MAC motor making a racket

[alfantastic]

I have fitted a brand new MAC 500w 10T to my Specialized Hardrock.
The controller is an Infineon 9 FET 30A with a direct plug in Cycle Analyst.
The C.A. is set to limit the amps to 25.

When it was built, I ran the motor with the wheel off the ground to check for smooth running.
It ran lovely and smooth, with just the usual motor whirring sound.

I started to road test the bike, ramping the throttle nice and smoothly on take off, with a little leg power help at every start.
At no time did the motor run past the amp limit, which means 1300w max with the Ping at 52v.
No strange noises, and running nice and smooth.

On the second day, with a freshly charged battery, it started making a clickety clack sound at around the 5 mile mark.
The sound only appeared under power and with all throttle positions. Gentle throttle or full power made no difference.
On the road, with no throttle applied, it freewheels without this clickety clack sound.
The bike under pedal power with no motor help, runs normally without the sound.
When stationary with the wheel lifted, on powering the wheel, it makes the sound. On releasing the throttle, it freewheels without the sound.
At no time has it been jumped off a curb or abused. As I say, I was trying to run it in gently.

The noise is really loud and definitely not normal, as it ran quietly for about the first 20 miles.
Could anyone throw some light on what may be the problem please.

*** Update on describing the sound. Like the regular clickety clack sound trains make, whilst travelling along the tracks ***

[alfantastic]

Update:

Since the hub started making the noise, I have noticed that on hand spinning the wheel, it freewheels fine and then binds at certain points whilst spinning.
It doesn't always happen on every revolution or at the same point either.
This binding wasn't noticed originally when the wheel was being spun at higher speeds, as inertia forced it past the binding point.
The rim brakes have been disconnected and there is nothing fouling the wheel in any way.

Internal clutch/gear assembly???

[neptronix]

Turn the amp limiting on the CA off and see if it still occurs.

You are probably hearing the clutch dis-engage and re-engage constantly. The CA power limiting is not smooth. And if you have an EB2 controller ( purchased before mid-2011 ), that is another problem in itself.

[alfantastic]

Turn the amp limiting on the CA off and see if it still occurs.

You are probably hearing the clutch dis-engage and re-engage constantly. The CA power limiting is not smooth. And if you have an EB2 controller ( purchased before mid-2011 ), that is another problem in itself.

Unplugged Cycle Analyst completely, no change to noise.
The controller is a post mid 2011 model.
It's definitely a mechanical noise, and as I mentioned, the wheel binds at certain points of it's revolution.
Everything ran lovely and smooth on tarmaced roads, for the first 20 miles.
Nothing was modified or changed, then it started showing symptoms of the problem.

[neptronix]

At constant full throttle, it should not be doing this.

Sounds like the clutch.

[alfantastic]

Yes, I thought so too.
The noise occurs at all speeds with throttle, whether crawling or full speed.

It should be simple enough to replace the clutch/gear assembly, if it's anything like my other geared hub motor.

But which side of the casing do I need to remove to access the clutch?

[neptronix]

It is not too hard of a job.
It's the disc brake side that contains the gear mechanism.

BTW, what is your no-load current at 36-48v? should be around 3-4 amps, tops.

[alfantastic]

1.8A @ 52v

[neptronix]

hm.. ok well open 'er up.

[veloman]

FWIW, I have a new Mac and I can't feel or hear any clutch engage or disengage. I am using an EB312 controller.

Maybe a magnet or hall came loose?

[knoxie]

Yes its the one way bearing they do go, you will have to replace the whole thing, its an easy job to do, you will need a 3 arm puller to do it, there are plenty of threads and youtube videos even showing how to do it.

Ilia at ebikessf sells replacement clutches and is great to deal with, he will get one to you, don't ride it any more because if the bearing breaks and the pawls come out they will ruin the gears, now you will get new gears with the new clutch but its nice to have a spare set so don't ride it till you have fixed it.

Link to my post when mine did the same thing

http://endless-sphere.com/forums/viewtopic.php?f=2&t=38710

Get your new clutch here

http://www.ebikessf.com/node/218

Youtube video on fitting them

[alfantastic]

hm.. ok well open 'er up.

Can I clarify, that all I need to do is undo the screws on the disc brake side cover, and lift that off to gain access to the clutch/gears?
Or do I need to use a puller, as shown in knoxie's You Tube video? That one shows a BMC, with what looks like screws on only one side of the casing.

[knoxie]

Its a rear motor right? if so it should be the sprocket side you remove, you dont need to take the cassette off as you can see in the youtube video (that isnt my video I have more hair and am far less chunky ) post up some pictures when you have it open, whichever side it is you will need a 3 arm puller to get it off, they are cheap though, think I paid 10 bucks for mine, ask a friend or borrow one though as auto guys will have them.

These motors are pretty easy to repair though and there is lots of help on here if you get stuck