Bosch Performance Line CX Gen 2 Strip Down

[crust]

Excellent posting, Beanie.

Mines just done 750 miles, I've never jet washed it and am very careful with the hose but it has got soaked more than a few times.

Am thinking either before Morzine in August or at the 1000 mile mark I'll probably send it to ebike motor pepes.

[DefTrap]

Good work.
Pushiron parts always seem so feeble compared to even light motorcycle parts. The juxtaposition of all those electronics and rusty, manky bearings are frightening ...

[Beancounter]

I can see me going for the Bosch Service Kit + on this occasion. Still cheaper than a secondhand motor.

They are good kits and nice to see Bosch supplying them tbh, rather than making people pay for it to be done.
There's youtube videos showing how and where all the bits go as well. Makes even people like me think they could have a go without totally cocking it up

Ordered the Service Kit + today. The difference between it and the Mega kit is that the Mega kit contains the tools needed to remove the crank arms and front sprocket. Still haven't fully stripped the motor yet but I figure that if I know what new bearings I've got I can be a little less cautious with removing the old.

Haven't looked at the Ebike Motor website fully yet but there appears to be a load of helpful info on DIYing.

Excellent posting, Beanie.

Mines just done 750 miles, I've never jet washed it and am very careful with the hose but it has got soaked more than a few times.

Am thinking either before Morzine in August or at the 1000 mile mark I'll probably send it to ebike motor pepes.

The service kit that I've bought talks about using different bearings because the standard Bosch ones are felt and just let water by, keen to see the difference.

Good work.
Pushiron parts always seem so feeble compared to even light motorcycle parts. The juxtaposition of all those electronics and rusty, manky bearings are frightening ...

Indeed. There's still a lot of heavy grease in my motor but I've no idea hos much, if any, has been washed out over the last four years. I'd be tempted to pack out the whole thing but am sure that would have other negative effects.


**Edit** just had a message from Parcelforce saying they've collected my package from Ebike Motor peeps and it'll be delivered tomorrow. Excellent service thus far!

[Beancounter]

Work and family-time has diverted my (lack of) focus elsewhere. As mentioned, ordered the Service Kit + from Ebike Motor Centre and it turned up a day later.

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[Beancounter]

The contents of the pack claim to be and certainly appear to be everything required to do a full strip down, including a new DS cover with some bearings already installed:

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[Beancounter]

The inclusion of a new assembled DS cover is a nice touch but it does present me with a problem. When I was removing the old cover a small locating pin broke off and remains in the motor case - circled red on the screen shots below:

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As I see it, my options are:

1. Try to remove remnants of the locating pin from the motor case. It's not very deep and only a few mm wide so there's not much room for error;
2. Grind off the locating pin on the new cover;
3. Remove the bearings from the new cover and install on the old.

Number 2 is my preferred option as I don't really want to be drilling out the broken part.

[Beancounter]

I'm not called the King of Procrastination for nothing...

Progress limited to cleaning up the rust on the crank and gear cluster. Used Kurust and rotary tool brass brush:

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That photo is part-way through the cleaning, you can see the cleaned area is much better but not brilliant. Am considering buying a cheap ultrasonic cleaner to see if it makes much difference.

Also purchased this at the weekend, should get it in a few days' time:

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It's a cheap eBay item but should be sufficient for my needs.

[Beancounter]

Hydraulic press arrived yesterday as planned. Standing at 95.5cm it's quite tall for a bench press but it's still useable. Very heavy and cumbersome as you'd expect so it's not really something to be moved around regularly. Putting it together took about half an hour, mainly because of the agg of trying to fit the bottle jack in place whilst fighting the return springs. In the end I used a scissor jack to extend the springs and tied six chunky cable ties around the platform which the bottle jack sits on (this platform being the ram for the press) which allowed me to fit the bottle jack.

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[Beancounter]

Once assembled it made quick work of removing the seized NDS outer crank bearing and the battered/partially removed needle roller bearing from the gear cluster:

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[Beancounter]

The NDS outer crank bearing doesn't look too bad but once I pried the seals away it was a different story:

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Scraped a lot of dirt out but most was still trapped in the bearing itself:

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Even using some pretty cheap and nasty engine degreaser could free the ball bearings.

The outer race of the needle roller bearing:

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[Beancounter]

Next stage is to remove the bearings from this gear cluster:

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The gears are sandwich between a needle roller bearing and a small ball bearing and to remove both bearings means removing both gears. Once the gears are removed you are left with this:

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This was one of the reasons for buying the bench press as to try tapping out the bearings could easily damage the 'fork' - not to mention how difficult it would be to tap them out in the first place.

[Beancounter]

Not particularly good close ups of each bearing:

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Neither bearing feels rough but no point coming this far and not replacing them.

[Beancounter]

With the kit I've bought I only have to swap four bearings myself as most of the others mentioned earlier are pre-installed:

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The red one is the NDS outer crank bearing.

The yellow is the needle bearing for inside this gear cluster:

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The final two are for this gear cluster:

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Hoping to get these swapped/installed over the weekend and the motor put back together if not installed on the bike.

[Beancounter]

The inclusion of a new assembled DS cover is a nice touch but it does present me with a problem. When I was removing the old cover a small locating pin broke off and remains in the motor case - circled red on the screen shots below:

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A bit of a result when pressing out the NDS outer bearing - the broken locator pin fell out too so no need for drilling or cutting.

[Count Steer]

Hydraulic press arrived yesterday as planned. Standing at 95.5cm it's quite tall for a bench press but it's still useable. Very heavy and cumbersome as you'd expect so it's not really something to be moved around regularly. Putting it together took about half an hour, mainly because of the agg of trying to fit the bottle jack in place whilst fighting the return springs. In the end I used a scissor jack to extend the springs and tied six chunky cable ties around the platform which the bottle jack sits on (this platform being the ram for the press) which allowed me to fit the bottle jack.

IMG_20240702_220231_487 (Medium).jpg

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Now that's a proper boy's toy.

[Beancounter]

Well I screwed this up quite spectacularly.

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The ball bearing came out very easily but getting the needle bearing out was proving very tricky because I wasn't comfortable with the pressure on the casting. I wanted to use a cheap socket to fill the gap left by the gears but the socket kept falling through the now-larger hole left by the ball bearing. To fix this I thought I would re-install the ball bearing and I naively thought it would go back in as easy as it came out - not so. The casting broke like a matchstick.

Spent the whole weekend feeling very annoyed with myself and contemplating the cost of a new/refurbed motor but the guys at Performance Line Bearings have saved the day - £24 for a new part.

[weeksy]

Whoops, we've all felt your pain

[Beancounter]

Finally had a spare weekend and the gumption to return to this. Won't lie, the longer I left it, the more daunting the task seemed in my head.

A mate from work wants to pop his uplift cherry so I had some external motivation. Everything had been bunged into a shoe box due to a friend from the States crashing at ours so first thing was to carefully unpack said shoe box and take stock of what parts I had and what the next step was:

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Motor clearly still in pieces however the bearing pack I bought came with the RHS/drive-side casing pretty much assembled - RHS crank shaft bearing, small idler gear and its clutch needle roller bearing were already assembled. This photo shows the new one at the top, old one below. You can see the new one already has the main motor needle clutch bearing pressed in - I removed the old one prior to buying the bearing kit, you can just make out the damage from the bearing needles on the old one.

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[Beancounter]

Next was to press this needle bearing into this gear:

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Easily done with the hydraulic press but you could probably do it just as easily tapping in with a hammer and drift.

And then fit it into this:

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This is a push-fit however my old one was all but seized together and was what made me decide on buying the hydraulic bench press.

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[Beancounter]

Next was to start working on the motor unit, first thing is to press in the LHS/non-drive side crank shaft bearing:

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Remember to fit the new circlip as that's not mentioned in the How 2 video.