Choosing Cams: How Far Your First Rack Should Go, Matching Sizes Across Brands, and 7 Current Models

🌏 中文版

Cams are the most expensive thing on a trad rack: common sizes run about US$70–160 each. They cover what nuts can't: cracks with parallel sides and no constriction to wedge into. Taiwanese climbers just call them cams, and some shops list them as 岩楔 (nuts), so check the model name before you buy.

This post answers one question: which cams to buy. Why cams hold, how to judge a placement and how far to retract the lobes are covered in Placing Trad Protection, so they aren't repeated here; for nuts, see the previous post, Nuts. By the end you should be able to decide which sizes your first rack runs from and to, pick a brand, and read the colours on someone else's rack.

Five criteria

1. Pick a numbering system first: the same as your partner's

Few people buy a full rack alone. A first rack is usually combined with a partner's, and the numbers in route info need to match. So decide which numbering system you'll use first, then pick a model.

Taiwan's route info and trad courses use BD Camalot numbers: nobodyclimb's Defulan routes say "single rack to #2", and the kit list for Adventure Taiwan's single-pitch trad course is C4 .4 to #3. TOCC's guide to a first trad rack (in Chinese) also warns that mixing brands makes it hard to tell your partner which piece you want.

Here's how the brands line up:

• BD Camalot, Wild Country Friend: same numbers; WC's product page doesn't list colours, so check the actual cams.
• DMM Dragon: same colours as BD, different numbers. Dragon 1 is purple and equals C4 .5.
• Totem, Metolius: each has its own colour scheme to learn.

Note that BD colours repeat: .3 and #3 are both blue. They're very different sizes, so you're unlikely to grab the wrong one, but shouting "the blue one" to your partner isn't clear enough.

Something you can do tonight: ask the person you climb with most what brand their cams are. If BD, look at BD or Wild Country first; if DMM, memorise the Dragon-to-C4 table below.

2. How far should your first rack go

Some commonly cited starting points:

• BD: How to Build Your First Trad Rack says a standard set is one each from .2 to #3.
• TOCC, Longdong on a budget: start with Z4 .2 plus C4 .3 to #2, 7 cams, add a set of nuts, and you can do most trad routes at Longdong; add anything wider than a hand later.
• TOCC, full Longdong rack: a set of Z4s (#0–.75) plus a set of C4s (.3–#3), 14 cams. This gives you two each of the most-used sizes, .3 to .75; TOCC says the most-used cam sizes at Longdong are 1–8 cm.
• Mountain Project's Longdong page: a single rack to 3" covers most routes; to climb everything, take doubles from very small to 4".

Two buying tips:

• Each buy a set and combine. Noah Kane says a standard rack is seven cams from .3 to #3, enough for most trad routes, and recommends beginners double it to 14 cams from the start; Brant Hysell (The Gravity Lab) writes in his video description that multi-pitch calls for a double rack, "at least as a team". UKClimbing suggests each buying half a set, one the small sizes and one the large.
• "To 3 inches" may mean one size up. A Valhalla Mountain Guides guide says a #3 doesn't protect well in a crack that's exactly 3 inches wide, so when a guidebook says protection up to 3 in, he brings a #4 (video from 0:39).

Something you can do tonight: pick three trad routes you want to climb on nobodyclimb and copy down the largest size each protection field lists. If all three stop at #2, your first rack doesn't need a #3 yet.

3. Double or single axle, rigid or flexible stem

• Double axle: the lobes sit on two axles, so each cam covers a wider range. DMM says neighbouring sizes overlap more, so you can carry fewer cams. TOCC recommends double axle for a first rack, noting that a C4 keeps its rated strength even fully open.
• Single axle, flexible stem: most small cams are built this way. OutdoorGearLab (OGL)'s cam comparison (updated April 2025) treats them as the pieces for thin cracks; rigid stems do worse in horizontals and shallow placements, so most people switch to soft-stemmed cams like the Z4 below .5.

In practice: double-axle rigid cams form the backbone in the mid and large sizes, and you buy flexible single-axle cams for the small sizes.

Something you can do tonight: take a friend's C4 and a small cam and bend each stem sideways to feel the difference. Picture it in a horizontal crack, stem sticking out of the wall, rope pulling down.

4. Thumb loop and extendable sling

This is the main difference between the big three:

An extendable sling means fewer alpine draws, less rope drag and less walking. OGL's text says the cams that did best in horizontals all had extendable slings, though in its own score table the Z4, which has no extendable sling, also scores 9 for horizontals, tied with the top score.

The thumb loop is a matter of feel. UK climbing instructor JB Mountain Skills uses C4s on his personal rack simply because he likes thumb loops; new trad climber Jonathan Ness uses Dragons and found he got used to the missing thumb loop. James from UK shop Outside says a thumb loop makes a cam less easy to drop, which helps most in winter with big gloves on (video from 3:48).

Something you can do tonight: next time you're in a gear shop, pick up the same size C4, Dragon and Friend, pull each trigger fully one-handed and let go, and see which puts your thumb in the most natural spot.

5. Are lightweight cams worth it

BD says the Camalot Ultralight replaces the cable with Dyneema and is 15% lighter than a C4.

How much do you actually save? By the weights on BD's product pages, swapping all seven C4s from .4 to #4 for Ultralights saves only about 139 g. BD's site currently lists only Ultralight #1 to #4; swapping those four saves 84 g and, at list prices on 2026-10-24, costs US$130 more.

Factor in lifespan too. OGL writes that BD recommends retiring Ultralights after five years, because Dyneema may degrade faster than cable. Brant Hysell also advises staying away from Ultralights at first because their trigger wires wear out (video from 13:37).

Buy C4s first. Once you know you'll climb a lot of long routes and really care about those grams, consider swapping your one or two most-used sizes for lighter ones.

Something you can do tonight: weigh your rack, then think about how long you'll carry it. Most Longdong approaches are short, so the saved weight won't feel like much.

Size chart: BD, DMM, plus Totem and Metolius

Same size, two names. This table follows DMM's spec table and Jonathan Ness's side-by-side comparison.

Totem has its own colour scheme, and its sizes often fall between two BD sizes. J. Adams compared them in hand: the blue Totem is a little bigger than a .3, between .3 and .4, and the black Totem sits between .2 and .3 (video from 12:38).

Metolius can't be converted by number or colour. Its #4 is red, with a usable range of 23.5–33.5 mm; red on BD is #1, a full size bigger. Grant Climb Big Rock also put a Metolius #6 next to a BD #6, and they're very different sizes. J. Adams also points out that Metolius needs eight cams to cover the range BD covers with seven, partly because each single-axle cam has a narrower range. If you mix brands, go by the manufacturer's mm ranges; his approach is to pick one colour scheme as the reference and use carabiner colours to mark the nearest BD size on other brands.

Seven current cams compared

Only models still sold on the manufacturer's website on 2026-10-24. Prices are the manufacturer's list prices that day, in the currency of the manufacturer's site.

Notes on a few of them:

• C4: OGL recommends it for a first rack because it's the most common cam, so once you know the colours it's easy to borrow or combine with a friend's rack. TOCC also calls BD affordable and durable.
• Dragon: double axle, but a single stem. In the UK, DMM will re-sling and service them; JB remembers it costing about £15 per cam.
• Friend (2026): the Flow Cord is a core-mantle extendable cord with a red wear indicator in the core, and Wild Country quotes a 14-year certified lifespan (10 years of use plus 4 of storage). Alpinist's review used them for a season in Joshua Tree and Red Rocks and found the new cord more durable than the old sling, and it no longer catches behind the thumb loop when extending.
• Totem: the four lobes load in two independent pairs, so every size can act like an offset; the head is narrow and the stem soft. OGL rates it the best cam for aid climbing, but it can be hard to remove. TOCC says its size range is incomplete: the smallest isn't small enough and the largest isn't big enough.
• Metolius: the 2025 version replaced the green-yellow-red size dots on the lobes with X marks and added a half loop under the trigger. Grant prefers the 2024 version. Noah Kane regrets buying the larger Master Cams: a single axle gives less range than a double axle, which is harder on someone still learning to place cams. He's happy with his small one, since everything below .3 is single-axle anyway.

Micro cams: add later

• Wild Country Zero Friend: 0.1–0.75, colours match Camalot, extendable sling, US$89.95.
• DMM Dragonfly: sizes 1–6, smallest about 7.8 mm, £86.50. UKClimbing says it's lighter and softer than a small Dragon and goes smaller, but is more delicate; small Dragons are stiffer and tougher.
• Fixe Alien Revolution: OGL lists it as a good pick for horizontals and aid; the soft aluminium lobes grip well but wear faster.
• Trango Flex Cam: single axle, two-length extendable sling, US$59.95–79.95, few independent reviews.

Review and experience videos

Only videos from 2024 onward that discuss specific models; start times were checked against the subtitles.

Start with these two: choosing between the big three. JB Mountain Skills is a climbing instructor in North Wales; his 2025 video turns to cams at 11:25. His personal rack is C4 .4 (grey) to #3 (blue), and his work rack is DMM Dragons; he then compares Friends and Totems, and notes that in the UK only DMM makes re-slinging easy. The description links to T-shirts and a tip page; there's no manufacturer sponsorship for the cam section.

What thumb loops and extendable slings actually do. James from UK shop Outside walks through the 2026 Friend. From 3:48 he covers the thumb loop: he's used to it, it makes the cam less easy to drop, and it helps most in winter with big gloves. From 4:10 he covers the extendable sling: in a horizontal break it keeps the carabiner off the edge, cutting rope drag and sparing the carabiner. From 4:52 he covers the new Flow Cord: no stiff bar tacks, so it extends wherever you grab it, and a red wear indicator sits in the core. Disclosure: Outside sells these cams and the description links to its product page; James says his parents founded Outside alongside Wild Country founder Mark Vallance and the two were once the same company; the test cams were manufacturer samples.

Buying a first rack. UKClimbing gets to cams at 3:56: cams go in parallel cracks and nuts in tapering ones, so the two complement each other; beginners should look at Dragons 1 to 4 (purple to gold), and can split a set with a friend. The whole video uses DMM gear and the description links to DMM's site; no sponsorship is stated.

Noah Kane has climbed for six years. His 2025 gear roundup covers the standard rack from 14:48: seven cams from .3 to #3, enough for most trad routes, doubled to 14 for beginners from the start. From 17:32 he covers brands: most of his cams are C4s, whose rigid stems feel solid in the middle and large sizes, and his one complaint is the non-extendable sling; starting over, he'd buy Wild Country Friends with extendable slings from .75 up, and he prefers Z4s with their flexible stems in the small sizes. From 19:37 he says he regrets buying the larger Metolius Master Cams. The video's sponsor is the eSIM service Saily, and he says no climbing gear company sponsored it; the gear links in the description are alnk.to shopping short links.

A beginner's take on DMM Dragons. Jonathan Ness is new to trad. From 1:55 he says the missing thumb loop hasn't bothered him, since you get good at whatever you use, and that a Dragon 0 equals a C4 .4. From 3:00 he shows that you must clip the strand with the stitching to extend the sling; clip the wrong one and it jams. So far he has only placed them in a practice crack in his garage, not on lead. He says he bought them on Amazon; no sponsorship is mentioned.

Totem in irregular cracks. A Totem test from Lacrux, a German-language climbing magazine, in German. From 0:25 it describes the many pin scars on Yosemite's aid pitches, where they had been strongly advised to bring offset cams or Totems; from 0:53, in Indian Creek, the Totems didn't shift at all as the climber moved above them; from 1:06, in Yosemite, they held solidly even with only two of the four lobes gripping, and not one Totem pulled out on the whole trip. The description says alpinist Anna Truntschnig put the facts together, and the channel is presented by German online shop Bergfreunde; the video says they were "lucky to be allowed to take the Totems along" without saying whether the manufacturer supplied them. This is how experienced aid and crack climbers use them; for a first rack, stick with the advice above.

Metolius: living with a budget cam. Grant Climb Big Rock bought his on sale from HowNOT2's web shop for US$40–50 each (list US$69.95) and says he has no affiliate deal. From 1:28 he compares the 2024 and 2025 versions; from 2:59 he puts a Metolius #6 next to a BD #6 to show numbers don't carry across brands; from 5:16 he says to check the trigger wires (not steel) and their plastic guards on used ones.

Mixing brands: matching colours and sizes. J. Adams's 28-minute video is entirely about colour schemes and sizes across brands and generations of cams. From 0:37 he suggests picking one colour scheme as the reference and using carabiner colours to mark the nearest BD size on other brands, so you can tell a partner "the one with the yellow carabiner"; from 1:50 he shows Metolius needing eight cams for the range BD covers with seven; from 12:38 he compares Totems: blue between .3 and .4, black between .2 and .3. From 27:04 he notes DMM and Wild Country now more or less use BD's colours, while Totem and Metolius have to be learned separately. The description has no sponsorship or shopping links.

The new Friend and the extendable-sling Camalot. UKClimbing's first look at a trade show. From 1:58, the new Friend swaps to an extendable doubled cord that pulls open without snagging, and the large sizes gain a closing lock. From 3:13, BD's 2026 Camalot, where the main change is the sling and an extendable version joins the range. These are trade-show first impressions, not long-term use.

Among Chinese-language videos, we found none from Taiwanese climbers comparing cam models. Hong Kong channel G for GoOut 朱遊記 has a Cantonese multi-pitch gear overview that mentions from 0:59 that most cams have extendable slings so you can carry fewer draws, but it doesn't name models.

Choosing by situation

First rack, mostly at Longdong

• Use the same numbers as your partner. Most people in Taiwan use BD, so C4s are the easiest; if you want an extendable sling, look at the Wild Country Friend, which uses the same numbers.
• On a budget, follow TOCC's 7 cams: Z4 .2 plus C4 .3 to #2, plus a set of nuts.
• Then build toward TOCC's full rack: add a #3, then use Z4s to double .3 to .75.

Buying with a partner

• Each buy a .3 to #3 set; together that's a double rack.
• Or do it UKClimbing's way: one buys the small sizes, the other the large, to make one set between you. When you climb separately, remember who took which cams.

Already have a set and want more

• First double the most-used middle sizes. Brant Hysell says a single rack is fine for single pitches at 5.10 and under, but it's good to have a couple of extras from .5 to #1 (video from 17:53).
• For smaller sizes, look at Z4s or Zero Friends; on a budget, Metolius.
• Totems and offset cams belong on a second rack, once you know you often meet flared cracks or pin scars.

Climbing abroad

• Racks vary a lot by crag. In an EpicTV video, James Pearson says he takes two or three sets of nuts and one set of cams to the sea cliffs of Pembrokeshire in the UK, but almost nothing but cams to Indian Creek (from 6:28). He's a Wild Country sponsored climber, and the description links to Wild Country products in the EpicTV shop.
• TOCC likewise says big cams are only worth considering for Yosemite, Indian Creek or offwidths. Check what sizes the local guidebook calls for before buying #4 and up.

Inspection and retirement

• Before every use: check the sling for wear, trigger wires for broken strands, lobes for deformation or heavy wear, and that the lobes spring back smoothly after you pull and release the trigger.
• Slings age before metal: OGL writes that BD recommends retiring Ultralight Dyneema stems after five years; the new Friend has a red wear indicator in the cord core, and when you see red, replace it.
• Re-slinging means the manufacturer: JB says DMM re-slings its cams, WC is hard to get re-slung in the UK, and Totems go back to Spain. If you bought your cams in Taiwan, ask the distributor whether they can arrange it.
• Used cams: Grant points out the weak spots on Metolius are the trigger wires (not steel) and their plastic guards. A used cam of unknown history, with no idea how many falls it's held or what it's been soaked in, isn't worth buying.

For the full inspection and retirement rules, see the last post in this series, How to Inspect and Retire Climbing Gear.

Seaside Longdong: wipe off the salt

Longdong is a seaside crag, and salt in the air corrodes metal. TOCC says BD axles and trigger wires oxidise and rust easily at Longdong (without affecting strength), while DMM and WC metal parts resist oxidation better. They estimate that cams used normally and well maintained last 10–20 years. Mountain Project's Longdong page also says to clean your gear after every trip: it may seem fine that night but not work at all after a month in your closet.

The routine from Wild Lily Rock's guide to trad gear maintenance (in Chinese):

• Every trip home: take the gear out of your pack and wipe it down with a damp cloth; don't leave the pack sealed up in your car or at home.
• Deep clean: climbing about eight days a month, soak your cams in warm water and scrub the joints every 2–3 months, then dry them thoroughly.
• Lubricate: use a dry PTFE or wax lubricant, not WD-40 long term. Keep lube off the sling and off the lobe faces that contact the rock.

Something you can do tonight: pull each cam's trigger fully and let go. If one springs back slowly or feels gritty, it's time to clean and lube it.

Practice: four scenarios

Answers are below each question; think first, then look.

1. Your partner uses DMM Dragons and you use BD C4s. The route info says "needs #1" and your partner says "I've got a 1".

2. You can only afford four cams and mostly climb at Longdong.

3. A friend tells you to buy a full set of Totems as your first rack because they're "the best-performing cams".

4. You get home from Longdong tired and plan to leave your pack in the car until next week.

Next

That covers everything you need to buy. The last post covers how to check your gear once you own it, and when to replace it: Part 12: Inspection and Retirement.

References

Manufacturer product pages and prices (checked 2026-10-24) are linked in the table above.

• 如何打造第一套傳攀裝備 / Building your first trad rack (TOCC, 2024)
• 淺談傳攀裝備保養 / Trad gear maintenance (Wild Lily Rock, updated 2022-10-20)
• Long Dong (Dragon Cave) (Mountain Project)
• How to Build Your First Trad Rack (Black Diamond)
• Adventure Taiwan: Single-pitch trad climbing course
• The Best Climbing Cams (OutdoorGearLab, updated 2025-04-04)
• New and Improved Wild Country Friends (Katie Griffith, Alpinist, 2026-05-23)
• C4 Extendable Sling Camalot (Black Diamond)
• Building a Trad Climbing Rack in 2025! (JB Mountain Skills, 2025-09-08)
• Buying your first Trad Rack (UKClimbing, 2025-09-01)
• How to Build a Standard Trad Rack (Valhalla Mountain Guides, 2024-10-07)
• DMM Dragon Review (0–5) (Jonathan Ness, 2026-06-29)
• Metolius Ultralight Weight Master Cams Review (Grant Climb Big Rock, 2025-04-23)
• Are NEW Wild Country Friends Worth it? (Outside.co.uk, 2026-07-13)
• All of the Climbing Gear You Need in 2026 (Noah Kane, 2025-07-01)
• Watch This Before Buying Climbing Gear in 2026! (The Gravity Lab - Brant Hysell, 2026-04-24)
• Produkttest Totem Cams (Lacrux TV, 2025-11-10)
• Building a Mixed Rack of Rock Climbing Cams with In-between Sizes (J. Adams, 2025-04-03)
• First Look: New Climbing Gear for 2026 (UKClimbing, 2025-06-23)
• Nuts Or Cams? James Pearson's Trad Climbing Tips (EpicTV Climbing Daily, 2024-11-08)
• 攀岩裝備全拆解！Multipitch 新手必睇懶人包 (G for GoOut 朱遊記, 2026-10-15)
• Placing Trad Protection
• Nuts
• How to Inspect and Retire Climbing Gear