brake mods on the Mercane (or Don Quixote does brakes)

upfront

Myself I'm not interested in this mod, I'm more the Sancho Panza and fundamentally the brakes on the Mercane are quite sufficient, have good lever feel and operate nicely (if you spend a little time tuning them). If you think they don't for then this most likely means either:

• you have a faulty caliper (so just replace it) or 
• it needs adjustment (and I've got descriptions of that here). 

Now pardon me being blunt, but if you are of such meagre mechanical aptitude (and unwilling to learn) then I think you should know right now that you won't be able to fit the (somehow) popular X TECH caliper ... because really that's going to require far far more work than just spending a bit of time unbolting the existing caliper, exploring it (and seeing how it works) then adjusting it.

Lastly there is a lot of misconception by people who just don't seem to have the faintest clue about how brakes work. The standard Mercane brake has two pads one on each side of the caliper but only one piston which pushes in. It relies on the flexing of the (its only 2mm for gods sake) disc to operate and push against the inside pad. So adjustment requires that inside pad to be kept in close (almost touching) to the disc; because it doesn't move.

Now naturally there are those who just like to mod for the challenge ... I used to do that, and for those folks, this is here.

The nuts and bolts

This is the XTECH beside the existing caliper ...

its should be immediately apparent that its bigger (and not clear here, but will be soon) its a lot fatter too. Now, if you're still enthusiastic you'll notice that there are two variants, a Front and a Back, they are different only in the supplied bracket (I bought the front)...

because it looked lower to the mounts and that looked like what I'd need. Take a moment to compare the center of the pistion and its relationship to the mounts with the center of the OEM part and its mounts ... the black one is too high and back ... but that's not where the problems end.

Next lets have a look at a quick video (sorry is vertical, but its easier to compare them one above the other like this).

So assuming you watched that, what it results in is that the extra bulk comes VERY close to the rim

less than millimeters in fact...

and as you can see also, I still don't have it in a place on the mounts.

Which sort of mirrors the configurations of the posts on Reddit where people have tried to mount this caliper ... always with odd angles and very small clearances (meaning rim or caliper damage is likely).

Now part of the problem is also that the mounting bracket will need to be shaved a few millimeters to allow that caliper to move further to the outside, which may allow it to clear the rim, but that's going to mean the disc will need to move out too (as here its actually seated on the disc).

Here I've bolted the caliper bracket onto the swingarm mount points and you can see how little clearance there is between this and the disc...

So not enough to move that caliper out without shaving that bracket. There is room to shave 2 or so mm off the outside of the bracket without compromising strength though if you're keen (and reports mentioned below suggest other users needed to do that too).

Of course to move that out, you'd also have to move out the disc, which would mean packing that out with (say) some 2mm washers. To be able to do that you may find its easier to take the wheel off ... but I think it can be done without removal.

Lastly you may have noticed that the bracket is not "even" or regular in shape:

with one side being higher than the other ... which means you can have some room for altering which tilt works best for the caliper by mounting it one way:

or the other

So if after this you've seen enough to energize yourself into getting one, please leave a comment on how you got it mounted and (better yet) what your long term finding of it was in terms of:

• pad life
• going spongey (can't be bled as its sealed)
• adjustment as the pads wear (should just be take up on the threaded adjuster)

I am in no rush to do mine, but as I have also bought some spare discs may make a project to add front brakes (which I'm also in no rush to do because I don't think front brakes will be a "good idea" on the scooter.

Lastly some reddit posts:

• one
• two
• three

Bottom line:
ultimately I could get this going if I was so inclined ... but for what? My brakes work fine with less time spent than modifying the brackets and I have not had to weaken anything or add more bolts into the mix.

A final point as yet un-mentioned is how much much heavier these calipers are ... compared to either the standard Mercane or the hydraulic ones on my MTB

because there has to be both master and slave cylinder built into one (just for starters).

HTH