Lafree motor noise

[Tintaglia]

It's the one in your first picture (the one of the motor itself) at the bottom of the motor shaft.

 

[Tintaglia]

I can see with a magnifing glass it has a number- 6901Z or is it Z1096? Trust me to get a number that can be read upside-down! I'm taking it as the former because round the other side it says "NTN Japan". That number doesn't seem to come up on google. I'll have to try some bearing suppliers.

 

[Tintaglia]

I have located a bearing. In fact, two so I'll have a spare if anyone here ever wants one.

Looks like I need a two legged puller to get it off.

Just hope all this works and I can remember where all the bits go

 

[flecc]

Fingers crossed!

That bearing could well be the offending thing that was causing the kick back as it bound up.
.

 

[JohnInStockie]

Flecc and Tintaglia

Not being funny but you 2 could run training courses on electric motors, you've both forgotten more than I know on the subject. If I tried anything like that I'd definately make such a mess I'd have to buy another bike!

Any tips on how you go about learning these things (without destroying half a dozen bikes)?

John

 

[Tintaglia]

My wife (whose bike it is) has already started saving up for a new bike (oh she of little faith) She yelps every time I remove another part!!

I would have been very wary of taking it apart at all without flecc's excellent article and ongoing help and advice.

 

[flecc]

Just a feel for the subject from a very early age, and the totalling of experience in my case John. I get bored with some forms of repetition and could never spend my life doing one thing.

I started in the cycle and motor cycle trade 57 years ago when they were often combined, moved onto the motor trade, cars, then trucks and transporters, moved on to somewhat more sophisticated areas of engineering, electrical, electronic, and even optical engineering, then got involved in design, particularly in some electronic and oddball areas. Eventually another complete change to an area of construction engineering.

I even trained in teaching and training principles at one point, but finally decided I'd had enough of working and retired at 54 to do my own thing. A varied life, but always in relation to engineering and technical matters, even during my army time.

Courses have very limited usefulness, aptitude is infinitely more important, in which connection at least 70% of the population have an arts bias and seem unable to satisfactorily acquire technical skills.
.

 

[nigel]

Nigel

Should have guessed i will have to start calling you professor flecc its good to know we have you on board. NIGEL

 

[flecc]

Thanks Nigel, but not professor please. It's embarrassing enough having the pedelec guru title.

I keep my feet firmly on the ground, simply because I know that for every one thing I do know, there's an almost infinite number of things I don't know.
.

 

[electric.mike]

flecc

I keep my feet firmly on the ground, simply because I know that for every one thing I do know, there's an almost infinite number of things I don't know.

the one thing we all should know is that we don't know what we don't know, we don't always know what we do know,i think or heck i don't know.

mike

 

[flecc]

Dead right Mike! (I think. )

 

[Tintaglia]

Flecc and Tintaglia

Not being funny but you 2 could run training courses on electric motors, you've both forgotten more than I know on the subject.
John

I can understand the purely mechanical things fairly well but I certainly don't have flecc's grasp of the electrical parts. But surely this is the great thing about sites like this, add any information you can and learn about the bits you don't know about

 

[flecc]

Exactly what I always say Tintaglia. Everyone has something to contribute and I'm grateful for the fact that I'm continuously able to learn from others experience in sites like this.

 

[Tintaglia]

Just to report back in case anyone else treads this way....

All back together now and it's nice and quiet now. The only really awkward jobs were getting the two-piece plastic cover back on after I refitted the motor unit and getting the old bearing off the motor shaft. I didn't have a puller that was small enough to get behind the pound-coin sized bearing. All of my tools are designed for cars. Even Mrs T's Uncle who restores vintage motorcycles didn't have one. In the end I used two small levers and various bits of wood to protect the plastic case. If anyone else tries this method remember to keep the shaft held into the motor so it doesn't try and pull out with the bearing. We achieved this by wedging one end of a long baton under a lowered motorcycle lift (complete with 1956 Moto Guzzi and Mrs T's Uncle on board) and the other just touching the top of the shaft to hold it in. It took a good pressure with the levers to pop the bearing off.

The plastic covers are just really fiddly, there are three loose rubber seals that all have to be in place at the same time as the two parts of the covers. Definitely not a job for anyone who gets impatient and throws things!

We eventually decided on thin epoxy sticky pads to hold the Hall sensor circuit board (the type used for mirror tiles) after some heat testing with an old credit card and a tin lid! This was all Mrs T's work since she has better eyes and thinner fingers.

The only odd thing is there is still a kickback on the pedal if you press it until the motor engages and then take your foot off it. It's not really the way you would ever ride the bike so I'm just assuming it always did it for now.

All in all it's quite a do-able job if you are fairly mechanically minded. Certainly cheaper than a new motor at £7 odd plus postage for the bearing.

 

[flecc]

Well done Tintaglia, glad it's ok now. As you say, those plastic covers need lots of patience to replace, it's easy to believe that they've grown in some way during the time they're off!