Enduro type frame front fork selection.

[kingjamez]

I see that most Enduro / Stealth style frames use the triple clamp / downhill type front forks. What advantage does the triple clamp give? Why aren't regular forks used?

I'm building a road-only 50mph bike on an enduro frame. What would you suggest as a good value front fork?

-Jim

 

[brumbrum]

'Regular' forks are likely to have a distance length of say 38cm between the fork dropout and the crown race. Down hill forks have much longer legs. The distance between droput and crown race on my manitou dorado forks is 60cm. So you may find that the geometry of your bike is all wrong if you use too short a fork. You could get 180mm travel single crown forks.

 

[mybike]

Go for the downhill type front forks, the bike looks good and sits more upright at the front, and easier to control.
So better put what brumbrum said.

 

[brumbrum]

The only problem with some dual crown forks is the poor turning circle as the crowns bump into the ebike frame. I was using rockshox domain RC forks and the the steering lock was awful. I now have the manitou dorado and it is much better. I think the dorado legs sit more forward from the neck of the fork. This is true with the DMN USD-8 dual crown forks which many forum members tend to use. They are reasonably priced but i believe its difficult getting replacement/service parts for them.

 

[kingjamez]

Thanks for the reply, that's a huge help!

I'll continue looking at dual crown forks then. I've found a 2005 RockShock Boxxer World cup that needs a rebuild kit for $150 locally. Think that would be a reasonable thing to purchase over a new DNM USD 8?

-Jim

 

[brumbrum]

Thanks for the reply, that's a huge help!

I'll continue looking at dual crown forks then. I've found a 2005 RockShock Boxxer World cup that needs a rebuild kit for $150 locally. Think that would be a reasonable thing to purchase over a new DNM USD 8?

-Jim

I would much prefer the boxxers over the the dmn.

 

[kingjamez]

Cool, thanks for the advise, I'll pick it up!

-Jim

 

[Overclocker]

picked it up really cheap, brand-new condition. came from a Giant DH bike

Rockshox Domain RC dual-crown. perhaps the best deal out there for an ebike fork. people upgrade from them because of the weight penalty of the steel stanchions which is a total non issue w/ ebikes. actually beneficial coz of steel's strength and fatigue resistance over aluminum stanchions.

look for the RC version. the low-end "R" rebound-only might have spiking issues, at least that's what i've read

 

[kingjamez]

Great tip, thank you! If the Boxxer World Cup is too beat up, then I'll start looking for a deal on a Domain RC.

-Jim

 

[the12be]

the axle on most single crown fork are 9mm or 15mm on good single crowns and most triple crowns have 20mm bolt axle .
So should be safer than single crowns at speed like 50mph

I used Marzcoohi super monster T

 

[MadRhino]

The speed itself is not an issue, hitting is. DH forks are made to hit harder, but even in mountain trails that are nice with moderate jumps, a good single crown fork is reliable. I like dual crown forks on the street because the top crown is a solid and convenient mount for battery and accessories. Yet I had to set it low and use an angle set to achieve proper road geometry for speeding.

Geometry is often an issue with some frames. A fork with too long or too short travel for a frame design, might require some means of geometry mods.

 

[the12be]

:lol: 300mm travel works just fine

https://www.pinkbike.com/photo/13688233/

 

[brumbrum]

Great tip, thank you! If the Boxxer World Cup is too beat up, then I'll start looking for a deal on a Domain RC.

-Jim

Keep in mind that the turning circle/steering lock is not very good when you team up an enduro type ebike frame and the domain RC forks as an ebike frame is much wider near the head tube than a normal bike frame, and the domain forks i think are particularly bad for the caster angle between the steerer tube and the fork legs. It is very noticable on a normal bike frame when changing over from a single to dual crown fork. It will feel very very odd to suddenly have the set up on an ebike frame. Just my opinion from going through these processes....

 

[Hardergamer]

Have a good read up on sum mtb/dh web sites, on the forks your thinking of using, as sum forks like the Fox 40 wear out very fast if you don't change the oil almost weekly! and that's on a light mt bike! and like brum said the steering lock is a big problem on lots of stranded triple clamps (yokes! to me as i,m old school lol)
and "only 50mph" is fast! you don't want a front end with loads of flex, not good when you hit a bump at speed, and or on a bend..your be coming off!
Why i went for sum old Marzcoohi monster T's with titanium springs and modern revealed internals much much better and lighter than stock monsters but not cheap, (cant wait to hit sum 15+ft drop off's )
But having very good forks is the most important thing on any bike for me.

Sorry did not see only for road use, so most good forks shod be ok, i like the Rockshox Domain, but i would stay away from any of DMN's offering my self..

 

[macribs]

:lol: 300mm travel works just fine

https://www.pinkbike.com/photo/13688233/

I think 10" suffice. Avalanche MTN-10 USD, the most crazy DH fork. 43 mm lower stanchions. 51 mm upper stanchions. Massive stance. Makes Fox 40 look like something out of a cereal box, like children toys. Because of the weight of the fork you will need 3 months of low carb diet to offset the added weight of the fork. It is so expensive you either need to pimp out your wife, or win big at the table. If you ever find one used Mtn-10" I am certain you will end marrying it.

http://www.avalanchedownhillracing.com/mtn10.html

 

[brumbrum]

Haah! ^^ that's a sexy fork

 

[MadRhino]

That is a collectors item, like the Super Monster. If you find one, you will be able to buy a much better, brand new fork for the same price. Collectors are not after performance, they are after aesthetics and nostalgia of another era.

10 or 12 inch travel forks are obslolete. They are from an era of gravity riders who were competing for the highest jumps, and even then, those big forks were not winning. It is like any development: You have to go too far, to find the sweet spot. Riding DH, the sweet spot is between 6 and 8 inches fork travel, according to the trail condition.

Then, if your are a collector and want to use an extra long travel fork, you have to build the bike for it. If you build with proper geometry and proportional travel on the rear, they will ride fine. Yet, they will always be a serious performance and efficiency loss.

 

[the12be]

We are all putting a big battery on are bikes so geometry go's out the window
I am hoping for 70mph plus so 300mm or 12inch fork are what I needed

But to answer the first question you can put any fork you like on that frame
In my opinion the faster the wheel spins the bigger the axle needs to be

 

[MadRhino]

We are all putting a big battery on are bikes so geometry go's out the window
I am hoping for 70mph plus so 300mm or 12inch fork are what I needed

But to answer the first question you can put any fork you like on that frame
In my opinion the faster the wheel spins the bigger the axle needs to be

Weight and geometry are very different factors. Weight slows you down because it has to be carried, geometry slows you down because of air drag. Weight does affect handling according to balance distribution, geometry does affect handling dynamically, in relation with the rider's weight and posture.

Speed and suspension travel have no relation, other than air drag cited previously because suspension travel does affect geometry. Suspension travel has a relation with terrain and obstacles it has to ride over.

20mm through axle is a standard that is well established, most forks now are 20mm through axle and there are none bigger. There still are some smaller, but with quality hubs they can beat the 100 mph safely. Motorcycle through axle had been 15mm standard for a long time, and many can ride above 200 mph. Axle size, matters much less than bearings. What you need when you ride hard and fast, is a good hub to lace your wheel to.

No frame is made to fit any size of fork. You need some means of geometry modification to use a shorter or longer fork that a frame is made for, or accept the effect of the difference in handling and air drag.

 

[the12be]

if you try to turn a 26 inch wheel at 100 mph it is spinning at 5000rpm

you tell me would you try to turn it with a 9mm pin a 15mm bot or a 20mm bolt ?
and this is a picture of a bike geometry it all about the centre of gravity



don't forget a battery needs to be added moving the centre of gravity depending on where you put it

 

[Hardergamer]

:lol: 300mm travel works just fine

https://www.pinkbike.com/photo/13688233/

I think 10" suffice. Avalanche MTN-10 USD, the most crazy DH fork. 43 mm lower stanchions. 51 mm upper stanchions. Massive stance. Makes Fox 40 look like something out of a cereal box, like children toys. Because of the weight of the fork you will need 3 months of low carb diet to offset the added weight of the fork. It is so expensive you either need to pimp out your wife, or win big at the table. If you ever find one used Mtn-10" I am certain you will end marrying it.

http://www.avalanchedownhillracing.com/mtn10.html

Sum mad looking forks there!! i bet with a bit of work they would be up there with the best of today's offerings!

 

[MadRhino]

http://www.dvosuspension.com/products/emerald/

If you ever find an Avalanche 10" ( that is a mod old Marz Shiver), the seller will probably ask about the same as you would pay for a brand new DVO Emerald. If one does prefer the old Avalanche, he is a collector and probably does not intend to ride it more than a few times a year. One who had tried both, does hang the Avalanche on the wall.

 

[macribs]

http://www.dvosuspension.com/products/emerald/

If you ever find an Avalanche 10" ( that is a mod old Marz Shiver), the seller will probably ask about the same as you would pay for a brand new DVO Emerald. If one does prefer the old Avalanche, he is a collector and probably does not intend to ride it more than a few times a year. One who had tried both, does hang the Avalanche on the wall.

Read only good things about the DVO Emerald. But never seen one or tried one. Does the carbon layer skin on the lower legs takes away the up-side-down fork problem keeping fork straight and in line?

You might be right, but Avalanche does suspension work for various racing teams I've been told. So there is a reason for their price tag. They got various other forks as well, not as crazy as the MTN 10. Also they do custom work to about all kinds of hi spec factory forks, likes Fox, DVO, Öhlins etc to get standard OTC forks and shocks perform even better then stock. Apparently they have a few decades of racing in their belt so I would for sure give them a call before dismissing them.

DH and e-bike is not directly they same. Where DH racers obsess with every gram of their ride, e-bikers don't have to. E-bikers should focus more on centralized mass and COG then loosing every possible gram of weight for the e-bike.

 

[MadRhino]

The DVO is heavy by racing standards, but some World Cup racing teams did win with it despite the extra ~ + 400g
I have never seen an Avalanche fork on the World Cup circuit, and very few in amateur racing long time ago. Even amateurs are not likely to accept double weight for a fork.

Pro racing teams have their own suspension specialists and tech crew. They don't send a fork to a 3 rd party to tune or rebuild. When a fork does need a rebuild anyway, they just use a new one. Suspension manufacturers are giving many of their racing novelties every year to WC racing teams, in the hope that they will equip their next bike.

Avalache specialty was established rebuilding and tuning forks ans shocks, with extensive mods like external reservoir, nitrogen filled sealed air suspensions, and longer forks mod from Marzzocchi Shiver and Monster T. Freeriders and amateur racers were fond of their stuff, I have been... Very long time ago. Today, an Avalanche fork is a collectors item. There were very few, most are on the walls of bike shops.

DVO team are not into mods and recycling of other manufacturers components. They developped a new fork, the racing fork that Marzzocchi would have made next if they had stayed in business. A fork that has a very wide tuning range, and very simple, innovative system. They did set a new standard for inverted forks, enough to make WC racing teams want to try and use it.

Ebikes don't have the same requirements as racing, they have more. They need a suspension that has a wide enough tuning range for their extra weight and speed. They don't need motorcycle heavy components, because weight is taxing their power and efficiency. Yet most bicycle components are not up to the task for fast ebikes.

Add to this that ebike riders, most of us on ES at least, are building and servicing their bike by themselves. I believe that very few here, would want to service a heavily mod older fork that has 900$ sealed cartriges in.

 

[the12be]

like this guy and he has more