Next Previous

True Stop Bobbins

Bobbins are mechanical descenders where the rope path follows the S-shaped path shown in the figure. In general the braking surface consists of two non-rotating bollards fixed to a sideplate, with a second pivoting sideplate provided to keep the rope from jumping off the other end of the bollards. A third (usually smaller) bollard may be provided. The seat maillon usually attaches to holes in extensions of the two sideplates; these holes are aligned when the sideplates pivot to the closed position.

I distinguish true bobbins from false bobbins by whether the spools (or bollards) move with respect to the frame. On true bobbins the center of the spools is fixed although the spools may rotate (on stop bobbins, the lower one usually does). On false bobbins, the center of the spools can move. I don't believe that there is necessarily any advantage of true bobbins over false bobbins or vice versa, it's merely a means of classification. Stop bobbins have a mechanism that applies additional braking force if the rappeller releases or squeezes (depending on the design) a handle on the bobbin. Sometimes the additional friction is enough to stop the rappeller, which possibly transforms the resulting injury from impact trauma to harness suspension trauma.

I find that the Petzl Stop is more likely to stop me than the Diablo, Dressler or Kong - in fact, on a clean rope, I can often rappel with these locked off. The Petzl I'D is a complex device that I've included here after trying it and seeing that the rope follows a bobbin "S" instead of the odd path shown in the instructions. The Tracson is another complex device that I've included here rather than create a new category. It combines a Jumar-type cam with a bobbin into a single rappel and ascent device. I would not like to rely on the stop feature because of the sharp cam teeth. My Tracson bent each of the first two times I tested it, so I haven't used it since. Its an interesting idea, but I think it needs more work to be practical.

Image

ID Device Description Acquired Weight Height Width Thickness Std. volume
Beal (ISC) D4 1494 Beal (ISC) D4 Al frame, SS spools, rotating handle Expé-Spelemat, 2016 681 197 82 78 1268
BO.VE Diablo 431 BO.VE Diablo Bent frame, solid spools, round brake, no-stop lock, stamped gate Repetto Sport, 1982 327 223 63 32 450
Climb Tech 138
24353
Climb Tech Stamped frame, solid upper spool (cut), cast ribbed lower spool /w stop, aux. rod, plastic gate
  • Climb Tech, 2012
  • Bob Thrun Collection, 2017
342 219 60 33 433
Climbing Technology Sparrow 1432 Climbing Technology Sparrow Irregular bollard /w handle & integral clutch, swinging face plate Lior Porian, 2015 524 181 86 53 816
Climbing Technology Sparrow 200 1479 Climbing Technology Sparrow 200 Irregular bollard /w handle & integral clutch, swinging face plate Inner Mountain Outfitters, 2016 548 180 85 53 812
Dressler DAD 432 Dressler DAD Bent frame, irregular cast spools, open top Repetto Sport, 1982 247 179 51 32 292
Epic Peak 2464 Epic Peak Stamped frame, solid upper spool (cut), cast ribbed lower spool /w stop, aux. rod, plastic gate Epic Peak, 2017 343 219 64 32 446
Great Makings 1418 Good Makings Stamped frame, solid upper spool (cut), cast ribbed lower spool /w stop, aux. rod, plastic gate Yungfeng Xiao, 2014 342 217 64 32 445
heightec D31 Prism 1496 heightec D31 Prism Stamped frame, solid pivoting upper spool (cut), cast hollow lower spool, stop on handle lever extension, aux. anvil, plastic gate American Alpine Club Store, 2017 510 239 78 31 570
heightec-PMI Powerlock 1168 heightec-PMI Powerlock SS Frame, Al spring-loaded upper spool, cast SS lower spool on handle /w red plastic grip On Rope 1, 2008 737 162 184 30 878
heightec-PMI Quadra 1169 heightec-PMI Quadra SS frame /w openings, Al upper spool, cast SS lower spool on spring-loaded plate /w spring/loaded Al handle On Rope 1, 2008 692 185 92 30 507
ISC A•B 1431 ISC A•B Bent frame, solid upper spool, solid lower spool (cut), spring-loadedlever /w folding handle & round stop, stamped gate Jon Edelman, 2015 454 206 65 35 468
ISC D2 Escape Descende 1398 ISC D2 Escape Descender Closed Al frame, cast spools, rotating handle, for 7-8 mm rope Rescue Technology, 2013 290 143 70 61 603
Kong, Version A 1434 Kong, Version A Bent frame, solid spools, cut lower spool, top brake linked to handle, stamped gate  Clear Out Our Stuff, 2015 398 232 55 27 342
Kong, Version B 522 Kong, Version B Bent frame, solid spools, cut lower spool, top brake linked to handle, stamped gate Inner Mountain Outfitters, 1996 397 230 65 32 478
Kong, Version B (modified) 528 Kong, Version B (modified) Bent frame, solid spools, cut lower spool reversed, top brake linked to handle, stamped gate Inner Mountain Outfitters, 1997 397 230 65 32 478
Kong Indy 903
2436
Kong Indy Bent frame, solid spools, cut lower spool reversed, top brake linked to handle, stamped gate
  • Inner Mountain Outfitters, 2001
  • Bob Thrun Collection, 2017
476 230 64 31 456
Kong Indy EVO NFPA 1395 Kong Indy EVO NFPA Bent frame, cast ribbed spools, top brake linked to handle  On Rope 1, 2013 455 216 62 33 444
Kong-Bonaiti 433 Kong-Bonaiti Bent frame pivots at top bar, solid spools, cut lower spool, top brake linked to handle, stamped gate Speleoshoppe, 1982 400 239 60 30 430
Krok Anti-Panic Aluminum, Version A 1342 Krok Anti-Panic Aluminum, Version A Bent frame, solid spools, high handle, push-button twist catch, no gate, painted Gear4Rocks, 2012 345 195 120 33 780
Krok Anti-Panic Aluminum, Version B 1361 Krok Anti-Panic Aluminum, Version B Bent frame, solid spools, high handle, push-button twist catch, no gate, painted Krok (Alex Dniprovsky & Alex Kostromitinov), 2012 408 208 118 33 816
Krok Anti-Panic Steel 1343 Krok Anti-Panic Steel Bent frame, solid spools, high handle Gear4Rocks, 2012 528 194 121 29 689
Krok Desant 1344 Krok Desant Bent frame, solid spools Gear4Rocks, 2012 373 184 84 26 403
Krok Desant Classic 1392 Krok Desant Classic Bent frame, solid spools (cut), aux. rod, wire gate Gear4Rocks, 2013 410 196 118 29 666
Krok Grisha, Version A 1345 Krok Grisha, Version A Stamped frame, milled cam on spring-loaded handle, single rope Gear4Rocks, 2012 399 156 84 31 402
Krok Grisha, Version B 1357
1362
Krok Grisha, Version B Stamped frame, milled cam on spring-loaded handle, single rope
  • Gear4Rocks, 2012
  • Krok (Alex Dniprovsky & Alex Kostromitinov), 2012
402 135 109 36 526
Krok Stopor-Desant 1352 Krok Stopor-Desant Bent frame, solid spools, high handle Gear4Rocks, 2012 476 150 121 31 560
NTR 1454 NTR Stamped frame, solid upper spool (cut), cast ribbed lower spool /w stop, aux. rod, plastic gate Linko Chen, 2015 343 218 62 32 436
Petzl I'D. Large, Version A 565
2432
Petzl I'D. Large, Version A Irregular bollard /w handle & integral clutch, anti-error catch, swinging face plate
  • Inner Mountain Outfitters, 2000
  • Bob Thrun Collection, 2017
526 194 83 54 870
Petzl I'D. Large, Version B 1166 Petzl I'D. Large, Version B Irregular bollard /w handle & integral clutch, anti-error catch, swinging face plate Rescue Response Gear Inc., 2008 525 203 79 52 840
Petzl I'D. Large, Version C 1218 Petzl I'D. Large, Version C Irregular bollard /w handle & integral clutch, anti-error catch, swinging face plate, horizontal mode button On Rope 1, 2009 550 212 80 54 912
Petzl I'D, Small, Version A 556
2433
Petzl I'D, Small, Version A Irregular bollard /w handle & integral clutch, anti-error catch, swinging face plate
  • Inner Mountain Outfitters, 1999
  • Bob Thrun Collection, 2017
536 194 83 54 870
Petzl I'D, Small, Version B 1219 Petzl I'D, Small, Version B Irregular bollard /w handle & integral clutch, anti-error catch, swinging face plate, horizontal mode button On Rope 1, 2009 558 212 80 54 912
Petzl RIG 1247 Petzl RIG Irregular bollard /w handle & integral clutch, swinging face plate On Rope 1, 2010 379 177 67 58 679
Petzl Stop, Version A 435 Petzl Stop, Version A Bent frame, solid upper (cut) & lower (/w steel brake) spools, stamped gate Repetto Sport, 1982 289 225 61 33 453
Petzl Stop, Version B 436 Petzl Stop, Version B Bent frame, solid upper (cut) & lower (/w steel brake) spools, stamped gate Caves Unlimited, 1984 302 226 64 32 463
Petzl Stop, Version C 1324 Petzl Stop, Version C Bent frame, solid upper (cut) & lower (/w steel brake) spools, stamped gate Geoffrey Storey, 2012 297 231 63 32 463
Petzl Stop, Version C 2420 Petzl Stop, Version D Bent frame, solid upper (cut) & lower (/w steel brake) spools, stamped gate Bob Thrun Collection, 2017 309 229 62 32 458
Petzl Stop, Version D 437 Petzl Stop, Version E Stamped frame, solid upper spool (cut), cast lower spool /w stop, aux. rod, stamped gate John E. Weinel, Inc., ~1987 327 240 63 32 484
Petzl Stop, Version E 438 Petzl Stop, Version F Stamped frame, solid upper spool (cut), cast ribbed lower spool /w stop, aux. rod, stamped gate Bob & Bob, 1991 322 225 62 32 446
Petzl Stop, Version F 541 Petzl Stop, Version G Stamped frame, solid upper spool (cut), cast ribbed lower spool /w stop, aux. rod, plastic gate TSA, 1997 325 223 68 32 485
Rock Empire 1368 Rock Empire Stamped frame, solid upper spool (cut), cast ribbed lower spool /w stop, aux. rod, plastic gate Climbing Terekpl, 2012 341 220 59 32 418
Russian, Version A 518 Russian, Version A Bent frame, solid upper spool (cut), solid lower, stamped gate Theresa Williams/Maury Benamy, 1995 255 220 62 27 368
Russian, Version B 451 Russian, Version B Bent frame, solid upper spool (cut), solid lower spool /w round stop, aux. rod, wire gate ? 246 222 55 32 391
Russian, Version C 973 Russian, Version C Bent frame, solid upper spool (cut), solid lower, aux. rod, stamped gate Ural Sport, 2004 286 208 74 30 459
SAR Scarab, Version A 1013 SAR Scarab, Version A Bent frame, solid upper spool, solid lower spool (cut), lever /w round stop, stamped gate SAR, 2006 436 195 62 35 419
SAR Scarab, Version B 1029 SAR Scarab, Version B Bent frame, solid upper spool, solid lower spool (cut), lever /w round stop, stamped gate SAR, 2007 430 195 62 35 419
SAR SARAB 1211 SAR SARAB Bent frame, solid upper spool, solid lower spool (cut), spring-loaded lever /w folding handle & round stop, stamped gate SAR, 2009 470 206 65 35 472
S.A.R.L. Voynett Tracson 452 S.A.R.L. Voynett Tracson, Version A Combination bobbin and ascender Repetto Sport, 1982 580 192 107 50 1027
S.A.R.L. Voynett Tracson 2409 S.A.R.L. Voynett Tracson, Version B Combination bobbin and ascender Bob Thrun Collection, 2017 589 192 107 50 1027
SMC Spider 1215
2434
SMC Spider Milled body, SS cover plate, rear handle
  • On Rope 1, 2009
  • Bob Thrun Collection, 2017
554 214 85 41 739
SUT 2460 SUT Bent frame, solid spools, cut lower spool, dual top brake linked to handle, stamped gate  Kangjin Liao, 2017 474 232 66 31 479
1468 Vento Stamped frame, solid upper spool (cut), cast ribbed lower spool /w stop, aux. rod, plastic gate Carl Janysek, 2015 340 218 64 33 452

Bobbins False Bobbins Bobbin Weight Distribution