Fat Man Commuter - 270lbs on 700c

[dogman]

FWIW, cellmans battery is "48v" nominal. So it will work fine with 48v controllers. He just likes to use the voltage a 16s lifepo4 actually is.

Still think you don't really need 40 amps, but it will certainly be more fun to ride with 40. Your ride is short, and the hills mellow enough, I doubt you'll overheat the motor too much. Pedaling some on the hills will help the motor stay cooler, by climbing the hills a bit faster. Aim to keep your speed 15 mph up the hills or more. Should be no problem.

Maybe you already understand this, but you won't use 40 amps all of every ride. 25 mph on the flat will only take about 15 amps. 40 will only happen when on a steep hill.

Good choices, HT winding or 2808, either one will have that little bit of advantage on the hills, without sacrificing too much speed.

If you get a kit with a CA from Grin, you will have a DP Cycleananlyst, which will allow you to limit amps if you feel you are heating up that motor too much.

[Drunkskunk]

The 52 volt battery is essentualy a 48 volt battery. Cell Man just believes in a little more truth in advertising. But it has a 30A BMS, so a 40A controller will cause the BMS to go into overload.

The Clyte 3525 is $100 more than the 9C. Its also heavier.
The 9c can handle the 5% grade at full speed for 6km with no pedaling on a 40a controller. on a 30A it will do it even longer, but at lower speeds. Of course, the Clyte can do it for twice as long, but you will rarely find your self going up a 5% grade hill continusly for 6 straight km without pedaling.
A 2810 would do so even long.

All 3 are good choices. All 3 motors will exceed your needs.

[MikeFairbanks]

Welcome to Endless Sphere.

You found the end of the internet. Most never get this far, but you reached it.

I wouldn't go anywhere else for E-bike advice. Nope. This is the headquarters, the central office, the peak of the mountain.

Good luck with your endeavor. Hey, you only barely mentioned your bike. What do you have? What kind of weight can it hold? That seems like a lot of weight for a bicycle. Is it heavy duty?

[wesnewell]

20km RT. Only 12.4 miles. That's under 20 minutes with my $600 total cost, including bike, 48v 1000W yescomusa kit (GM motor), including 18s battery pack and new controller capable of up to 100V pack.. If I kept the speed down to 20mph (~30kph) I could make 2 trips a day on one charge. Why on earth would you want to spend more than that?

[dsullivan]

excellent post thank you.
Regarding using sensored vs unsensored, all the reading says that the only big advantage to sensored are smoother take offs and many people are reporting fine take offs with sensorless. The comparison here http://endless-sphere.com/forums/viewtopic.php?f=3&t=15491 even suggests that the setup is easier and with less parts to go wrong, the sensorless should be even more reliable.

My question is what can you tell me from your experience that might change my current thoughts. Remember I have no experience so I am actually hanging on everyone's words.

[dsullivan]

Dogman thank you -"If you get a kit with a CA from Grin, you will have a DP Cycleananlyst, which will allow you to limit amps if you feel you are heating up that motor too much." -- I will definitely be using the DP Cycleanalyst. +2

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...

Thanks in advance guys. Really great info here. I am already doodling plans for welding a custom bike together for my next play rig

Dave

[Drunkskunk]

Sensorless require you to be moving forward for the motor to work. the latest Clyte are suppose to be able to start from bearly any turn of the wheel, but they still require forward movement.

However, a sensored can start like a car, or motorbike: Instantly. it can even start forward if you're rolling backwards. 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.

Install and setup for a sensored motor is harder. You have 1 extra plug to plug in. I know 1 extra plug is hard, right? Its a single 5 wire plug that runs along side the main phase wires from the motor to the controller. Nothing else is needed for setup.

To be fair, sensorless had their place. older motors were not as weather resistant, and water in the motor could damage the sensors. Newer motors are much better sealed, and don't often have this problem. The sensors could be replaced.

Sensored are just superior. Ride one and you'll understand. Plenty of people are happy with their sensorless motors, but I don't know of anyone who would trade their sensored hub for a sensorless.

[MadRhino]

I don't like sensorless, for I am in hills most of the time and that is where it bugs on a start, even tries to start backward sometimes. They also bug at high speed. Some don't care, mostly those who run low performance on the flat. I have 2 small 12 fet sensored-sensorless controllers that I keep on a shelf as backups, but most of my controllers are 18 fet sensored and upgraded for performance. A good controller and sensored motor are a must in the mountains.

If you are not after performance, the 12 fet sensored-sensorless can run both. If you buy a sensored motor, you will have the benefit of instant start, and can ride sensorless if you have a signal failure that you don't want to fix right now.

[dsullivan]

Thank you for the in depth explanation about sensors. I'm glad you include the one connector comment.

How about throttles? Do we have a preference?
My bike has a shimano quick fire trigger with triggers over and under. I'm wondering which type of throttle I should use? Ideas?

Dave

[GrayKard]

Thank you for the in depth explanation about sensors. I'm glad you include the one connector comment.

How about throttles? Do we have a preference?
My bike has a shimano quick fire trigger with triggers over and under. I'm wondering which type of throttle I should use? Ideas?

Dave

Since you have trigger shifters then a half twist throttle should integrate nicely with them. I prefer the half twist to a full twist for a couple of reasons.

1. The full twists have been know to come apart with the grip sliding off the handlebar which leads to wide open throttle on the motor. It's pretty rare but can happen.

2. It's easier to hold a set speed over bumps with the half twist.

Gary

[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.