# Action Tec head tube Pro Shok. Anybody using one?



## eccentricbottombracket (Nov 13, 2006)

I have always thought the head tube shock was a great idea. I have a Cannondale, and have no complaints. I have never seen an Action Tec, and the number of reviews is miniscule. Are they really terrible, or what? Why are there not more around?


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## laffeaux (Jan 4, 2004)

There's at least a ouple of regulars on here that have them. One on a Curtlo and one on a Fat Chance.

I think that they weren't super popular due to a lack of marketing; a lot of people didn't know that they existed (and still do). Plus they can't be retro fitted on to a bike (except maybe a Cannondale), so they are really only available on custom built bikes.

Speaking of the Pro Shock, did Cannondale pay royalties to ActionTec for using the design?


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## Rumpfy (Dec 21, 2003)

Do a search and you'll find a picture or two of Action Tec set ups.

Veloculture has a Curtlo with the Action Tec front end.

Scooderdude has a Rocklobster with the same.

My understanding is that it's an expensive set up and requires the frame to be specifically built around this suspension design.
So in addition to getting the suspension, you'll have to find a frame builder that can build a bike to cater to this. It's probably why there are so few out there. 
It can still be none though if you want.
I'm also told it works very well, though I've not ridden one.


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## Veloculture (Dec 18, 2005)

eccentricbottombracket said:


> I have always thought the head tube shock was a great idea. I have a Cannondale, and have no complaints. I have never seen an Action Tec, and the number of reviews is miniscule. Are they really terrible, or what? Why are there not more around?


the Curtlo that i have with the Action Tec fork is still one of my all time favorite bikes. that fork is still the fork that i compare all other forks to. one day i want a 29er with that fork. that would be one sweet combo

as others have already mentioned they were not popular since you needed to have a specifically built custom frame to run it. they were one of the earliest suspension forks and was considered the best back in the early 90's but the fork was $600 which was way more than anything else on the market. match that to the cost of a custom built frame it was too expensive for the average person. i was lucky enough to have been sponsored by both Action Tec and Curtlo so it was a dream bike and certainly a great rig for a teenager. the design hasn't changed in all these years and to this day that fork is still best riding short suspension fork i have ever touched. pretty good considering nobody in their right mind would put a Rock Shox RS1 on a modern bike.


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## uphiller (Jan 13, 2004)

*Questions*

I looked at Action Tec website, actiontec.us, and the price isn't too bad, around 400 bucks, and can be customized for rake, length, wheel size, and brake type for no extra cost.
Can anyone else tell how well the thing actually works for absorbing bumps? Is it as rigid as a Cannondale Headshok? How impervious is it to the elements? Anyone know what's going inside the shock unit itself? How advanced is the damping?


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## First Flight (Jan 25, 2004)

Crappy pictures of our Curtlo

<img src=https://www.firstflightbikes.com/_borders/Curtlo1.jpg>

<img src=https://www.firstflightbikes.com/_borders/CurtloFrame1.jpg>

<img src=https://www.firstflightbikes.com/_borders/CurtloFront1.jpg>


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## uphiller (Jan 13, 2004)

Jeff- can you say well the fork rides? Do you know anything about the fork's internals?


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## First Flight (Jan 25, 2004)

uphiller said:


> Jeff- can you say well the fork rides? Do you know anything about the fork's internals?


The fork feels pretty decent but it is a tiny bike and comes nowhere near fitting me (14" or 15" frame with 6' 4" rider doesn't work too well).


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## ~martini~ (Dec 20, 2003)

There are a couple 29"s out there. Go over and ask on the 29 board. It is an intriging fork, thats for sure. And in todays cost range, $400 is pretty reasonable, especailly if you're after a custom frame to put it on.


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## geoffss (Mar 23, 2004)

I remember meeting a friend of a friend who raced expert or elite DH for Intense back in '95-96. He had one of the first Spyder frames and it had an Action-Tec front shock. It had more CNC bits on it than the Paul Components warehouse.

That was when I first got into mountain bikes and I remeber getting a boner and thinking that it was the coolest bike ever. I never got a picture of it and I think he quit racing along time ago. If I ever find him and he still has it then its gonna be mine.

EDIT: I dont think this is it and sorry for the crappy pic taken fron Intense's website, but heres an early Spyder with Action-Tec Pro-Shock.


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## dompedro3 (Jan 26, 2004)

check out this thread:
http://forums.mtbr.com/showthread.php?t=235201

for info on the action tec forks and i think terminaut also has a beautiful willits ti with an action tec fork.


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## itsdoable (Jan 6, 2004)

I'm still running a ActionTec Pro-Shock on my SS, I've had 2 of them. They are very light, stiff, short travel forks that hold up well. Valving uses simple ports (separate compression and rebound) in a throu-shaft oil cartridge, spring is a combination of 2 concentric steel springs, and an elastomer "cross-over tube". The 2 steel springs can be of different lengths, and that along with different spring rates, allows you to tune the progression. The cross-over tube mostly acts as an adjustment to ramp up the rate to prevent bottom-out.

Ride is on the harsh side compared to todays standard (the current fork has the same internals as it did 10 years ago), but I find it suits my SS riding just fine.

Warning - the stock c-a distance is short - you cannot put a big tire in there (~2.2"max, although you _can_ get a 2.4" motoraptor in there if you don't ride in mud, and use a narrow rim...). My current one was built with a longer c-a so I could run 2.5" tires (in mud).

They also require a 1-1/4" headset - not many frames can accommodate that (mine was custom).


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## uphiller (Jan 13, 2004)

Sounds intriguing- a light, torsionally solid short travel fork. But the lack of an even halfway sophisticated damper is a turn-off.
Tim


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## Veloculture (Dec 18, 2005)

uphiller said:


> Jeff- can you say well the fork rides? Do you know anything about the fork's internals?


the suspension feels awesome. for having less that 3" of travel it feels to most riders like it has 4" since it has no binding tendencies like normal forks do. it runs on ball bearing so the travel is very smooth. for cornering this fork and the cannondale headshock are the best i've ever felt by far. your front wheel will stick to the ground like nobody's business. the fork feels exactly the same on the trail as it does when you are pushing on it when you are stopped which is something you dont get ever with other bushing style forks. personally i think all forks should have bearings for the travel to stiffen the fork and make for smoother travel under situations where other forks bind up in high stress situations.


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## uphiller (Jan 13, 2004)

Veloculture, and anyone else riding this fork-
One question for you, which I would like you to answer very honestly, as I am considering getting a 29er with this very fork:
Is any of your enthusiasm for the Action-Tec fork coming from the fact that this is a small guy who got screwed by a big one, ie Cannondale, and the fact that it is an old design from the good old days? Or is it really on the same level as other short travel forks out there today? Am I better off just getting a Reba or reduced travel Lefty?
Tim


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## Veloculture (Dec 18, 2005)

in my opinion it is the ultimate 29er fork. not too many bikes can take such a short travel fork these days but it's perfect for 29ers. don't take my word for it though. ask the 29er group. a few of those active MTBR members have that exact setup and will give you the low down. the guys i've talked to were happy beyond words. i know thats what i would get. the Lefty has too much travel in my opinion for a 29er. the action tec just plain looks cleaner too. we know how important looks are  

i think oldmanriding has a 29er Curtlo with Action Tec fork. i think thats his MTBR handle.


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## itsdoable (Jan 6, 2004)

I'm having trouble figuring out when I got my first ActionTec fork, it was pre-29er era in any case (ie: before there were good mtb tires for 700c rims). My forks were all 26'ers.

There are very few sub-3lb short travel "race" forks around (then and now) and I can count the number of _steel _sub-3lb forks on one finger...

Because you can tune the spring rate and end ramp-up, the simple damping is adequate for a short travel fork. However, on fast / sharp edge hits, you do feel the spike since there is no speed sensitive blow-off. However, any big hits are harsh since you only have 2.375" to soak it up, no amount of fancy damping is going to change that. The spikes that do come through are manageable - especially if you are use to riding rigid as well.

At the time I bought it, it was for a custom Rohloff frame, and it worked fine there for 90% of my riding. But it was much nicer to run a Fox Forx on the trips to Pisgah & Moab - however when I'm single speeding, I prefer the ActionTec over the Fox. The ActionTec is a nice fork during standing climbs. If I could have sourced a Cannondale Headshock at that time, I probably would have gone with that. In retrospect, the Actiontec is less maintenance, while the Headshock would have had better damping, especially since you can upgrade the damper to a Magura unit.

Would I buy another ActionTec fork? Yes.

I don't have any experiecne with the Lefty, but all the riders that have then like them. And you can get them with an inertial valve, SPV, TCP or conventional port dampers.


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## uphiller (Jan 13, 2004)

Guys- thanks for all the advice. It's good to hear the honest pluses and minuses here, I guess now it is a toss-up between the Lefty Carbon SL, which I would slam to 80mm and weighs only 2.7lbs, comparable to the Action-Tec fork, and Pro-Shock. And yes, the Pro-Shock does look much cleaner than the goofy Lefty.


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## uphiller (Jan 13, 2004)

Okay, a few final questions:
-How 'bout temperature sensitivity? Does the elastomer harden up when it gets cold? And the damping? This is especially a concern on a non-adjustable fork.
-Can it be made with aluminum legs? It could be a way to cut the weight even further.
-How is servicability? What if I want to switch the springs out, or change the oil?


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## Veloculture (Dec 18, 2005)

uphiller said:


> Okay, a few final questions:
> -How 'bout temperature sensitivity? Does the elastomer harden up when it gets cold? And the damping? This is especially a concern on a non-adjustable fork.
> -Can it be made with aluminum legs? It could be a way to cut the weight even further.
> -How is servicability? What if I want to switch the springs out, or change the oil?


i raced mine nearly every weekend for 3 years and had it rebuilt once. that was also the first design which was inferior to the later fork designs. i've changed the spring and it was easy. adjusting the spring tension is easy too. i never changed the oil in mine.

at least until about 1996 there were only two aluminum action tec forks made. they were both on my team so it can be done.

when it comes to repairs or major servicing i would just send it to Action Tec. he's a good guy over there. i never pulled the fork apart myself but im told it's a bit scary so i would just leave it up to the professional.


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## Veloculture (Dec 18, 2005)

First Flight said:


> Crappy pictures of our Curtlo
> 
> <img src=https://www.firstflightbikes.com/_borders/Curtlo1.jpg>
> 
> ...


this is one of my teammates old bikes. one of the only two aluminum Pro Shock forks ever made as far as i know.

Jeff, that bike was owned by Tomarra Notch. she's one of the very top pro's at the moment racing for Team Trek. her husband Bruce Muhlfiled is also a Trek Pro.


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## itsdoable (Jan 6, 2004)

uphiller said:


> Okay, a few final questions:
> -How 'bout temperature sensitivity? Does the elastomer harden up when it gets cold? And the damping? This is especially a concern on a non-adjustable fork.
> -Can it be made with aluminum legs? It could be a way to cut the weight even further.
> -How is servicability? What if I want to switch the springs out, or change the oil?


The main spring is steel, so it's not temp sensitive - the crossover tube (small elastomer) only has an effect at the end of the travel, and I don't notice it in the cold (and we ride all winter - regularly to -20C).

The damping unit is available separately and you _can _get another frame-maker to build the legs in any material you want (with the right interface). That was an option on my fork, but Russ at ActionTec convinced me not to. The stock legs come in True Temper OX-II or OX-III, and I think you'll be hard pressed to find lighter legs in Aluminium. Russ is a weight wienie.

Spring change is easy. Oil change is harder, but if you've disassembled dampers, it's not impossible. It's alot easier sending it to ActionTec.

Oddly enough, I don't mind the look of the lefty - there is something to be said about the mud clearance and being able to change the tire without taking the wheel off....


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## schneidw (Mar 8, 2005)

ANother sweet Action Tec setup is offered by Waltworks in CO.. See LINK

http://www.waltworks.com/dev/faq/actiontec.php


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## drzrm (Apr 1, 2007)

I rode an Action Tec Head Shock on a Moots YBB with a 1.25 inch headtube for years and really loved it. I fode XC and raced a bit, and the fork was perfect. Of course it didn't seem like so little travel in the mid 90s. It literally had no wheel slop at all (no surprise given its design). When I replaced it (broke it actually) in 2001-2 it was six years old and years out of warranty and I could not replace it (poor graduate student) so I used a Chris King reducer and installed a B-2 Bomber. I've replaced that with a White Brothers Magic 80 this season to keep the geometry close, but I had no idea that they were still in business. I probably would have gone back to the shock the frame was built around.


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## scooderdude (Sep 27, 2004)

I'll chime in. I purchased this bike from my buddy after he moved from the loamy soils of the SF bay area to the rock and scorpions, and all day adventures indoors under an A.C. climate, of Phoenix. For some reason he found little joy riding this XC bike on South Mountain. Imagine that.

Personally, this is one of the best single track and climbing bikes I've owned. The fork on this particular bike was 8 or so years old, and NOS, by the time he commissioned Paul to build the frame to mate with it in 1999. 

The ride reminds me a bit of the carbon ProFlex fork (minus the "J" axle path) in terms of there being zero flex. You can manuever through rocks and roots with absolutely no fork twist. Go figure. But it's a short travel XC fork. Don't confuse your anticipated ride quality with the spate of 25% sagged long-travel trail forks. It's simply an efficient XC fork. I like it very much.


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## colker1 (Jan 6, 2004)

is your buddy by chance mike ferrentino?


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## scooderdude (Sep 27, 2004)

colker1 said:


> is your buddy by chance mike ferrentino?


Nope. LukeDuke.


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## terminaut (Dec 19, 2003)

Here's my Willits B2 29"er with the Action-Tec fork. It works pretty well but IMHO is no match for a Lefty. With its short travel, think of the Action-Tec as a very plush rigid fork. ;-)


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## ShortTravelMag (Dec 15, 2005)

Being a "curtlo dork", I too had a curtlo with Action Tec fork (and some AT ti chainrings among other expensive stuff, or as Action Tec called it, ELS...his actual product name, which stood for Expensive Lightweight ****...I had a 17" steel Curtlo with custom Shades paint, and raced that from about 1995 - 1998. Did some downhill races too at Norba nationals in Traverse City, Michigan. It had to have a -5 deg. steel stem to offset the extra front end height. It did work well, no real bottoming out at all. Doug Curtlo still has them listed as an option on his site, and even mentioned to me recently he was considering a 29er himself with one. 

I stupidly ebayed the thing, one of the first things I ever ebayed, to some guy in CA who really didn't even know what it was...probably sitting in a garage rusting away. 

It had such a cool paint job, I'm going to dig it up and post it here.


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## mtroy (Jun 10, 2005)

I was involved with Curtlo when Russ was supplying Action Tec forks to the race team. I still have a bike hanging in the garage with one of his forks on it....along with Grafton brakes, Shades paint, etc. Cool looking bike, all camo'd with anodized green parts.

Anyway, the forks worked really well and pretty much blew away anything at the time like the Manitous (not sure...maybe Manitou 2s or 3s by then?). They had real hydraulic damping, steel springs you could cut and swap to change rates, etc. They were pretty darn stiff torsionally and handled well. One issue from the eyes of the bike builder, was that the frame was a dedicated system so the choice of going to another fork later was not an option. I don't really recall any kind of adapter to retro-fit other forks, but there may have been.

Curtlo was building in 1.5" head tubes anyway, so that part was easy. Really a coool fork, but they cannot compare to anything with longer travel these days.......BUT...I bet they would make a sweet 29r or SS frame. Seems to me the design called for a higher head tube than normal....not sure how that would work out for a 29r.

ELS....man, that is funny. I had forgotten about that. Russ was (and probably still is) a real character and a cool guy.


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## kikolemus (Jul 12, 2005)

I have a old Curtlo that I recently bought with the Action Tec fork on it. I love the whole setup but it needs a bit of tuning because it is not a plush as it could be. Even not set up correctly for me it is a nice fork with great control because the lowers are nice and stiff

I am dating myself a bit but I used to ride years ago with Russ when he was still down in Silverado Canyon. his shop was right in his garage. His bike was super plush but still a great cross country bike so I know you can get them so they could be fairly comparable to todays forks. 

Mike


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## geckocycles (Sep 3, 2006)

*They work great for what they are.*

I used them on several bikes when Russ first started making them. The only adjustment then was changing the spring or oil. No fine tuning was easily available at that time. They have changed since then and are now improved. They have an awesome feel. I love them. Now I would build my own blades and weld it to the steerer. Back in the day he wouldn't sell just the Steerer assembly. Im glad to see that he now sells just the steerer.
The quality of the fork was terrible and I hated to use this fork on my custom frames. These were very early designs that I had though. 
I remember closing my eyes and hitting a curb and going over it. One thing to note is that you don't want to get dirt under the boot. Keep that boot in good shape and you will love it.
Russ insisted on servicing the forks himself. He is a very friendly guy.
When possible I still use the HT length that will accommodate his steerer and I have a frame in stock that was made for his fork. 18" C/C Y-Fileit.


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