Crash bungs
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Something like this would do the job, you'll have pleanty spare at 100cm, https://www.ebay.co.uk/itm/M8-M10-M12-1-0mm-FINE-PITCH-Threaded-Bar-Rod-Studding-Full-Nuts-Washers/292737174175?var=&hash=item44287eca9f
Just select M8 diameter as it fits the drilled axles rear axle nicely. You might want to check the diameter of the drilled part of your front axles mind, I don't have standard forks and axle so it may be slightly narrower and need drilled out for the bar to work.
Also you'll probably get the threaded bar and nuts allot cheaper from a local firm, I think I only paid a couple quid if that.