... quick photo of the one I have- it looks as though you can move the "arms" out to the wider hole spacing for bigger wheels, though I was using it on 17mm dia. quite happily at the smaller setting. cheers Richard ps. not been "dipping into" the Templot Forum quite as frequently as before- bit of a hiatus here as I have finished all the pointwork for Singleton and can't do much more till I have made the baseboards, which requires me to clear the garage...1763_250452_090000000.jpg posted: 4 May 2015 01:31 from: Andrew Duncan Hello Rob and Richard Yes I also have both these tools from George Watts and I don't know what I'd do without them. I've certainly used the puller on wheels up 6'8" in 4mm (26 ish mm) so your 21mm wheels are well within its capacity. Kind regards Andrew Parts of Templot Club may not function unless you enable JavaScript (also called Active Scripting) in your browser. Templot Club> Forums> Off track> Gear/ Wheel puller ...