How To Adjust Draw Weight On A Martin Compound Bow

Someone contacted me recently asking about my various chemical compound bow repair and tuning services.

Tuning Services

Adjusting the depict weight.
Adjusting the draw length.
Cam synchronization.
Reinforcing the peep sight (in the event it is loose).
Some newer models also allow you lot to tune the depict cycle to make information technology smoother or harsher, which effects FPS speed. Scroll to the * at the lesser of this post to learn more.
Etc. If I didn't list it here, just ask.

Although information technology actually depends on what the customer needs and what the bow is capable of. All bows take for example a minimum and maximum describe weight / depict length, and you tin adapt betwixt the two limitations fairly easily.

Information technology too helps if you have a re-create of the possessor's transmission with respect to changing the depict length/weight, as in that location are differences betwixt manufacturers and models, but mostly speaking there are certain similarities that are mutual to all compound bows.

A elementary chore like "adjusting the draw weight" I would argue is something that lxx% of the time y'all probably don't need me for. (It is the other 30% of the fourth dimension which yous exercise, and that mostly is due to more mod compound bows that allow y'all to radically alter draw weights.)

Below are two such bows:

The Bear Cruzer (left), which has an adjustable draw weight of 5 lbs to lxx lbs.
The Diamond Infinite Edge (right), which has an adaptable draw weight of 5 lbs to 70 lbs.

The Diamond Infinite Edge model came out in 2022 and it was the first affordable "broad range" compound bow which could be adapted anywhere from 5 lbs to 70 lbs, and with a draw length that could be adapted anywhere from 13 inches to xxx inches, with a maximum let off of 75% (actual let off varied on the poundage and draw length).

Simply attaining that wide range of adjustability meant the cams on the bow are rather complex, and the owner really should accept the manual before attempting to adjust it.

The adaptability and the affordable price of the Infinite Edge fabricated information technology very pop with new archers and old archers who but wanted a super-adjustable bow - that doesn't need a bow press to adjust. That popularity led to huge sales, and this did non go unnoticed by other manufacturers.

The Bear Cruzer model came out in 2022, boasting nearly identical stats, just with one extra inch of adjustable draw length (12 to thirty inches instead of xiii to 30). Every bit you tin can see from the photograph in a higher place comparing the ii, they accept a lot of similarities.

Besides in 2022, Diamond came out with the Infinite Edge Pro model and improved upon their design, giving the new version a maximum permit off of 80%.

Below is a close up image of the cam blueprint of the Infinite Edge Pro:

Looks pretty complicated, correct? And this is pretty standard for modern compound bows. Nigh all of them at present use a complex cam organization which requires the owner to be using the possessor's manual, or for them to hire someone who is familiar with fixing such things.

Next lets compare the cam system of an older model compound bow, and see how much has changed:

Look how simple that is. Not much complication, is in that location? The higher up cam actually only has 3 settings, and they are all for adjusting the draw length. See the following post to learn more than.

How to Suit Depict Weight

Adjusting the Draw Weight on older compound bows, and to a large extent on modern compound bows actually comes down to adjusting the limb bolts (shown on the correct).

If you want a lighter poundage you turn the bolts counter-clockwise, starting with the top limb bolt and so the lower limb bolt.

If you want a heavier poundage you lot turn the bolts clockwise, starting with the bottom limb bolt and then the top limb bolt.

I recommend turning either by 1/2 turns or 1 full turn each time, keeping both the meridian and bottom even in a progressive manner. It takes longer, but it is safer for the bow. Do non turn the tiptop bolt say 5 times or more all at in one case and so do the aforementioned with the lesser bolt. Making sudden rapid changes similar that puts extra strain on the bolts, the limbs and the cams. You desire to suit it slowly and safely.

If yous think you have reached your desired weight, you can check past drawing back the bow and meet how comfortable or hard information technology feels. (Having the Owner'south Transmission is handy at this stage for determining the poundage.) Y'all and so repeat this process until you reach a draw weight that feels right for you (or measures the desired corporeality on a bow scale).

If you don't have an Owner's Transmission, merely you desire to exist really precise, then you volition need a bow scale.

I utilise a 100 lb digital bow scale from Allen. I employ it both for adjusting draw weights on compounds, merely also for the tillering procedure when I am making longbows and flatbows. When tillering a bow, it is very handy to have.

Costs about $32 CDN on Amazon.ca. (This is but info, not a paid promotion. Notice the lack of links.)

But turn information technology on, attach the claw like you would a mechanical release, and then pull back until you reach the allow off bespeak.

The scale and so tells you the peak poundage that was reached during the draw bike (or change the settings and it will tell you the belongings weight).

And then yes, if you really want to mensurate the precise poundage then you volition want a digital calibration. (Likewise works well for weighing babies and toddlers who don't want to stand still.)

So what do you lot need a Chemical compound Bow Repairman for then?

Honestly, most of what I do is Not tuning. I can certainly practice it if the customer needs me to, but repair work is usually things like:

Reassembling a chemical compound bow that has been dryfired and is at present in pieces.
Restringing a compound bow that has been dryfired and the cord and/or cables roughshod off.
Replacing parts that are cleaved, aptitude or otherwise damaged.
Etc.

I also find that some places refuse to do certain types of repair work and try to sell the client a new bow instead. They see an older (possibly vintage) compound bow, they think it will be too hard to repair, and they don't want to bother trying to repair it when they could just sell yous a new chemical compound bow instead (and go a commission).

In my case, I typically don't sell chemical compound bows. I will sometimes purchase compound bows for parts, or buy compound bows, repair them and then sell them, but near of the time my "stock of compound bows" is limited to my personal bows that are not for auction. So there is no motivation for me to sell a customer a brand new chemical compound bow, because I don't sell such things.

I also really savor the procedure of fixing compound bows, especially older / vintage models. And then to me function of the fun is taking something old and cleaved, and fixing it again. (Often I besides clean it also, so it looks shiny and new-ish in photos and when I give it back to the customer.)

I don't know of anyone (anywhere!) who is into repairing vintage compound bows.

So do you demand me to arrange the draw weight on your compound bow?

If it is an older model, you can probably do information technology yourself just by adjusting the bolts.

If it is a modern model with a larger variance in the draw weight, you probably need to read the owner's manual or you lot will need a repairman like myself. Y'all can certainly try to adjust it yourself using just the limb bolts. If the variance in draw weights is comparatively small (say 40 to 60 lbs, instead of 5 to 70), then you lot probably won't need me at all.

* Adjusting the Draw Cycle

So you might take noticed that way up at the top I mentioned that some new chemical compound bows (mostly that came out within the last ii-3 years) also have an choice to adjust the draw bicycle of the bow. This adjustment allows the archer to choose between.

A harsher draw cycle and a harder wall earlier reaching the let off, which stores more kinetic free energy and offers more FPS speed.
A smoother depict cycle and softer wall before reaching the let off, which offers more user comfort and less FPS speed.

Thus the archer can peradventure start with a smoother draw cycle and a lower poundage, and as their strength grows they can arrange the settings and so that it becomes harsher / faster as they progressively get stronger.

People with shoulder and/or dorsum problems may as well wish to utilise the smoother settings.

The compound bows that currently offering this feature typically cost $1,000 CDN or more, and it is a detail type of person who spends that much on a compound in the first place. Typically, such a person also buys a new compound every year or every two years, and their onetime compounds stop up collecting dust in a closet or in a example waiting for the day when its owner might be struck by the thought of "Hey, I should shoot that old Hoyt or Matthews sometime."

Adjusting the Draw Cycle on 1 of these modern chemical compound bows is no more complicated than adjusting the describe length - provided of class that y'all accept the owner's manual.

Never, ever throw away the owner's manual.

Sometimes you can find a copy of an owner'due south manual online, but there is no guarantee yous can find it. So please don't throw them out.