I am relatively new to climbing, and so far I have only done bouldering climbing. The hardest route I have climbed is a V5, and I am a solid V4 climber. My question was, to anyone who has climbed East Bustress, how hard is it? From the ratings I saw, It converts to a V0 in bouldering scale, with the hardest parts being a V1. Is this accurate?
First, the difficulty of a V1 is not consistent everywhere, especially for climbers with limited experience. A V1 crack is a very different animal from a V1 slab. Yosemite climbs and boulder problems, especially in the V1 and 5.10 range are typically very stiff for the rating. These do not compare to gym routes or ratings.
The East Buttress starts with a chimney. If you have never climbed a Yosemite chimney, or any chimney, your day is over at this point even if you boulder V10. It doesn't matter if you lead or second this, making upward progress in the chimney is difficult.
The next pitch has crux which is a couple of moves on a thin granite face. A solid V4 climber who is not freaked out will dance this. The crack after the crux is not a cake walk if you don't know how to climb cracks. If you are leading, finding good pro is non trivial. If you make it to the second belay and are not leading, you should be fine unless the exposure gets to you. If you are leading, the next 200 ft (60m) or so has some run out sections.
While I don't generally think equating multipitch trad routes with bouldering is a good idea, the crux of the East Buttress on El Cap is a lot like a boulder problem. If it was on the ground, I think a V1 grade would be reasonable. The crack climbing is generally easy with an occasionally harder (i.e., 5.9) move. There of course is the additional difficulty of being a traditional climb that is long and exposed and sometimes run out.
Climbing technique wise, I am certain you are fine or need minor brushing up , most folks who get to a certain level of climbing and can boulder honest V5 would have enough in their tool belt and muscle control to tackle any given pitch or problem on a classic moderate trad route like east buttress.
However, Endurance and trade skills are something else. As a commenter says, it's apples and oranges.
Much energy is wasted by spending an extra 30/60 minutes per belay hanging around and being drained of energy in the sun, slow transitions, uncomfortable stances, slow and unsure leader, unfamiliar placements, slow rigging all combine for epic days where you spend 10+ climbing hours getting whomped on routes other mortals cruise in 2/3. As your energy gets drained you slow down even more, less efficient movements, just more plain suffering .
In my opinion , You would be best off cutting out any hard bouldering , which is counter productive for this endeavor, and switching to low intensity endurance training: traverses, doing laps of 5.8/5.9/5.10a and cracks , or alternatively 4 by 4s of V0/V1 in the gym or local crag until you puke
Keep in mind it's really easy to "french free" and pass a hard part by using gear as a hold, so being bad at any given style is less of an issue, but the sustained vertical endurance can't be cheated.
Success in most "moderate " multi trad is about efficient movement and transitions, high yield simple moves and techniques (stems, jams) , not really about that much advanced technique or fancy moves. Remember the OGs climbed this stuff with hemp ropes and hiking boots.
Your best bet is to go with someone very experienced so you can focus just on the climbing, in that scenario I have seen folks in your exact situation be succesfull.
The off width pitch would mean that a bouldering grade is just not applicable.
The difficulty of a multipitch free climb should not be assessed in just the difficulty of the climbing but also in the difficulty to place protection, the length and the level of sustained difficulty.
No you cannot climb this in any case as you as a boulder you do not know how to belay a leader, rappel, route find, lead climb, clean gear, palce gear, ascend a line, escape the belay.... the list goes on.
I have climbed east butress free. I have no idea why you are using bouldering grades as they do not apply to a multi pitch climb. The climb is rated 5.10b and includes a 5.9 off width pitch.
Its 11 quite long pitches and must be descended by rappelling the east ledges. A novice climber would be lacking so many required skills that the outing would be extremely dangerous and would probably end in rescue or worse.
All that said, its actually quite an easy 5.10 by Yosemite standards.