My VO 25.4mm stem has about 1mm clearance top and bottom between the cap and stem with Nitto Randonneur 25.4mm clamp diameter bars installed. This was also true with the same bars in a VO 26mm stem using the 26.0mm stem to 25.4mm bars shim that VO offers. No noted bolts bottoming out.
Regardless of the bars listed diameter I would double check them. If the bolts are bottoming out in the stem threaded holes I would shorten them very slightly, only 1mm or less. Be careful to not bugger up the threads on the bolts when doing so.
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Gear Hubs Owned: Rohloff disc brake, SRAM iM9 disc brake, SRAM P5 freewheel, Sachs Torpedo 3 speed freewheel, NuVinci CVT, Shimano Alfine SG S-501, Sturmey Archer S5-2 Alloy. Other: 83 Colnago Super Record, Univega Via De Oro
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