The Brooks Caldera 6 is an ultra-devouring monster (but)

Posted by Conor O'Neill on Monday, May 22, 2023

UPDATE: See below for a major proviso to this post.

My entire history with Brooks until a few months ago was one pair of Adrenaline 19s which did not suit me at all. I always associated the brand with big reliable heavy running shoes for conservative joggers. The Caldera 6 takes that reputation and shreds it, in the best possible sense.

Caldera 6

The perfect shoe doesn’t exist

I’ve been on the hunt for the ultimate ultra-distance trail running shoe since I started going longer in 2017. After a few false starts, I thought I’d found the perfect shoe in the Hoka Speedgoat 4. It was absolutely perfect for the Kerry Way Ultra Lite and all the training for the Kerry Way Ultra. The GTX version added too much weight but was superb for the nastier muckier stuff. Then they went and ruined things with the Speedgoat 5. It went from a completely locked-in shoe that felt part of your foot to this stretchy sloppy, albeit lighter, disappointment. Whilst it worked fine on the Kerry Way Ultra, I cinched the laces down so hard to stop slippage that I gave myself tendonitis. And whilst I loved the 4, there is no getting away from the fact that the much-lauded Vibram Megagrip is not very grippy at all on wet smooth stones.

So I was on a mission to find a replacement for the SG5.

Salomon Ultraglide

First stop was the Salomon Ultraglide. I’ll do a full review soon but overall it’s “fine”. And definitely a major step backwards in grip.

Saucony Xodus Ultra

Next up was the Saucony Xodus Ultra. Again full review soon but it was a disaster for me. The lugs are amazing on wet grass and mud. They are lethal on wet stones and rock. Worse than road shoes. And they have exactly the same problem as the Peregrines for me - horrendous heel pain due to an excessively narrow heel-counter. Which is weird since I adore the fit of the Endorphin series.

New Balance Fresh Foam X More Trail v3

More recently, I tried the New Balance Fresh Foam X More Trail v3. This is an interesting shoe. Vibram Megagrip outsole with massive lugs. The giant slab of Fresh Foam X is incredibly comfortable and bouncy. On top of this is a roadshoe-like soft upper and 1970s Irish school-shoe laces. The NB is definitely on my short-list for the Kerry Way Ultra and other less rough ultras where comfort is the key, now that I’ve bought proper laces. But they weren’t great on a 5 mile rough loop around Coumshingaun in Waterford. The upper is far too sloppy with poor lockdown and the lugs had the same issue as the SG4/SG5 - fantastic on the mucky/wet stuff but slip-sliding on rocks. I split open my knee as a result. And a few weeks later, I fell again on some damp rocks.

Caldera 6

And so on to the Caldera 6. They look like moonshoes, particularly in the Black/Yellow version I bought. First impressions were of a good fit/lockdown and decent bouncy midsole but not massively cushioned despite the height. The lugs aren’t particularly deep.

Some initial short trail runs showed that it could hold its own compared to all the others above on the mucky/grassy stuff. But it was when I went long and on lots of rocks that its true capabilities shone through.

The rubber in the Caldera 6 outsole is amazing on wet rocks, stones and slabs. I haven’t had one slip. It grips like glue and gives massive confidence when running on mixed terrain. It transformed my experience of doing recces for the Waterville Trail Running Festival.

And the midsole just seems perfectly tuned for ultra distances. Not too squishy and not too harsh, just right. So far I’ve done one 44km, one 88km and one 60km in the same pair and my feet were in perfect condition at the end of each. My forefoot was starting to ache after the 88km of the Waterville Trail Running Festival and the rough terrain of the Beara Way Ultra was starting to cause hotspots at 60km, but that’s it.

The lockdown is better than it looks but very rough conditions will challenge it. As for stability, the overall footprint of the shoe is very wide. So despite the high stack, you don’t feel unstable. I did roll my ankle a lot at WTF but I put that down to me, since it stopped as soon as I started watching my foot placement more. I had no rolls on the Beara Way.

Dirty Caldera 6

As I don’t want a repeat of the SG4-SG5 disappointment, I’ve already bought a second pair of Calderas and put them aside. I suspect version 7 is coming soon since I just got a pair of v6 for €97 when the RRP is €150!

If you’re tired of tip-toeing on wet rocks, this is the shoe you’ve been looking for.

Update - Maybe not so perfect

Things had continued to go well with the Calderas and I did multiple shorter trail runs after the Ultras. Then two weeks ago, after 150 miles, whilst out again on the Beara Way, I realised my left foot was sliding around badly. I looked down to see a complete separation of the two parts of the upper. I really can’t believe Brooks only used glue to hold two highly stressed sections together with no stitching at all. It was almost guaranteed to fail eventually. For this reason I have to withdraw my recommendation unless you only run on very gentle American buffed trails. I’ll continue to use the Caldera 6 but only now that I have re-glued and awl-stitched the two parts together on both shoes. They happily survived a very tough 64km trail run last weekend after my repairs. Hopefully Brooks sees this post and my tweet and fixes the problem for the Caldera 7. (No response on Twitter after a week. What is going on with major brands and the complete collapse of their customer support/interaction quality?)

Busted Caldera 6

Sewed Caldera 6

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