# Dual and single crowns?



## Moosey (May 18, 2010)

Just go started on fr/dh and am curious, what's the difference between dual and single crowns, and what is a crown? Thanks.


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## Iceman2058 (Mar 1, 2007)

1...


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## PepperJester (Jan 2, 2003)

Dual crown forks are (generally) stiffer and less flexy and over all stronger then their single crown counterparts. Also most dual crown forks offer a bit more travel, most around 200mm where as generally single crown forks top out at 180mm.

Advantages of the single crown are mostly in them being a bit lighter due to less material be used and they allow you to turn your bar further so their handy for super tight trails.


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## SHIVER ME TIMBERS (Jan 12, 2004)

think of crowns as the cross members on the fork...hence a single crown has one connection between the two tubes (plus axle when on a bike). 

Dual crowns have two crossmembers around head tube but most are really technically a triple crown fork (one above tire and the two surrounding head tube)...

only inverted forks (upside down forks like a shiver or dorados are true dual crowns-everything else is technically a triple crown)


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## Iceman2058 (Mar 1, 2007)

SHIVER ME TIMBERS said:


> think of crowns as the cross members on the fork...hence a single crown has one connection between the two tubes (plus axle when on a bike).
> 
> Dual crowns have two crossmembers around head tube but most are really technically a triple crown fork (one above tire and the two surrounding head tube)...
> 
> only inverted forks (upside down forks like a shiver or dorados are true dual crowns-everything else is technically a triple crown)


Have you been at the pirate rum again SMT?  So are you also saying that single crowns are actually technically real dual crowns, like Shivers...? :skep: (  )

Pay no heed to this rambling old seaman. Dual crown = triple clamp. They have 2 CROWNS (the things that attach/hold the stanchions to the steerer tube), each of which has three CLAMPS (one for each stanchion, and one for the steerer tube). Thus, confusingly, a single crown has no clamps (pressfit), whereas a dual crown has 3. Well actually 6.

Plus the brake arch. Which has nothing to do with brakes anymore.

:thumbsup:


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## rdhfreethought (Aug 12, 2006)

SMT is correct, and wrong at the same time.

AFAIK that is why people call dual crown forks "triple crown". It is true they have 3 crossmember, but they do not have 3 crowns. Crown is derived from 'head', hence 'headtube'. The crown, or 'head' of the fork is what holds the stantion tubes. There are only 2 of those on a 'Dual Crown' fork (i.e. Boxxer, 888, 40). 

Hence, the term 'triple crown' is both archaic and inaccurate.

Also, due to the lack of a longer clamp area, a long travel single crown fork will need more material in the single crown, than a dual crown will need in its lower crown. Hence the weight advantage is minimal with a 180mm single vs dual crown. If you were to build a 200mm single crown, with equivalent stiffness as a 200mm dual crown, you would lose all the weight advantage, and likely the single crown would be heavier.


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## ryan_daugherty (Oct 8, 2006)

Dual Crown =









Single Crown =


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## trailadvent (Jun 29, 2004)

RDH is correct however to confuse things slightly more, as per usual in the MTB world its caught between the road cycle industry and dirt bike world or moto.

Triple crown or dual crown really was a take on the correct term triple clamp. there is no single clamp forks in moto so no term, so RDH is correct for mtb speak lol.

That said the key difference in performance is not so much stiffness as stiffness is dependent on many factors, bike frame, head tube dia, e.g 1/8th in a single or 1.5 in a single crown fork, same with triple clamps or dual crowns lol so the waters can muddy.

For example a Totem fork, 40mm dia stanchions the tubes between the lower legs and crown/s can be a very stiff fork, especially more so with a 1.5dia fork steerer tube, interfaced to a 1.5 head tube on a freeride bike..

Its arguable which is stiffer as a shorter fork will or can be stiffer as less material to be flexed,

The best term to describe the key differences is stability, this was proved somewhat a few years ago when a few pros tried to race 1.5HT single crown long travel forks, it did not catch on.

Having had too forks for example a 66 170mm [single crown] and a 888 203mm [dual crown or triple clamp fork] I can tell ya the big diff was stability. Both 35mm stanchions/20mm thru axle clamps.

Better is relative to the type of riding ya want to do, if ya can Dh then ya can ride it anywhere no matter how tight the corners!

If ya just entering and want to ride up and down and go big then a single crown might be more suitable, only you can really answer that.

Never a better time to buy a top fork though :thumbsup:


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## Moosey (May 18, 2010)

Ok, I have an old risse and I think it's double crown, and I really like it, soi might look into a cheap single crown and try it out. My risse seems kinda stiff. Got any ideas on cheap (used) single crown forks for a DH bike (intense m1)? I was lookin at a marzocchi drop off with 170mm of travel. What do you think?


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## rdhfreethought (Aug 12, 2006)

TA:
I have often wondered how much stiffer the Totem 40mm was compared to 66 (at 35-38mm) or now the Fox180 at 36mm. It would seem a simple test to measure deflection against a specific load. I know the engineers designing these forks spend many hours tweaking the designs of fork braces, crowns, etc to get good numbers (for stiffness, strength etc) that can be manufactured efficiently. But we have no numbers. The only thing we get every now and then is "8% stiffer than last year" or some other BS.

Maybe there is a German or Japanese magazine that actually tests some of these forks and holds them to their word? In the end, it only matters what rides better for a specific person, but I would bet 95% of people couldn't tell a 10% stiffer fork from it's weaker brother.


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## trailadvent (Jun 29, 2004)

rdhfreethought said:


> TA:
> I have often wondered how much stiffer the Totem 40mm was compared to 66 (at 35-38mm) or now the Fox180 at 36mm. It would seem a simple test to measure deflection against a specific load. I know the engineers designing these forks spend many hours tweaking the designs of fork braces, crowns, etc to get good numbers (for stiffness, strength etc) that can be manufactured efficiently. But we have no numbers. The only thing we get every now and then is "8% stiffer than last year" or some other BS.
> 
> Maybe there is a German or Japanese magazine that actually tests some of these forks and holds them to their word? In the end, it only matters what rides better for a specific person, but I would bet 95% of people couldn't tell a 10% stiffer fork from it's weaker brother.


I agree totally.

Maybe one area of key difference as thrown up by Moosey, depending maybe on how much you've ridden experienced different forks etc you might not fel a stiff weakness as such, but if you had both forks setup for your ride then compared you may feel a difference not so much which is stiffer but more how it rides, sometimes a little give is a good thing just depends where in the fork, Ive often heard qouted that 40mm van give a non delfective ride and at times ya want stability yet you get that in combination of the fork, quality,setup and a bit of flex or give might be a better word in the right area's

Moto's went overboard some years ago, up to and above 50mm and now some of the best are around 47mm or or 48mm 50mm is often a bit stiff, ***********.

Dunno, I stil like the Totems and 66s, yet not so much a fan of the 40 for this reason, its a great fork, but on a triple I like the combination of the right amount of stiffness to track well and maintain stability yet also not to be so stiff it can deflect at sped no matter how well tuned, top rider can handle this because there reflexs are so quick, but it could cost them a sec or 2 here and there.

Why I chose the boxxer, for a single crown I doubt this is as important for the duites say a Totem would perform or 38mm 66, it will be interesting how the 36180mm goes te 66s @ 35mm were pretty good, but the key diff there was that the 66s had much thicker materail esp in the fork steer tube area and lowers hence they heavier chassis, 36s will be light.

In that fork I think for me I'd be choosing the new Lyrik DH, if I wanted a longer travel single crown def be a 66 or Totem.

I do think weight vs stiffness can come at a price if ya really pushing it, some riders on LT will love the new 36 though Im sure, but not for a Feerider that could get interesting to see how muddy those waters get lol.


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## 2clue (Jun 9, 2007)

wow.....I went from not being confused on what a single crown and dual crown is to being utterly confused..  you kiddies are funny


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## trailadvent (Jun 29, 2004)

We like being funny lol

thats what the dub dub dub is about


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## 123ski (Jun 16, 2008)

I know this is an older thread.. but here is a hypothetical that I would like answered.. as hypothetically as possible.. haha:

2004 RockShox Boxer - 178mm travel. 32mm stanchions (or was it 35mm?). non-direct 50mm stem. triple crown. 1.25" steer tube. 

v.

2011 RockShox Totem - 180mm travel. 40mm stanchions. single crown. 50mm stem. 1.5" steer tube. 


Which would be stiffer. Which would be more stable. 

both have 20-thru

opine


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## istandalone (Feb 6, 2011)

my guess would be the Totem, but that's just a coin toss. 

i wish they'd make a Totem dual crown, if nothing else it would look sick.


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## Moosey (May 18, 2010)

i'd go totem... it has 7 years of technology over the old boxxer... those things are stiff. my bud rented a faith at northstar a while back, and it had a totem on it.. that thing was so burly...


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## davec113 (May 31, 2006)

123ski said:


> I know this is an older thread.. but here is a hypothetical that I would like answered.. as hypothetically as possible.. haha:
> 
> 2004 RockShox Boxer - 178mm travel. 32mm stanchions (or was it 35mm?). non-direct 50mm stem. triple crown. 1.25" steer tube.
> 
> ...


I have rode both and the Totem is probably 10x as stiff as the old Boxxer. The Totem is a far superior fork vs the 32mm Boxxers IMO.

A double crown fork is only stiffer than a single crown in the crown, the fork stanchion diameter is at least as important, if not moreso.


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