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Author Topic: SPV  (Read 6234 times)

Simon

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SPV
« on: November 11, 2003, 06:35:49 am »
Just wondering what you think regarding SPV shocks and forks,I can see the thinking when used in single pivot applications and it seems a good idea,however not totally convinced in all applications its such a good idea,though I've never tried one so cannot speak from experiance,as I understand it an SPV shock or fork has a preset or an adjustable threshold which has to be overcome before the shock/fork will compress,this is set at a point where the shock/fork won't compress with the forces applied by pedalling whilst standing/seated etc, but will compress when hitting a bump/obstacle and sounds ideal,but my concern is this (mainly applies to a fork application) how much threshold has to be overcome, set to low misses the point set to high forks will fail to compress,set in between will it cross over between not bobbing and not compressing,I can't see the threshold that will stop compression (fork bob) yet will still cope with slow to medium speed stutter bumps which require an active fork to cope mainly in single track,set the threshold low the fork will then bob,set high you'll get an inactive fork for those small stutter bumps,but will be fine for fast medium/large bumps,my opinion is they will suit some and be great for there style/type of riding but they won't suit everyone still a compromise but a move in the right direction?interested in other opinions and experiances if you've tried/own an SPV shock/fork. Simon      
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Matno

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Re: SPV
« Reply #1 on: November 11, 2003, 07:34:37 am »
As with most newer technology, it's geared toward racing. The magazine reviews I've seen say it works as advertised, but that means it sacrifices some small bump compliance.

Personally, I'd rather have super smooth small bump compliance. I don't even mind if my bike is slightly "mushy" feeling, as long as it feels like it's floating over the rough stuff. I don't race, but I often ride for fun and exercise. With some of the newer shocks, you sacrifice a little bit of fun (comfort) and a little bit of exercise (more efficient) in order to go slightly faster. Not the best trade off in my book. Of course, lately my only riding buddies are much slower than I am anyway, so speed is a waste unless I want to ride circles around them... :D

I'd say that a shock that feels plush on the small stuff, but ramps up toward the end of its travel is ideal. My X-vert with TPC+ and Helix Pro with air-assist seem to do the trick perfectly. (If only the rebound on my Helix were a little lighter...)
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kiwi

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Re: SPV
« Reply #2 on: November 11, 2003, 06:45:49 pm »
matno can you change the oil to a lighter one in your shock??????
kiwi proflex rider

Matno

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Re: SPV
« Reply #3 on: November 11, 2003, 11:35:03 pm »
Possibly. The Stratos shocks use ATF though, so I'm not sure how that would work. I'm not familiar with different viscosities of transmission fluid the way fork oil comes in different "weights"... Anybody know? I supposed I could always just ask Stratos. I did actually ask them why the rebound was so slow, and they told me I was probably used to other shocks, like a Fox, which don't have good rebound damping! What a stupid answer. Foxes I've ridden adjust from slow to fast. My Helix Pro adjusts from slow to super slow.
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pedro

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Re: SPV
« Reply #4 on: November 13, 2003, 10:08:11 pm »
most rear shocks don't allow home maintenance, I think only cane creeks can be taken apart at home.

What I have read about spv's make me want to buy one right now.   If not on this site, elsewhere we may find users of the spv's and inquire about their performance from real users..
I imagine, the spv's will start to trickle down and soon ebay or other markets, will have them available at reasonable, (buy for experimentation) prices.

Matno

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Re: SPV
« Reply #5 on: November 13, 2003, 11:24:45 pm »
Quote
most rear shocks don't allow home maintenance, I think only cane creeks can be taken apart at home.


Not really. I know that Stratos has instructions for "burping" a shock on their website (i.e. getting rid of excess air by adding oil to a cavitating shock). I assume you could just drain the old oil that way and replace it. I don't know if Stratos recommends it though.

Risse has instructions for taking their shocks apart for changing the oil right on their website. I've been meaning to try that with mine since it's a little loud...

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numbnuts

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Re: SPV
« Reply #6 on: November 14, 2003, 02:35:31 am »
I'm not sure about forks but I think spv type rear shocks are going to become a standard and will be spec'ed on most new bikes. Manitou licensed the technology from progressive [ or is it curnett?] but have one-uped them by adding a 6th adjustment at a lower price, hence allowing their shock to come on cheaper models. I now hear that both companies are bringing out cheaper versions ie prog 3 and spv4 , is propedal from fox another version ? I am not sure if I want any more knobs and dials on my bike, although I did once mess with the rebound and preload on my trusty van r [rear]. My motto "set the sucker and ride till it breaks" ;)

kkeen

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Re: SPV
« Reply #7 on: November 14, 2003, 04:02:22 am »
 Matno- I wouldn't try any @ home service on a Stratos shock. I made the mistake of compressing a Stratos w/o air pressure which will cause air to actually pass the shaft seal and cavitate the internal oil. No amount of "burping" fixed the unit.  A Stratos tech informed me they fill the shock in a tub of ATF subjected to a vacuum.

pedro

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Re: SPV
« Reply #8 on: November 14, 2003, 05:08:33 am »
Matno---------
Thanks for the info regarding home maintenance to rear shocks.

Can I service  my Vanilla R, which has a bit of cavitation. Any how to guides available?

I have an old stratos air shock which needs service, I may give it a hand. (Or it may be better to trade in for a new helix)
bye
Pedro

Scott

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Re: SPV
« Reply #9 on: November 14, 2003, 01:28:12 pm »
Matno, ATF has a weight of 10 so adjust from there with standard shock oils.  Simon, the Fox Terra Logic is the only "smart" spv I know about-rather than a high bump threshold their design actually recognizes inputs from rider or terrain.  BTW, I have the original Rock Shox RS1 ('87?) and it too had a bump threshold, really a small blow off or bypass washer at the head of the dampning rods.  I reversed it to defeat the valve as it was much too high for my 135 lbs. but was probably just right for an average weight rider.  
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Simon

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Re: SPV
« Reply #10 on: November 16, 2003, 03:20:30 am »
Still unconvinced about SPV for fork application,scott just read a test on a Specialized Enduro with a Fox SPV shock,there only complaint the SPV shock reduces small bump sensitivity,having not tried one cannot comment, but they dispute Foxes claim that there small bump sensitivity isn't affected,hard to see how you can mechanically engineer a shock to differentiate between shock compression by the rider against compression from a bump,maybe one day electronic sensors will come into affect, eg if they could sense the torque being applied through the cranks and then compensate shock compression, all sounds fancifull now but just look how far things have come since F/S Mtb's became popular,Simon
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proflexGB

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Re: SPV
« Reply #11 on: November 16, 2003, 08:11:57 am »
Hi Simon M8ty

I agree with you 100%, how can any spring (air or otherwise) know if it is being squashed down from above or up from below? Basically it just disables the small bump part of the travel. (which is the most difficult to engineer in the first place).

Read another write up some time ago that slated the SPV / Brain type of shocks as the threshold can be overcome in the middle of a tricky high speed manover. ie mid corner etc, because of a rut or whatever,  so you go from locked level flight to dive/change of line  instantly, eek.  

Sounds well dodgy, at least normal constantly damped travel is predictable/rideable and consistant.

Nige.
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Dennis

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Re: SPV
« Reply #12 on: November 16, 2003, 08:43:22 am »
numbnuts said "Manitou licensed the technology from progressive [ or is it curnett?] but have one-uped them by adding a 6th adjustment at a lower price, hence allowing their shock to come on cheaper models."

Actually, as I understand it Manitiou and Progressive both build their shocks under license from Curnutt. One reason they are less expensive is that very early in the development of this technology, Curnutt signed an exclusivity agreement with Foes Racing so that only Foes bikes have the Curnutt shocks. They don't make Curnutt's to fit any other manufacturer's frames and the Curnutts are designed specifically and exclusively for Foes' frames.
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Scott

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Re: SPV
« Reply #13 on: November 17, 2003, 12:38:04 pm »
Simon and proflexGB,
I agree about it, Terralogic, sounding dodgy but the description of the internals made it clear to me at least that they had something very much not an SPV type unit that ignores traill chatter.  Maybe the rear shock by Fox doesn't live up to its promise but our LBS tested the fork at our national bike show and thought it was for real.
Scott
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Simon

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Re: SPV
« Reply #14 on: November 18, 2003, 05:50:03 am »
Quote
Simon and proflexGB,
I agree about it, Terralogic, sounding dodgy but the description of the internals made it clear to me at least that they had something very much not an SPV type unit that ignores traill chatter.  Maybe the rear shock by Fox doesn't live up to its promise but our LBS tested the fork at our national bike show and thought it was for real.

Thanks for the info Scott,I suppose in the end we all will just have to try them for ourselves and see if they suit our individual needs,still interested in anyone else's experiances or opinions,also interested if you think it suits shocks but not forks or vice verser ??? or both/neither,Simon [smiley=nod.gif]
856 FAUX BAR,Fox float,formula B4, Hope Ti,Raceface,FSA ISIS Ti,WTB Ti,Mega-air,XTR,Easton ct2,Easton monkey lite SL,Easton EA50,Goodridge Hoses,Eggbeaters,Ti bolts,DT swiss,