Fat Man Commuter - 270lbs on 700c

[bc_dc]

Do you know the range of twist on the throttle between closed and wide open? That might play into the decision between half or full grip.

[MadRhino]

This is a personal choice Some like a full twist throttle like motorcycles, some prefer a thumb throttle like many commercial Ebies. I like half twist, that leaves enough steady grip to handle the bike without accidentally twisting the throttle, yet has the motorcycle feel control. Half twist and full twist have the same turn range, the half twist is an half grip in reality.

A 3 speed switch can be added, that most controllers have a connector for, to limit the bike's top speed at 3 programmable levels. There is also a cruise control switch that can be added, but not all controllers have this function implemented. Some controllers have auto cruise, that is engaging automatically when you hold the throttle steady for a given amount of time, but I don't like those for they can surprise you by holding the throttle signal when you release.

Some throttle have a regen button, that is braking by pulling regen current from DD hub motors. I prefer regen to be activated by the rear brake lever, that feels more natural and is a great braking performance helper, somewhat like compression on a motorcycle. This function is programmable with most controllers, and can also be activated on throttle release.

Shifters sometimes require creativity, to make shifting handy with the throttle and switch in the way. I use a grip shifter on the left to control the rear derailer, that makes the gear and throttle controls very natural for they twist in the same direction to high and low. Most of my bikes have a single chain ring, so don't have a front derailer. You will find that shifting gears is not important anymore, and most ride on the high gear all the time for the motor let you start with no effort.

[GrayKard]

Some controllers have auto cruise, that is engaging automatically when you hold the throttle steady for a given amount of time, but I don't like those for they can surprise you by holding the throttle signal when you release.

My bmsbattery controller has that type but another member here found that if you cut the wire loop on the controller that will disable the cruise you then hook those wires up to a momentary switch and then when you press the button it turns it into a latching cruise control only.

Not sure if it works on other controllers but easy enough to test.

Gary

[sk8norcal]

Yup.
And guess what? a 700c doesn't necessary have lower rolling resistance. This is a common misconception perpetuated by some of the most hardcore cyclists! rolling resistance is a function of tire friction, and hub drag, not the diameter of the wheel!

Just yesterday i had the 1.8" 26" 'city tire' wheels on my pedal bike inflated to about 50 PSI and i was blowing past the local lycra folks all day, LOL. I am a fairly strong pedaler, but here i was on a $80 wal mart mountain bike with tires that had lower rolling resistance than theirs.. and... win

I am pretty sure you are wrong on this,

there is no way that your 1.8" 26" 50psi have less rolling resistance than standard 700c 23mm 90psi tires....
if so, Tour de France riders would be riding those....

http://www.tomsarazac.com/tom/opinions/wheelsize.html

[Joseph C.]

Yup.
And guess what? a 700c doesn't necessary have lower rolling resistance. This is a common misconception perpetuated by some of the most hardcore cyclists! rolling resistance is a function of tire friction, and hub drag, not the diameter of the wheel!

Just yesterday i had the 1.8" 26" 'city tire' wheels on my pedal bike inflated to about 50 PSI and i was blowing past the local lycra folks all day, LOL. I am a fairly strong pedaler, but here i was on a $80 wal mart mountain bike with tires that had lower rolling resistance than theirs.. and... win

I am pretty sure you are wrong on this,

there is no way that your 1.8" 26" 50psi have less rolling resistance than standard 700c 23mm 90psi tires....
if so, Tour de France riders would be riding those....

http://www.tomsarazac.com/tom/opinions/wheelsize.html

All other things being equal the wider the tyre, the less rolling resistance it offers. A larger width tyre deforms less than a narrow tyre.

However, a higher pressure filled tyre will offer less rolling resistance than a lower pressure tyre. Therein lies the advantage with skinny tyres - they can take much higher pressures.

Someone posted a video of a someone preforming tests on rolling resistance about a year ago that supported this. Schwalbe say the same thing on their website.

[dsullivan]

Wow, really great and insightful information everyone.

My next question is regarding controllers.
I am planning to run a 40amp for plenty of hill climbing power and if I'm understanding it correctly , I can use the cycle analyst to limit my speeds and/or my amps. I'm also sold on the sensored motor/controller setup.

Using a HT3525 hub should I use their controller or are there others I should consider?

Thanks again
Dave

[MadRhino]

Rolling resistance is not only about the tire, it is about the surface that you are riding on too. Try the rolling resistance of a hard thin tire on soft or rough surface, you soon will want bigger and softer tires.

Long distance racers are all about lightweight, and average pavement condition. You can beat them on a short stretch where you have better rolling tires (and are fresher), but on average long course their setup is optimized. Then, many Lycra Sunday racer wannabees are set to ride the TDF, yet only ride 40 miles where they'd do better with a different setup.

[MadRhino]

I am planning to run a 40amp for plenty of hill climbing power and if I'm understanding it correctly , I can use the cycle analyst to limit my speeds and/or my amps. I'm also sold on the sensored motor/controller setup.

Using a HT3525 hub should I use their controller or are there others I should consider?

You can upgrade the kit to a 40A controller, if you want more than that you want to PM Lyen for highway speed controllers and upgrades.
Then, chose a battery that can output the current that your controller is set to.

When buying an H series motor, make sure it is sensored, and had the axle seal mod done. Many of those H motors that are stock production, are sensorless and=or have a problem with the seal cutting the wires. Buying from Methods or Grin, you are making sure that your motor is ready to ride.

[wesnewell]

Wesnewell - Could you explain more about your situation. How much do you and your rig weigh, how hilly is your trip and is it used as a daily commuter or just for fun? I am interested in seeing if your setup can help me modify my plans...

I weigh 275lbs. Not sure what the bike with battery weighs, maybe 50-75lbs. I ride 10+ miles a day 7 days a week year round, but not for commuting. Longest round trip was about 20 miles using about 65% of a 10ah 18s lipo battery pack @ 20mph. If you want to know the terrain, map it from hwy 78 and Kreymer in Wylie TX to fm 544 to Shiloh in Plano TX. and back. There's 2 or 3 valleys in that route but not real steep. Around here I usually ride on fairly level streets unless I go to one of the lakes. Then I climb some grades that are close to 30%. Starting out, I'd recommend the stock controller (30A) running 10 ah of 12s lipo. that'll give you a top speed of about 28mph (45kph). If you need more speed than that, you could go to 15s lipo on that controller. That would put at about 33mph. Battery choices are many. I just like lipo for lots of reasons I won't go into here. In any case, the stock controller will handle up to 63V max. I replaced the stock controller with a 40A controller that can take up to 100V pack. Not for the faint of heart at 100V. Lots of torque and over 40mph.

[hjns]

If you go for the HT, stick to either Grin (ebike.ca) in Canada or MethTek (methtek.com) in CA US. Justin at ebike.ca pretty much is the Zeus of Ebikes, and "owns" this forum in pretty much every sense of the word. Methods at MethTek.com must be the Apollo from the same E-bike Walhalla, and he is an admin here. Both sell very good stuff without much advertising and will prevent you from making too many beginner's mistakes.

With regards to the controller, both Grin and Methtek sell programmable controllers fit for your voltage and current. You may want to try and look into the future to see whether you may like higher speeds with your bike. Higher speeds means higher voltage, so you may want to buy a 72V or even 100V controller for later upgrades. However, more voltage also means that you will have to carry more batteries....

You may have seen people mentioning lipo. Unless you are way into RC and have experience with lipo, I would recommend to stay away from it and keep to Cellmans A123 triangle pack. You don't want to learn too many things at the same time. Getting the electronic components right is hard enough.

I would recommend the 3-speed switch and half grip throttle as well.

[sk8norcal]

All other things being equal the wider the tyre, the less rolling resistance it offers. A larger width tyre deforms less than a narrow tyre.

However, a higher pressure filled tyre will offer less rolling resistance than a lower pressure tyre. Therein lies the advantage with skinny tyres - they can take much higher pressures.

Someone posted a video of a someone preforming tests on rolling resistance about a year ago that supported this. Schwalbe say the same thing on their website.

This is what most road cyclists know from experience, skinny high pressure tires are faster on the road,
not low pressure fat tires...

I used to ride 700c 28mm 90psi tires on my road bike, mostly for more comfort than 23mm 100psi ...
but they take more effort to accelerate..


http://www.schwalbetires.com/tech_info/ ... resistance

Small diameter tires have a higher rolling resistance at the same tire pressure, because tire deformation is proportionally more important, in other words the tire is "less round". Wider tires roll better than narrow ones. This assertion generally generates skepticism, nevertheless at the same tire pressure a narrow tire deflects more and so deforms more.

Why do Pros ride narrow tires if wide tires roll better?

Wide tires only roll better at the same inflation pressure, but narrow tires can be inflated to higher pressures than wide tires. However, they then obviously give a less comfortable ride. In addition to this, narrow tires have an advantage over wide ones at higher speeds, as they provide less air resistance.

Above all, a bicycle with narrow tires is much easier to accelerate because the rotating mass of the wheels is lower and the bicycle is much more agile. At constant speeds of around 20 km/h, the ride is better with wider tires. In practice, the energy saving is even greater than in theory as the elasticity of the tires absorbs road shocks, which would otherwise be transferred to the rider and so saves energy.

[sk8norcal]

Long distance racers are all about lightweight, and average pavement condition. You can beat them on a short stretch where you have better rolling tires (and are fresher), but on average long course their setup is optimized. Then, many Lycra Sunday racer wannabees are set to ride the TDF, yet only ride 40 miles where they'd do better with a different setup..

obviously that's not true... (see above)
racers would use the same wheels whether its a 100 mile race or a 40 mile race,

average joe riders should go for a bit less pressure and more width because its more comfortable.... (why beat urself up on high pressure skinny tires for just a bit more speed when ur not racing)

[Lebowski]

Its also smoother and more efficent, as the sensors tell the motor when to fire each phase, instead of just guessing like the sensorless do.

Oh Dude you're so wrong here !

[dsullivan]

Its also smoother and more efficent, as the sensors tell the motor when to fire each phase, instead of just guessing like the sensorless do.

Oh Dude you're so wrong here !

Lebowski - can you explain your position?

[tofuuu]

Well I might not be as knowledgeable as some people on the forums, I can definately speak from my own experience.

I just recently did a similar build. I also live about 10-14 km from work/school and i weigh just under 90kg/180cm. So im not really that fat but not a light rider either. I did cycle recreationally before and didnt have much problem doing those distances before i went electric. It just took more time and i had to wear lycra underneath my shorts (it helps alot for long rides and cycling)

I ended up modifying my flatbar roadbike and putting a 350w mac motor on it and a 52.5 * 11.5ah battery from cellman on it. I get around 10-15 wh/km on it and usually closer to 10. avg speed on commute is anywhere from 25-30km/h. It really just depends on traffic . Top speed is about 44 from just the motor but i have taken it to 55km/h with some pedal power! But i wouldnt really reccommend going that fast without diskbrakes and suspension cos all that extra weight from the motor/battery hasnt helped my braking power and bumps/potholes can really rattle you if you dont anticipate them. I run a 32mm schwalbe marathon plus on the front @ 80psi and a 28mm on the back. The fork is crmoly and has no suspension. the bike pretty much glides everywhere cos theres no suspension sapping away at power although the ride is pretty harsh and the vibrations will rattle things loose. If you actually cycle with the bike it will extend the range ridiculously. I dont think i have ever gone past half capacity on the battery.

Anyways just something to think about since it sounds like you are already cycling/hiking quite a bit and just want to get to work without too much effort.

[dogman]

Rolling resistance.

Who cares at the wattage you are planning? 40 amps x 53v = 2120 w. Run on tires with old rags substituing for a tube if you feel like it. Well, maybe not that far, but you won't really care if you run 2.5 inch knobbies at 30 psi or street slicks at 90. Sure, a big handling change, but either way with that kind of power you will get there fine on either one.

Sensorless.

Sensorless starts smoother than most think, but I don't recomend it in higher wattage, or higher speed applications. I really like the Aotema 20 amp sensorless controllers I have. I run one on my cargo bike, even though the 2810 motor has sensors. Starts and runs plenty smooth, but does like a 1/2" of forward roll as you hit throttle.

Since you want 2000w, I'd say go sensored. But a spare 20 amp controller is a great thing to have for backup. If you kill a hall sensor, and it does happen unexpectedly at times, you can still slap on the lower wattage sensorless controller till you have time to crack the motor to replace some halls.

One last time, your ride, even with your weight, will not need 40 amps. But 40 amps is funner. 30 amps is a really good compromise, get's you 1500w, which rarely cooks off a dd motor.

[dsullivan]

Hey Guys I appreciate all the information.
In trying to keep on topic, I believe we have beat the Rolling Friction argument around enough.

New information for my build. I have mapped my route, calculated elevations and hill grades.
My route will take me 6 Miles one way, 12 Total.
From my house I first climb a 1km(0.6Mile) 4% grade. This is the steepest grade until one 500Foot 14% grade.
I end the whole trip climbing a long slow grade that gradually increases to 3% for a final 0.6 mile

I am 270lbs, my bike is an standard (Rocky Mountain Whistler 10) 19inch mountain bike with 700c hybrid tires (flat smooth center with knobby edges) running disk brakes.
Speed is not my concern 35 Km/h is plenty for this bike. I am more concerned with durability and being able to get up the large hill.

I'm shopping on the ebikes.ca site (so far) has been highly recommended.

So far my build looks like this.

ebikes.ca DirectDrive conversion Kit( comes with throttle and Cycle Analyst)
Crystalyte Motor (Currently they only show the HS3540 Version, I'm wondering if I need the HT3525) Sensored
Inferion 40A Sensored Controller
48V 10AH eZee battery Pack (a Cellman A123 Triangle 52v 11.5AH if I can get one)

Other than this I think this is the build.
Any more suggestions?

[Joseph C.]

I am 270lbs, my bike is an standard (Rocky Mountain Whistler 10) 19inch mountain bike with 700c hybrid tires (flat smooth center with knobby edges) running disk brakes.
Speed is not my concern 35 Km/h is plenty for this bike. I am more concerned with durability and being able to get up the large hill.

I'm shopping on the ebikes.ca site (so far) has been highly recommended.

So far my build looks like this.

ebikes.ca DirectDrive conversion Kit( comes with throttle and Cycle Analyst)
Crystalyte Motor (Currently they only show the HS3540 Version, I'm wondering if I need the HT3525) Sensored
Inferion 40A Sensored Controller
48V 10AH eZee battery Pack (a Cellman A123 Triangle 52v 11.5AH if I can get one)

Other than this I think this is the build.
Any more suggestions?

Torque arms.

[dsullivan]

Definitely good Torque Arms. Thank you for bringing this up. I have just sent my first email to ebikes.ca outlining my thoughts and will update soon.

Thanks Dogman.
Your point is really hitting home.
I am planning to use the CycleAnalyst to limit my amps to 25 or 30 (I just want the head room this way I could always turn it up if want)

I actually didn't join in the Rolling Resistance conversation for exactly that reason.
After some experience with this first bike, I will put more thought into my next build.
Accounting for comfort, range and power will be next bike.

Bike two will probably run something like a 20 or 26 inch wider street/dirt hybrid having front and rear suspension and a comfy seat.
I am also planning on playing with Recumbent bikes

We can save all those conversations for another Thread

Thanks
Dave

[MadRhino]

Yep, recumbents are another story. But your bike having disc brakes can easily swap to 26 in, that makes life easier for your motor and controller, especially if you take the HS 3540 that is faster and pulls more current. The HS is good for your hills and offer better upgrade potential for the day you'll want more power.

Grin have a new, thicker torque arm, if you don't want to make them yourself.

[hjns]

The HS is good for your hills and offer better upgrade potential for the day you'll want more power.

Don't you mean "HT"?

[MadRhino]

The HS is good for your hills and offer better upgrade potential for the day you'll want more power.

Don't you mean "HT"?

No, I suggested an H series motor. With his 700C wheels it would be logic to go for the HT, but with 26in the HS will do fine and has the potential for a more powerful and faster bike in the future.

[dsullivan]

NO he meant HS - the HS/HT label is actually misleading. The HT is just a slower motor. It still produces the same torque. Meaning it still does the same work just slower. It doesn't work like bike gears where slower is more powerful. It is just slower. Its like having a throttle limiter right in your motor.

Just got the email from Justin@ebikes.ca and he has sent me in a new direction. Similar but new.

ebikes doesn't carry the HT3525 because it has the same torque as the HS3540.
The HS3540 will climb the same hills and faster. Obviously producing more heat and using more power. Thank goodness these are not long hills.

Using the HS3540 with a 35amp controller and a 36V battery extends my range from 16kms un assisted to 25 kms and will still get me up the 5% hills.
especially when I pedal.

So ...
ebikes DirectDrive kit +
Clyte HS3540 Sensored Motor in a 26" Wheel
Infineon 24-48V 35A controller, 12xAOT460 mosfet, ON/OFF button, regen, and CA connector
36V 14Ah LiMn eZee battery pack, with matching 4A aluminum charger
ebikes torque arm kit.

Grand price .... Guess ....

[wesnewell]

After a week, you'll wish you had gotten a higher voltage battery. A higher voltage battery will give you more speed, more torque, and more range if you run at the same speed as the lower voltage battery. Anyone that says different is just ignorant.
Watt Hours (wh) is what matters for range.
Voltage is what matters for speed.
Watts is what matters for torque.
14ah 36v battery has ~504wh.
14ah 48v battery has ~672wh.
With a 35A controller and 36v battery, max nominal watts is 1260.
With a 35A controller and 48v battery, max nominal watts is 1680.

I don't know what the price is but I can tell you this for a fact. My inexpensive setup ($500 for kit and battery) will run circles around what you plan to buy. It will be faster, climb steeper hills, and get more range run at the same speed. 1000W motor, 40A controller running 10ah 18s lipo (66.6v nominal).

[MadRhino]

My inexpensive setup ($500 for kit and battery) will run circles around what you plan to buy. It will be faster, climb steeper hills, and get more range run at the same speed. 1000W motor, 40A controller running 10ah 18s lipo (66.6v nominal).

Remember what you started with. He will want more power, as we all do, but he has to start somewhere. With this kit, he is beginning with a quality system that will be easy, complete and reliable. Then, when he want more power and can get into mods and performance, he will have a motor that is capable of a lot of power. With this motor on my 55 pound road racer pulling 100v 100A off my High C-rate Lipo, I can do to your rig what you pretend to do to his, and some here can do it to mine. Performance start with building a first bike, getting addicted, and do better every next build.