What’s the issue here, why don’t they work ❓

Don’t they? I had a pair on a Day 1 SS briefly .. quite liked it but the tyres were too skinny )

Your hands would surely end up in the wrong place? CX frames being designed for drop bars, Jones bars would bring your hands out wide, but quite far back. Still, it’s going to be down to personal fit/comfort.

Ah. Just curious. Last year I milled out some Deore hydro levers and ran the on Midge bars on a Croix De Fer. Worked alright.

Have you thought about/tried Woodchippers?

Just had a look. Here’s what I did, and it was easy in use. Idealy I want a Jones type bar that throws the straight grip sections forward.

Oldgit – how much did you have to mill from the lever clamp to fit (what is the difference in diameter between MTB and road brake clamps, I know the road ones tighten down, or between the bars at that point?)? Was looking at doing similar on my cross bike as have spare hydraulics, and the lever position between some disc levers and road levers actually looks fairly similar… Yours look as though they were sticking out a little, could you fix that by adjusting the reach? How were they to ride in terms of hand position etc?

I can’t recall the actual difference, but it’s very little.

There’s no way you could do it with normal drops as they would throw the levers out too far. Those bars are designed to be ridden in the slight drop, and reaching the lever was easy. They might look like they protrude a lot, but they didn’t. And I could easily wrap my fingers around them, but because the braking seemed so powerful I only needed to use one finger.
If you wore gloves you could simulate riding on the hoods.

mountain bar diameter is 22.2mm and road bars are 23.8mm, so 1.6mm in dia, 0.8mm off the thickness of the clamp all the way around. Really depends on the brakes as to whether you are likely to have this to ‘spare’. Though TBH brakes are one of the last things I’d want to fail while riding….

As to the initial question – of course there’s no reason you can’t, just it’s likely to result in too upright a position. the newer jones bars which sweep forward a bit would help in this respect. As above, I’d recommend looking at Ragley Luxys or Salsa Woodchippers for bars which give a similar hand position but are more likely to work with CX geometry.

I put some jones original h bars on a cx bike, made it feel like a hybrid.

Switched to on one midge and they felt a lot better.

Had some on a Roadrat and it worked well.
Saying that it was a commuter bike not a CX.