2008 SD990 Intermittent Speedo ??

Hi Guys , my problem is an intermittent speedo , just started happening today . Revcounter & all other electrics working but speedo stuck on 0mph then starts working again ..Just wondered if it's a common thing ? My front wheel rim is a bit buckled , would this cause it ? Bike is fitted with a Datatool alarm which I recently switched to "Winter Mode" as it was killing the battery ; I see a cable going to a sensor in the front wheel ...
Is there a workshop manual online ? Any help appreciated , Cheers John

Buckled rim ain't great but shouldn't affect speedo as sensor on lhs fork picks up brake disc fixing bolts to monitor speed - first step, clean face of sensor and disc bolt heads - if that doesn't work, could be faulty sensor, wiring, connectors or, worst case, faulty clocks - workshop repair manual is here viewtopic.php?f=18&t=16897 re location of respective parts and check procedures.

If its simply a case of a sticky speedo needle, clocks are relatively simple to dis- and re-assemble and there are post(s) on here re how to.