No chinups, still gaining weight and strength though

[beast]

I am on the novice progression again after resetting and messing around with westwide programs i pissed around and made very little progress and lost strength on squats and presses. I saw A.C videos and now am inspired to get up to higher weights in the novice program which is working.

However currently i can't do any chins at the moment, and doing negatives doesn't seem to be helping, and gaining weight makes this virtually impossible. How do suggest i implement this pulling work? Would it be better to stop trying to gain weight as i am about 20% bf(possibly higher). However i realise i am not very strong, but eating well my progress is going rapidly again, and all previous stall points have now gone. I effectively wasted 6 months got fatter and not stronger.

Stats if useful: weight 253, 6-4, 17years old

195 bench for 5's
165 for 5 press
1 rep max, 505 sumo deadlift (changed to these after rounding all the time, this lift is much stronger in relative terms than others, sumo and long arms is probably the reason)
300 squats for 5
175 power clean for 2

What do you suggest?

Thanks

[Mark Rippetoe]

I'd suggest you stop doing sumo and go back to deadlifting the hard way to get your back actually strong. I'd suggest you clean your diet up a little, and that you keep working on the chins. At 17 you're very young, so we'll excuse you for this hole in your strength, but your upper body needs to catch up and chins are an important part of this. Get some bands.