Help a newbie who's 'changing codes'!

2mm on tyre width won't make any significant difference. I'd try lower pressures initially (60-80 psi), so they have a bit more 'give', in case that helps make it feel a little less of a knife-edge.

Make sure the bike fits you properly and is set up properly - saddle height etc. A higher handlebar position will feel more secure than running with a low stem or riding in the drops.

Do some skills practice somewhere safe like a car park, or an imagined slalom course. As others have said, road bike handling feels sooo different from MTB but it's merely a recalibration of input, feedback etc, not totally relearning how to ride. Same goes for braking and shifting gears, but some time practising these without worrying about traffic etc will soon make you more confident. The more miles you do the more natural it will feel, so get out there!

One other thought, with a road bike steering is almost leaning, weight on the bars will turn the wheel, rather than turning the bars. Quiet flat-ish roads and practice riding one handed, you'll get the hang of it. Then there is the joy of learning to switch from hoods to drops. I agree with JonSP, I can ride with no hands for much longer on my road bike now than my mountain bike, though the MTB feels more stable initially. Lastly get your LBS to check the headset is greased properly at the first service. I had mine serviced recently and it helped a lot.

I've noticed a couple of times recently that I've nearly lost the front wheel on my MTB when using it to commute to work when nipping through traffic. I think because when I'm on my road bike I shift gears less due to using unindexed gears on the down tube, so when on the MTB I can thumb shift and keep both hands on the bars and my head up. This means though I'm in a higher gear when I go to stamp down and accelerate away, I'm kicking up the front wheel a little bit, fine and barely noticeablein a straight line but a bit of a "whoah there!" moment when turning slightly with (invariably) a Germanic Crushing Death Machine breathing down your neck.

Same as you Wingfoot, when you get used to seeing a smaller tyre in front of you and get ion the MTB, wow a HUGE tyre and wide bars

MTB and Road riding are very different so twitchiness when riding a Roadie is expected. I made the switch to Road about 6 years back, and I remember my first foray down a hill (geez, where do my hands go? Is being hunched over like that normal? Where are my brakes? Woah, that sure was hairy) LOL... So yeah, do not worry about what you are experiencing, it's perfectly normal.

Some advice would be to set your bars a little higher (same level as your seat at best). And gradually lower the bars as you get more comfortable with the position. You will get the hang of it after a couple of rides. So hang in there. I would not change the tire width, as it really isnt going to make it less 'skitchy'.

I ride both MTB and Road now and actually find it weird getting back on the MTB. So the main issue is probably a case of getting used to what you are used to doing. No worries!

Agree with all of the above (apart from the rollers, far too much like hard work). Get out when the roads are quiet and take it easy. After a couple of sessions, you'll wonder why you were ever concerned.

Perhaps easier said than done, but make sure you are relaxed, part of the skittishness is likely to be your tension, not the bike. Make sure you're not gripping the bars with a death grip and that your arms aren't locked.

I wouldn't bother with 25mm tyres, it's really not going to make a difference.

Relax and enjoy

I still get that feeling if I haven't been on the road bike for a while. Earlier this year after a week mtb'ing round Menorca, first time back on the road bike felt quite wobbly. But you do get used to it.

And actually it's more stable than you think. My road bike is probably easier to ride hands-off than the mtb – which does seem to confirm that a lot of the 'skittish' feeling (good word BTW) is down to the narrow handlebars.

The more you ride it, the more 'normal' it will feel.

So, the only answer is to get out and ride. I would suggest getting out when the roads are quiet e.g. 6.00am on a Saturday / 7.00am Sunday. A nice empty road should help build confidence.

I love riding at these times - blis

I changed from a tourer to a race bike a couple of years ago and it took me a while to get used to the feel of the shorter wheel base - particularly going downhill I felt as if I was on the edge of control which sounds similar to your 'skittish'. The shop the sold me the bike told me to take it easy over the first few rides because it would feel so different. Two years on and the road bike now feels normal and it strange when I'm back on the tourer.

One thing that helped, I think, was using rollers in the winter which improved my balanced particularly with pressure on the handlebars - as smaller wheelbase and handlebar width mean small movements effect the bike more. However, as Darthshearer said, give yourself time to get used to the difference and hopefully it will soon feel fine.

Can you be a little more accurate than "skittish"?

You will notice more bumps and road imperfections due to no suspension. You also have a smaller handlebar width so controlling is different.

You have only dont a couple of short rides, give it time, youll get used to it