Bicycle Conversion Recommendations

[amberwolf]

What is the value in a solution that recaptures bicycle braking to help recharge the battery?

Not much, given the extra weight/etc. (requires a DD hubmotor, not geared, so more resistance just rolling along without power to it, meaning harder to pedal when not using the motor, and usually heavier). Might get 5% back that way, under the right conditions.

For the extra motor weight on a normal bike I'd rather carry a good vibration-proof charger (Cycle Satiator, HLG-A Meanwell, etc) and plug in at my destination to recharge, or carry a 5% bigger battery pack, etc.

It can save on brake pad wear if you do a lot of braking though.

Sorry for all the wandering questions. I find this field fascinating.

Keep in mind that just about everything you can imagine (and lots you havent' yet) has already been covered in many threads on the board, so if you use the search function or just read thru various forums for other new member / conversion /etc topics, you'll probably find the questions answered before you even ask.

See the "welcome" thread at the top of every forum list for some pointers.

 

[chas58]

You sound a lot like me. Those are my bikes in the thread mentioned in the second post here.
If you (like me) want to be an integral part of the power, keep the bike light, and KEEP the Amps low. 12amp max will make sure you help move the bike forward! Otherwise it’s too easy to let the motor accelerate you from a stop.

I do 25mph on 36v (328rpm), but you might be happier taking a 260rpm (@36v) motor and over voting it to 48v to get 25mph. From what you describe, you are happy putting out about 150watts through your legs.

I’m using a 36v9.5Ah battery that can get me 50 miles round trip, with charging half way (at work).

My bikes ride like normal bikes when the electricity is gone. Sometimes I just remove the 3.4lb battery and ride it just like a normal bike. (they weigh roughly 25-30 lbs without the battery)

I think the Q100 CST will work with your 10 speed drivetrain. That motor isn’t very wide. You’ll have to check the numbers though. Mid drive sounds nice – it’s a little heavier, a noisier, a little more complex, a little more maintenance. Not a big deal for most people. Geared hub motors are transparent – you can’t tell mine are there other than you are going a lot faster.

How much work you put into pedaling is up to you. At cruising speed, the power of the motor is falling off linearly as speed increases – so the more power you put into going faster, the less power the motor is giving, and typically its power is falling off faster than you can make up for both its drop in power and the exponential increase in wind resistance.

Are you planning on using PAS? That is almost the only way to do a throttle on a drop bar bike. Send pictures, and enjoy!

 

[jhotchkissca]

I am thinking about going in this direction.

http://www.ebay.com/itm/Electric-bi...386903?hash=item41bc9ea197:g:8SIAAOSwVFlT~1fg

I was also thinking about a rear rack battery, one of those racks that have 2 shelves, one for the battery and the top for my trunk. Am I getting too top heavy?

My needs now (after much more research) is 20 miles pedal assist at 25-30 mph with 2 chargers, one at home and one at work.

I am concerned that I might eventually run into problems with my Shimano 105 rim brakes not having enough stopping power.

Riding the Diamondback now for a few weeks I have noticed that ebikes put me in more dangerous situations than I am used to getting into with my normal commuter (mostly speed related... with a little weight, inconsistent pedal assist added in.)

Thoughts?

Thank you all for your help.

Jim H

 

[dogman dan]

Set up right, your rim brakes should be fine. But if you do add a disc brake, put it on the front wheel. Brakes won't fix your mistakes, however good you make them.

You will have a learning curve, riding fast as a racer in the city is very hazardous. Some can cut it, some can't. Previous survival of riding motorcycles in the city is a plus. If you have to, slow down enough to survive till you get the skills.

I like to say, if a car crosses you, you let it. They always will, so you let yourself be in position to have that happen. That was your choice, you know that car will f- you. Faster riding, take the lane like a motorcycle.

Carry the battery in the middle frame triangle if you can. If not, put your cargo low in panniers. Carry only light stuff, like your extra coat on top.

 

[chas58]

Rim brakes are fine, and basically have the same stopping power as disks. The only problem I have ever had with quality (105 grade or better) rim brakes was going 40mph down hill on a 500lb bike. That tended to overheat the brakes – which is a big problem with rim brakes. Well, it overheated the drum brake too, but that is a different story.

There are some relatively rare circumstances that disk brakes are better than 105 level rim brakes, but if you don’t have a specific problem to fix, don’t worry too much.

Battery rack.
It depends. I put a 10lb battery above the rear wheel on my race oriented bikes, and it was a PITA. It was doable but awkward. But do that on a longer wheelbase bike designed for touring, and it wasn’t too bad. So, depends on the weight and the bike design. But, I like in the frame batteries so much better!

If you are happy at 25mph, you could be fine. That typically takes 600watts. I’m not exaggerating when I say your power needs go up exponentially with speed. 30mph needs 1000watts (bigger motor, bigger battery). If you have a $1,500 budget, you could do it. So, how bad do you want to go over 25? Clearly at 30mph your pedaling is mostly to make you feel good, but isn’t doing much to make the bike go faster. Dogman Dan is right – 30mph is crazy fast on a bicycle. There is a learning curve.

The motor looks nice enough (not knowing too many details). That wheel DP18 is 700x12c, so it is rated for 18-25mm tires only. I put a 32mm on mine, but it’s not ideal. If I were doing it over, I would get a much wider rear wheel.

 

[d8veh]

I am thinking about going in this direction.

http://www.ebay.com/itm/Electric-bi...386903?hash=item41bc9ea197:g:8SIAAOSwVFlT~1fg

I was also thinking about a rear rack battery, one of those racks that have 2 shelves, one for the battery and the top for my trunk. Am I getting too top heavy?

My needs now (after much more research) is 20 miles pedal assist at 25-30 mph with 2 chargers, one at home and one at work.

I am concerned that I might eventually run into problems with my Shimano 105 rim brakes not having enough stopping power.

Riding the Diamondback now for a few weeks I have noticed that ebikes put me in more dangerous situations than I am used to getting into with my normal commuter (mostly speed related... with a little weight, inconsistent pedal assist added in.)

Thoughts?

Thank you all for your help.

Jim H

Hmmmm! "High speed controller and motor made in USA by Bistro. ". That's an S12SH controller made by Kunteng and sold by BMSBattery in China. I can't understand why they didn't provide an LCD display instead of that LED one, which would be much better.

I think you're right to be concerned about breaking. Rim brakes are OK for light bikes with light riders. For a kit like that, I wouldn't use anything less than hydraulic discs.

 

[RTIII]

[...] I want to be able to ask the bike to help me out and have it respond, like giving me a tailwind. I can ride 60 miles at a 15 mph average with just my legs. I am looking for a boost with the least amount of intrusion on my normal cycling feel (balance, drag, shifting, etc.)
That being said, I am concerned that once I introduce an electric motor into my commute I will use it more and more and eventually lose my hard won legs. But I guess that is between me and me.

I don't need a 60 mile range at the expense of an oversized battery. I need a 30 mile range with the motor mostly assisting my pedaling.
[...]

Hi jhotchkissca,

I think it's readily apparent what your best choice is right there from the parts I've excerpted!

I've just gone through something like you are in your decision making process but I'm a bit more informed today than I was when I first posted (just like you, I bet!), and the best thing I read on the subject was right here on this forum, on this page:

https://endless-sphere.com/forums/viewtopic.php?f=28&t=79788&start=375

That link goes to the end, but I started on page one and read all 16 pages and am now quite convinced that the e-bike solution presented there is the best one for you because it discusses the smallest, lightest weight, most efficient solution out there, and, as you importantly point out, you don't want a moped; the TSDZ series (TSDZ2 and TSDZ3) are assist-mode approaches! They only provide assistance as you yourself give power. When you give no power, the system gives no power, when you give more, it gives more, when you give a lot, the system assists you a lot - EXACTLY what you are asking for.

Best of all, no worries about modifying your brakes and such to cut out the motor when you dont' want it, no distractions from having to deal with a throttle, none of that. And the range reported is amazing, in large part because you, the rider, are still contributing a lot!

I'd give a testimonial but I only decided on my own path today and still have yet to receive any pieces. However, LOTS of others have given their testimonials in the thread and on the pages I cited. ... Here's what I'm about to add to my own bike:

Tongsheng TSDZ2 Mid-Drive kit, 48V 500W 42T Chainwheel Electric Bicycle DIY Conversion With Torque Sensor
http://auto-ebike.com/index.php?main_page=product_info&cPath=25_1&products_id=1780

48V 10.4Ah SANYO lithium battery electronic bicycle with Charger and USB output:
http://auto-ebike.com/index.php?main_page=product_info&products_id=1738

Expecting about three weeks in transit and a total cost of about $600 plus my wrenching the parts onto the bike. There are larger batteries, of course, but I don't need the range you do daily, and when I do need long range, my plan is to use an automotive deep-cycle Yellow-Top Optima (I already own) with a DC-DC converter to feed the system, putting the huge (59 pound) battery on the heavy-duty luggage rack I built for the bike. Instead, you might well get away with a 15Ah or 20Ah Lithium Ion battery in a much more conventional packaging.

Lets keep in mind here; this is an assist package. The other suggestions here are basically about turning your bike into a moped and this solution does not do that! SO, you do NOT need the same battery as their solutions would. Also, the system stops when you do, so it's very efficient that way.

The Tongsheng units are NOT the only "torque-sensing" units on the market, just the cheapest. Maybe you're up for another model. I understand Bosch makes one. I'm not sure who else, but I'm sure that now you know what to look for, you can find them.

Best wishes,
RT

 

[dogman dan]

Torque sensing PAS is the best, but only if you have the physical ability to pedal at all times. So its the best choice for at least 90% of folks out there.

But not for me. Unless it has a throttle to over ride.

Back to brakes, when I was still healthy, and commuted 30 miles a day, I ran through two sets of decent brake pads a year. And did have to occasionally re adjust them, if they loosened and got twisted out of place. I had some big hills to go down, but only average weight so no big problems.

Other stuff on the bike needed very frequent checking at least, so I tended to spend an hour each weekend checking out the whole bike, looking for loose spokes, loose axle nuts, problems with a connector, etc. On the road I carried a very complete tool kit, including a tube, spoke wrench, even a chain breaker.

 

[tomjasz]

Torque sensing PAS is the best, but only if you have the physical ability to pedal at all times. So its the best choice for at least 90% of folks out there.

I like PAS. I like it on my bbsxx and the Grin 12 magnet disc. I get very low level exercise but it keeps me moving my legs with limited stress. A bit more with low settings. To hell with torque. <g>