First E-Bike - Doing DIY BBSHD - Critique my plan

[RunForTheHills]

I am not sure a racing bike is a good comparison to an electric bike. An elite cyclist is hardly in the seat at all. Their weight is forward on the bike and they are putting a lot of power into the pedals. They would be able to absorb the bumps in the same way a skier does.

My commuting bicycle has drop bars, but I have them about saddle height and I ride it in a much more relaxed position. I get up on the pedals when I see a bump coming, but normally most of my weight is in the saddle with some weight going to the pedals and the bump will jolt the bike and myself pretty hard if I don't react in time. People break spokes and taco wheels all the time by not getting out of the saddle when they should. It is possible to ride the bike in a way that will trash it. However, it is also possible to avoid trashing it. It just takes a little skill and practice.

 

[furcifer]

We're talking twice the weight here as well. OP is looking at +300lbs with the BBSHD and battery.

That's pushing the maximum carrying capacity of a 125cc motorcycle. But yah, no problem on a rigid frame bicycle.

 

[furcifer]

Affordable (but not horribly cheap) bikes are stronger and more durable than ones built to the minimum reaching weight limit.

And of course you don't get to where you can put out nearly 2hp in a race without having done it lots of times when training.

Tandems go faster than single bikes, with twice as much weight. They don't use suspension either. Most bikes don't, at any price. It makes little sense for the street, and it costs performance and versatility in other ways.

You think riders use their race bikes to train? Are you sure you worked in a bicycle shop and not for Bicycle making playing cards?

I'm not sure if you're talking about frames or components??? "Affordable" bikes have cheaper components that don't last as long as good ones. I have a Shimano 600 groupo that's 30 years old and probably got 10 000 miles on it. It's in better condition than new ones on an "affordable" bike. If you're talking about frames then yes, I agree with you there.

My first bike shop mechanic job was in 1992. I know what lasts, and what doesn't. I use steel chainrings, for instance (cheap), when I want them to last. Shimano 600 is pretty nice, but nothing special. Sachs New Success is hardier and nicer looking in any generation, and never cost more than 600/Ultegra. Dura Ace (the "good" stuff) is more likely than not to be deciduous crap. The few decent bits that hang around manage to color people's opinions about the product line overall.

But what isn't even in the same ballpark is the endurance of suspension bikes (abysmal) versus normal bikes of any price range above Wally World garbage. You can have any pet idea you want about them, but suspension bikes go to shit at a young age. Even the ones that only see pavement and tame riders. Squish bikes from two seasons ago are already making a racket, and by the point where it's time to overhaul a normal bike to bring it back to like-new, you can't even overhaul the boinger because the manufacturer has stopped supporting it.

Meanwhile, in the real world, all the manufacturers making high output ebikes are using full suspension. EVERY SINGLE ONE OF THEM.

Granted, they're mostly intended for off-road use and we're talking about the road. But at least in my area there are some pretty nasty patch jobs and potholes. The problem I find is once you're going 25 or 30 mph you really don't want to be watching the road, you want to be watching the traffic. Having the suspension to take up the odd bump you can't avoid isn't a luxury, it's essential.

 

[E-HP]

Interesting second half of this thread :wink: . Same topic that causes so much "discussion" on mountain bike forums. I ride both hard tails and full suspension for different kinds of riding. Since my ebike is a hard tail, I just use the same techniques when the road surface if rough. Unweighting the rear wheel, bunny hop over big bumps, etc. I like to stay alert, when riding two wheels, and watch the road surfaces pretty closely. Could be habit maybe from logging a quarter million miles on my motorcycles with only 3 big crashes that weren't because I wasn't paying attention.

As far as an advantage of a hard tail, you can bunny hop a lot higher with a hard tail, unless you lock out the rear shock on the full suspension.

 

[Chalo]

Since my ebike is a hard tail, I just use the same techniques when the road surface if rough. Unweighting the rear wheel, bunny hop over big bumps, etc. I like to stay alert, when riding two wheels, and watch the road surfaces pretty closely.

That's right. On a real bicycle, you are the suspension. Unless for some reason you're incapable of filling that role. Not mentioning names.

 

[E-HP]

Since my ebike is a hard tail, I just use the same techniques when the road surface if rough. Unweighting the rear wheel, bunny hop over big bumps, etc. I like to stay alert, when riding two wheels, and watch the road surfaces pretty closely.

That's right. On a real bicycle, you are the suspension. Unless for some reason you're incapable of filling that role. Not mentioning names.

Ya, but not everyone is the same, or rides for the same reason. I LIKE to concentrate on the road. With so much crap to juggle at work and home, it's nice to block everything out and concentrate on riding; it's like a vacation. Every hobby I have has some aspect where my full attention is necessary; which oddly is relaxing to me.

 

[RunForTheHills]

The Road Bike Party videos are kind of fun to watch:

[youtube]HhabgvIIXik[/youtube]

 

[donn]

Meanwhile, in the real world, all the manufacturers making high output ebikes are using full suspension. EVERY SINGLE ONE OF THEM.

Granted, they're mostly intended for off-road use and we're talking about the road.

Meanwhile, in the real world that we're really talking about, the legal 750W ebikes I see on the road around here may have suspension - in the front. Or they may not. Rear suspension though, seems to be pretty unusual. The local hero whose bikes I see most commonly, radpowerbikes.com, have 6 models, and the one I notice most often is the "wagon" model with no suspension.

The fact that my bicycle and that GSXR are both considered motorcycles under the law is hysterical.

This is my point. The law is what it is, but "legally motorcycle [like a GSXR]" gives you no basis at all for to how to design an ebike.

It seems counter-intuitive but I think the hub motor is more suited to a rigid frame.

Why? The drive train is the weak link in the crank-drive system, right? So that would fail before the frame, in a failure due to motor power. A hub drives the rear dropouts, and notoriously drives them hard. As for load, crank drive weight is on the bottom bracket, which I think would be the normal peak load bearing site on an upright bicycle, where a hub motor is a load in an unusual location (and unsprung whether you have rear suspension or not.) Not seeing anything here that would make a big difference, but for the frame specifically it seems like there might an advantage to the crank drive, assuming it can be installed without compromising the frame.

 

[amberwolf]

This is incorrect as well. Both Canada and the US have similar federal laws and both are well under 1000W. (500W and 750W respectively)

Nope.

THere is no USA federal law defining an ebike.

There is a federal CPSC regulation defining what a manufacturer can call an ebike, which has no bearing on what classification such a bicycle will be in any particular state. The federal government does not, in the USA, determine what is and is not allowed on the roads (or classified as what type of, vehicle, HPV, EV, or other transportation, or speeds or power levels of such things, etc) (though they can pressure states into it by withholding federal funding). That is a state-specific thing.

Each state in the USA has it's own laws on what is and isn't an ebike.

Some of them specifically forbid any form of them, so even one meeting the CPSC regulation are illegal to ride there.

Some of them specifically call anything with any kind of assist a moped or motorcycle or other motor vehicle classification.

Some of them just call them bicycles, with no restrictions (or varying very basic limits, like one may only have a speed limit, one may have a weight limit, one may have a power limit, etc).

Several of them have changed to a three-class system defining an ebike, and some have higher power limits than the CPSC regulation, some have the same, and some may have lower limits; the speed limits are generally the same, but details of the classes may vary.

The BBSHD is a 1000W
<snip>

going this fast on a vehicle and using public roads is dangerous

Having 1000w available has NOTHING to do with the speed someone goes.


I have a few kW available, but I ride at "bicycle" speeds (under 20MPH). For me, that power is for hauling heavy cargo, big dogs, etc., and for quick acceleration from a stop to those speeds in traffic so cars/etc don't run me over, or get pissed off at me for "slowing them down", since riding in traffic is the only option, or sometimes the safer one, in many places I have to ride.

The same is true of others on electric bikes, as well as on vehicles of various kinds.

At least some of them are geared or otherwise limited such that even at maximum power they cannot go faster than some practical speed (sometimes the legal limit in their locality, sometimes slower, etc).

If your logic of available power to do it automatically = fast speed was true, then cars and trucks capable of more than the actual speed limits of the roads they are used on would have to have much smaller engines, and/or be limited in engine power quite significantly from what they are now, so they would not be able to exceed speed limits.



Regarding the suspension / no suspension argument, and other things I see you post around the forum, Furcifer, you appear to have an extremely narrow point of view, and don't seem to understand that your usage, and your experience, is not the *only* possible way things can work.

Other people have different needs, different usage, different conditions, etc.

You might consider that before pressing your personal viewpoint upon everyone and everything out there.


Now, all that said, we should really stop arguing OT in this member's thread, and start helping him with his project.

 

[furcifer]

Nope.

THere is no USA federal law defining an ebike.

There is a federal CPSC regulation

It's actually an Act, and it's law.

 

[furcifer]

Regarding the suspension / no suspension argument, and other things I see you post around the forum, Furcifer, you appear to have an extremely narrow point of view, and don't seem to understand that your usage, and your experience, is not the *only* possible way things can work.

Hey, don't put words into my mouth. If you actually read my posts I clearly stated this is my opinion.

OP is +300lbs. with motor and battery - that exceeds the weight carrying capacity of any rigid frame. It's really more than any bicycle frame can carry. This is the reason vehicles have suspension and this is why I would strongly suggest looking into a bicycle with full suspension. I'm riding a hardtail with a very good front shock and a BBSHD. It's pretty sketchy riding at 30mph over train tracks, pot holes, uneven pavement etc. It can be white knuckle at times having to deal with watching the road for obstacles and watching traffic. I'm about 75lbs lighter and have much stronger wheels on my bike and I know I'm pushing the limits of what this bike can handle.

Sorry, but I firmly believe it's downright dangerous to suggest using a rigid frame bike to the OP. I've read your counter arguments and they still come off as false bravado. Basically all I'm hearing is "I'm a super awesome rider so I can ride a rigid frame, if you knew how to ride you could too". It's nonsense, suspension is specifically allows for a better ride with more weight, which is exactly what we are talking about.

And I clearly stated it depends on the route. If you have nice roads then suspension becomes less of an issue. But I would also suggest relying on suspension instead of relying on the condition of the road. I had decent road conditions along the route I normally take and then they put sewers in. You can't bunny hop +300lbs over an 8 foot wide patch of uneven ground.

This is my opinion. I haven't ridden an ebike for very long. I have ridden for 30 years though, I got my class "M" before I got my driver's licence and have ridden numerous motorcycles over the years. That's why I can say at about 30mph on my ebike things behave more like a motorcycle than a bicycle. It gets harder to watch the road, you can feel the bumps in the road more, it's harder to weave and you need a more direct path. And the weight makes bunny hopping much more difficult.

If you want to talk about fallacies, having the power but not using it because "I'm a responsible person" has to be one of the biggest ones. It just doesn't happen. For one, 30mph in terms of traffic flow is slow, so most people are going to max it out. Second, going slow in traffic comes with its own perils. It's much safer to keep up with traffic and since you can't on an ebike, going as fast as you can is preferable IMO. Plus with an ebike most of the power is used at lower speeds. It's just a characteristic of electric motors. The basic function of a controller is to keep the electric motor from tearing the wheel off the bike when you turn on the power!

So my critique of the OP's plan remains the same. If you're going to run a BBSHD I would strongly consider getting a full suspension bike. It's a better ride on the road and leaves you more open to trail riding than a hard tail. Keep an eye out for higher end 10 year old bikes with air. Only consider a hard tail if you have really good roads, but even then you might be better off with a 1000W hub on a hard tail. Riding a full rigid frame bike, with a springy seat post, is just a bad idea.

 

[wturber]

Nope. Most are actually bicycles as is the OP's build. An average top speed of around 25 mph is bicycle, not motorcycle speed. 28 mph max assisted speed is Class 3.

This is incorrect as well. Both Canada and the US have similar federal laws and both are well under 1000W. (500W and 750W respectively)

You keep using "average top speed", there's no such thing. It's weird.

I was talking speeds because that was your initial argument. Speeds and safety. Now you want to get into the weeds about the technical legality of the motor wattage which wasn't your original point.

I'm using "average top speed" because that is what the OP said. Remember the OP. This is supposed to be about what he wants to do and what is the best way to accomplish that.

And no, bicycles aren't operating at a sustained 25mph. That's like world class cycling on a road bike speed. Even then a cyclist is putting out only about 250 watts. In general bikes are made to go about 10mph.

No. Bikes - good bikes - are typically designed and engineered to go well past 25 mph. I've done so regularly throughout my life. 25 mph is not world class speed when you are in a peloton. But the fact remains that they are designed to operate and operate well beyond 25 mph even if the average person doesn't ride that fast.

The weight and power we are talking about with a 1000W BBSHD is equivalent to a moped or small motorcycle. Legally.

Maybe. Depends on the state and law and how you interpret the 750 watt limit. But that wasn't what you were talking about initially. The point initially was speed and whether you need suspension at the speeds in question, or not. Now you are seeking refuge in legal definitions because it has been made clear that suspension is clearly not necessary at around 25 mph. The difference between 1000 watts and 750 watts is pretty minor - about 3 mph at the top end on a bike like the OP is describing.

I think of it like this, even a really good full suspension bike is under what would be considered "properly engineered" for 1000W. If you were to actually engineer a 1000W ebike you'd probably double the frame thickness, use 2in rims, have shocks designed for about 400lbs of weight etc. Some of the downhill bicycles are close to these type of specs but they are designed with gravity as the motivating force, not a motor.

You are simply restating your argument here. There are tens if not hundreds of thousands or real world e-bike riding miles that demonstrate that you don't need suspension for a 1000 watt bike that isn't operated regularly above 30 mph.

 

[wturber]

I've ridden thousands of road bike miles at around 20 mph on 700x25c road tires pumped to 110 psi. 2 inch tires at 50 psi are just fine at 25 mph on a rigid front fork.

As for good gear, that is one of the negatives. Added cost. And now you have to modify and maintain it. More cost and hassle.
Things just aren't as cut and dried as you make them out to be.

*sigh

You don't seem to understand, you're only putting out about 200 watts, NOT 1000W. We're talking 5 times the power!

Surely you get the idea that as you scale up the power you need to scale up the components? It's very basic.

We are talking speed. I've screamed down hills at sustained speeds over 35 mph on rigid forks and skinny tires. They work fine. A more robust mountain bike frame designed to withstand the impacts of mountain bike riding is probably over engineered for road riding at 25 mph. This is one reason that they are a favored platform for e-bike conversion. The biggest issue the OP faces with his 1000 watt bike will be the wearing out of the drivetrain, not the durability of the wheels and frame. There's just tons of real world info that bears this out.

 

[kcuf]

some only think

others actually do

the later know

 

[furcifer]

We are talking speed. I've screamed down hills at sustained speeds over 35 mph on rigid forks and skinny tires. They work fine. A more robust mountain bike frame designed to withstand the impacts of mountain bike riding is probably over engineered for road riding at 25 mph. This is one reason that they are a favored platform for e-bike conversion. The biggest issue the OP faces with his 1000 watt bike will be the wearing out of the drivetrain, not the durability of the wheels and frame. There's just tons of real world info that bears this out.

Yah, this just isn't true. I worked in a bike shop and commuters (usually 700c) with rigid frames would come in looking for shocks ALL THE TIME.
Commuter bikes get beat up pretty bad. And that's not with a 1000W, that's with 200W, and that's at maybe 200lbs, not +300lbs. ANd that's averaging maybe 15mph.

Sorry but you keep presenting anecdotal evidence "Well I did this once and it was fine". I've seen maybe 100 commuter bikes in my time and they just don't last with a normal rider at normal speeds. They don't.

I find it flabbergasting that someone could say, double the weight and put 5 times the power to it and it's going to be fine. It makes absolutely no sense. Seriously, stop by a bike shop and ask if they have someone's commuter bike in the back. They look like they went through a war.

You think they look for potholes and don't get up on the pedals? That's a joke, people who commute know how to ride just as well as you. You're not gifted with super riding powers that nobody else has. No offence, I'm just saying I don't buy this line of reasoning. People that came in with wrecked bikes never "missed seeing a pothole", it's always "a car turned suddenly, or I couldn't get over in time". You know, accidents.

They aren't favored, they're in ridiculous abundance. We probably sold 400 hard tails a year to 2 full suspension. That was 15 years ago, I don't know if the numbers changed much. Looking at used bikes recently I found 1 suitable bike, a Kona Deluxe, to about 100 hard tails. Cheap WalMart special FS bikes abound, if I see another Jeep Comanche I think I'll puke.

But yah, let's talk facts. The fact is commuter bikes get the crap kicked out of them with just a regular rider at regular speed with regular legs. The BBSHD easily doubles the wear and tear, not just on the drive but the frame, bottom bracket, shocks, steer tube, handlebars etc. I'd say with the weight we are talking about triple the wear and tear is more accurate.

Don't forget a big factor in all of this is weather. People don't ride their bikes in the rain. Commuters do. The chain wear on my bike is probably 10 times as much. I put a new chain on in February and it's starting to wear. Usually a chain lasts years, not weeks.

The only valuable consideration being made here in regards to FS is the maintenance. I tend to agree that getting parts for older FS, bearings, shims, fittings etc. can be problematic. You need to become a bike mechanic to own an ebike simply because of the added wear and tear. Avoiding FS if you don't need it is a good idea for these reasons. Unfortunately I don't see this being the case in this instance.

 

[wturber]

some only think
others actually do
the later know

One of the key factors in the building my ebike the way I did was watching the 10,000 mile video below. It's a clear and practical demonstration of function, durability, cost, etc. And it provides a roadmap of important things to consider.

[youtube]2_zVFn6x3jg[/youtube]

My personal mileage on an ebike isn't nearly as important as all the miles ridden and experience gained by others.
[youtube]oCvo6ffWRdE[/youtube]

 

[furcifer]

I was talking speeds because that was your initial argument. Speeds and safety. Now you want to get into the weeds about the technical legality of the motor wattage which wasn't your original point.

No, the point was there are good reasons to consider a bicycle with a BBSHD more like a motorcycle than a bicycle. Namely the sustained speed and power, and second the law., because technically in most countries a BBSHD puts it into that class. There's really no argument here.

I'm using "average top speed" because that is what the OP said. Remember the OP. This is supposed to be about what he wants to do and what is the best way to accomplish that.

No. Bikes - good bikes - are typically designed and engineered to go well past 25 mph. I've done so regularly throughout my life. 25 mph is not world class speed when you are in a peloton. But the fact remains that they are designed to operate and operate well beyond 25 mph even if the average person doesn't ride that fast.

Yes, I went back and read that. It's still incorrect and you shouldn't be repeating it.

The rest is bogus. Mopeds were restricted to 30mph and there were plenty of warnings on them that they were not designed for speeds about 30mph. They are much beefier than a bicycle in every regard. Saying bikes were designed for 25mph simply because they occasionally attain that speed does not make sense. You can taco a bicycle rim easily at 25mph on a bicycle. You hit a curb at 25mph on a bicycle and it's over.

A good road bike might be made to sustain those speeds but you're riding a thin line. Those bikes get trashed after 1 race, a lot of times they don't even make it the full race. I'd say this comparison is similar to driving a Forumla car on the road. They don't have much suspension either. It would get trashed pretty quick on the roads around here too, if you didn't beach it coming out of the driveway.

Road bikes are really apples and oranges to this conversation. It's plain and simple,you can't compare a rigid mountain bike to a road bike and draw any conclusions. I'm talking about having a swing arm on a bike or not. Period.

Personally I'd love to for a ride with you an a road bike with a BBSHD. I think it would be very interesting.

 

[Chalo]

I worked in a bike shop and commuters (usually 700c) with rigid frames would come in looking for shocks ALL THE TIME.

People love gimmicks. You're entranced by gimmicks, obviously. But it's almost always the noobs looking for that stuff, not experienced riders. In my shop, most of our fork retrofits other than crash repair are longtime commuters converting the other way, to a rigid fork, because they understand it works better.

We get it. You like bicycle suspension enough that you think it's worth all the tradeoffs. You're like the guy who drives to work in a 4x4 truck with a lift kit and mud tires. If it makes you feel badass, great. But the rest of us aren't wrong for responding to real world conditions in a pragmatic way.

 

[furcifer]

some only think
others actually do
the later know

One of the key factors in the building my ebike the way I did was watching the 10,000 mile video below. It's a clear and practical demonstration of function, durability, cost, etc. And it provides a roadmap of important things to consider.

[youtube]2_zVFn6x3jg[/youtube]

I haven't finished watching the first one but he's already talked about breaking spokes, breaking one frame and bending a new one. That looks like a 1000W hub motor as well. There's significantly more power going through a BBSHD mid drive and flexing the frame.

I don't know if this is common knowledge but most 7 speed freewheels are hollow, 6 speed more flat. It's not as simple as changing from 7-6 with a hub motor because the 6 speed freewheel body rubs on the hub. The only one I saw that might work is a Shimano Mega Range 6 speed. FWIW

I don't think riding an ebike is like becoming a Master Carpenter. Most of what I've heard in that first video I think most people can figure out in a month of riding. It's not going to take 10 000 miles to find out a BBSHD is going to shred a rigid frame in about 6 months of commuting.

I will say this, it might be better to just buy a hard tail and think of it as disposable. It's going to fail, and as long as it doesn't kill you when it does you can swap the motor over to another similar frame and go for another 6 months. 8 if you bunny hop everything.

 

[furcifer]

I worked in a bike shop and commuters (usually 700c) with rigid frames would come in looking for shocks ALL THE TIME.

People love gimmicks. You're entranced by gimmicks, obviously. But it's almost always the noobs looking for that stuff, not experienced riders. In my shop, most of our fork retrofits other than crash repair are longtime commuters converting the other way, to a rigid fork, because they understand it works better.

We get it. You like bicycle suspension enough that you think it's worth all the tradeoffs. You're like the guy who drives to work in a 4x4 truck with a lift kit and mud tires. If it makes you feel badass, great. But the rest of us aren't wrong for responding to real world conditions in a pragmatic way.

That's actually true, but if you read what I wrote I was talking about commuters. People that ride every day 5 days a week.

The gimmicks are the seat posts with springs you're trying to sell. I've never sold one to a cyclist. My mom's bicycle had one though.

I've never owned a truck. I have owned a lot of VW's and as they say "VW's don't get older, they get lower to the ground". So you've got that backwards again, I usually remove some of the suspension from my cars. Motorcycles I have always added.

Again, your argument stems from bravado and not logic. Suspension is designed to absorb forces. At some point it becomes necessary. Like this one.

 

[kcuf]

10000 miles cute

nothing wrong learning from others

however doing final proof



bbshd do not shred hardtails in six months

utter nonsense

apparently offered by think not facts



good luck op

 

[markz]

The 10 speed cassette is not as strong as a 8 speed because 10 speed chains are thinner. You wont be using much of the 10 speed cassette. Only reason to go with mid drive is for specific riding terrain. If there are long steep hills, then a mid drive is good to have. Its not good to have it if you want to not stick out because that motor in front of the crank is going to stick out to everyone. Plus the noise the gears make, perhaps the noise is reduced with a sinewave controller, but gear noise is gear noise, coming from gears meshing. Maybe different material gears will reduce the noise, maybe not.

https://endless-sphere.com/forums/viewtopic.php?f=3&t=98988&p=1451145&hilit=mid+drive+noise#p1451145

https://endless-sphere.com/forums/viewtopic.php?f=3&t=98988&p=1451345&hilit=mid+drive+noise#p1451345

https://endless-sphere.com/forums/viewtopic.php?f=3&t=96431&p=1412535&hilit=bbshd+noise#p1412535

Also the wearing on the drive train is something to consider.

 

[furcifer]

10000 miles cute

nothing wrong learning from others

however doing final proof



bbshd do not shred hardtails in six months

utter nonsense

apparently offered by think not facts

1000W mid drive, 4300 miles with +300lbs, in all types of weather, Pacific Northwest...

The normal commuter gets about 10 000 miles on a bike before it's to the point where you've replace everything on it or it's not worth repairing anymore. You can extend that with good maintenance but 10 000 miles is pretty much rule of thumb in my experience. Most ride mid-level "Deore" grade components; the sweet spot where you get decent quality and you're not paying stupid money to shave a few grams. $1000 give or take. That's exactly what the OP has chosen.

These are all the facts people seem to over look.

It's hard to find good info from people using these as commuters. I've found most people take about the longevity of the motor and not the bike. How well the bike holds up is actually an important consideration when building one.

 

[wturber]

I haven't finished watching the first one but he's already talked about breaking spokes, breaking one frame and bending a new one. That looks like a 1000W hub motor as well. There's significantly more power going through a BBSHD mid drive and flexing the frame.

OK. The funny thing here is that the frame that broke was a Mongoose Impass - a full suspension bike. After riding both, the guy in the video strongly recommends the hardtail.

Broken spokes were from the fact that these inexpensive hub motor kits don't come with the best spoke and rim components. Chalo will be happy to give you chapter and verse on wheel building strength.

I'm unclear on the bent frame issue. This guy suspects that the frame was bent when he got it.

BTW, if it weren't for the OP's current body weight and that he has to deal with hills, I'd strongly recommend the DD hub motor for a commuter. He's more likely to be wearing out drive train components than he is likely bend a hardtail or thrash a suspension.

 

[Steve.Morris]

BTW, if it weren't for the OP's current body weight and that he has to deal with hills, I'd strongly recommend the DD hub motor for a commuter. He's more likely to be wearing out drive train components than he is likely bend a hardtail or thrash a suspension.

Hello - OP Here...

Wow - So this thread took off.

I considered a hub drive because I could add a torque sensor to it - and I'd really like to have a torque assist motor - but I just don't know that I can afford the new kid on the block (BBS Ultra) or if the other one I've found (TSDZ2) would be strong enough to power my slowly shrinking self.

I also live in the same (hilly, pothole ridden) city as the author of the 10k miles video - so, yeah, hills are a concern. That's why I settled on a mid-drive.

1. Hills
2. I'm large - don't want to break spokes/wheels all the timem
3. Changing a tire would be a real challenge on a commute

I also have settled on the hard tail bike I bought for a couple reasons:
1. Larger triangle for larger battery
2. Less things to wear out
3. My commute is all bike path (old railroad line that has been paved) with a mile or so on the street
4. Cheaper to buy and maintain


Thanks to this thread (and also a duplicate post I made on reddit) I've decided to go with the (more expensive) Luna over em3ev and get the better battery tech (most likely a 24Ah w/ the Panasonic GA batteries)

I'm still hesitating on whether I should get a DD or Geared hub w/ torque sensor vs BBSHD... I'm visiting Seattle this next weekend and may go test drive a RAD bike to get a feel for the hub drive -- and to pick their brains on HUBs for BIG GUY riding. I'd still be interested to hear any feedback from you guys here regarding this or other aspects of my build.

Further debate on Hard Tail vs FS seem pointless though - I understand there are pros/cons to both... and I'm fully aware of the risks.

To be clear - Yes, I'd like to have an average TOP speed of 24'ish MPH - and overall I'd like to be able to complete my 12.5mi commute in 35-45 minutes (which would be an average sustained speed of 21mph to 16.67mph).