Is it possible to ride up 30% on a 34x28 compact?

Depends how fit you are! I've done Hardknott/Wrynose on 38x24 - all there was available for road bike 20 years ago.
Scrubbing off speed coming down was more of a problem!

34/26 on Hardknott Pass = no dabs
Wasn't bothered about time just getting up the hill without walking.

Just in case these may be handy (or the SPD-L equivalent)

http://www.wiggle.co.uk/look-keo-cleat-cover/

i am crap at hills and did the etape cymru on 34/28. this had similar switchbacks. always choose the outside lane, it is alot shallower than the inside. i deliberately slowed down in the granny gear between the switchbacks so i had a little more to give and i could choose my line as i approached the hairpins. i also used the granny gear from the bottom and deliberately went slowly, say 75% effort. you never know how far it is to the top! I occasionally passed collapsed riders who had overtaken me at the bottom of the big hills. satisfying.
I learned this technique/ limitation from a weekend in the peak district and failing 3/4 up a big hill. had to lie down for 5 minutes to get the lactic acid out of my thighs. i was then fine for the next 50 miles.
also, im not sure what`s to be gained going lower than 34/28. you may just pedal faster and get just as stuck/tired.

The cymru stretched me, Im not sure I could do the FW without getting off and walking, which, for me, would be a fail. I defo want to go cycling in the lakes though.

Good luck!

I'm with Gizmo, learn to track stand...on the steeper bits you'll grind to a halt between pedal strokes so it's really all or nothing, but it's ride-able.

The hardest thing about the Fred is that you already have 90 miles in your legs and there'll be a lot who are walking up Hardknott, so the temptation is there. Grit your teeth and refuse to get off!

I managed to do it last summer on a 34x28 and I was far from being in top condition (I only took up cycling as a proper sport about three months beforehand), or in possession of a super light bike. Hurt like hell though!

Just be glad you aren't riding the FW on a fixie:

http://www.lakesroadclub.org.uk/events/the-fred-whitton-on-fixed/

Maybe a slightly different approach, but maybe you could ask "what setup will get you up most comfortably and let you enjoy the whole experience more?"

The steepest hill I've tackled to date is Barhatch with its claimed 25% ramps. I rode 39/23 simply because that was on the bike I was using at the time and it turned out the ramps were short enough for me to come out of the saddle and not be a problem.

I am convinced though that a lower gear would have been a)more comfortable, b) save energy (spin vs grind) and c) be quicker overall.

You don't HAVE to do it in the hardest possible gear. Just a thought.

I've only come across the odd 30% ramp so far, but regularly do 20-28%ers on my 34/28 with no problems whatsoever, had even been considering a 25 (but decided against it purely for my knees' benefit - it's hilly as **** over here). Have no fear, conquer it!

It'll be hard and it'll be slow. Learn to track stand... if you can stop without falling over, it doesn't matter how slow you're going

When I was very young, I did LEJOG with a TA triple (can't remember the exact gearing but it was very low) and, although I successfully road up some seriously steep grades in Devon, my new Sedis "narrow" needed replacing by the time I got to Bristol.

Even if I could do the Hardknot, which I know I couldn't at my age, I don't understand the need to put that much strain on a transmission, when walking up can actually be faster when things get really steep, especially when you consider that the extra weight (and probable slight reduction in areodynamic efficiency) of a wider range of gears is something that you have to "carry" all the way round the course.

Also, I don't know whether it's my imagination or my age, but I think that walking up some of the really steep bits actually improves my overall times, perhaps because of giving certain muscle groups a rest, if I can put up with a bit of ribbing from my mates.

what, no one done it in the big ring yet?

Its not worth worrying about. You'll be able to get up it. I've never used anything smaller than a 39:25 and not walked yet, or even thought about walking. 68" on birdlip pretty much gave me a double hernia though.

I did it on 39 x 28, but with a cadence of about 40, and a lot of gurning. It was hard work, but possible, as said before it's all about choosing the right line on the key switchback, and working out how to get up enough speed to not have to pedal hard over the cattle grid.

My advice, for what it might be worth, would be to go and try it first! Then you will also know what the right sort of lines might be, and more importantly, where the recovery sections are.

Did it last year on 30x38 on a heavy bike, definitely possible just a matter of whether you can turn the gear so do some strength training. the switchbacks are the steepest so line choice is really important, snake all the way!

A 14 stone friend recently done it on a 34-30, he has only been cycling seriously for 18 months, so I would say a regular compact no problem.

also, I've been at this 30 years and although I've not done the Hardknott pass myself, a 42 - 28 was considered a girly gear back in the day. Since I've been older/fatter I run a 39 -28, which gets me up almost any road, though nearing 1 in 20, I'm really struggling and away down at 4 mph.

Zoncolan's 1000m+ though, and he spins a fair bit faster than us mere mortals when he goes uphill, I suspect.
Strava reckons the average for Harknott is 12% with 30% ramps... Zoncolan's 13% for it's ascent with 25% ramps.

Anyway, you'll be fine. You don't like your lungs or your legs anyway, and they'll hate you afterwards. SO it's all ok really.