Fehlerdiagnose: Gasannahme bricht weg

[Pinky]

Nein, aktuell ist der Motor blockiert. Ich vermute, dass ich beim Zusammenbau das Innenleben "falsch" eingesetzt habe. Der von bob beschriebene "test" ob das Rad "frei" dreht wenn man es in die Schwinge hängt, schlägt jetzt fehl. Auf diesem Wege lässt sich das Bike auch nicht mehr schieben.

Ich muss also bei Gelegenheit den Motor nochmal auseinandernehmen. Das von mir oben beschriebene Lagerauspress-Werkzeug eignet sich aber nicht. Ich brauche eine größere Variante. Die Felge ist zu "Dick" für die Länge des Werkzeuges.

[bob2.0]

Did you use my method to use long bolts to guide the rotor, and lift from underneath?

I think it is important to allow a smooth and careful refitting.

Once the bolts are in place (with the rotor dropped down), lift it up to engage the tool (leave 2cm for the axle to come through) then the magnets will lift the rotor.

It should then glide in smoothly, with no problems.

It takes a few minutes to get the bolts lined up because that is awkward. But it is more time spent preparing, for less time spent repairing.

If your magnets are rusted and loose, it may have knocked them off if the refitting was sudden.

I think you have the "rust-magnet" problem.

I think every e-Odin will have it, eventually. Mine was one of the first 2.0 out of China, and was stored outside. So, I got it first. I think it is a 'when' problem for this bike, not an 'if' problem.

[bob2.0]

I did not use the arm pushing tool, I used a bearing extraction tool (it is larger, and a purely parallel action).

It was not intentional, but it was the only tool large enough that I had in the garage. I did not want to buy a larger claw tool. I think in the end it is a superior tool for this work.

It may help to get one.

(It seems we also need it to replace the head bearings, which is why I bought it originally, to replace bearings on my sports bike.)

In my first removal/refit, I cable tied it to the brake disk so it was solid and nothing moved as the rotor dropped out. This meant it was an exact position and did not move around. You can then leave it attached to the brake disk while you work on the motor, and it is ready when you work on refitting it.

[bob2.0]

This is how I refitted it.

Bearing removal set (cheap, ~$20).

Layout of parts (using the pulling parts by rotating them outwards and using them as big washers), then I cable tied it to the brake rotor.

Sealant on the hub lid. Lift the hub into approximate position, top axle end through bearing, bottom resting on wooden block. Insert guide bolts.

Set tool to allow a few cm of the top axle to come up. Lift up hub until the magnets 'catch' and hold it.

.... If the tool is too low, release the tool slightly, in small increments until the magnets holds the hub.

Then with the rotor engaged in the tool, wind the tool off, and the hub rises gradually and controlled into the rim.

Eventually it goes in as far as the bearings will allow.

Then you need to use a hammer and drift, with rubber or wood or something for protection, to hammer home the bearing, by hammering the shoulder around the axle. Don't try bringing the lid together by screwing it together, this leaves residual stress in the lid.

Once the gap is paper thin, you can tighten the bolts to 4 Nm, in a crossed-sequence. (I did opposite bolt, then opposite (2 bolts), then the 2 at 90 deg, then rotated to the next set of 4, then the final set of 4, then each one in a circle twice, so none were missed.)

I recommend, leave the guide bolts in place until they are the last few bolts to fit, so that the lid does not misalign during the bearing seating process and initial torqueing.

You then need to tap home the shoulder some more, again to relieve the residual stress in the lid. Then retorque cross-pattern to 5Nm.

Personally, I then marked each bolt head, so that I could see if it moved. The torque is too low to 'retorque' after X miles, you need to check for bolt movement than torque tension.

[bob2.0]

PS: The 5 Nm is what I chose to be the right number. What you choose is your choice. I am not aware of an 'official' value.

It is quite high because it is only an M5.

I would definitely not recommend going higher, as there is a risk to strip the threads. It is a maximum. Possibly less is a good idea.

(In theory, Grade 8.8 is 6.9 Nm. I took the first few to 5.5 Nm and they felt like the thread was giving way. I do not think this metal is Grade 8.8. So I kept them to 5 Nm.)

But it is into the steel part of the rim, and it is VERY critical to get it properly positioned and torqued.

All of the road load is going through those 24 x M5 bolts. They are the only thing that holds the back wheel on to the bike. Pay attention to these bolts and don't over-torque them, because they will strip, and a stripped bolt hole cannot hold the wheel to the bike.

[jeff-jordan]

Thank you bob!
I think the relevant point is to get the M5 x 120mm guide bolts first.
Don't know if a real bearing removal kit is required to push the axle down the bearing, maybe a "normal" 3-legged puller will do the job as well.
As far as I understood, you are pushing (from down under) against the assembled rear brake disc.

...
But it is into the steel part of the rim, and it is VERY critical to get it properly positioned and torqued.
...

Are you sure that our rim is made of steel? I thought it was cast aluminium (same material as the triple tree).
But I agree with the torque. I wouldn't exceed 5Nm.

_______

Danke Bob!
Ich denke mal das Wichtigste ist erstmal sich die Führungsbolzen M5 x 120mm zu besorgen.
Ob ein spezieller Lagerabzieher notwendig ist weiß ich nicht, möglicherweise tut's auch ein normaler 3-Bein Abzieher.
So wie ich das verstanden habe drückst Du ja letztendlich von unten gegen die montierte Bremsscheibe.

Bist Du sicher, dass unsere Felge aus Stahl ist? Ich dachte das wäre eine Alufelge (gleiches Material wie die Gabelbrücke).
Aber ich stimme bezüglich des Anzugsdrehmoments völlig zu, 5Nm sollte man da nicht überschreiten.

[bob2.0]

I don't think it is important to use the bearing puller or the jaws. But the bearing puller worked out very well. I could cable tie it (so when I lifted up the hub to the magnets, it was held in place, that made it very easy) and it spread the load.

If I had to buy one to do this particular job, I would recommend the bearing puller as I have done. If you already have jaws big enough, then of course use what you have!

The rim is aluminium.

But there is a magnetic steel insert onto which the magnets are glued, and it is about 8mm thick. The M5 bolts are tapped into that magnetic steel.

It's the best bit of quality engineering in the motor/rim. It has been accurately done and it is almost seamless between the steel and aluminium. That is tricky because the aluminium has a much lower heat coefficient, so I am not sure how they did that. They must have cooled the steel and used a press to push it in, I suppose?

There is not too much force on the brake disc, I saw no issue to push against it, but I feel that the larger area of the bearing puller (rather than small jaws) helped spread the load out and kept the force close to the centre of the disc (so, no bending). I would not say there is any mechanical advantage for either piece, and the brake disc is robust to this work. There is no other way to do it. If it did damage the disc, then buy another one and keep the old one as 'the tool'!

[bob2.0]

Also to mention, if you wanted to pull off the other plate (where the cable comes out) then you would need the jaws extractor. You might need to do this to access the wiring. I expect Pinky has already figured that out if he has replaced the sensors?

(There are two sets of sensors.)

There is no other need to remove the cable-side plate unless you want to change the seal.

If you need to change the bearing on the cable side, on the 2.0 you have to completely remove all the wiring from the windings.

[bob2.0]

The steel may have been friction welded, and then the centre was machined out afterwards (there are machine marks suggesting to me the whole wheel rim was lathed at some point). It's quite a bit of engineering, whatever it is they did.

It is no surprise they cheaped out on thin 2-plate zinc/nickel and not enough glue. They were trying to save money after that big cost.

[jeff-jordan]

Cool, thanks for that detailed explanation!