Effect on draw weight?

Brian P. · November 25, 2015, 06:59:00 PM

When switching limbs to different length risers, how is the draw weight affected. Thinking of taking limbs from a 60" bow and putting them on a 62" bows riser. Both bows are by the same maker, of course. He changed bow length by changing length of the riser. All limbs were the same.
Is there a general rule as to how much limbs will gain or lose for each 2" of length? Such as 53# limbs from 60" to a 62" riser will cause a draw weight of?

FAV 52 · November 25, 2015, 07:29:00 PM

Good question Brian ! This interests me too .

monterey · November 25, 2015, 07:50:00 PM

It's going to drop a bit, but I'm not sure how much or how to calculate it. If I were going to take a SWAG, I'd guess about two to four #. If you have both risers handy It would be interesting to have you measure It.

McDave · November 25, 2015, 07:53:00 PM

I recently bought extra limbs for my Schafer Silvertip recurve. The limbs were listed at 40# assuming they would be used on a 17" riser. On my 15" riser, Dave said they would come in at about 42# (I haven't received them yet).

BigJim · November 25, 2015, 08:14:00 PM

Depends on the builder. I specifically designed my recurve risers so the draw weight Wouldn't change from 16" to 18" risers.

Bear td is two lbs from a to b riser.
BigJim

November 25, 2015, 08:22:00 PM

Generally one pound per inch of bow length.

**DONOTDELETE** · November 26, 2015, 12:00:00 AM

Its going to vary on the limb design and bowyer/ manufacture. Same exact limbs will vary between 2-4 pounds for 2" of riser.

Hermon · November 26, 2015, 07:36:00 AM

QuoteOriginally posted by BigJim:
Depends on the builder. I specifically designed my recurve risers so the draw weight Wouldn't change from 16" to 18" risers.

Do you accomplish this by varying the limb pad angle?

Brian P. · November 26, 2015, 08:46:00 AM

Thanks guys.
I don't have both risers just yet. Got a second Assenheimer coming that I got on the secondary market. It is 49# @ 29" 62" bow. My current Assenheimer is a 60" 53# @ 28". I am hoping by switching limbs between them I will end up with two bows around 50# @ 28". That seems to be my comfort zone now days.

ProAlpine · November 26, 2015, 09:57:00 AM

Interesting question...

Forgive my ignorance, but would someone explain how riser length effects draw weight with the same set of limbs (or doesn't as in the case of Big Jims).

Thank you!

Brock · November 26, 2015, 10:26:00 AM

...i believe it is because depending on riser design it affects the draw amount the limbs are ACTUALLY FLEXED during the draw for same length draw....more flex is more weight, less flex is less weight...plus will have different length strings and string angle at full draw. Not sure they all affect weight but may also affect performance to some extent....all other things being equal.

wingnut · November 26, 2015, 11:35:00 AM

In ILF risers the rule of thumb is one pound for inch of riser. Shorter is more and longer is less.

Our bows are engineered so that the limbs remain constant weight with all riser lengths.

Be careful changing limbs on bows that are built and fitted by hand. Each set and riser is unique and may not work with others.

Mike

wingnut · November 26, 2015, 11:36:00 AM

In ILF risers the rule of thumb is one pound for inch of riser. Shorter is more and longer is less.

Our bows are engineered so that the limbs remain constant weight with all riser lengths.

Be careful changing limbs on bows that are built and fitted by hand. Each set and riser is unique and may not work with others.

Mike

**DONOTDELETE** · November 26, 2015, 01:23:00 PM

QuoteOriginally posted by Brian P.:
Thanks guys.
I don't have both risers just yet. Got a second Assenheimer coming that I got on the secondary market. It is 49# @ 29" 62" bow. My current Assenheimer is a 60" 53# @ 28". I am hoping by switching limbs between them I will end up with two bows around 50# @ 28". That seems to be my comfort zone now days.

Are these bows designed for interchangeable limbs? If not... i would heed Wingnuts warning.

Brian P. · November 26, 2015, 05:58:00 PM

Yes, Assenheimer would accept different limbs. In fact, I used limbs off a 64" assenheimer on my 60" riser while Don was making limbs for it. I bought the 60" as a stock bow but the limbs he had on it weren't what I wanted. I took the riser home since I had other limbs available and just waited on him to make the limbs I wanted.
As far as I know, all of Dons limbs were the same, just the length of the riser varied.