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Single Crown vs Dual Crown Fork: Which One is the Best for Enduro? 39

Dave Cerutti of Rulezman Suspension pulls off a very in-depth study to answer this burning question with data and real-life testing.

Single Crown vs Dual Crown Fork: Which One is the Best for Enduro?

Single crown vs dual crown, which one is the best for enduro? Yeah you hear me right, a dual crown for enduro? You think I am crazy? Well….read this!

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Enduro is a type of race where all timed stages are pointing down, you may have some narrower tracks compared to what you see on the downhill but you are still pointing down. Enduro races are to me camouflaged downhill races where you have to pedal up your bike instead of taking a chairlift, and is it not the case that some of the best enduro racers out there were formerly downhill champions before making the switch to enduro?

You can watch the video below if you prefer that format, or keep reading the article to find out how the testing went.

 

100% of downhill bikes are equipped with dual crown forks because it is known and recognized worldwide that dual crown forks give the best performance when you are pointing down, the question is straight forward: why not use dual crowns forks for enduro ?

Are you the one that thinks that your single crown is already good enough? Maybe with a dual crown we can go faster and shave off some seconds and gain a podium , or are you scared you cannot pedal the dual crown uphill? Are you scared you can’t manage the tight corners with the dual crown?

Lots of open questions here.. so single crown vs dual crown for enduro , which one is the best?

A long time ago I started to think that single crowns forks they may all have a big weak point , and the big point to me is actually the “single” crown design.

What about big stanchions? You may have single crown forks with really super stiff O.D big stanchions, yes, I really think we could even build a beefy fork with 50mm huge and stiff stanchions but if we attach those legs to a single crown sort of weak design we may have no benefits out of the bigger legs - in practical words you can translate this visually looking at any of the pink bike’s huck to flat series.

In the dual crown we have 2 crowns, the forces are better distributed and handled, especially if the dual crown is an upside-down design.

My idea was to pick up 2 forks, one single and one dual and make a side by side ride test on enduro trails, and see which one is the best.

The TEST

Initially I had to think at which forks I could have brought in the test, I wanted the best of the two worlds: single and dual, but the problem was there is no specific enduro dual crown fork in the market, and so I had to pick up a downhill dual crown fork and transform it completely to make a real enduro dual crown fork.

For the single crown the choice was pretty easy, I took the best I am aware off: the stiffest, the lightest, the best riding out of the box , Manitou Mezzer 37mm chassis, pure perfection in a extremely lightweight 2 kg package, to me the best fork hands down in the beefy single crown forks market.

For the dual crown it was an easy pick too…I selected the most advanced, versatile, and best performing downhill fork, I know since more than a decade, which is the Dorado with some of the upgrades I implemented through the years which I call RRT, Rulezman Race Tune.

Steps done to transform the downhill dorado into the enduro specific weapon for enduro (this is something no one did before):

Step 1: Air Leg

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Originally the Dorado has 203 mm of travel, Mezzer is at 170, I had to rework the internals to get the same travel, same axle to crown height as the Mezzer: a difference in travel and / or height would have changed the geometries of the bike and I don’t want to ride two different bikes in the test. I reworked the air leg internals, doing all the modifications required to obtain on the Dorado exactly the same, masterpiece Mezzer air curve: all this verified and certified with one of the best machines I have in the workshop , which is the spring dyno. At the end I had two identical forks.

Step 2: Hydraulic Leg

Dorado has a semi open cartridge , while the Mezzer uses a sealed cartridge with compensating bladder: the difference is too big and not acceptable for a fair test, so, after a week of studying and trying things, I came up with some magic tweaks to create a prototype Mezzer cartridge that fits into a dorado right leg.

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This not only made the test super fair because I will ride same cartridge and clicks with both the forks, but this also helped me shaving off another 100 grams out of the already light custom Dorado RRT, ending up at just over 2700 grams, not bad for a dual crown enduro fork, solid as the Dorado is!

Step 3: Stem and Cockpit

We are all used to see enduro stems in the 35-40mm range, while the downhill typical stem length is usually a few millimetres longer, 45-50mm. I run a completely different setup from what you are used to see around, this just rides better: I am on a 10mm stem and dual crown forks, with 1 size up longer bike.

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Luckily there is a brand that makes 10mm direct mount stems, even before I had to machine my own one back in the days, this time I had to machine a couple of stem spacers to match on the dual crown the handlebar height of the single crown build, both the handlebars must come up in the same final position with same height with both forks.

Step 4: Offset

Dorado is a full native DH beast, 49.55mm offset while my Mezzer is at 37. The difference is not acceptable for a fair test, so the only option was to change the crowns on the Dorado and transform it into a full 37mm baby. Sadly I saw there were no different offset crowns available after-market rather than original, so..I went down to Bologna Emilia-Romagna, the land of the motorsports in Italy, Lambo, Ferrari, Ducati…Maserati...all there and I looked for the main man of moto GP frames/metalwork guru master inventor I am aware of…. went there and asked him to make me a pair of custom crowns , staring off a solid block of 7075-t6, reduced offset, completely custom made , unique on planet, a task that only he could have done properly - period.

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It has been a long wait but when the courier knocked my door with the parcel containing the freshly made new custom crowns…wow, I was like a young boy on Christmas eve when he opens the gifts and discovers he just got his first mini-motocross bike.

Step 5: BRAKE DISC

Dorado uses 200mm only, but I ride 180 in enduro, big difference here! I guess many of you now are wondering why I am on 180 disc only instead 200? Well, I reply saying that I am only 70 kg, and I run good brakes and I break only when needed ….180 is more than enough for my ride. On top of this, there is actually a more meaningful reason for using smaller discs: and it’s the weight! Keeping the unsprung masses light is a good little trick to improve suspension performance, the lighter the wheels, the better the suspension works.

So I created an adapter to go 180 on enduro dorado, it was an interesting work to make my own custom caliper mount, a day of thinking, drawing, milling machine and hand filing, and the custom brake bracket came out nice and clean.

Two identical forks sharing same air progressions, a2c, travel, cartridges, offset, and geometry….except weight and number of crowns.

Let’s install for the fist time the custom enduro dorado RRT 170 on the bike…

Ohh man, wait wait…I forgot that MTB industry changes every other day the standard of something, Dorado is meant to be a downhill fork and this means 20x110 standard hub ….Mezzer is enduro, different standard: 15x110BOOST. And so my super nice, stiff, light, front wheel that I ride with the Mezzer does NOT work with the Dorado!…f#$@ off.

Let’s browse the net, fill some baskets, click some buy it now buttons and wait for the new parts to arrive , so I can start lacing up the enduro Dorado front wheel. I want the two wheels to be identical for the usual reason : a proper test is not a true test if I don’t zero all differences rather than what I want to test: so both wheels must be similar, have same tension, components, rubbers, weight, same stiffness, ride quality. I really gave my best to clear out the variables in this test.

PRACTICAL PHASE

This test is a test for ENDURO riding and racing, and to me this means pedaling up somewhere on an easy gravel or tarmac road no stress and then perform a flat out timed stage pointing downhill. For the practical test I decided to use a typical section of an enduro EWS race, and since Finale Ligure is the backyard where I grew up, it was pretty easy to find the right spot for the test.

I selected the best enduro loop I know, a nice 20k ride composed by 1000mt uphill transfer on tarmac from Feglino to Nato Base, followed by a 1000 m of descent single track style, enduro 100% Crestino trail, by the way some sections of this trail were used for the fourth stage Finale EWS back in 2016.

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I cycled this loop more than 30 times in 4 months alternating the two forks: single and dual crown, and rode it in almost any climate condition, cold, hot, dry, rain, muddy…I’ve done a total of 600 km with 30 thousand meters of climb and 30 thousand of descents: that was like doing about 15 EWS races within the time of the test.

I was not kidding on this, I really gave my best for a consistent and reliable test. On all my days out on the bike I recorded everything with GPS, bike computer, GoPro, cardio meter, including a few days out with suspension data logger too.

Most of the days I was riding alone, no stops, no talk, no time loss, but a few days out I ’ve been riding with some pro racers, people like Fabietto for instance, following me with GoPro which was a nice way to have some real video takes, like the one you are seeing in the video. Let’s see the results of the loops but let me split in two parts; uphill and downhill….let’s analyze the uphill part first..

UPHILL TRANSFERS

All guys I talked to about this test asked me “Dave, how can you pedal uphill a downhill fork”…you crazy. WELL.. this is not a downhill fork, this is a USD dual crown prototype ENDURO fork, I replied. The only difference with your single crown enduro fork is the extra weight I have and the number of crowns, but rest of things stays the same: my body position on saddle is the same, reach is the same, handlebar height is the same, head angle, wheels, rolling resistance and so on. To me the ONLY big open question for the uphills with a dual crown is if pedaling with an heavier fork is a limiting factor for the uphill performances on the enduro transfers.

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Before going practical, I met one of the best road-bike guru I know (he is a Giro d’Italia road-team coach), and I told him the story…I asked him, what I should expect going uphill adding 700 grams on top of my 70kg and 14 kg of bike. He did some calculations and ended up saying I should expect a 0.8% delay on the uphills. This means 34 more seconds out of 1h10m of climb, for my standard 1000 m climb. That day I was really shocked…what the f#$@...he said? 34 seconds more only?

Yes, I trust him, I know he knows the stuff more than anyone else around, but I really like to go practical and test the numbers values with a stopwatch: This is why I climbed 30times the thousand meter transfer even if I was already convinced that his answer was the right.

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Instead of climbing with an easy pace on the uphills as required on the EWS races, I pushed hard because I really wanted to see if dual crown is a a problem going up.

Let’s see some data: out of 30 times I climbed, let’s report the 10 most meaningful climbs :

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Sometime I was faster on climbs with dual crown and other times with single crown, the only meaningful thing I can note from the numbers is that the more I was trained (and so deeper into the training season) the less time I needed to climb to top, no matter what type of fork I had upfront.

The last day has actually the fastest time one because I had the best fitness level through the few months of tests, it is only circumstantial that I had the single crown installed .

We can observe some great timings in the chart with dual crown too done in days where I was even less trained.

So my friend was right: on the climb, a weight of 700 grams gives you a 0.8% delay on the uphill time, don’t forget this value is calculated on a 70kg rider plus 14 kg bike.

If you are 85 kg, and/or your bike is 15 kg heavy maybe equipped with an heavier single crown than the Mezzer, say 2.4 -2.5 kg , this percentage drops at meaningless 0.2%.. which is 8 seconds of delay on an hour and 10 minutes of climb.

Enduro races have pretty large transfers timings and so result of my test for the uphill clearly demonstrates that: there are no issues on climb transfers having a dual crow fork.

DOWNHILL STAGES

Here it comes the nicest part of the story: I know the trail Crestino pretty well, been riding it for at least 30 years…..all trees call me by name when I pass by…Crestino is a trail with a lot of flow upper part, the rocks, roots, and a few power pedaling uphill sections too, perfect type of trail for a classic enduro long stage, last but not least the most difficult parts come at the lower part of it….exactly when you start to get tired .

I do warranty you that I did 100% of descents gaining the top by pedaling like in races, and every single day out on the bike I squeezed my self trying to beat my PR both uphill and downhill. Real old school enduro, no shuttles, no chairlifts and no coasting downhill…full gas mode only ON.

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As seen for the uphill, I made a chart with the most meaning-full 10 descents.

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First place, dual crown with 13m:26 s

Second place single crown, with 13:46 (+20 gap) followed with a mixture of runs with dual crown and single crown.

As you can see we are talking about a long 13-14 minutes stage, perfectly as expected for hard core enduro EWS stage.

Let’s talk about the results now:

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20 seconds gap between single and dual crown may not seems a big gap on a 13 minutes run, but we must note that the winning run with dual crown was done with super nasty wet conditions while the best run with single crown was done with a lovely dry easy perfect condition, so I think we should start looking at that the 20 seconds gap as a huge difference in time.

Overall my riding feelings said that I was faster and with more control with dual crown, and the stopwatch confirmed it. Funny thing is that with single crown I felt I was going super fast too, and felt also super controlled and stable having a log of fun, but…timed results said I was slightly slower than dual crown.

Some of the descents were done with data acquisition installed, to cross checked the travel used, suspension speeds, balance, residual accelerations on the frame and many other technical numbers to make sure both suspension were set in same way: nothing strange to report here, all perfect. There is a big variable however in the downhill test made at the CRESTINO: my fitness condition !

Since I’ve climbed those 1000 meters with my own forces 100% of times squeezing me out to death trying to beat my PR on the climbs too, my physical condition at the beginning of all the 30 descents was always different time to time, in fact I had days I felt really tired at the top and others I felt stronger before commencing the descent.

So I decided make a second group of downhill tests, and I brought both the forks to an enduro bike park to perform runs on same track, on same day, with same weather condition, and most important, using 100% of times a chairlift to reach the top, without wasting any physical energy. Location of the test, Viola St Gree, a local, but extremely nice bike park 1 hr from Finale Ligure, a park where I can find one of the most gnarly tracks for hard-enduro training and tests, a sort of a more difficult Crestino: this one is a full rooty, rocky, off-camber trail with super steep sections in the last part.

I‘ve done a dozen of runs there of which the first batch to learn the lines, gain speed, and trust myself and the bike until I was ready to shred…Then, I did 3 flat out runs with dual crown and 3 more with single crown.

These are the times recorded:

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Dual crown, first place overall with 05m:32s followed by single crown with 05:48 (+16s gap). I have to admit one of the runs with the Mezzer seemed to me the winning run in the mean time I was descending…but on a steep section at the end of trail I crashed, and so game over.

I was really happy descending with both forks, confident and fast with both, and with single crown I felt faster but maybe a bit too excited ending up doing more riding mistakes, …. the stopwatch is completely spot on saying that dual crown was the faster on the day, at least it was the fork that brought me down home without any crash.

Not finished yet There is also a third and last riding phase, which Is not a proper test because I brought only the dual crown to real French Alpine environment, using it for long tours enduro simulating those big EWS Alps descents, did some long tours with 2000 meters of climb and extremely long natural descents. I’ve been there the previous years with the single crown and so I remember how was to ride single crown over there.

I had zero issues with dual crown over the single even on the alps environment!

CONCLUSIONS:

Who is the winner? SINGLE vs DUAL CROWN

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My feelings were pretty good with both the forks even if the stopwatch assigned the title of faster fork to my enduro dual crown prototype Dorado. Differences between the two were really minimal. On top of everything I felt the stiffness of the cockpit “in hands” and what happen beneath the crown.

Let me explain better: the handlebar on dual-crown is attached to the fork with a direct mount stem which gives you a pretty solid connection between the rider and the bike and at the same time, under the crowns, the fork works out the obstacles pretty nicely with its mix of stiffness and compliance, making a really pleasant ride.

I’ve heard a long time ago this is the magic feeling of the upside down design. On single crown / classic stem combo, I felt the handlebar being a tiny bit more flexy side to side even if my carbon handlebar is high quality and really stiff, I also felt a minimally stiffer lower end which gives a little more snappier ride especially on direction changes: I don’t wanna say this was better or worst, the single seemed to me a little more prone to snappier trajectory changes and more overall reactive and nervous, while the dual crown seemed more stable, more composed, perhaps more relaxing.

Minimal may seem the time differences recorded with the stopwatch between both forks, but I’ve seen world cups won by a fraction of a second, so a minimal difference in time could be a huge difference in real life between a world champion and a runner up.

This is another last but not least minor difference I felt between single and dual: there are times when you are going to crash, and then you pass through the line alive, say thanks to your god…you know those scary moments you are in the air seeing yourself landing nose down onto an off camber root bracing for impact….well, in those cases the dual crown had some magic stuff inside that makes you walk away alive without crash this may-day avoiding magic-property seemed to belong to upside down dual only, so far.

We have to change the single crown with a dual crown to ride enduro?

And in my opinion for the classic average rider there there is no need because the average rider do not ride on the limits, those few times I gave the max passing my 100% looking for the PR or a KOM,… the dual crown seemed to be the one that helped me a little more. If shaving off precious seconds to gain enduro podiums is your need, well,  then yes the enduro dual crown is the clear winner, hands down. If you are looking for having fun every day, riding any type of terrain without going crazy with a stopwatch or STRAVA, just having fun no matter the difficulty of the trail, you can ride any black trail with a good single crown…then single crown is more than enough, trust me.

Until a few years ago, there was a clear and huge gap in performance between single and dual crowns but today, after having ridden the Mezzer , I have to admit the gap is really narrow, nearly zeroed, and this blows my mind a lot: engineers did a great masterpiece with this single crown fork.

I would really like to see what a real pro could do with both, I am not good enough to find the fork's limits that may be larger than the one I never found with either. Weight wise also, I am pretty light, but I guess that the heavier is the rider the better dual crown responds.

Last but not least, don’t forget, we were all running 26” wheels, 135mm hubs, and crappy forks and…we were all having fun, so don’t get mad on this debate now.

Enjoy your rides.

Dave

www.rulezman.com

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