# Draw weight vs riser length



## Razith (Mar 24, 2013)

I think the general rule of thumb is + or - 1 pound for each inch you take/add to the riser. So limbs for a 17 inch riser, rated at 50#'s, on a 25 inch riser would be close to 42. That's just the rule of thumb though, it will change i"m sure from limb to limb and riser to riser.


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## Viper1 (Aug 21, 2003)

va - 

If you are talking about Tradtech BM limbs, they will be 4# lighter, not 8#. 
Due to differences in riser limb pocket angles, the limb weight rated on a 17" Titan riser will have the same weight on a 21" target riser, such as the Excel. Since you're going to a 25" riser, drop 4#.

If you're talking about custom limbs, all bets are off and you'll have to talk to the bowyer.

Viper1 out.


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## Razith (Mar 24, 2013)

Hmmm...that's interesting Viper. My Tradtech BM"s are pulling about 43 on a Sebastion forged, and about 48 on my excel. Perhaps it's just the limbs. Good to know about the limb angle, thanks.


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## grantmac (May 31, 2007)

The BM limbs will lose 8# going to the 25" riser, I've seen two different sets on two different risers do it.

The 21 and 25" Excel run fairly slack pad angles so they pull close to the same as a 25" riser, at least when I scaled them.

-Grant


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## vaguru (Jan 2, 2003)

Those are the limbs I'm referring to, in long on a SF Forged riser. Would like to get close to 41# with limb bolts maxed out at 28".

Not in any real hurry, may have to wait for other limbs to arive at vendor. Just thinking I would like the black limbs better than white.


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## Viper1 (Aug 21, 2003)

Grant - 

There is no 25" Excel, that would be the Horizon. All Excels and the Horizons and most of Hoyt's risers use the same limb pocket angles. A lot of the Koreans use the same as well, but I haven't checked all of them. The only real difference is with the shorty hunting risers, where the angle change is required to prevent stacking / over stressing. Remember that bolt position will make a difference. 

va -

Odds are you are going to need 45# BM limbs to get a 41# draw weight on a 25" riser. Happily, you don't have to guess about it. Call Lancaster Archery and ask them to assemble a rig and check the weight. John Wert is a good contact.

Viper1 out.


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## n.negron169 (9 mo ago)

vaguru said:


> Looking to put limbs designed for a 17" riser on a 25" riser. What will happen to the DW? I know the length of the bow will increase the 8" difference of the riser, but have no idea what will happen to DW.
> 
> Thanks in advance.


what about limbs rated for a 25in riser on a 17in riser. does the same rule apply?


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## stick monkey (Mar 9, 2015)

In reverse…you would gain 1 pound per inch of riser length. Rough estimate only…I have had a few different bows and 4 inch difference was always 4 pounds. Had a 19” Morrison riser with 32 pound Hoyt limbs that were rated for a 25” riser and they scaled 38 in the middle setting. Limbs by most manufacturers can be +/- a pound or 2…I guess everyone may get a little different depending on how close they are actually rated to their actual draw weight


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