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Fixed gear guidelines in the Grampians 1-Jun-2018 At 5:58:17 PM kieranl

Message

On 1-Jun-2018 gfdonc wrote:
>On 1-Jun-2018 kieranl wrote:
>
>>What you're describing suggests that these sleeve bolts aren't correctly
>>installed. Sleeve bolts should be installed with the hanger fitted around
>>the sleeve, not with the top of the sleeve flush with the rock surface.
>
>Says who?
>There was a fair bit of debate among a few bolters I know about this issue
>a while ago, with no firm consensus.
>I'm interested in more facts if you can add. Pros and cons that I recall
>were:
>Pro: Sleeve deeper in the hole is generally a good idea. More rock surface/depth
>engaged.
>Pro: Sleeve flush with the rock generally avoids 'spinners' as the hanger
>is being tightened against the rock surface.
>Con: sleeve inside the hanger means the bolt-to-hanger connection is stronger
>Pro: generally bolts are made assuming the sleeve is flush, meaning (depending
>on the bolt) when you tighten a bolt that has the sleeve inside the hanger,
>you have a few mm of extra thread protruding above the nut. This can then
>be tall enough to push a gate open, which is generally accepted to be a
>bad thing.
>
>There may be a couple of other 'cons' I've forgotten.
>
>Hilti are generally considered expert in this field. Installation on
>their web site shows the sleeve component flush with the rock/concrete
>surface, or even recessed slightly. (There's a chart on their web site,
>for example, that mandates a sleeve recess of 2mm to 8mm depending
>on the bolt - but never protruding!)
>

http://www.ramset.com.au/Product/Detail/82/DynaBolt-Plus-Sleeve-Anchors

The Ramset Dynabolt instructions say to "insert the dynabolt through the fixture". You can't do that if the fixture hole is smaller than the sleeve. It also gives the maximum fixture thickness for different length bolts. For example the 70mm M10 bolt often used in hard rock requires a 12mm hole and has a 15mm maximum fixture thickness. Try adding a 15mm thick bracket when the sleeve is embedded in the hole.