Motorcycle News (UK) - - This Week - By Ben Purvis

Tur­bocharg­ing is set to be­come wide­spread on fu­ture bikes as man­u­fac­tur­ers com­bat emis­sions lim­its while striv­ing for im­proved econ­omy and per­for­mance. And Suzuki will be at the fore­front of the forced-in­duc­tion rev­o­lu­tion as a pro­duc­tion ver­sion of the Re­cur­sion con­cept bike is creep­ing ever closer to show­rooms.

Since the Re­cur­sion broke cover at the 2013 Tokyo Mo­tor Show, Suzuki havenõt de­nied a pro­duc­tion turbo bike will fol­low it. Two years later, at the 2015 Tokyo show, a near-pro­duc­tion turbo en­gine, the XE7, was un­veiled. Now patents have emerged that show how the two will be com­bined into a pro­duc­tion ma­chine.

Suck, squeeze, bang, blow

The Re­cur­sion used an SOHC, 588cc par­al­lel twin with a turbo mounted be­hind the front wheel. Blow­ing through an in­ter­cooler mounted un­der the seat it made 100bhp and an im­pres­sive 74ftlb of torque.

The XE7 en­gine is bet­ter still. While no fig­ures have ever been re­vealed, itõs a sim­i­lar size to the Re­cur­sionõs en­gine and uses a DOHC head, hint­ing at more per­for­mance. Itõs also pack­aged bet­ter, with the in­ter­cooler mounted above the cylin­der head to fit the whole thing into a smaller space. Im­por­tantly, the 2015 XE7 show en­gine was pro­duc­tion-ready; there were even vis­i­ble part num­bers cast into some of the com­po­nents.

Per­for­mance is hard to guess at since tweak­ing boost can make vast changes to the power of a turbo en­gine. Ex­pect at least 600cc sports­bike power lev­els com­bined with as much torque as a 1000cc su­per­bike, all de­liv­ered at rel­a­tively low revs. One new patent hints at a five-speed gear­box; the wide torque spread could make any more than that un­nec­es­sary, and fewer gears will al­low larger, stronger ones to be used.

Com­plete con­trol

Suzuki have filed more than a dozen new patents re­lat­ing to de­tails of the new turbo bikeõs frame, en­gine bal­ancer shaft and the cool­ing sys­tem. Gone is the Re­cur­sionõs alu­minium chas­sis, re­placed by a steel trel­lis that lets the ad­di­tional pipework of the forced-in­duc­tion sys­tem snake through holes in the chas­sis.

While the patents show Re­cur­sion­style body­work and a sin­gle-sided swingarm, these el­e­ments arenõt key to the patented ideas and could be changed for the pro­duc­tion bike. In terms of ap­pear­ance, for in­stance, the fi­nal bike is sure to get a pil­lion seat.

Hav­ing re­vealed steps to­wards its tur­bocharged fu­ture at each of the last two Tokyo Mo­tor Shows, in 2013 and 2015, it will be no sur­prise if Suzuki re­veal the fin­ished pro­duc­tion bike at the 2017 event this Oc­to­ber.

Re­cur­sion con­cept edges closer to re­al­ity

Par­al­lel twin XE7 en­gine could make as much torque as a litre su­per­bike

Lat­est patents show steel trel­lis frame

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