K2 / Proflex Riders Group
General => Tech Forum => Topic started by: 5500C on February 02, 2004, 02:12:04 pm
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I need some advice on my rear shock dilemma. I upgraded my bike last year and put a 100/120 Manitou Black Elite (Love it!) and a 7.875 Vanilla RC (Love it too), but I think I feel the changed geometry and not quite sure if I like it. It is awesome when I'm bombing downhill, but here in So-Calif. most of our riding is straight up and then straight back down. I feel that the front is extremely light, even in the 100 mm setting.
Would the 1/2 inch gained by going to a Stratos or Risse make that big a difference. (Is the eye 2 eye measurement 8.25 for those shocks?) I've even thought about making some sort of adapter for my current Vanilla RC to give me the proper 8.25" spacing. Can I run a 8.5" i2i Fox shock with sag without changing my rear tire?
OR AM I JUST INCREDIBLY ANAL AND NEED TO GET A LIFE?
Thanks.
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I ran my 01' Disco Monkey w/ a Stratos Helix Pro (8.25" iei) and a Psylo fork @ 4". I felt I had the perfect balance for most riding. According to my angle gauge my HA was about 69.5*. I tried a Marzocchi Z1 @ 5" but the front end lifted on climbs and the bike steered slow. I was going to run an 8.5" RC w/ the 5" fork. The DM was spec'd w/ a Noleen fork w/ an 18.5" axle to crown height. Most modern 4" fork have a 19-19.5" axle to crown, most 5" forks are 19.75" - 21". As you can see they can change the geometry pretty good. An adapter would allow for the use of a common iei. I can't speak for Risse's products but Stratos bites.
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Stratos bites huh? I was leaning towards that as an option b/c they look a lot better than the Risse. Any other opinions?
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I had my Stratos Helix Pro in for service twice within a year after light XC use. The shock woked ok but the my main problem w/ Stratos was their poor customer service. I never had such a hard time dealing w/a company. If you do some research you will turn up this info. Check MTBR DH board "El Hefe" you will find a Stratos post now. In retrospect, When my DM was my primary ride, I should have looked into an adapter as it would have opened the door to a larger selection of shocks in the 7 7/8" range - 5th Element, Romic, Fox pro pedal etc.
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I'm running a 7.875" RC on my medium EVO frame with a Marzocchi 100mm fork. The steering did slow down a bit when I changed the fork from a 80mm to a 100mm. I noticed about the same change again when I went from a 8.25" to 7.875" rear shock.
Once I got used to the slower turning, I no longer noticed it. One advantage to my present setup is that it's easier to pull the front end up for drops or wheelies(thru water holes). Just after first installing the Vanilla RC, I flipped over backward while wheelieing thru a water hole! Fortunately I was past the water so I didn't get wet. I landed on my Camelback while still clipped in! :o The good news is that no one saw it. ;D
One thing that I do notice is that I seem to hit my pedals more often with the 7.785" shock. Placebo effect? Maybe.
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My Helix Expert is the stock, 8.25", length and it's an outstanding shock. Never had any problems with it. I'm not so sure that it would make an appreciable difference compared to the Vanillia RC. My Helix is very plush and has way more sag, and more travel, than the stock Noleen. I've never measured the i2i distance while I'm sitting on the bike but my guess is that it's not much different than your Vanilla. Climbing performance with a 105mm fork on my Evo is fine.. I'm suprised that you say that your front end is "extremly light". You might try altering your riding position, or just give yourself some time to get used to it.
Any change in a bikes geometry is going to be a compromise somewhere.
If you do fabricate a spacer, I'm sure many here would be interested in your results.
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Following Garys suggestion-if you are happy with current steering but want a heavier front end try a straight bar-you already have a relaxed angle up front so a straight would not feel too fast-acting on descents. Try a lower profile front tire, I believe the Mutano Raptor fits the bill here. Small changes, dollars and parts wise, are usually a good start when ironing out handling issues.
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to answer your question, I'd go with the Helix expert or pro, however , my LBS called Stratos a few months ago, 'cuz i was looking into getting one for my Oz and the said they might not be making any more for that frame. that seemed weird, but they would not commit to building one for my bike.
straight up and straight down...you will have to compromise somewhat, the geometry of the frame is XC. when you put a longer travel fork up there you really pay.
[smiley=beer.gif]
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I have a Z1FR on the front and a ProPedal 7 7/8 out back and haven't had any real issues. I figure the head tube is 'bout 69 degrees. If the front wanders on you, you could try a stem with less rise?
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Cool, thanks guys. Maybe I'll just hang tight for a while. I will try looking into an adapter though.
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I've a 8½" i2i Vanilla RC on my Oz with 2½" stroke with a Ti spring - gives me 6½" of pure smooth travel (max travel for the Oz frame). Bike gives fantastic confidence with my USE SUB 100mm fork.
The BB height from ground has gone up by 5/8" (with no rider), it feels great on the trails.
Nigel here in the UK says his SID rear shock has an i2i which is too short, so that concurs. Personally, if you have gone for more travel up front than stock, then you definately need to increase height in the rear so going with a shorter i2i than stock (209mm) is a no no. Anyway, if you want more rear wheel travel as well then you really have to increase i2i and stroke.
What is your stem length? Shorter than 100mm and this could be making your problem worse.
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I thought that you need to run a smaller rear wheel for the 8.5 i2i shock? That might actually be the better way to go and just run more sag to compensate and get the actual i2i to 8.25".
Why are most of us going with the 7.875 and not the 8.5?
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I'm going to guess a 24" is required on EVO frames with an 8.5 e2e but not on an Oz/C.?
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To answer 5500c:
Why are most of us going with the 7.875 and not the 8.5?
Personally, because I prefer the slacker angle and slightly lower BB. It makes fast or technical riding alot more pleasent. I didn't want some high BB quirky handling bike.
To Scott:
I'm going to guess a 24" is required on EVO frames with an 8.5 e2e but not on an Oz/C.?
Not true, it's dependent on frame size only from what I've understood. To fit an RC without a 24 rear wheel you'd need to have a L or XL frame. The small and medium require the 24. And I beleive this is because on the SM/Med frames you have to run the reservior at the bottom and that's why you need the 24 for clearence. On the larger frame you can run it at the top so there are no clearence issues.
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And I beleive this is because on the SM/Med frames you have to run the reservior at the bottom and that's why you need the 24 for clearence.
I'm running a 7.785" Vanilla RC on my medium Evo with the reservoir on top with no clearance problems. As a matter of fact, you sold me the shock a year or two ago and it still works great. [smiley=nod.gif] Thanks! [smiley=beer.gif]
Phillip
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Now I'm getting confused, all along I've heard that van rc can't fit on a med evo wiv a 26" rear wheel, now Phillip says he's quite happily running that set up, either he's using 1" tyres or everyone else has been feeding me bs. What is the answer, can a van rc work on med evo with a decent size tyre [2.4]. Also is the propedal the same dimensions as the original rc. :-/
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and why does it HAVE TO be a 7.785 I2I? how come the 8.5 i2i, wont work with a 26" wheel?
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It must only be for the 8.5" i2i b/c I have a Medium frame with a 7.875 and 26" wheels and it fits fine with no frame or swingarm mod's.
http://idriders.com/cgi-bin/album_k2.pl?photo=5500C/P1010103.JPG
http://idriders.com/cgi-bin/album_k2.pl?photo=5500C/P1010101.JPG
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Is it the same stroke on both shocks? My 7.875 Cane Creek with 2" stroke did not work on my Oz-swingarm contacted frame in last .25 stroke or so.... Some claim a stroke longer than actual too-please no bad jokes here either!
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New viewer here, great forum.
Just put a Manitou Swinger Coil 4 i2i 8.5" on my Large Oz M. Manitou provided the correct bushings and everything mounted up great except the spring keeper hit the swingarm mount when tilted towards the frame mount. I flipped the keeper over and problem solved. Shock body tucked in perfectly into frame mount. I can't see why small and med frames would be any different using the same shock configuration.
Shovelon
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Lokomonkey, aren't you using a 8.5" rc on your Evo, I know you switched to a 24" rear but did you ever try it with the 26" ? What is the stroke on the 7.8 and 8.5 ? Anyone know? [smiley=blankstare.gif]
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Phillip,
Could you post a picture of your RC mounted on your medium evo.
Most of us believe the Medium evo can not accomodate the RC. I am curious to see how you fitted the reservoir on the frame mount, I thought it could not be done.
thanks
pedro
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New viewer here, great forum.
Welcome! Always glad to have new "faces" around here!
Just put a Manitou Swinger Coil 4 i2i 8.5" on my Large Oz M. Manitou provided the correct bushings and everything mounted up great except the spring keeper hit the swingarm mount when tilted towards the frame mount. I flipped the keeper over and problem solved. Shock body tucked in perfectly into frame mount. I can't see why small and med frames would be any different using the same shock configuration.
Shovelon
Please post pictures of your swinger mounted to the Oz. That would be great. Also, if you happen to know the size of the bushings you got from Manitou, that would be great. Thanks!
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New viewer here, great forum.
Just put a Manitou Swinger Coil 4 i2i 8.5" on my Large Oz M. Manitou provided the correct bushings and everything mounted up great except the spring keeper hit the swingarm mount when tilted towards the frame mount. I flipped the keeper over and problem solved. Shock body tucked in perfectly into frame mount. I can't see why small and med frames would be any different using the same shock configuration.
Shovelon
me, too, Matno!
i wanna see a pic of this. i know the "Air" version won't fit
[smiley=beer.gif]
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Pedro,
Click on my gallery below to see a picture. I don't have any close ups of the shock, but if you click on the photos they willl enlarge and you can see it fairly well.
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Matno,
I will send photos when I get my camera working again. In the meantime I can give you the bushing sizes that Manitou made for the shock.
Upper mount: 37.5mm wide X 6mm bolt hole
Lower mount: 24mm wide X 6mm bolt hole
I did play with the spring keeper a bit by filing 2 grooves into it so that it could swing forward without contacting the mount, and then ground a bevel into the spring slightly. It mounts correctly now with a bit of clearancel. Sent the 500 lb spring back for a 450 lb at no cost. Ride height is now nearing what it was before. I may part with 30 bucks and try a 400 lb spring for the heck of it, and pump more threshhold pressure into the chamber, which tends to also increase preload.
Terry
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Hey Phillip, does the rc reservior thingy get in the way if you lower the seatpost?
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Numbnuts,
There is plenty of clearance between the seatpost holder and shock resevoir. Also, the seatpost could extend 2.5 " below the seatpost holder if you were to grind off the seatpost stop in the frame. I would take a closeup picture and post it except my camera was stolen and I have not yet replaced it. [smiley=dead.gif]