 12V12A SLA?

What about putting two or three of the batteries in a front mounted basket? I guess i would have to get rid of the suspension fork. I am suprised not to see anyone else doing this.

Thanks.

 

[gwsaltspring]

Thanks for the info X

Aaron

I just picked up two of these bags and think I have solution to attaching them together and slinging the pair over the frame like a pair of motor cycle tank bag panniers. I had been planning on a pair of triagular 36V battery packs from Justin @ e-bikes. He might be able to advise you about fitting SLA batts into the bags.

MEC Large Cycling Frame Bag

http://www.mec.ca/Products/product_detail.jsp?PRODUCT%3C%3Eprd_id=845524441775829&FOLDER%3C%3Efolder_id=2534374302693353&bmUID=1182354558412

 

[xyster]

Here's another one that looks a little bigger, but would still require about 2" of extra width. Any good at sewing?

http://tinyurl.com/28jkbe

gwaltspring: try http://www.tinyurl.com to downsize those really long thread-blowing strings.

 

[Aaron DenHerder]

I found the link below for a front rack that will work with a suspension fork with a listed capacity of 25lbs. Maybe two batteries in panniers on the front rack, one battery in a handlebar bag, and one battery in a frame bag. That solves the balance issue. Still worried about the majority of my weight over a rear hub motor but from looking at xysters previous posts and pics, it would seem that his riding style must exert the same loadings or greater than what I would exert on the rear wheel on smooth surface.

Whether it be a front or rear motor, it seems to me that a front rack may be a good choice for some of my batteries.

http://www.modernbike.com/itemgroup.asp?IGPK=2126175375

http://www.modernbike.com/itemgroup.asp?IGPK=2126175375

 

[gwsaltspring]

Xyster:

Like this?

http://tinyurl.com/2ny7x9

 

[agent86]

I'd be wary of putting batteris over the front wheel - in panniers on a rack might be OK but in a basket would really upset handling. Unless you've got one of those bike trucks with a front rack welded to the frame so it doesn't turn when you turn the wheel.

Couple of interesting things to look at:
http://www.evdeals.com/Batteries.htm
Bottom of the page - you can by the Lashout from pack for 2 12AH sla's.

http://www.currentcyclebikes.com/
Have probably the neatest way to mount 4 SLA's. wonder if someone could figure out how to duplicate it, or if they'd sell just the battery mount. (their bike is single speed.) Not sure all bikes would have enough clearance between the front wheel and the bottom frame tube though.

 

[agent86]

ah - worry too about that delta rack failing with 2 SLA's on it. Here are some _pricier_ and supposedly more sturdy racks that will fit a suspension fork:
http://www.oldmanmountain.com/Front_Rack.htm

 

[Aaron DenHerder]

Thanks for all the links. The help is great. I would never find all of this stuff on my own.

Ebike's 48V 5A NiCd's are cheap enough at $145 ea. Parallel two of them for a 10A/hr pack. How do you charge them? I do not see 48V chargers. Wouldn't it be nice if my 48V, 25A Lester Charger would work (I know it would fry them but wouldn't it be nice).

How would a 10A NiCd pack compare to a 12A SLA? I am all too familiar with the Peukert effect on lead acid batteries. My 225A/hr boat pack will not last 2 hrs at 85A. I think I read somewhere that the NiCd's aren't as affected by this.

 

[Instant Karma]

I use nicads and sometimes throw on an SLA brick for extra speed sometimes. I use 7AH 48v nicads with a 20 amp limit controller and they have some voltage sag but nothing like the lead acid. I would say offhand 10AH nicad would be equivalent to around 14 or 15 AH SLA since they can be run down real low. They're lighter than SLA and best of all you don't have to recharge them immediately after using them like lead acid batteries. In cool, mild or cold temps I think they're superior to NImh but in real hot weather they can get very hot when you're going full bore and that has to be detrimental to cycle life i would think. I myself will keep using them until I go to lithium whenever thay may be -I'm still searching...

 

[Aaron DenHerder]

What do you use to charge your 48V NiCd's?

 

[Robbie Hatfield]

I'd also consider the southbeach diet as 280lbs will stress the other bicycle components as well.

Robbie

 

[Instant Karma]

What do you use to charge your 48V NiCd's?

I have two 24V packs and usually charge them with Astroflight charger they use for RC, you can choose the charging rate with them, sometimes I use the cheap charger that came with the packs also. Those prices are really good that you quoted, other places have raised prices quite a bit on nickel batteries due to low nickel availability, or so they say. THat's another reason I may switch to lithium since the price difference has shrunk some between lithium and nickel batteries.
But if you're going to use a 500 series hub motor you'll have to go for a greater energy dense battery like Nimh or lithium to power it, if weight of batteries is going to be a factor - takes a lot of AmpHrs to power that motor at a good speed.

 

[D-Man]

Best deal out there is Nimh 10ah individual cells. Solder them yourself and save a bunch. $7.16 a cell, 40 cell = 48volt = $286.40

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=325