[RECURVE] Easton Contours - how to you switch to the larger 5/16"-24 weights?

chemistry

Member
All,

I am struggling to switch the weights on my wife's Easton Contour stabilisers from the traditional ??-20 weights she has been using, to the larger 5/16?-24 weights :duh:

As I understand it, to switch to the larger weights, I have to unscrew the ?stud? at the end of the long rod, then ?either reverse it (for a single or 4 ounce weight stack) or install the longer 5/16-24 stud included with weight stacks in other configurations.? (Radical new stabilizer from Easton- 2015 Contour | Easton Archery).

Unfortunately, I am having some problems configuring the stabilisers/weights in this way!

Firstly, the stud can?t easily be reversed as it only has a hex-bolt socket on one side (the smaller side); if I flip it round so that the smaller thread goes inside the long rod then there?s no way to tighten it up using a hex key.

Secondly, all of the bolts supplied seem too short to be secure. For example, if I remove the original ?reversible? adaptor and add a 5/16?-24 base weight using the (short) threaded bar that comes with it, only about 5 turns (~5mm) of thread can go into the longrod and the same into the weight, which doesn?t seem very secure. If I then try and add (say) a 4oz weight on top of that (again, using the supplied thread), I face the same problem, with each weight being secured with just a few turns of a thread.

Overall, the whole arrangements seems confusing (i.e. the lack of a hex bolt on the large side of the reversible adaptor) and somewhat insubstantial (as each weight?s threaded bar is separate and very short). If I compare this to (say) my own Shrewd stabilisers, in that design there?s a very long threaded bar that moves in and out of the end of the longrod and connects all weights on a single piece, which seems much more secure, so I?m worried that I?m missing something with the Contours!

So, please can you tell me, am I configuring the Contours correctly? Is the reversible stud designed to only have a hex bolt socket on one end (and if so, how do I tighten it)? Am I supposed to connect stacks of weights together just using the short bars they come with or is there a longer threaded bar/adaptor that enables the weights to seat more securely in the long rod and/or stacks of weights to be assembled?

Thank you!

chemistry
 

ThomVis

Active member
I don't know what thread the Contour has, but if you can buy a bolt with the same thread at the hardware store you can adapt any weight system to it.

if I flip it round so that the smaller thread goes inside the long rod then there?s no way to tighten it up using a hex key.
No need to, you can tighten the weight against the long rod. Or if the bit that sticks out is long enough run two nuts on it and tighten them against each other, and use the outer one to secure the bolt in.

only about 5 turns (~5mm) of thread can go into the longrod and the same into the weight, which doesn?t seem very secure.
5 threads engaged is secure enough. IIRC with each nut/bolt combination the first three threads carry the majority of the load, 2 more for security, the rest is just added mass. Talking steel here, aluminum might require more threads engaged.
 

KidCurry

Well-known member
AIUK Saviour
...5 threads engaged is secure enough. IIRC with each nut/bolt combination the first three threads carry the majority of the load, 2 more for security, the rest is just added mass. Talking steel here, aluminum might require more threads engaged.
Generally I would agree but there are caveats here that need to be considered:
1) The female thread will have a countersink. This can void the first 2 threads or at least the first and some of the second. I usually default to 2 threads.
2) If a washer is to be used you may void another thread pitch.
3) If the female thread is aluminium then the tensile strength ratio is something like 3:1 steel:aluminium.

General rule... ish is that approx 0.7xdia will give sufficient strength. Or 3 treads will give 70% full strength and 5 threads about 99%, from memory so don't quote me :) but this assumes similar materials.To match the aluminium female tensile strength to the steel screw, the screw threaded length will need to be 3x that of steel into steel. However another caveat here as the male thread will always fail before the female in similar materials, although I generally ignore this.
Summary:
Screwing steel into steel I would want 7 threads if a washer is to be used, nominally 5 for calculations.
Screwing steel into aluminium I would want 15 threads (full strength) 11 threads minimum 80% ignoring the 2 negated by the countersink, should do the job.

You should also consider effects of vibration. If your initial 5 threads, assuming steel/steel, (reduced to 3 due to the countersink) starts to vibrate loose you wont get much of a warning before the weight falls off:) Also if the steel male thread is only holding 3 of the female, or worse 2 with a washer, you are at real risk of stripping the female threads over time.
 
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