n81

It's manageable but boring as hell if you're on your own. As Lumen says there are alternative routes which are harder but not as mind numbing.

If you're going over the M50, there's a pedestrian/bike underpass that you should use, I wouldn't use the main roundabout.

I cycle out the N81 quite regularly and don't find it too bad, though it's generally Sunday mornings when it wouldn't be that busy anyway. There is a wide hard shoulder along a lot of it which is fine to cycle in, the bit just after Jobstown when it starts to rise is narrow but doesn't last long. That roundabout at the m50 is a bit intimidating but it helps that it has traffic lights. Give it a go when it's relatively quiet and decide then if you want to use the alternative.

Was coming in the N81 on saturday and was caught in big downpour . Coming along the road there was slurry being washed out onto the road from a farm yard, by the rain, had no choice but to go right through ........

It's mainly national roads so they can be busyish. I've gone as far as Baltinglass and back. But I've also done from Clonegall to Enniscorthy, just typical N roads and N road traffic. Just haven't done the middle third but wouldn't expect it to be much different to first third and last third. Depends how quickly you get bored 🤣

Hard bit is always balancing the difficulty of the route with the scenery. N-roads are boring but usually flatter and shorter than any other route.

Go up over Sally Gap, down to Glendalough, Rathdrum, Aughrim, Carnew, Bunclody, Enniscorthy. About the most direct without an N-road, but not for the faint of heart, quite a lot of climbing. You could skip around the hills to Enniskerry, Roundwood and onto Glendalough. It's a bit further but a bit flatter.

If you like coastal routes, then sticking to the R-roads from Bray to Greystones to Brittas bay, Gorey, etc, is flatter again, but adds quite a few KM to the trip.

I've done it a few times from Tullow to Dublin. It can be busy but it's nothing mental. While the scenery is good, there are more scenic options but if time is important then, for me, the N81 would do the job. Plenty of places to stop for a quick sambo if needed.

Cycled down the N81 Friday, was pretty much a headwind the whole way which made it tough. Was quite a few lorries and trucks up until Blessington and then calmed down. The N80 to Enniscorthy had some nice scenery but again lots of big trucks going past at 100kmh. Probably wouldn’t do it again.