I tried to fit the H2C riser to my Euro spec Rebel 500 abs, with the standard bars and struggled. There just isn't enough 'slack' in the brake master cylinder feed hose. I'm sure I could of pulled enough but I concluded this wasn't a safe option. In the end, I had to buy some other 'drag' type bars that do not have the backward rise of the originals.
The result sure looks good but is totally useless if you're wanting a more comfortable, arms not so stretched ride. The riser combined with flat type drag bars, produces about the same reach as the original bars mounted as standard.
Incidentally, I didn't have an issue with finding the extra bit of slack required in the speedometer cable.
In conclusion, for safeties sake, with an ABS Rebel, I would suggest that if you want the original bars with the H2C riser, you're going to have to get a new brake line made, with an extra 'inch' or so length.
But this is purely from my own experience, I'm sure that there are others who'll say otherwise... Suum cuique.
The best of luck.