The chin-up bar that forms part of the rack – as much as I love it – was just too thin. At a diameter of around 2.5cm/1″, it was one of the thinnest bars I use.
Fattening it up a little was a relatively simple (and cheap) process, involving nothing more complex than a length of pipe insulation (just rubber tubing), some super glue and a little cloth tape. If you’ve never used the tape, think of duct tape with fibres embedded to strengthen it a bit.
The final bar is now a little under 5cm/2″ in diameter (not quite as large as I’d like, but much better than it was), and presents just a little more of a grip challenge.