Is my bike good enough?

[mike662]

Hi everyone, I'm back! So it's been 3 weeks today since I ordered my kit and it finally arrived in Canada just after midnight. Now I'm getting really excited! I ordered a torque arm off ebay (http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=310220047394&ssPageName=STRK:MEWNX:IT#ht_1152wt_911) and after waiting two weeks for it, I emailed them and they said they haven't shipped it yet and are awaiting it to come from a factory! Now it's almost been three weeks and they still haven't shipped it, so I do not recommend buying from them. I did, however, take a look into myelectricbike's idea (http://goldenmotor.com/SMF/index.php?topic=45.msg401#msg401) and found that taking an adjustable pipe wrench and adjusting it to the size of the axle would work fine on my bike as my rear frame would line up perfectly with the wrench. I just hope the wrench isn't too thick and I'll probably end up replacing it with the ebay torque arm once I get it for aesthetic purposes. I'll keep you guys updated once I get the package and start building. I'll take some pictures and videos along the way too if anyone wants. Fingers crossed that all goes well!

[Leslie]

I did, however, take a look into myelectricbike's idea (http://goldenmotor.com/SMF/index.php?topic=45.msg401#msg401) and found that taking an adjustable pipe wrench and adjusting it to the size of the axle would work fine on my bike as my rear frame would line up perfectly with the wrench. I just hope the wrench isn't too thick and I'll probably end up replacing it with the ebay torque arm once I get it for aesthetic purposes. .

Make sure you have enough thread over your wheel axel, it must be completely on or else it will pop off and possibly damage the nut or you axel.


If you feel your wrench adds too much width at the dropouts, bench grind it down until the width is acceptabe, I know your excited but make sure you have everything 100% perfect.

Adjust your derailer so it cant rub against the hub and make sure your tires are pumped up well.

[mike662]

I know being excited can make a person rush but I will be sure to do everything up to 100%. I wouldn't want to have to wait another month to get stuff reshipped in case I break something. I don't have access to a grinder so I might have to use a non-adjustable wrench or something thinner than an adjustable one to make things fit.

[TRK]

I used a Combination wrench (aka combination spanner), similar to this one:


The guys who built my bike bend it in the right shape and the ring is ideal to fix it to the fork with a strip of metal and a bolt (and a piece of old inner tube to keep it from scratching the paint).

[mike662]

Hi everyone, so I finally got my package on the 23rd and got straight to work on it. First problem was the inner tube valve being short, so I went to Canadian Tire and got some valve extensions which did the trick. The biggest problem I've had and still can't rectify is that the wheel is very hard to turn once the bolts are tightened up. At first the wheel wouldn't spin at all, but after taking it off and putting it back on a few times its a little looser now and it's possible to pedal. I looked for some help on here http://goldenmotor.com/SMF/index.php?PHPSESSID=a83d8b8990d274d6a230aef43fe38c22&topic=1790.0 and I really couldn't do much as I was not able to even take the gear cluster off the hub. It was suggested that the wheel stiffness may be coming from the gear cluster binding with the hub so I should put a shimmy between the two. Anyone know where I can get a proper shimmy? I looked at Canadian Tire and Home Depot and couldn't find anything. Even if I find something I can't get the gear cluster off even after using a long wrench and trying to get it loose by hitting the wrench with a hammer. I just don't understand why the gear would bind to the hub if the hub is from GM and the gear is from GM too. Shouldn't the parts fit properly? Later on I finally got everything hooked up and the wheel spins, but stops instantly after power is no longer applied due to the excessive friction that is occurring somewhere. When I tried to ride the bike, there is an insanely loud squeaking noise coming from the hub, so bad my ears were ringing for a while after I ran the motor. Could it be from whatever is causing the excessive friction (gear cluster binding to hub?). I've attached some pictures if anyone can tell me.

Also, just wanting to make sure, if the wheel spins counter-clockwise then the axle would spin clockwise and I should have the torque arm set up to take mostly clockwise movement, right? Thanks!

Pictures (it's a link because I can host them in higher definition on google): http://picasaweb.google.com/mike662/Ebike#

[Bikemad]

Mike,

Is there any sign of binding on the sprocket side of the freewheel when you turn the pedals backwards, or does it just ratchet normally?

Does it run true, or is it possible that it may have been cross threaded and has not screwed on correctly?

It almost looks as if the freewheel is slightly too wide, and its centre part (the fixed part which is threaded to the hub) is rubbing against the inside washer on the axle.  (see attachment below)

If you can slide a piece of paper in between the freewheel and the washer and turn the wheel without damaging the paper, then it should be ok, if you can't, it doesn't have enough clearance.

It may be necessary to put a washer with a smaller outside diameter between the axle and the existing washer.  It probably won't have to be very thick to make the slight difference required, but it must be small enough to fit inside the centre of the freewheel.

You might have to file out the centre of a smaller washer to the correct shape to fit over the axle, or possibly cut a small piece of steel tube to use as a spacer instead of the extra washer.

As far as the torque direction is concerned, you may find more torque is generated in a counter-clockwise direction by the regenerative braking than the clockwise torque from the motor under full load.

The torque arm must be able to resist the torque in both directions!

Alan
 

[mike662]

Ah thank you Bikemad, this solution makes much more sense to me! I can move the pedals backwards no problem, so that is why the freewheel-binding-against-the-hub idea wasn't making much sense to me. This is why I was asking about the spacer tube before because I thought if it was a little longer it might fix the problem. I will give this new idea a shot in about an hour or so and if that does not work I'll take it down to a bike shop.

[mike662]

So I found the problem. Looks like the washer that GM included is too large or the spacer tube is too short. Either way, the part of the gear cluster that is affixed to the hub was grinding against the washer, hence the hard-turning wheel and the ear-piercing squealing coming from the hub when it was turned. I can't find any washer that will fit just right so I'll try to grind this one down a little or go to the bike shop and see if they have anything. Maybe I'll pick up a 3-speed gear cluster too. Here is a picture of the grinded washer:

[DSC]

For simplicity's sake I used a single speed gear (intended for BMX bikes) instead of a gear cluster because I had clearance issue's.  Pedaling without the motor on is HARD work for anything but the shortest trip's.  I rarely use anything but the lowest gear for starting off and then apply power.  I can't imagine you would use your bike from now on without power to  the motor, it's just not enjoyable trying to push that much dead weight around... Good call on the torque arm's, just remember to check brakes, tire pressure, etc on your bike on a regular basis.  Your brakes will also wear down faster, even with regen I went through a set of pad's pretty quick so you might want to keep a spare pair around.  Lastly you might want to switch to "slime" intertube's.  This has saved me from pushing my bike home after getting flat's atleast 3 time's in the last year.  Have fun!

[bike lover]

Hello there

It is my first post in this site and I am not sure how to get around it , but I wanted to write to get an opinion of a techie as I value knowledge like a plus in life.

This is my e-bike and about one month ago  I asked to have my brushless motor to be replaced being under warranty.
I complained rightfully that I did not have enough torque compare to other same models e-bike , I could hold easily the bike from going forward with my legs, not even being able to climb a little hill.
In the other hand that bike was flying at about 40-45 km/hour leaving most of e-bikes behind, the torque was the problem.

The company installed a new brushless motor, same one , I could see the difference in torque but to my disappointment I have lost speed now going the same speed as others around 30km/hour.
I tried to get back the old one to see what was the difference but the old motor was shipped back to the company.

I am trying to understand the technical reasons for that, gain in torque and loss of speed, before loss of torque but higher speed, somebody has an answer ?

question:
Is there a way I could get my e-bike going faster as before, it is a 350w with 48 volts battery.
I measure the voltage going to the brushless motor and I only get 33-35v, as I believe it may have been higher[/img] before.
I there a way to change settings on the throttle so it can increase the voltage going to the brushless motor.

Any answer would be appreciated.

Thank you

charles

 

No. 

Sorry just kidding. 

It looks awesome.

People say alloy frame can be a problem but I rode alloy with 27kg of lead acid and it was fine.  The hub was a rear hub.

Some more important questions need to be asked.

What is your max rider weight of anyone who may ride this bike?

How fast do you want to go?

What are your ambition for this bike.  Is it a town bike on flat roads?  Or is going off road?

[MonkeyMagic]

I measure the voltage going to the brushless motor and I only get 33-35v...
I there a way to change settings on the throttle so it can increase the voltage going to the brushless motor.

Hi Bike Lover,
Firstly, welcome to the forum!

May I ask what controller are you using on your shiny beast?

Great ride, I also would like to know how many girls fit on the back as I am tipping it's lots! I like that

[bike lover]

Hello

I have the original controller in my home so I can read the info.
The brand of the controller is written in chinese.
I can read :
 48V                              ERT-WZKC4815D-B
15+-1A                           R-CH091-1
42+-1V
2009.08

at the bottom right 022-28752071.

This is the original one, I asked the manufacturer to replace it with a 20A thinking I could get more speed and gosh the torque is great, can easily pull a car, no kidding, but I feel the speed is the same, so I am disappointed, no 40-45km/h as before.

About your question my wife and daughter can squeeze in the back, they are also small in size.

Any clues how to make it go faster?

charles

[muzza.au]

G'day Bike Lover,

Are you sure they replaced the motor with the same type. On the outside it may look the same but how the coils have been wound may be different. The first one may have been wound for more speed, less torque. The one you have now may be wound for more torque, less speed. See the following for info on differences in windings on hub motors: http://www.ebikes.ca/hubmotors.shtml

Also changing the controller to a higher amp one, as you have, will only increase torque, not speed. You see increasing current increases torque. To increase speed, you have to increase the voltage. If you want more speed, you may have to change your battery to a higher voltage one, or add a battery or series to what you've already got.

muzza.au

[Leslie]

So I found the problem. Looks like the washer that GM included is too large or the spacer tube is too short. Either way, the part of the gear cluster that is affixed to the hub was grinding against the washer, hence the hard-turning wheel and the ear-piercing squealing coming from the hub when it was turned. I can't find any washer that will fit just right so I'll try to grind this one down a little or go to the bike shop and see if they have anything. Maybe I'll pick up a 3-speed gear cluster too. Here is a picture of the grinded washer:

An XLR three pin plug jacks the type used on a microphone, if they are long enough, can be pulled apart and manipulated to work as the spacer tube.  I missed place one of mine and used and XLR, When I found the spacer tube they were almost identical in size. .  Maybe you could use one as an extender on the old one?

You can get them at a musical instrument store.  


Maybe Gary will have a solution and help you out here.

[Leslie]

question:
Is there a way I could get my e-bike going faster as before, it is a 350w with 48 volts battery.
I measure the voltage going to the brushless motor and I only get 33-35v, as I believe it may have been higher before.
I there a way to change settings on the throttle so it can increase the voltage going to the brushless motor.

Any answer would be appreciated.

Thank you

charles

Your voltage is severly lacking if it is a 48v battery.

The pack voltage and controller output voltage should be no different regardless of your throttle because the controller only limits the 48v in pulse width not pulse ampitude.

It depends how you are testing the voltage.  Have you tested the battery voltage?  Its hard to get the voltage tested with a multi meter on the controller output as a multimeter is not good at DC pulses .  Well my meter freaks out with PWM.

I soon am going to purchase a hand held ocilliscope for cheap to measure PWM under 1mhz.  Maybe this is not fast enough but I assume that the PWM is under 1mhz on most controllers.



http://cgi.ebay.com.au/ARM-DSO-Nano-Pocket-Sized-Digital-Oscilloscope-2-8-/270548972022?cmd=ViewItem&pt=AU_Security_Equipment&hash=item3efdf9b1f6

Things to check.

Is your battery charging?

Are your battery connections good and strong and allows lots current to the controller?

It sounds like a flat battery to me.  But I have been wrong before..