K2 / Proflex Riders Group
General => Tech Forum => Topic started by: Jak on August 15, 2004, 06:52:35 am
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Does anyone know the maximum front travel a K2 proflex 5000 will take :)
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I don't think you should exceed 100/105mm travel on a standard 5000 setup,some I believe have fitted longer travel forks along with a longer i to i and stroke shock thus increasing the front and rear travel but keeping the head angle close or same as stock,however you do raise the b/b height and run the risk of the bike becoming unwieldy,though I believe those who have done it are happy with the results.
Simon.
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Agreed. I think the 105mm Manitous I have on my 5000s are perfect for XC/Trail riding. However, I doubt that a 5" fork would be overly "unwieldy." A lot of guys have successfully used psylos and other similar forks. In fact, some people have even put 6 and 7 inch dual crown forks on their evos, and I don't think I've ever heard anyone complain about the handling. Go figure...
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The 80 mm carbon crosslink with smartshock that came with my Oz never felt like enough travel. After comming off my 97 beast with 100mm dual crown chubby forks, I was spoiled.
I upgraded to Psylos and would ride at 120 mm all the time except when climbing where I would reduce the travel and height to 75 mm because the front wheel would lift some.
Descending there is no question that 120 mm of travel is the way to go.
But there is the question of whether the aluminum frame can take the stress at the head tube. The 5000 frame is aluminum?
Terry
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and also remember the head tube angle is quite "XC".
the frames were not constructed nor designed for over 4" from what I can conclude
a good single crown 5" would be the max I would consider.
i have seen some dual crown 6" on a few EVO but I cannot attest to their longevity or safety.
[smiley=beer.gif]
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What would you think of putting a 150mm(6 inch) travel fork on a carbon frame? Do you think that it could handle the stresses?
I am looking to go that way to match the 160 mm of travel that I now have in the rear.
Terry
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With 150mm forks and 160mm of rear travel what height would you envisage the b/b to end up at compared to stock ???
I'm a bit at a loss with what seems to be an obsession with large increases in travel on Oz and evo frames,if I needed that sort of travel I've got the wrong bike for my type of riding,yes if you can increase the travel with extra shock stroke or running with more sag thus keeping the head angles and b/b height as standard (its been noted that as standard the b/b height is aready on the high side for some) then thats different,I'm not against it in fact I'm probably one of the first as many know to try any mods etc but increasing the travel and overall bike height this I'm not so sure, I'd just buy a bike thats built around that sort of travel to start with,good luck anyway, I'm just not so sure
Simon.
Ps I ran my 4500 with psylo's at 120mm and disliked it on single track and obviously climbing,ended up running it at 100mm in the end and found it vastly improved infact still running a 100mm fork,just what I found but maybe different for others.
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Simon,
I plan on having an increase in BB hieght of about 25 mm unloaded. There is about 25 mm of sag when I ride the bike, therefore I ride at near the same as stock because I ran the Noleens with little or no sag to prevent bobbing.
The forks I am looking at are the 150mm/100mm Maverick air forks with on the fly travel adjust that has a relatively short headtube to axel distance. So set in 100 mm position and a little more sag, I am very close to where the crosslinks put me before. All in all I will ride a little higher and bottom a little lower, but what is in between is heaven.
I am just an old guy that likes a cushy ride and can't take the beating he used to.
Terry
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Terry sounds like you've really thought this out,should work out great for you,I've aways run at 10% sag of shaft/slider travel, maybe its my riding style but I've never experianced bobbing with any of the forks/shocks I've run on my 4500, then again I'm a stay seated most of the time kinda guy,
let us know how it goes I'm always interested what others are upto with there carbon/evo rigs,inspires me to look into new ideas,had one on the backburner for a while,winter project I think.
Simon.
Ps Terry you have a metal fabrication shop ??? I have this idea/design would you be interested in looking over the design for me if I emailed you a basic drawing ???see what you think.
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Simon, I would be happy to look at your drawing. My email is shovelon@aol.com.
Use a PDF format if you can as I can open very easily. Otherwise use what is convenient for you and I will give it a try.
Terry
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I'm running 120mm on te front of te Oz. very plush and great in the French alps but I do notice a (slight) slowing of the steering in tight slow speed single track.
My thoughts are that 130mm is probably as high as you can go with the Oz.
However, I am just about to fit a 5th Element coil with a longer I2I. I am hoping this will push the back of the bike up and steepen the head angle back to where it was and cure the above. As noted by Simon, it will raise the BBheight but I too believe that with sag it will return to the same height when being ridden.
What I do notice is that when I ride the Razorback (which I have done quite a bit lately) I smack the pedals on ruts and roots a lot compared to the Oz - even on mild trail riding here in the south of the UK.
I now have two K2/Proflex bikes set up for different disciplines / uses. The Oz for free-ride /DH - fun big hill stuff and the razorback for XC/all day trail and mixed off-road on road use. With it's continuous seat tube, very low standover height and very leight weight it has proved to be an ideal bike to lend to girlfriends to try out MTBing. All have commented how nice it is to ride and what a good climber (the bike!) it is.
Sprucey
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I have always felt factoring in sag to suspension geometry was wrong. I had a Z1 FR on my Disco Monkey w/ the orig. 8.25" iei rear shock. On steeper climbs the front end would top out and sag was no longer an aid to suspension geometry. The same apllies to the rear - take a steep down hill and add a little brake dive and you rear is w/o sag. I'd prefer not build around sag.
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love my psylo sl -
shorten it for climbs and technical xc and lengthen it for downhills and fast bumpy stuff -
best of both worlds
(http://www.progressivesuspension.com/Images/customers/nicholas-h.jpg)
OP
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Jak, I think 130mm is the max but you will want a fork that can adjust to reduce for climbing and tight single track. It also depends on the overall fork length, some have a much higher crown-axle ht. I recently swopped a 2002 z1 with 130mm for a 2003 fr sl Z1 [130mm]. Even though the travel is the same the was a huge difference in the end result, the newer fork lifted the front and slowed up the steering, I like it for the type of riding I'm doing but it is not for mellow xc. I think the fox forks pack a lot of travel into a relatively short fork, but I've not tried one. Like OP indicated, adjustability is great.
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I too love the adjustability of my Psylo. I use the lockout alot also.
Speaking of Psylo, I have had talks with Stratos Shock. They are working on a series of dampener cartridge replacements that will add stable platform characteristics to forks. They have licensed with Fox Shocks to make aftermarket replacements for Rockshox, Marzocchi, Maverick, Fox, and others.
The Psylo cartridge will be available in about 4 weeks.
Since my cartridge is failing (OK I messed it up by dinking with the shaft during a relube, spittng oil out) and I would rather apply the rebuild money to an upgrade, I may purchase it.
Might be worth considering when purchasing a fork.
Terry
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i use my lock out and change the damping quite a bit during a ride -
i'd be interested in that SPV cartridge, cost and function -
let us know, could be worth looking at -
OP
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as some of you may remember, I put a Fox Talas R fork on the front of my Oz. I really like the way it works, but have ended up with it set at around 90 mm of travel. Sometimes I increase it for downhills, but the trouble is that on the trails I ride, there are mostly short steep downhills followed immediately by short steep uphills and no time to mess around with adjusting shocks or forks.
I checked out the stratos site and they have an Inertial Damper upgrade for the Talas, sounds like a must do for the winter for me.
also, while cruising around the web, I came across PUSH industries. they do stable platform rebuilds on fox rear shocks. trouble is, the fox float rear shocks do not come in 8.25" lengths, only 7.875. the talas rear comes in 8.25, but PUSH does not list a stable platform upgrade for the talas. I currently run an astro 5 in the back, a great shock, so I emailed PUSH to see if they would do an upgrade on it. I'll let you guys know what they say. seems all of a sudden I have a need for new generation shocks.
Here's the link for PUSH:
http://www.pushindustries.com/
Questions:
1. has anyone done a 7.875" shock on an Oz? does it screw it up? it would lower bb height a bit, maybe good for me with the minimal SO clearance, but I do like not worrying about bottoming the bike.
2.I think it would be real cool to put a 5th element air on the Oz, but don't think it comes in the right size. anyone have any ideas on this? thanks.
3. Does anyone have experience with the propedal fox shocks? how well does it work?
[smiley=groucho.gif]
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Questions:
1. has anyone done a 7.875" shock on an Oz? does it screw it up? it would lower bb height a bit, maybe good for me with the minimal SO clearance, but I do like not worrying about bottoming the bike.
[smiley=groucho.gif]
Dennis
I don't know if I'm being much help here but I did ride proflexGB's evo with a shorter I2I sid shock,I can't remember the I2I length but I think 190mm/7.5" or may of been 200mm,see said I may not be much help, but for my height 6'1" and long legged I felt like I was sitting in the bike and not on it,I also had a problem with the cranks hitting the ground,it was also running 80mm travel fox forx's that may account to the fact I didn't notice a slackening in the head angle,steered fine to me,proflexGB though loved the setup but he is shorter than me and shorter in the leg maybe thats the reason or maybe he's just used to it,I did also notice the s/arm very nearly fouled the frame on full compression.
Simon.