Having given the Kong Rakong micro rack a fairly intensive shake down over the last few months I have drawn a few conclusions:

I really like the micro rack concept, particularly the hyper bar which facilitates easy lock off's.

On the downside the aluminium bars on the Rakong are a real issue, I managed to put a three mil groove in the bars on a dirty forty foot rope.

I also feel that the frame was too short which means that you can't decrease friction on stiff or mucky ropes or on inclines (when one's full weight is not on the descender).

In conclusion the Rakong is a great tool on nice clean, vertical, not too stiff rope. Within these limits the Rakong is a cracking tool, however I am not convinced that it is the ideal tool for mine exploration.

With these considerations in mind I have been looking longingly at the BMS long micro rack. A major problem is that the BMS is not available in the UK - this means importing one from the States.

I purchased the rack from Inner Mountain Outfitters via paypal.

http://www.innermountainoutfitters.com/ 

The rack cost me $85 which equates to £50 near as dammit. Postage by USPS was $47.45 or about £28.

The rack took a couple of weeks to arrive, this included two Bank holidays.

Whilst I did not have to pay customs duties (as the value of the item and p&p was under £135) I did have to pay import VAT of £14.42 and a "clearance fee" of £8.

Total cost was around £100, or twice the purchase price of the rack.

The rack itself looks very nice, the bars stainless which should wear a lot better than the ally bars of the Rakong and the longer frame should overcome many off the Rakong's issues.

🔗Personal-Album-3574-Image-94318[linkphoto]Personal-Album-3574-Image-94318[/linkphoto][/link]

I am planning to give the BMS a good work out over the next few months - I will post my findings.

I am not convinced that it is the ideal tool for mine exploration.

It sounds like an absolutely terrible tool for mine-exploring never mind a far from ideal one! :confused:

I am not convinced that it is the ideal tool for mine exploration.

It sounds like an absolutely terrible tool for mine-exploring never mind a far from ideal one! :confused:

Given the choice between a rakong and a stop I would choose the rakong over the stop. In spite of my criticism I do rate the rakong (I was using it the night before last).

I am not convinced that it is the ideal tool for mine exploration.

It sounds like an absolutely terrible tool for mine-exploring never mind a far from ideal one! :confused:

I wouldn't use anything other than a rack, apart from when there is some ridiculous caving involved, which demands the use of something else. I use an ID purely because the stop is a thoroughly nasty piece of kit. Anything which requires the use of a braking crab is not designed properly - end of.

TM, I would go for a J rack if you want a bigger one for bigger drops. It makes the whole thing better for knocking a bar out on big pitches.

I wouldn't use anything other than a rack, apart from when there is some ridiculous caving involved, which demands the use of something else. I use an ID purely because the stop is a thoroughly nasty piece of kit. Anything which requires the use of a braking crab is not designed properly - end of.

Have no objections to Racks generally, rather like 'em in fact. I was commenting upon the Kong model in particular.

On the downside the aluminium bars on the Rakong are a real issue, I managed to put a three mil groove in the bars on a dirty forty foot rope.

I also feel that the frame was too short which means that you can't decrease friction on stiff or mucky ropes or on inclines (when one's full weight is not on the descender).

But ultimately Stops, much like decent Racks, are fine. They work everywhere if used properly.

They don't work on stiff ropes (not necessarily old) on long pitches.

Last time I used a stop it was on a 260ft pitch on a stiff old edelrid caving club stick. NEVER AGAIN.

I can waft down a similar rope, maybe even worse on a rack in total control and it's just better.

I did a drop the other day with a chum who changed from a Rig to a Rack and I went from a Rack to an ID. I was not impressed. It's good for fiddling on 10mm caving ropes in a cave, or adjusting yourself whilst painting a bridge, but no good for actually dropping a shaft. Stops are just crude, that horrible painful handle you have to use all your force to grab and then it all of a sudden lets go.

No thanks.

People use U racks because they are compact. My chum and utterly legendary big-balls explorer came up with the perfect solution, USE 2 NORMAL SIZED RACKS!!! Problem solved!

I wouldn't use anything other than a rack, apart from when there is some ridiculous caving involved, which demands the use of something else. I use an ID purely because the stop is a thoroughly nasty piece of kit. Anything which requires the use of a braking crab is not designed properly - end of.

Have no objections to Racks generally, rather like 'em in fact. I was commenting upon the Kong model in particular.

On the downside the aluminium bars on the Rakong are a real issue, I managed to put a three mil groove in the bars on a dirty forty foot rope.

I also feel that the frame was too short which means that you can't decrease friction on stiff or mucky ropes or on inclines (when one's full weight is not on the descender).

But ultimately Stops, much like decent Racks, are fine. They work everywhere if used properly.

My main problem with stops is the poor, jerky, ride. The fact that the stop needs an additional braking crab to make it work safely is an issue which has already been highlighted.

I am not too keen on classic J racks given that they can be awkward to lock off. Whilst I realise that some people are happy with this for me, at least, its a deal breaker.

The micro rack with hyper bar seems a good compromise between the two: it gives a smooth ride and is dead easy to lock off.

Locking off a J rack. It's just technique....much like doing a changeover with one

Heading back to racks, I would be interested to know what, if any difference you get between ally bars and steel, preferably stainless ones.
Particularly, is there any difference in braking?
Do you get a difference with larger hollow stainless bars.
Does different colour anodising matter? 😉

A rack is a very simple thing to make so it would be interesting to see what works & what doesn't. I like the idea of stainless steel frame & hollow stainless steel bars as a starting point.

Also what do people think are good features? Number of bars, available length to space bars out, extra bit sticking out the side for locking off, temperature gauge, cup holder, cuddly toy, etc.
Yes I know it is a safety critical thing but I design safety critical things for a job albeit significantly heavier and despite what manufacturers like to say the materials are not exotic.

---

Heading back to racks, I would be interested to know what, if any difference you get between ally bars and steel, preferably stainless ones.
Particularly, is there any difference in braking?
Do you get a difference with larger hollow stainless bars.
Does different colour anodising matter? 😉

A rack is a very simple thing to make so it would be interesting to see what works & what doesn't. I like the idea of stainless steel frame & hollow stainless steel bars as a starting point.

Also what do people think are good features? Number of bars, available length to space bars out, extra bit sticking out the side for locking off, temperature gauge, cup holder, cuddly toy, etc.
Yes I know it is a safety critical thing but I design safety critical things for a job albeit significantly heavier and despite what manufacturers like to say the materials are not exotic.

In terms of wear I think ally bars are a dead loss on anything but good clean rope, I am hoping that the stainless bars on the BMS will be more resilient. Certainly the ally bars on the Rakong were pretty crap.

The advantage with ally is that it gives more friction than stainless.

Building your own rack is interesting and is something I have given considerable thought to. I guess it comes as no surprise that in terms of design I would fly the flag for a four bar micro with hyper bar.

I would use 8mm 316 stainless round section for the frame and 1/2"nb schedule 40 316 stainless for the bars. I would terminate the bars with nylocs and dome nuts

Length is interesting, get it too long and changeovers become harder; get it too short (like the Rakong) and you can't spread the bars to reduce friction - somewhere there has to be a sweet spot; at a guess I would say it lies in the 9" to 11" range.

It lies round about where the Petzl rack is.... 😉

Heading back to racks, I would be interested to know what, if any difference you get between ally bars and steel, preferably stainless ones.
Particularly, is there any difference in braking?
Do you get a difference with larger hollow stainless bars.
Does different colour anodising matter? 😉

A rack is a very simple thing to make so it would be interesting to see what works & what doesn't. I like the idea of stainless steel frame & hollow stainless steel bars as a starting point.

Also what do people think are good features? Number of bars, available length to space bars out, extra bit sticking out the side for locking off, temperature gauge, cup holder, cuddly toy, etc.
Yes I know it is a safety critical thing but I design safety critical things for a job albeit significantly heavier and despite what manufacturers like to say the materials are not exotic.

In terms of wear I think ally bars are a dead loss on anything but good clean rope, I am hoping that the stainless bars on the BMS will be more resilient. Certainly the ally bars on the Rakong were pretty crap.

The advantage with ally is that it gives more friction than stainless.

Building your own rack is interesting and is something I have given considerable thought to. I guess it comes as no surprise that in terms of design I would fly the flag for a four bar micro with hyper bar.

I would use 8mm 316 stainless round section for the frame and 1/2"nb schedule 40 316 stainless for the bars. I would terminate the bars with nylocs and dome nuts

Length is interesting, get it too long and changeovers become harder; get it too short (like the Rakong) and you can't spread the bars to reduce friction - somewhere there has to be a sweet spot; at a guess I would say it lies in the 9" to 11" range.

That is interesting that you would use 316 stainless, I dont knwo the measurements that you are planning on using, but I would have thought 321 would be the grade you would want for something like this?!?!

That is interesting that you would use 316 stainless, I dont knwo the measurements that you are planning on using, but I would have thought 321 would be the grade you would want for something like this?!?!

I must admit I hadn't considered 321. I looked at both 304 and 316 which are the most easily obtainable and came down on the side of 316 for its better corrosion resistance characteristics. That said, in the real world, I don't know how noticeable the difference between 304 and 316 would be.

Of course the other option, rather than designing and building a rack, is to make off with someone else's stop 😉

316 is better on corrosion which is why I use it in the day job for marine applications. 321 is optimised for welding so no advantage here.

Physical properties otherwise much the same.

The corrosion resistance of 316 wouldn't be an excuse to not keep your gear clean of course!

I don't need to make off with a stop as I've already got one. Just interested in a rack & too tight to buy one!

Does anyone in the Durham/Weardale/Nenthead area have a rack I can look at and maybe try?

---

316 is better on corrosion which is why I use it in the day job for marine applications. 321 is optimised for welding so no advantage here.

Physical properties otherwise much the same.

The corrosion resistance of 316 wouldn't be an excuse to not keep your gear clean of course!

I don't need to make off with a stop as I've already got one. Just interested in a rack & too tight to buy one!

Does anyone in the Durham/Weardale/Nenthead area have a rack I can look at and maybe try?

The reference to making off with stops was aimed at J25GTi who is "not averse to borrowing" people's stops. - Something of an in joke. :flowers:

Is the difference in thermal conductivity between aluminium and stainless steel an important factor when deciding which is preferred?

From the amount of anti-stop comments I'm surprised anyone would want to borrow one! :angel:

---

From the amount of anti-stop comments I'm surprised anyone would want to borrow one! :angel:

To be fair the stop is perfectly adequate - I just think that a micro rack does the job better.

Those who advocate traditional J racks are mere luddites, dwellers in the stone age who haven't experienced the true faith of the micro rack.

A sideways pressure failure comparison between ally based bar and nb stainless would be useful (after drilling of course).

---

A sideways pressure failure comparison between ally based bar and nb stainless would be useful (after drilling of course).

What diameter are the ally bars?

---