Fitting a PAS

[John Galvin]

I'm feeling a bit guilty asking all these questions and thank you all for your help so far.
I promise I'll document the build once its finished in case it would be of help to anyone else.

I've everything fitted on the handlebar now, which was no mean feat given the space constraints. It's looking quite tasty.

I also broke out my shiny new crank puller for the first time and successfully removed my first crank.
I then unscrewed the bottom bracket cassette? and thought that there would be some sort of lip that would hold
the PAS sensor against the bracket. There doesn't appear to be though. If you look at the two attached pics, one without the PAS and one with it held up against the bottom bracket, you'll see that it just sits flush with the BB. Is this normal? Presumably glue is the answer here - what's the recommended type? My frame is aluminium. Should I remove the paint before gluing?

I've managed to break a tiny plastic part off my socket wrench, so now it will only remove stuff and won't go into reverse. I'll have to get a new one tomorrow to tighten up the BB.

While the crank came off beautifully, obviously some force will be needed to put it back. Is it enough to fit the crank and tighten the bolt - will that be sufficient to get the crank back on the bike?

I haven't worked seriously on a bike for years. It's great craic altogether.

TIA

 

[Deleted member 4366]

You need one of these:
http://www.ebay.co.uk/itm/REPLACEMENT-24-TPI-BOTTOM-BRACKET-LOCK-RING-IN-SILVER-/271206943287?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item3f25318a37

You might have to unscrew the bottom bracket a bit to have enough thread to screw it on. It only needs two threads altogether.

Don't forget to reverse the magnet disc if you put it on that side.

 

[John Galvin]

Dammit - there's always something missing!!
I'll try my LBS and see if they have one. Can I do a temporary job if I can't get one?
According to the supplier's website, the PAS goes on that side (the one opposite the chain). There are arrows on the magnet disc too.

 

[trex]

the last picture shows the sensor facing the frame, it has to face the other way, toward the disc.

 

[John Galvin]

Ah, I get ye now.
Don't know why I did that - probably handier for the photo but of course the wire has to face the other way when it's mounted.

 

[Deleted member 4366]

Test that it works before you put the crank back on. If it only works when you turn the pedal backwards, flip the magnet disc. It's as simple as that.

 

[John Galvin]

My LBS came up trumps again. He had a lock ring and lent me the tool to tighten it. Looks like I'm good to go.
Hopefully, that's the last glitch.


Happy days.

It all went perfectly as far as I can see and the PAS is mounted securely with the crank back on.
Only the wiring to go now and the routing should be quite straightforward.

Famous last words!

 

[Deleted member 4366]

I hope you tested it!

 

[John Galvin]

I tested it on the bench last week. I'll go back to it in around an hour and hopefully get it wired up tonight and test it properly on the bike.
Judging by eye, I'm a little outside the 2mm recommended gap but I can always nudge it if necessary. Think I got the arrows pointing the right way too.

I hope you tested it!

 

[Deleted member 4366]

I meant I hope you tested that it works in the right direction before you put the crank back on. You can't go by the arrows.

 

[John Galvin]

Now you tell me! Thought I'd be grand going by the arrows.
Happily, it turned out alright.
Wired it all up in around an hour and it works. Just need to adjust the brakes tomorrow and it's ready for its first road test.
I'm using a large unused workspace in the office so I had room to give it a quick test and it all seems good.

Quick pic attached and I'm going to bed now.

Thanks to all.

I meant I hope you tested that it works in the right direction before you put the crank back on. You can't go by the arrows.

 

[Deleted member 4366]

I've just thought of something that you need to look out for. The frog battery mounts fom Chinese suppliers are not strong enough. After a while, the battery sags down, which will bring it in contact with your wheel. Each time you bend it back up, it gets weaker and before long a crack opens up in the corners, which weakens it further.

Some of the OEM frog mounts were reinforced with a bit of extra angle steel welded in the corner. If yours doesn't have that, you should consider a modification if yours sags.

There's something about the problem here:

http://www.pedelecs.co.uk/forum/threads/frog-battery-cracks.16413/#post-201400

 

[John Galvin]

Thanks. Will keep an eye out for that.
In any case, I'll mount it a little higher as it's fouling the brake line slightly on the fold. I'll get away with it for now but there are a few more little things I want to do but they can all wait for the winter months.

Just given it the first test ride and it's great. It holds 27-28 km/h just on the throttle and there's strong assistance when pedaling.

Been very worthwhile so far.

I've just thought of something that you need to look out for. The frog battery mounts fom Chinese suppliers are not strong enough. After a while, the battery sags down, which will bring it in contact with your wheel. Each time you bend it back up, it gets weaker and before long a crack opens up in the corners, which weakens it further.

Some of the OEM frog mounts were reinforced with a bit of extra angle steel welded in the corner. If yours doesn't have that, you should consider a modification if yours sags.

There's something about the problem here:

http://www.pedelecs.co.uk/forum/threads/frog-battery-cracks.16413/#post-201400