irc wrote:Some combinations just don't work. Especially with disc specific rims. As the rim is shallower there is less scope for working the tyre bead into the well of the rim to gain a bit of slack. I had a disc MTB supplied with. Nokian tyres. I ended up tossing them in the bin because even in a shed with plenty tools getting them on the rim was touch and go and took loads of force despite techniques that work with other tyre)rim combinations. Other tyres were a tight fit but went on with levers. I just couldn't face a puncture with the Nokians miles from the road.
As well as disc rims being shallow rims I suspect some rims are a few mn bigger or smaller than average. Likewise tyres will vary a few mm. If you get a "big" rim and a "small" tyre you will struggle.
I've no idea what variation there is between different batches of rims. Have you measured both sets of rims to see if they are the same? Ir tried fitting the 35mm tyres on the second set of rims?
My limited experience with disc specific rims was so off putting that if I was ever getting wheels hand built for a disc touring bike I would use normal rims with a brake track and deeper well. Obviously in some areas of cycling that is an unwelcome weight penalty.
The deeper but narrower well does seem to be a problem as the tyres just can't be forced into it. I even tried it without an inner tube, but that didn't work either. The Schwalbe tyres are recommended by Fulcrum, so they can't help with further advice.
I need 28/30 tyres on this wheel since it has to fit into a bike with mudguards. Identifying a tyre which will go into this rim is a real problem - I'm building a stock of unusable tyres at present, and I can see my wife beginning to look askance at my 'inexpensive' hobby.