2wd : Mxus 3k 3t in a motorcycle fork

csc

100 W
Joined
Dec 13, 2016
Messages
176
Hi

I've just disassembled my front wheel for maintenance, good occasion to show with more details how I installed an Mxus 3k 3t in a Showa 35mm reversed 50/125 cm3 motorcycle fork (was installed on Rieju mrx 50, derbi senda sm 125, etc) (this should work with any fork having the same axle design)

20170906_1551081-e1504707566268.jpg


(https://www.spomotoscooter.com/index.php?page=pieces&id_piece=72989)

I noticed that this kind of fork, on the "non-disc" side, has exactly the same axle diameter than the plain part of the axle on an MXUS 3k (aka not the bolt tightening part of it, but the circular plain part on which you put the bearings). Therefore, it would accept quite a lot of hubs, I guess.

The non disc side of the fork has not been modified. It has a native bolt/nut axle locking system (check all the pictures below to see exactly what I mean).

non disc side no mod.jpg

The lock has easily been reproduced on the disc side - a straight cut and two holes. This disc side has a smaller axle size, so it had to be quite a lot modified to let the mxus axle go through and let the bolts be tightened. As a clean aspect is not strictly necessary, as soon as the final result is simili flat, I saved a few hundred euros through a home made job performed with some kind of a "butcher style".

modified disc side 2.jpg

But the torque arms have been made of special hardened steel, by a professionnal. These cost me their weight in gold (almost) !!!!

torque arm 1.jpg

The disc side TA has a flat side that forces the bolt and therefore the axle angle :

torque arm disc with flat.jpg

They fit exactly in the holes that you'll find underneath the fork :

torque arms go there.jpg

When inserted it looks like this :

torque arm inserted.jpg

Hub and torque arms tightened : 72v 120 amps battery/ 240 phase peak + 40 amps regen on front wheel with no issue (rust underlines what I'm talking about) !!!

hub and TA tightened.jpg

I also had to make a spacer that fits with the plain part of the Mxus axle :

spacer.jpg

It goes there ("non disc" side) (notice the area where the motor axle will fit exactly the fork's original axle hole, and its associate tightening system) :

spacer installed.jpg

The disc cover was modified to accept a motorcycle disc : more pictures later







And sorry but oddly I can't move nor remove this picture showing the disc side mods, that I'd have preferred to place above (??!!) :
 

Attachments

  • modified disc side 1.jpg
    modified disc side 1.jpg
    134.4 KB · Views: 645
Back
Top