vja4Him

I'm really a dummy when it comes to anything mechanical or electrical! If I understand correctly, if I buy the electric hub motor for my Electra Townie, I will no longer have the gears that came with my bicycle available for pedaling?

I need to keep the gears that came with my bicycle, so I can still ride my bicycle with no motor as often as possible. I need the exercise and enjoy riding, but also need to commute to various job assignments where there is no bus service, and too far for me to pedal (10-15 miles each way).

I want to get something that will last many years, and allow me to attain speeds of at least a good solid 35mph (45mph would be better, so I could ride on the country roads where the speed limit is between 45-55mph), with my weight, plus groceries (will not be riding fast with groceries!!!, only around 10mph then!).

When I go to work, my weight is around 210, plus my large backpack, which normally weighs around 15 pounds. Groceries will add another 15 pounds, sometimes more ....

So, I need a good quality motor that will easily carry over 250 pounds, reliable, effecient, long lasting ..... I've been checking around on different websites, but am still a bit overwhelmed ... !!! Help please ... !!!! Thanks!
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martybucs

OK, I'll bite.
What you describe doesn't exist. You're looking for a motor scooter, either gas powered or they make electric ones.
A hub motor on your bicycle, won't give the capabilities you've listed in either speed or range, unless you, yourself are a very strong rider.

Map tester

If you get a front hub motor, you will still have all the gears your bike currently has.

Two issues here: the size of the battery and the terrain you will be riding--flat or hilly? If you carry your recharger with you and recharge when you can, you should be able to make a *few* of these trips. Problems come up if you have many hills--the battery will be warm/hot after these trips and will not recharge as well.

If you want a motor-assisted bicycle, you need to re-think those speeds; you will not get those speeds and distances. And have you traveled any distance on a bicycle going 35 mph? Think more along the lines of 15 to 25 mph.

With the right motor and battery, your weight should not be a problem.

Disclaimer: I have no business connection to Ebikes.ca

I recently bought a Ezee kit from ebikes.ca for my wifes bike. I bought an upgraded battery (upgrade from stock 36v to 48v). The kit is well made and has enough power to carry me (260 lbs--and losing--plus the battery and bike) up the many hills we have here in Atlanta. I have done one test ride to my work (11 miles) and believe I could easily do the roundtrip (22 miles) with some power to share. I would suggest you contact ebikes.ca and discuss your needs and see what they recommend.

crackerdog

At those speeds you are not looking at a legal bicycle. You are looking at a motorcycle. 20mph is the federal limit. The rear cluster on a hub motor seems to be limited to a 7 cog freewheel. Other than that, your bike will use the gears just like any other bike. My new batteries (17 lbs) will take me about 40 miles at 15 to 20 mph assuming I am pedaling which I always do, it is a bicycle after all.

Abneycat

If you have a Townie 21, the freewheel included on your current rear wheel is all you need. Transfer it over to the electric hub motor, and you'll still have all your gears with little work. Its a very easy bike to convert.

As mentioned, a front drive motor would also allow your gears to function. However, the Townies don't have good forks for electric hub motors, and on my own personal experience I would advise against it. Either go rear drive, or change your fork from the timid SR Suntour fork to a Cromoly steel one.

vja4Him

So, how do people get the high speeds from their bicycles? People have posted that they can get up to 50 mph on their bicycle ...

Abneycat

It is possible, but the power consumption for those speeds is quite immense. Crystalyte "5 series" motors for instance can nearly made to reach such speed, but they require extremely high capacity batteries which will be consumed quite quickly. The system weight, cost and complexity increases greatly as speed needs do. Legal issues also arise, and the ability of the bicycle to be enjoyed *as* a bicycle decrease.

Motors like the 5 series are massively heavy, and not enjoyable to pedal about.

Practically, it makes more sense to go 20-25mph as mentioned by some other users. The investment and hassle is much less severe, systems can be made to meet those standards fairly readily.

For instance, even my rather mundane setup of a Crystalyte 408, 36/20 controller, 48/10.5 li-polymer battery will meet your range needs at around 25mph. Thats not a heavy investment, and the bicycle remains light enough to be enjoyed. It will soon be either a BMC 400w or a BMC Thunderbolt 600w, which will make it even lighter and easier to enjoy as a bicycle.

vja4Him

What is the expected life of the Crystalyte 408? That looks like something that is more practical .... What about extra-long-life batteries? I think the batteries would be more of a practical concern for me ....

I think that a speed of 25 mph (maybe even 30 mph?) on my bicycle would be quite acceptable for the area that I travel the most. Even when I drive to work, I usually can only average 20 mph. Sometimes I might even average 25 mph ... !!! There are just too many stop signs, traffic signals, and so much traffic!

vja4Him

I just watched a video of someone riding their bicycle with the 600W Thunderbolt electric motor!!! Man that was awesome! Has anyone used that motor on their bicycle? What other motors would be comparable to the 600W Thunderbolt?

Abneycat

A Crystalyte 408 will last you forever if you take care of it and nothing abnormal happens. For the longest life in your batteries LiFePO4 is the current king, offering many years of use before needing replacement.

I'm going to be testing the Thunderbolt motor soon. Snowranger might have one, not sure which model of BMC he is using. From the information i've recieved, the Thunderbolt has comparable power to the Crystalyte 5304, but at 1/3rd the weight, with a lower power consumption, higher efficiency, and freewheeling ability.

That sounds pretty good to me. There are a few tradeoffs. The BMC would not excel at extreme modding like the Crystalyte is known for, it hasn't got the same robust wiring and is more subject to parts wear. But for users wanting good power from low weight, it will be tops.

There are a couple of motors like these. BMC, eZee and Heinzmann are the most commonly known geared hub motors. In the hub motor class for power to weight ratio and efficiency, no direct drive motor can touch geared motors like the BMC. They also freewheel, making them very easy to pedal without the motor's assistance.

Downsides are mostly small. Planetary gears may eventually require servicing after a few years use, regenerative braking is not possible, and a small amount of noise is generated while in use. The noise is what is the biggest downside to most people, and a benefit in the direct drive motor's favour.

vja4Him

Do you have any good links to the Crystalyte motor? I like the lighter weight with the Thunderbolt, but would be nice to have something that might last longer, with fewer potential problems ... What is the price range for the Crystalyte?

Abneycat

https://www.ebikes.ca

^ is the most comprehensive website I can think of for Crystalyte. You can obtain Crystalyte quite readily just about anywhere, but the Renaissance Bicycle Company (ebikes.ca) has the most information on them. They also allow you to order components independently instead of a whole kit, which is nice, and their prices are good.

Crystalyte is quite affordable. According to the website at a glance $415 USD would buy a rear drive 408, a 36/20 controller, and a throttle of your choosing. You could read up on them all and find what works for you, but the Crystalyte is pretty fairly priced.

vja4Him

Will I need to buy a freewheel in addition? I was thinking maybe I could change my 21-speed into a 24-speed, or a 27-speed?

Duracutter

Those are short bursts. You'll never go 50mph for any longer than 20 to 40 seconds for many reasons including safety, batteries won't last long, you'll be arrested...lol, the bike will break up over rough pavement etc...

It's nice to have good top speed for some situations in traffic, but mostly a person will settle in at about 30 to 40km/hr for a long trip.

Duracutter

I currently run the 5304 crystallite front wheel and my other bike has the 5303 crystallite front wheel.

It's safe on the front wheel is you follow common sense rules. Never ever accelerate full bore, no offroad at all, steady acceleration at all times and go easy on the throtlle.

Otherwise, I've had no issues, both bikes have front suspension and one is even aluminum.

I do however have torque arms that are sold with the kits. Do use the torque arms.

Also, lithium is the battery of choice and with the 5303 if you use lithium, you'll be able to achieve bursts of speed around the 45mph range. Bursts, not steady speeds like that...


Btw, with front wheel install, you can do whatever you want with the gears... they won't be affected.

Abneycat

You do not necessarily need to purchase a new freewheel. A bike shop would be able to remove the freewheel from your old wheel for you, which you can then thread on by hand to the motor when it arrives (no tools are needed to install, just to remove). You could go to a bike co-op if you have one locally and borrow their remover for a minute or something, too.

You could change to a 24 speed.. Be careful with choosing this route, as the 8sp cassette is wider and may make your motor too wide, or fit improperly. When I had an 8sp freewheel on my Crystalyte, I had to insert an additional washer on the right hand side and spread the dropouts of my Xtracycle a small amount: that was fine as my Xtracycle was steel, but you would not want to do that to an aluminum frame townie.

27 speeds is not possible with Crystalyte. One would need to spread the dropouts on your bicycle considerably, as well as placing multiple washers to have the freewheel clear the inside of the right dropout at all. As well, your Townie would need 9 speed shifters, chainrings and chain, increasing cost and difficulty farther.

Many speeds aren't really needed for an electric bike. The 21 speed setup of the townie is just fine. One thing you will benefit from is having high gearing so that you can still pedal well at high speeds. I would consider ordering a freewheel that goes all the way down to 11 teeth.

vja4Him

I'd rather have the rear motor ... Will there be any problem with usign the 21 gears that came with my Townie, and still be able to use the hub motors? I have to go off the road many times around our town. The roads here are very bad ... There isn't enough money to keep the roads in good repair ... Many places I travel have no sidewalks. There are many potholes everywhere, huge cracks in the roads ... piles of stuff everywhere along the roads, and tons of obstacles everywhere .... !!!

Riding a bicycle where we live is a total nightmare ... !!! You really have to be alert and know the roads and sidewalks very well. So, realistically, I can see now that 20-30 mph is plenty of speed for me. There are some places with smooth riding surfaces, but not for great distances .... I know the travel routes pretty good now ... that I've been riding for so many years around here ....

I really like the 600W thunderbolt ... But I'm also considering a Crystalite ... Still need to reserach several other possiblities ...

vja4Him

I still don't understand the difference with the number of teeth ... What difference does that make?

I think I'll stick with the gears that came with my bike. I'd rather not take any chances of having problems. We don't have any really steep hills like you find in San Francisco anyways. The only hills around here are the overpasses, and I only have to contend with one overpass, which is not that bad to pedal up ...

cerewa

If you buy a rear hub motor you will need a freewheel to go with it. If your current bike is a 21-speed then it almost certainly doesn't have a freewheel, but a 7 gear cassette instead.

To avoid having to deal with getting different shifters, you should probably stick with a 21 speed setup rather than going for more gears. 7 gear freewheels are common, but freewheels with 8 or more gears can be very difficult to find. (almost every bike with 8 or more gears on the rear wheel uses a cassette.)

martybucs

I don't think those speeds are legal, if obtained by using the assist. In other words, the bicycle isn't really a bicycle anymore and you would be breaking the law - perhaps this doesn't bother you.

I don't think it is safe to travel those speeds on a bicycle for an extended distance. Going downhill, I've gone as fast as 40 mph and it's fun for a short distance, but the possibility of permanent disability is astounding and terrifying to me. If one of your wheels is the least bit untrue, you'll know in a hurry at those speeds. Every bit of debris could mean disaster.

Truly, you should consider something made for those speeds or adjust your expectations to riding a bicycle in a realistic, safe manner. Just my opinion.

Abneycat

Townies have a 7 speed freewheel. However, the teeth: the Townie freewheel is a Shimano MegaRange 14-34, basically the smallest cog is 14 teeth, the largest 34. The 14 teeth cog is not considered a very high gear at all, and depending on how fast your bike ends up going, and how fast you like your cadence (how fast you like to turn your pedals), the Townie's range might make you spin too fast.

Buying a freewheel with a smaller high gear (11,12,13 teeth) will be likely to increase the likeliness you will enjoy pedaling while using the motor at high speeds. You can obviously just try using your original freewheel and changing it later if you don't like it.

Its your mention of not having hills that makes me think you might enjoy higher gearing. The 34t low gear of the original freewheel isn't going to be a benefit without any real hills, but the 14t could potentially be a detriment. Still, trying it out first is the easiest way to know if you need something else - and a 7 speed freewheel shouldn't be something you need to special order, its still a common part.

bikefreaks

45-50 mph on a bicycle is pretty much a guaranteed death sentence, or at the least its something that will cripple you for life.

Bicycles are simply not made to handle that kind of speed the down forces and up forces from hitting a bump at those speeds will simply leave you on your face sliding down the road.

A motorcycle or a scooter are made for this type of forces and anything less is extremely dangerous to say the least

unime

Change that to most bicycles and I'll agree.

My Optibike is equipped with very capable full suspension, motorized bottom bracket drive that keep unsprung mass to a minimum, strong mountain bike wheels, tough tires, and hydraulic disc brakes with a 10" front rotor. At 51 mph (on a steep downhill) it rides extremely well and handles bumps in stride.

Still, a fall or collision at that speed is unthinkable.

Vim

vja4Him, you're getting some great advice here. I'm glad you're reconsidering your desired top speed...25-30mph should be more than enough for a commuter bike. Once again, I'll vouch for my AmpedBikes kit shown over on Endless-Sphere that you posted on. Mine is 37v and does 22mph, but if you up it to 48v and 15 to 20 amp hour rate, it would fit your needs perfectly (28-30mph with 20+ mile range), all at around $1100 for the rear wheel kit and LiFePo4 48v 20ah battery. And you could make your own custom battery box to fit inside the frame like I did. My setup is perfectly balanced like that. It's a real joy to ride.
You might want to add AmpedBikes to your consideration list.

vja4Him

I have decided that speeds of more like 20-25 mph would be just fine! Even when I drive to work, I usually only can average 20 mph anyways! So, if I can use the electric motor to get me around between 15- 25 mph, that would be quite acceptable.

I know what you mean about riding a bicycle downhill at 40 mph! I've done that, and it can be scary!! I had a terrible accident riding my stingray bike (actually I was the passenger on the back!). We were going downhill, about 30 mph, and hit a curb. I went flying about 80 feet and broke my left femur!! Took a couple of years to fully recover, but I still have problems with my knee (from the traction).