If your cams aren't in time, nothing else you do matters. You can chase a paper tear for an hour and not get a bullet hole. You can move the rest. You can twist the d-loop. You'll still be off because the two cams are hitting the wall at different moments and the arrow is getting a kick at the last millisecond.
Cam timing is the single highest-leverage thing on a compound bow. It's also the thing most shops skip.
What Cam Timing Actually Means
On a two-cam or hybrid-cam bow, both cams need to rotate the same amount during the draw cycle and hit the back wall at the same instant. If the top cam hits a hair before the bottom, the arrow gets nocked up or pulled down at the shot. If the bottom cam leads, the opposite happens. Either way, the arrow leaves with a vertical kick you can't tune out at the rest.
Modern binary cams (Mathews Crosscentric, Hoyt HBX, Bowtech DeadLock) self-correct better than old hybrids. They still go out of time when one cable stretches more than the other or when the cables settle after a hundred shots. Every new string on a Mathews ARC 30 goes out of time inside 200 shots. Every one.
How to Check It Without a Draw Board
You don't need a draw board if you have eyes and a phone.
- Draw the bow back to full draw. Hold against the wall.
- Have somebody photograph the top cam, then the bottom, from straight on. Same angle both times.
- Compare the draw stop position relative to the cable. On a synced cam, both stops touch the cable at the same exact rotation point.
- If one stop is buried in the cable and the other is barely kissing it, you're out of time.
Better: use a phone in slow-mo while a buddy draws. Watch the cams roll over. They should hit the wall in lockstep. If one beats the other, you can see it at 240fps.
How to Check It With a Draw Board
Crank the bow back slowly. Stop at the wall. The draw stops should contact at the exact same crank position. If you have to go 1/8 turn further to seat the second stop, that cam is leading and needs cable adjustment.
This is the gold standard. Every pro shop should have one. Most don't.
What Out-of-Time Looks Like on Paper
A bow that's out of time shows a tail-high tear that won't respond to nock point changes. You'll lower the d-loop 1/16, the tear stays. You'll raise the rest, the tear stays. That's the signature.
It can also show as a tear that's clean at 20 yards and ugly at 40. Because the timing-induced kick has more distance to express itself.
How to Fix It
On a Mathews or Bowtech with cable yokes, you twist the yoke leg on the cam that's lagging. One twist usually moves it noticeably. Half-twists for fine work.
On a bow with split cables and no yokes, you adjust the cable length itself by adding or removing twists from the full cable. Quarter-turn the cable on the lagging cam to advance it.
Always check ATA and brace height after any twist. If you've changed ATA by more than 1/8", you've gone too far on one side and need to back off and split the adjustment between both cables.
Why Shops Skip It
Because it takes time. Because customers don't ask for it. Because most customers don't know what cam timing is. So the shop sells them a new rest and a paper tune and sends them home with a bow that's still off.
This is exactly why The Forge exists. The software walks you through cam sync as step three of the tuning sequence — after grip and before center shot. You log your ATA and brace measurements and it tells you which cable to twist and how much. No draw board needed. No shop trip.
The Test
Pull your bow back tomorrow. Have somebody photograph the cams at full draw. If both stops aren't seated the same, your tune is built on sand. Fix it before you touch anything else.