[Closed] Formula dual crown prototype fork for enduro

Makes sense, you don't really notice the dual crown when using a lefty for XC or a dual crown fork for DH so stands to reason it'd be a non-issue for the inbetweeny-enduro bikes.

Maybe this will wake the big players up? Just seems a better solution than ever chunkier crowns and thicker stanchions on single crown forks.

Chris Porter is an advocate for these type of forks (Morc).

Wait, does that mean my 170mm Super T's are back in fashion?

Ever single I watched those Pinkbike super slomo huck to flat videos I’ve been convinced that double crown is the right way for longer travel bikes. There’s so much leverage around a single crown on a 150mm+ 29” fork!

My own 160mm 29” Lyrik needing a new crown steerer unit at its last service has further convinced me…

Wait, does that mean my 170mm Super T’s are back in fashion?

Junior T surely at that travel?

Which raises a point, they were a bit rubbish as the upper crowns were fairly straight and the offset was in the lowers as they re-used single crown ones which meant very limited turning. I wonder if Formula will sort that for the final production versions?

Remember the Judy XL? I'm all for a twin crown fork on trail and enduro bikes.

Single crown forks have grown so much of late, I think there's a good chance that a twin crown wouldn't need to be any heavier.

Surprised it hasn't been done already, no more creaky crown units, adjustable axle to crown heights thus also adjusting head angle, larger air chamber and it could be even lighter by removing material from the steerer tube, like Intend's infinity fork, I think formula are on to something with this.
Didn't sam hill have a reduced travel boxxer on his mega at one point.

spaniardclimber

Chris Porter is an advocate for these type of forks (Morc)

He's the Formula distributor too. Wouldn't surprise me if he's had more to do with these than just inspiration.

The new superenduro bikes with 170-180m travel it makes a lot of sense

Love Formula's fork top controls, I could never own one, I'd just want to constantly flip the lever and spin the dials. Like having a Bop It for suspension.

Love Formula’s fork top controls, I could never own one, I’d just want to constantly flip the lever and spin the dials. Like having a Bop It for suspension.

I've got the Selvas and yeah it's always tempting! Super good forks too, very curious about this new enduro dual crown. A couple of guys I ride with have fox 40s reduced to 170mm on their bikes and they absolutely love them. They climb just as fast as everyone else but say with descending that they just feel amazing.

I think dual crown enduro forks have been a long time coming. The big names just want to sell us another couple of generations of increasingly porky single crown forks which still flex and creak before unveiling the 'new big thing'. Sam Hill or Richie Rude will turn up at an EWS with a FOX/RS prototype dual crown and there will be an overnight switch. They'll be slimmer, lighter, stiffer, all that good stuff. They'll probably have a 17.5mm floating axle so you need a new wheel.

Might as well put your Zeb's and 38's on the classifieds now.

If it puts an end to creaky crowns, then I'm all for it.

Of course these were really popular werent they....!?

Anyone else remember the 'Boxxer ride' basically a U-turn Boxxer (can't remember if it had lock out), either way it wasn't a big seller either.

Much as I loved dual crown forks on my DH bikes (when I rode such things) all the extra metalwork and clamp bolts are probably of limited appeal on a Trail/Enduro bike these days where weight saving is a consideration.

Plus I'd actually question how beneficial moar stiffness really is, a bit of fore/aft deflection in a fork has probably helped many of us without actually being noticed.
If fork stiffness really mattered that much 20mm axles wouldn't have been retired from general use/sale.

It's more than likely widespread adoption of dual crown forks for enduro would just precipitate lots more frame write-offs, as people's 780mm bars provide a lovely lever arm to smack an upper leg into the top tube of their carbon dandyhorse in a tumble...

Pace did it back in '99 RC37s 🙂

cookeaa

Plus I’d actually question how beneficial moar stiffness really is, a bit of fore/aft deflection in a fork has probably helped many of us without actually being noticed.

Rockshox reckon the Zeb isn't very different to the Lyrik in terms of fore/aft stffness, it's torsional stiffness that it's better at or the most part.

Of course these were really popular werent they….!?

They might have been if they worked. They were garbage.

 all the extra metalwork and clamp bolts are probably of limited appeal on a Trail/Enduro bike these days where weight saving is a consideration

It'll be interesting to see how much of that extra weight can be offset by using sensibly sized legs and losing the comically over built crowns.

An enduro specific dual crown can't be that much heavier than a Zeb or 38. And if it's a handful of grammes in exchange for stiffness and less creaking lots of people will be willing to make the trade.

This is an annoying development. Mainly because my mate has been riding Boxxers on normal XC rides, claiming they're better than the alternatives. If he's vindicated it'll make our lives so much worse.

Pace did it back in ’99 RC37s 🙂

I had a set of these.... they were bloody awful.!! 🙂

cookeaa
Full Member

If fork stiffness really mattered that much 20mm axles wouldn’t have been retired from general use/sale.

Yeah, that was literally nothing to do with stiffness though, or the actual advantages of the axle sizes, it was all about 2 things- manufacturer power (with Fox and Shimano backing 15mm and having more OEM influence than Rockshox back then) and the ease with which you can convince people that since 15 is less than 20 it must be lighter, even when it's generally not.

Arguably it was the first time manufacturers really tested the fact that the end consumer who buys 1 fork or 1 bike with a fork, has no real buying power compared to the OEM procurement guy who buys 20000 forks. Fox and Shimano flexed their muscles and the better standard died.

The fork is already around the same weight as the Zeb so I don't think weight will be a deciding factor considering a direct mount stem can safely drop below 100g, also letting you chop more off the steerer or Formula could lose most of the steerer, both Intend and Chris Porter's Morc crowns have shown you don't need a full steerer sliding through your headtube with dual crowns.
And we're already seeing enduro bikes entering the market safe for dual crown use so I think its the next big thing.

Junior T surely at that travel?

Nope, Supers and Juniors both topped out at 170mm, to get more travel you needed to go for a Shiver or 888.

My Supers weigh an absolute ton despite being 32mm, 3kg IIRC but that's a twin coil setup. Wonder how light you could get them with a single ti spring or an air cart?

Plus I’d actually question how beneficial moar stiffness really is, a bit of fore/aft deflection in a fork has probably helped many of us without actually being noticed.

I'd be tempted to say fore/aft flex in forks is probably the most detrimental flex that's still accepted or left to be fixed in bikes? I probably need to think that through a bit more but it still bugs me on more of my bikes than it should and I have a Jones with a truss fork to compare to. That rearward flex isn't going to stop you riding something and I expect some of the bigger recent forks don't have much of a problem with it - been a while since I rode a new, large-stanchion suspension fork - but for sure some sus and rigid forks flex in negative ways.
Flexing forward can add a bit of comfort so on some bikes it's seen as a benefit but the same amount of flex happens under braking. +/- 5-10mm? And we thing offset is important. Depends how much you notice or care about these things though.

I expect if weight and performance were equal, if you blind-tested a stiffer fore-aft fork vs a standard one you'd pick the stiffer fork as the better-performing overall. The more hard braking or steep rough stuff you ride the sooner you'd make the call.

Plus I’d actually question how beneficial moar stiffness really is, a bit of fore/aft deflection in a fork has probably helped many of us without actually being noticed.

Said nobody who rode a set of USD forks ever.

A bit of flex is fine but long travel single crown forks have far too much, hence the ridiculously beefed up stanchions, steerers and crowns.

I wonder if Formula will sort that for the final production versions?

Not if they're set on their plan of sharing the lower castings with other forks.

both Intend and Chris Porter’s Morc crowns have shown you don’t need a full steerer sliding through your headtube with dual crowns

Let's not forget Rex Trimnell...

Interesting option for those who want this, but I wonder if it's as many as the internet comments might have you believe?

And I wonder how many of them have actually ridden the Zeb, because IMO it feels closer to a dual crown than it does to a Lyrik. Similar to a Totem or 66 for those who remember.

Also, if I were taking that extra weight, I think I'd prefer it to be in the form of a coil spring.

“Flexing forward can add a bit of comfort so on some bikes it’s seen as a benefit but the same amount of flex happens under braking. +/- 5-10mm? And we thing offset is important.”

This relationship between fore-aft flex and offset is something I’ve been pondering for a while - under hard braking or when we hit a large bump, do we gain increased stability from the flex reducing the offset and thus increasing trail?

What's the risk of damaging your frame in a crash with dual crown forks due to the upper leg contacting the frame?

High. And the frames have to be designed and tested with dual crown forks in mind as well, as the stresses are distributed differently. There are lots of considerations sitting in the way of any move to dual crown use in a class of bikes currently not running them. But the benefits are arguable far greater than widening the rear dropouts a few mm... so it's not impossible that it'll take off.

What’s the risk of damaging your frame in a crash with dual crown forks due to the upper leg contacting the frame?

Well Trek and a couple of others think single crowns need stops on the frames so it's not really a triple crown issue.

This relationship between fore-aft flex and offset is something I’ve been pondering for a while – under hard braking or when we hit a large bump, do we gain increased stability from the flex reducing the offset and thus increasing trail?

Bear in mind I ride rigid forks far more than suspended these days. I expect the moment that the fork is flexed back is so short that theoretical stability gain from increased trail is lost in the noise, but the distraction of fork flex and flutter under braking is noticed. If your sus compresses under those forces your head angles steepened and that's a greater change than the flex could account for. Still, it's there, if only briefly.
Also that I'd say the Jones's truss fork feels as it it helps keep momentum or rolling through steeper, slower chunky stuff better than a bike with a flexible rigid fork, less momentum goes into bending the fork and can feel a bit twangy-stally at times. It's all subtle stuff in reality but it feels more capable or confidence inspiring as part of a system all pulling in that direction. When the front and rear wheels are moving / suspended it might be more masked and the bending forces my be changed or reduced by the sus allowing the wheel to move over things anyway.

Coming to a Geometron near you....

They actually look pretty good - lets not forget that Dual Crown forks make your bike look bad-ass!

Well Trek and a couple of others think single crowns need stops on the frames so it’s not really a triple crown issue.

Trek do this because they've chosen a downtube design which could be hit by the fork crown.

Other brands have a bit of a bend or whatever to avoid the potential for contact.

I know that and what they are for but it's still not just a triple crown issue is it?

Exception that proves the rule IMO.

All these perceived pros and cons are irrelevant. As soon as they start showing up on EWS bikes your single crown forks will be obsolete. The marketing departments are probably working on the copy right now. All they need is a few shots of Sam Hill going sideways in the dust with a dual crown fork and it's all over.

High. And the frames have to be designed and tested with dual crown forks in mind as well, as the stresses are distributed differently. There are lots of considerations sitting in the way of any move to dual crown use in a class of bikes currently not running them

Do you really believe that they want you to buy a new fork and fit it to your existing frame? Why not buy a new frame? Something optimised for dual crowns obviously. Probably with a new headset standard.

I personally can't wait to see the end of swoopy downtubes. I want them straight and fat.

But Sram and Fox aren't making dual crown enduro forks and have bet on beefy single crowns instead, so the comment-section-conspiracy-theories don't really stack up.

The big manufacturers can be quite stuck in their ways. They won't even offer coil sprung forks, despite there being a clear demand and performance benefit (along with the downsides obvs).

Can't see Sam Hill wanting a dual crown either. He said in a recent interview he was even thinking about racing the Reactor in some enduros.

Do you really believe that they want you to buy a new fork and fit it to your existing frame?

Not in the slightest. I'm pointing out that for the bike brands to shift a class of bikes to use dual crowns doesn't just mean a change of build spec. It's like the shift to boost148 or SuperBoost rear... it'll need designing into the frames. I hope they do as it happens. I won't be crying about "marketing" if they do, because it could offer real advantages... unlike a few mm in OLN spacing.

chiefgrooveguru
Free Member

This relationship between fore-aft flex and offset is something I’ve been pondering for a while – under hard braking or when we hit a large bump, do we gain increased stability from the flex reducing the offset and thus increasing trail?

Yes, but you lose that stability from the flex shortening the wheelbase 🙂

But Sram and Fox aren’t making dual crown enduro forks and have bet on beefy single crowns instead, so the comment-section-conspiracy-theories don’t really stack up.

Because they're busy selling comically fat but still flexy and creaky single crown forks which are the latest greatest thing. And they'll continue to sell them until they need to sell the next big thing. Where else are they going to go with forks now?

Because they’re busy selling comically fat but still flexy and creaky single crown forks which are the latest greatest thing.

Tell us about your experiences riding the Zeb or 38 then.

Thing is flex in different places does different things. Like, the only time I've ever ridden a fork and gone "this is flexy enough to be a big problem" was a long travel Fox 32- basically an XC chassis that they'd stretched way too far, to try and compete with the much stiffer rockshox of the time. When you braked hard, it flexed enough to cause the fork to seriously bind up in the lowers, horrible. Changing that to a dualcrown would only make it worse, because all the same forces that used to flex the entire fork, are now going to flex the weakest spot even harder.

So it's a balance. Adding stanchion strength makes the whole chassis from the crowns down stiffer. Going dualcrown makes the top of the chassis stiffer. It's not doing the same thing as say switching from a Pike to a Zeb. It comes a point where stiffening up the bottom of the fork where it's probably most impactful overall, puts more stress on the top and then something that worked great before, might prove not good enough.

And then the real question is, where do you actually want the stiffness? Where is it not enough, where might it be too much. Lots of space to have different opinions. I'll stick with my singlecrown 36s personally, but then I weigh 10 stone and I'm not that fussed about a bit of flex as long as it's not actually causing the forks to function poorly. Tried a Zeb, it's a worse fork for me. But a heavier rider, or someone that really likes a direct stiff fork, could want something different and we'd both be right.

I reckon most riders would be better served with improvements in dampers and springs than in chassis, though. And I can see a stupid timeline where half of 2023's new models are dualcrown forks with basic airsprings, motioncontrol and grip dampers, and the like, because the novelty and headline grabbing nature of the dualcrowns sells easier than a coil spring.