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Motorcycle News (UK) - - GARAGE -

Me­tal magic

The Mupo Mag­neto sys­tem con­trols the damp­ing force with MR fluid which comes from US firm LORD and con­tains tiny iron par­ti­cles. When you pass an elec­tri­cal cur­rent through the fluid us­ing elec­tro-mag­nets built into the sus­pen­sion units, the align­ment of the par­ti­cles in­creases or de­creases the vis­cos­ity, stiff­en­ing or soften­ing the sus­pen­sion damp­ing and feel in mil­lisec­onds.

Rapid re­sponse

The stan­dard Mag­neto sys­tem has just one power cable from the bat­tery to the ECU and two wires from the ECU to the shock and one fork leg (the other fork leg sim­ply has a match­ing spring). The ECU is mon­i­tor­ing and con­trol­ling the damp­ing force 1000 times per sec­ond, but the MR fluid is two to three times slower, but that is still a mat­ter of mil­lisec­onds. How­ever, the feed­back from even the fastest bike en­coun­ter­ing a bump in the road is 20-50 times slower, so re­sponse time isn’t the chal­lenge – it’s how the sys­tem re­sponds.

It’s about con­trol

Rapid con­trol of the damp­ing force is one thing, but it has to re­spond to road con­di­tions. A stan­dard set-up has pretty fixed damp­ing, linked to the spring rate.

This sys­tem senses the move­ment of the chas­sis and the speed of the sus­pen­sion units them­selves to fine-tune the damp­ing in real time.

This gives the bike a much larger range of damp­ing forces, which mas­sively in­creases the us­able range of a stan­dard spring. That means your sports­bike can have the soft char­ac­ter­is­tics of a tourer on cob­bles, but then have the firm con­trol that you ex­pect at speed.

Feel your way

For back-to-back test­ing, Mupo used two iden­ti­cal Moto Mori­nis run­ning the same springs, with one on the stan­dard man­ual set-up, the other us­ing the Mag­neto sys­tem. The Mag­neto sys­tem calms down the move­ment of the bike, so that there isn’t so much pitch­ing back and for­wards. For the first five min­utes it feels un­usual, but af­ter that the test rider re­ported a feel­ing of greater sta­bil­ity.

Rac­ing fu­ture

The road-go­ing sys­tem is based on sen­sors that mea­sure the move­ments of the frame. For rac­ing it is pos­si­ble to add two lin­ear sen­sors (po­ten­tiome­ters, com­monly used in the rac­ing) to im­prove the con­trol, based on the sus­pen­sion ve­loc­i­ties (front fork and rear shock). The sus­pen­sion ve­loc­i­ties are worked out by the ECU, which pro­cesses the data from the sus­pen­sion po­si­tions, as mea­sured by the lin­ear sen­sors.

The sys­tem also has the po­ten­tial to man­age chat­ter. Chat­ter usu­ally has a fre­quency of 16-17 hertz and stan­dard sus­pen­sion’s 50 mil­lisec­ond re­sponse time means it strug­gles to cope.

The Mag­neto’s mil­lisec­ond re­sponse means it can fine­tune the damp­ing so those forces aren’t trans­mit­ted to the rider. How­ever, cur­rent reg­u­la­tions limit its use in pro­to­type classes like Mo­togp and un­til it is fit­ted to street ma­chines and ho­molo­gated it can’t be used in pro­duc­tion classes ei­ther.

The sys­tem works on the front and rear sus­pen­sion

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