Mxus 3k turbo disc brake

Can someone tell me why the mxus 3k turbo has a disc brake mount that is too close to get any caliper behind the disc and a spacer is the only way around it I can see ?
If someone can slap me round the head please do.

Lot of riders just use a front brake and regen on the rear wheel. I'm not saying its a good idea, just that...if you need a thin aluminum spacer to get a caliper to fit, add a spacer. There's hundreds of frames out there, and every Chinese company is just taking the easiest path they can find.

Trust me there's a guy out there telling MXUS that the disc brake mounting boss sticks out too far. They already think we are nuts. These are scooter motors in China, for ebikes they often have a small motor and a small battery...

Although...you bring up a good point. There are definitely products in Asia that are not imported here until some wholesaler is willing to risk paying cash for 100 units, and then hope that they sell...Maybe there's a thin caliper in China that drops-in?

It's a good point it's all disjointed size wise any ebuilder has to make do and tweak whats available it can be quite troublesome on times if your a new like myself, The disc sits so close that a pad is all that will fit any caliper would need to be wafer thin and titanuim to have any chance of stopping rather than bending.
I can see the point of no or little back brake with regen specially with adjustable regen on a lever why waste the energy when it can he recovered, but I still like to know that there is a disc for emergencys that works well to be sure even if it's extra few pounds mass both rotating disc and fixed caliper.

What if you use a 203mm disc there should be enough room I would think. What size disc are you using? This same subject was posted about a month ago.

wow only 10mm space, just looked it up.

203mm floating disc, The calipers I use are hydraulic and fairly compact I'd be suprised if any caliper would fit behind a 160mm disc, because the mxus and turbo badge are raised from the surface thats an obstacle that the 203mm disc and mount just pushes the caliper out far enough to miss.
But a 160mm disc and mount set up would foul straight away so the 203mm is already saving me space, I can get away with 5mm minimum now where I would need 7mm + with a small disc and no room for phase wires
I suppose they know the motor will be fitted to a whole variety of frames and they just trying to allow for all outcomes but the stock setting is no use to man or beast but it won't beat me.
I see theres a 5k version in the horizon so I wounder what improvements they have made to the ergonomics of the design as well as increasing power output.

Ianhill said:

Can someone tell me why the mxus 3k turbo has a disc brake mount that is too close to get any caliper behind the disc and a spacer is the only way around it I can see ?
If someone can slap me round the head please do.

Click to expand...

I can confirm the 3K-Turbo disc brake cover has an extraordinarily tight space for the caliper. Use a spacer (or two) and longer screws.

Believe me, these things don't go unnoticed by some, and some are actively working on improvements. :wink:

This has never been a problem for me, so...I don't have any hands-on experience with potential solutions. Forgive me if this is a stupid question...

The idea occurred to me that some of the possible disc selections have a separate spider. Is it possible or even advisable to use one of these, and put spacers between the spider and the disc, as opposed to putting the spacers between the hub and the center of a disc? (our ebike rear axles are sometimes cluttered, and having the spider up tight against the hub side-plate might be desirable in some cases...)

Pic link for an example: http://carverbikes.com/wp-content/uploads/2014/08/BR-Rotor-Vented-cvr2348-160.jpg

My rotor is very simular with two pieces riveted together and I did look at it scratch my head and think mmmmm I could split the disc.
I measured what little space i have and by the skin of a whisker I can get it to clear otherwise spliting the disc or bending one out would be the only option of getting the phase wires out and clear of the hub without putting them in harms way when the hub and disc assembly start to spin, but with the strength losses of splitting the disc and sitting them out on the alloy bracket plus the fact i just paid for them I didn't fancy splitting them.

... but I still like to know that there is a disc for emergencys that works well to be sure even if it's extra few pounds mass both rotating disc and fixed caliper.

Click to expand...

I thought about this too. I don't even have a rear disc mount on this current frame. Instead, for now, I use two (somewhat crappy) front brakes for extra brake power and some redundancy - one rim and one disc. Two separate levers, both hydraulic. Most all my controlled braking is performed with the regen at the rear, this is right now a thumb button close to the brake lever.