another annoying rappel question??

[Stridergdm]

If a Cole-type rack is long enough, has an open frame, and is not skinnied down too much, it will work rather well. There are dopes that on't work well in a rack (or in other descenders) but let's not discuss hardware store ropes here.

Dopes huh?

[gdstorrick]

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[Marduke]

From what you describe, your rack is attached incorrectly. A rack should be attached so you are looking at the END of the bars, and the opening should be down and away from your body, not to the right or left.

Not to pick a fight, but this is an OPINION shared by some cavers and not by others. Not a hard and fast rule for all, because doing it the other way IS safe and DOES work. Also it doesn't apply quite the same to U-racks as it does to J-racks. But yes, with an open-frame rack this is quite an efficient way to maintain control and add/drop bars.

Well, it's how John Cole designed it from the start. It's otherwise, VERY difficult to add/drop bars with a weighted rope.

OR1 has a concise description:

John Cole, inventor of the rack, designed it to be oriented so the user is staring straight down at the ends of the bars, not looking at them from the the side. There is a very popular idea in place in today's world with thinking that racks need to be turned to the left or the right. In fact, racks are correctly oriented when the open leg is facing down & out away from the user. This orientation facilitates easy changing of the bars by swinging the rope side to side, as opposed to the front & back motion necessary if the rack is improperly oriented. When extreme rope weight is encountered, such as during a drop like El Capitan, the user will then fully comprehend the necessity to properly orient their rack as it was designed.

[chh]

Turning on the maillon shouldn't affect the way the rack works. As far as the transition from a friendly slope to a dead vertical my suggestion would be as follows. Use however many bars you need to make controlled progress on the diameter or rope you are using. As the slope changes or you approach the lip: 1) anticipate these changes 2) put your ascender on above the rack 3) add or drop bars and continue. Pretty straightforward with no new skills to learn.

A 12mil rope will definitely change the friction. Using all 6 bars on a 12mm in anything other than a vertical drop would be difficult.

[NZcaver]

Well, it's how John Cole designed it from the start. It's otherwise, VERY difficult to add/drop bars with a weighted rope.

Be careful about believing everything you read. There are several well-known vertical caving texts in the world, and of course they don't all line up perfectly. The key is to be able to read each one with a discerning eye rather than blind acceptance of doctrine.

John Cole, while receiving the lion's share of the credit, was not the only inventor of the rappel rack. Nor, to the best of my knowledge, did he invent the U-rack. Ask Gary about this. If anybody knows the history of devices, it's him.

You make a good point with the weighted rope thing, but of course not all rappels involve multiple hundreds of feet/meters of heavy 11mm rope. My own J-rack is the 90-degree eye version which allows me to operate it they way you describe (although I seldom use it because I personally find other devices much better for my current on-rope needs). However I know many world-class cavers with a lot more experience than either you or I who continue to use their J-racks quite successfully in the "flat" configuration. While I seldom hold back suggestions (no surprise there), I would not presume to try to "correct" this one with competent cavers.

[Scott McCrea]

J-frame racks work better in the perpendicular-to-your-body, short leg out orientation.

[NZcaver]

J-frame racks work better in the perpendicular-to-your-body, short leg out orientation.

I think we crossed that bridge already.

Incidentally, on the subject of rack preferences, U-frame racks work better when the bars hinge up (towards you) to open - not down. But I often see cavers with them rigged the other way. Go figure.

[Scott McCrea]

Just to clarify, J-frame racks work (demonstrated in many places for many years) in the parallel (flat) orientation. But, they work better in the perpendicular.

U-frame racks are not designed to have bars removed/subtracted/added while rappelling. Sure you can do it. But, you shouldn't—it is quite risky.

[NZcaver]

U-frame racks are not designed to have bars removed/subtracted/added while rappelling. Sure you can do it. But, you shouldn't—it is quite risky.

Absolutely correct. I should clarify my last statement to avoid confusion. The bar orientation I was referring to with a U-rack makes it smoother to operate and gives a greater range of friction (especially if you need to reduce friction) while descending with all bars engaged. You should ONLY open the bars to attach/detach the rack while on solid ground and/or while connected to the rope with an additional device (ascender, cowstail, etc).

Again, this bar orientation preference is just an common sense observation/opinion rather than a hard and fast safety rule. Your choices are your own.

[Dwight Livingston]

Incidentally, on the subject of rack preferences, U-frame racks work better when the bars hinge up (towards you) to open - not down. But I often see cavers with them rigged the other way. Go figure.

I've always preferred the set up you describe, in order to have a great range of friction. I heard, though, a preference for the opposite threading so that the rope does not run between the top bar and the rock face or edge you are sliding against. I see the point, though I think the rope itself is probably not sliding. All said, It seems a small thing compared to getting down a dirty project rope without feeding the rack.

[NZcaver]

I've always preferred the set up you describe, in order to have a great range of friction. I heard, though, a preference for the opposite threading so that the rope does not run between the top bar and the rock face or edge you are sliding against.

Interesting point, although in that situation if you are scraping your rack against the rock as you descend at least the rope should be relatively stationary in relation to the rock. Different than if you're hauling or lowering, but that's a whole other ballgame.

[Cody JW]

Just to clarify, J-frame racks work (demonstrated in many places for many years) in the parallel (flat) orientation. But, they work better in the perpendicular.

U-frame racks are not designed to have bars removed/subtracted/added while rappelling. Sure you can do it. But, you shouldn't—it is quite risky.

I agree I am over 200 lbs. and I know that the difference in weight between someone at lets say 220 and 180 lbs. is quite a bit in terms of friction with a rack.Always being heavier than alot of cavers I have never added or changed bars on rope, I have regretted it on a few drops as I have left top with six bars and force fed the rack for a couple hundred feet before moving well, that wears out your arms. I have found out in bicycle riding that the nice light stuff for road bikes is not made for big boys , you will break things much sooner as the design intent is for guys less than 180. I wonder how that works with a rack as for the design intent in respect to body weight? I have always had a 6 bar standard rack and thought about using 6 bars on a long rack to give more room for bar movement.

[gdstorrick]

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[Cody JW]

What I was getting at was actually the length of the rack frame. It seems the standard 6 bar frame does not give you much room to move bars with 6 bars engaged. It seems with my weight 5 bars on a reg. rack is not enough friction and 6 I have to force feed, of course this depends on rope condition.A new slick rope 6 bars is fine.But that is not always the case. With 6 I cannot move the bars enough to make much of a difference at the top of a drop. That is why I may consider the next size up in rack frame.The strange thing is a figure 8 seems to have the right amount with any rope for me at least.

[gdstorrick]

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