I'm doing the Transpennine Trail route from Sheffield to Manchester. I'm going via Dunford Bridge and the Longdendale trail, as I'm on a SS cross bike and doing it for the journey rather than the challenging terrain.

What's the ride like from there to Manchester?

The TPT proper goes through Stockport, which is manageable as I'd be following that trail. But I fancy Manc, so what's the run like? And how long is it likely to take from the top of Woodhead?

It's pretty bleak and very boring. I'd highly recommend coming in to Stockport and then taking the trail out along the banks of the River Mersey up to the other side of Sale Waterpark and then heading in to town from there over going straight in to town from Woodhead'ish.
We're doing Manchester to Sheffield on road, Sheffield to Manchester off road again only coming back via Cutgate in a few weeks if you fancy joining in?

pretty bleak and very boring.

By bleak do you mean 'rough'? I'm just thinking of different but not dangerous rides to do in the daytime while I'm unemployed, so boring isn't really that bad. Traffic free but not extreme. Towpaths, railway trails and the like are about perfect for gentle solo riding. I love the Peak proper but I'm not doing solo rides midweek out there.

We're doing Manchester to Sheffield on road, Sheffield to Manchester off road again only coming back via Cutgate in a few weeks if you fancy joining in?

There and back might be a bit much for me at the moment. I was thinking of riding one way and catching the train back.

I'm on the waiting list for ankle surgery – if I'm not on crutches by the time you do it, I could possibly join you for your return leg and catch the train back. Thanks for the offer, keep me informed, I might be up for it :o)

TPT from Woodhead is mainly only train line all the way into Stockport, to get into the city centre from Stockport you're on the A6 really.

What you could do depending on time and inclanation is head to Marple and get the canal via Ashton. None of it is going to set your world on fire but if it's a pleasant jaunt you are looking for it's not too bad.

I'm planning on going the other way at some point to Worksop

Bleak as in very industrial surroundings and derge type of countryside. It's not a pretty section but utterly flat and non bumpy.
Flying in the face of what Flash says (which I do at every and any opportunity just for the fun of it :-} ) I would stay off the A6 whenever possible past Heaton Chapel in Stockport (and i say that as confirmed liker of road riding).
You could do as mentioned ride the canal right into the city centre from Marple which goes past God's own football club or take the TPT along the banks of the River Mersey which is quite pleasent for a flat ride.
Before I go though, if you decide to ride the canal(s) to Manchester (or Workshop(sic) Flash) – go early or it will take days and days. I did the Cheshire ring setting off at 5;30am and it soon got it done no problem but set off to ride down to Bristol via the canals from Marple at 9:00am and it took 5 hours to get to Alsager! I was stopped more than I was started with chatty people on the canal tow path.
I binned it and went on the A roads instead.

Picking up the canal from Marple to Manchester centre sounds like a good call. With a sunrise start from home it'll be late-morning (on a weekday) by the time I get that far, I would have thought.

I'm really only doing it for the journey. Just an itch I need to scratch, not looking for anything adventurous. I quite like industrial stuff, just spent the morning on my bike exploring the rivers, canals and general industrial dereliction of Sheffield.

Thanks for the info chaps, much appreciated.