just got my 101st airborne by bowtech! set at 55# 29"draw a 275grian arrow 306fps then i chang my valley by 1/8" and loss my speed why is that[:@]

What arrows set up are you shooting at that length that you got 275grs finished?

Ya that's a feat. What do they got on the front? 40 grain nibs? Are you sure you don't mean 375?

29"in. arrow finish. gold tips ulights 500 80 grain tips

kg, kudos on the light arrow man. Question though, how is the flight? That seems on the line between needing a 400 rather than a 500. Different bows like or dislike more spine. I know my 101 seems to like a little stiffer shaft. To your original question though, how much speed did you lose?

about 20fps. if you use a light tip like a 75grain you will stiffen up the spine a heavyer one will weaken it. the flight is awsome 1"groups at 60 yds.

Unless I'm missing something even a GT UL500 cannot get down to 275grs finished.....the reason I'm asking is even at 55# 306fps at 29" 5grs/lb of draw sounds slow.

GT UL500 = 6.3grs / inch X 29 = 182.7grs
Tip = 80grs
Factory .246 nock = 10.4grs
Factory .246 insert = 14.6grs

Finished arrowbefore fletching = 287.7

Example three 2" Blazer vanes weighs 15grs itself, so even with feathers your finished arrow would be mid 290's and with even small vanes like Blazers around 302ish grains.

What did you fletch them with and did you actually weigh them or were you TOLD they weigh 275grs?

You're saying you lost 20fps by changing your valley 1/8" and you can shoot 1" groups at 60yds.

Sorry dude I just spit the hook.

That's nice, your arrow has enough momentum at 60 yds to split a few hairs

20fps? You need to shoot it more than once through that thing. Might have been a false reading.

Germ, basically said what I think about the arrow.