Giant Lafree no2 dies

[alanterrill]

The electrics have just failed on my wife's Giant Lafree Twist, just over two years since my own did the same. This time, it didn't fail completley - the motor still gave a kick at start up and continued to give power for a while until the speed increased to about 9 miles and hour then just cuts out. I thought I was in with a chance as I'd kept my old Giant for potential spares, so I set to work replacing both the sensors this morning with the help of Fleccs trusty notes. All back together and off up the road and the same thing happened again. As the motor turns on and it's not the sensors, then it has to be the circuit board again I guess. This bike is five years old but it's only used for weekend pleasure riding, plus the odd holiday, so its probably not done more than 4000 miles in its lifetime. Mine was only 3 to 4 years old so had probably done less. Its an expensive pleasure this electric bike lark. I'm loathe to spend out £1500 plus on a Kalkhof or Gazelle if there's no guarantee parts will be available beyond the warranty period (has anyone heard otherwise?). As I've now got four Giant batteries and three chargers, I have a certain vested interest in sticking with the lafree, so ebay here I come..

 

[flecc]

Sorry to hear that lightning has struck twice Alan.

Would you like the right hand half of my new spare unit's crankcase, complete with circuit board?

I can't guarantee that it's a perfect one, but it is a new unit so there's a good chance it's ok.

If so, let me know if you're still at the Hope Valley address and I'll get it into the post to you.

regards, Tony

 

[flecc]

Part on way for Tuesday AM delivery to you Alan.
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[alanterrill]

Thanks for the board flecc! I spent most of yesterday fitting it then went out for a test ride -as before the light came on and the bike set off normally and went fine until I started to climb the steep drive frokm my house, and the motor cut out before the top. Starting again on the flat it was fine but before I'd got 100yards it had stopped again. At this point I have changed the motor sensor, pedal sensor and circuit board, but the fault has been consistent throughout. Very mystifying, so I thought - well it must be the handlebar control switch -so I removed it and replaced it with the one from my other bike and set off again. Result- exactly the same as before!
So I've now changed 100% of the electrical parts, (and yes I have tried another battery long ago), and yet the fault is still the same as before I swapped anything over. I'm confused -all thats left is the gears and they don't appear to be slipping or jamming. As I'm now left with enough parts to rebuild a second motor, I'll try that and see if I can revive my original bike. But as to how a fault can stay the same as I gradually replace all the parts -it sounds like homepathy theory -you dilute the substance so many times not a single molecule of the original remains, yet the water still has the originals properties -or so they say...

 

[flecc]

That's truly weird Alan, these e-bikes can certainly be cussed things.

However, have you tried swapping the motor itself?

Possibly a heating up fault or windings problem. I'm guessing you have a spare working motor.
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[alanterrill]

Bike working again!

Flecc,

I'd overlooked the fact that it could be the motor itself -I assumed that as it turned on and pulled away from a standing start nicely that it couldn't be the motor. However, I took the motor from my older unit and put it all back together and I now have a fully working bike again! Thanks for the advice.

The fault on my first failed bike was a complete failure to even start and I'd tried replacing the two sensors then given up. So it could have been either the motor or circuit board at fault. However, now I've proved the motor works, it shows it must have been the circuit board at fault. So now I've got one bad circuit board and one good one, but only a bad motor. So if you have a spare motor left I'd love to hear from you, but if not, you can have the circuit board back to pass on to another needy Giant fan.

Thanks for all your help,
Alan

 

[flecc]

Hello Alan, pleased about the good news. Yes I do have the new motor from my unit and you are welcome to it. I'm away from tomorrow evening for a few days but I'll post it to you later in the week.

Meanwhile, forum member PeterG had suffered a fracture on the left hand crankcase and that's going for his unit, so all I'll have left are some of the internals, gears, bearings and pedelec sensor. To date that new unit I had will have got three others working, four if you use the motor for another one, can't be bad.
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[alanterrill]

Bike no1 revived!

Thanks for the motor - my original Giant has just flown up the drive in rude health after being hung on the shed wall for over two years! So that confirms it was a circuit board that failed on the first one, and a motor on the second. But, they can be repaired if you can get the bits. So now we have a spare electric for visitors -very civilised. Many thanks for your help.

Alan

 

[flecc]

A pleasure Alan. The reward is that two Lafree bikes are now back in full action, they're too good to die.
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