Results 1 to 50 of 50
  1. #1
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631

    Tested the rear triangle stiffness on 4 FSR bikes

    I test road the following XL Specialized FSR bikes back to back up a steep hill yesterday: 06 Epic Disc, 07 FSR XC Comp, 07 SJ FSR Comp and 07 SJ FSR Elite, which was my favorite. The hill was a sidewalk that was inclined by about 2+% and about 1/2 mile long. Riding these bikes up this hill with the chain on the middle chain-ring yielded the stiffest rear triangle out of the bunch, which I subjectively measured by the ease of peddling. Both of the 07 SJ FSR's were noticeably easier to peddle up the incline than the 06 Epic, which came in third followed by the 07 FSR XC. The SJ Elite for some unknown reason was the easiest to peddle up the hill-I did not have to shift down to a lower gear (the forth largest cassette cog) on this hill, which I road up 5 times on this bike. The SJ Comp needed to be shifted to the next lower gear, the 06 Epic required two gear shifts and the FSR XC needed to be shifted up three gears to the largest cog and really needed the to be down shifted into the smallest chain-ring to match the peddling pressure of the other bikes up the hill.

    All of the bikes were locked out (front and rear), had the same air pressure in the rear shocks and the front forks, with the exception of the FSR XC, which has a coil spring fork.

    The SJ FSR Elite was the smoothest and stiffest out of the bunch because it has large diameter a-symmetric chain stays and (4) 6800 RS bearings (two bearings in each dropout) with M10 bolts in the dropout pivots. I surmise that it made it up the hill easier than the SJ Comp because it is equipped with stiffer cranks-Shimano XT Hollow Tech II. The bike did not creak with the Triad locked-out like the SJ Comp and the FSR XC. And counter to popular believe, the bike seemed to climb easier with the Fork set to 140mm (creating a more slack ST angle) than it did when set to 120 or 100mm.

    The SJ Comp is somewhat summarized above.

    The Epic: I though this would be the best climber out of the bunch because it has the steepest seat tube, flat handlebars and a Fox F100 fork and Brain shock that are locked-out and make the bike feel like a hard tail. The bike was easy to peddle on flat and slightly inclined surfaces; however the flexy rear triangle zapped away pedal energy on when climbing up the steep hill. Most of this flex is from the single 6800 RS bearing in each dropout, which are sandwiched by plastic bushings and held together with a M10 bolt. Like the SJs, the Epic also has asymmetrical chain stays.

    The FSR XC rear triangle had the most flex out of all of the bikes tested because 1) the chain stays are small and are symmetrical and the four 688 RS dropout bearings (two in each dropout) with M8 pivot bolts are the smallest out of the bunch. Unfortunately, the X-Fusion rear shock bobbed and made a lot of noise when locked out, so this shock skewed the data. Technically, the double 688 bearings should be stiffer than a single 6800 in the Epic.

  2. #2
    Knomer
    Reputation: Dusty Bottoms's Avatar
    Join Date
    Jan 2004
    Posts
    3,373
    You lost me at "test road".

  3. #3
    mtbr member
    Reputation:
    Join Date
    Sep 2007
    Posts
    1,746
    sounds like you had a defective XC, my 07 XC comp doesnt bob creak flex etc, locked out the x fusion is stiff as a hardtail and it doesnt make any noise whatsoever

  4. #4
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    1) Dusty Bottoms I test drove the bikes.
    2) darkest_fugue the X-Fusion perfomed well on flat surfaces when locked-out but was overloaded when I climbed the hill. I wish the bike shop had an FSR XC pro with a Fox Triad on hand to test as well so I could eliminate the shock from the equation.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Sep 2007
    Posts
    1,746
    that x fusion was still faulty in my opinion, i do a lot of road riding with mine up down you name it, locked out, its hardtail stiff, it doesnt budge

  6. #6
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    I may be skewing the data or overloading the shock because of my weight, which is 215 pounds, but this is the second FSR XC to perform this way up a steep incline for me. The first one I tested was a 08 FSR XC expert back to back with an FSR XC Pro with a Triad. Both of the rear shocks were aired up to yield 25% sag and when I climbed a very steep short hill the X-Fusion fizzed out-this made the bike very hard to peddle where as the FSR XC Pro's Triad was a lot stiffer and as a consequence much easier to peddle up the steep hill. Like I said earlier on flat smooth terrain the FSR XC equipped with an X-Fusion feels pretty good and is easy to peddle.

  7. #7
    mtbr member
    Reputation: Student Driver's Avatar
    Join Date
    Jul 2006
    Posts
    1,246
    Quote Originally Posted by bwalton
    1) Dusty Bottoms I test drove the bikes.
    2) darkest_fugue the X-Fusion perfomed well on flat surfaces when locked-out but was overloaded when I climbed the hill. I wish the bike shop had an FSR XC pro with a Fox Triad on hand to test as well so I could eliminate the shock from the equation.


    I believe DB means you used "road" and not "rode" (http://dictionary.reference.com/browse/ride). And, while we're at it, you might want to use "pedal" and not "peddle" as you are not trying to sell something. These tend to detract from the meaning of your post.

    http://dictionary.reference.com/browse/pedal

    http://dictionary.reference.com/browse/peddle
    1997 Specialized Stumpy Pro
    1998 Specialized Allez Epic
    2007 Specialized Stumpy FSR Elite
    2010 Specialized Roubaix Expert

  8. #8
    mtbr member
    Reputation: Student Driver's Avatar
    Join Date
    Jul 2006
    Posts
    1,246
    Quote Originally Posted by bwalton
    And counter to popular believe, the bike seemed to climb easier with the Fork set to 140mm (creating a more slack ST angle) than it did when set to 120 or 100mm.
    What was the grade of the climb (I see 2+% but that seems awful low)? What gearing were you using? How much sprung weight (rider, chassis, gear, etc.) was involved? How much torsional flex could be observed, measured, and repeated?

    The reason I ask is not to be argumentative, but rather point out that this is subjective. And, as being subjective, it's hard to state that "contrary to popular belief..." in that manner. Now, for you to observe this makes sense, and the feelings you have are reasonable. But, you seem focused on the bearings (as you have been since your earlier posts about your own SJ FSR) and chainstay measurements without taking material, pivot placement, or construction technique into account (well, at least as far as I can tell). Also, if you used a steep gear and have a fair amount of sprung weight, you can create a significant amount of chainline force (applied torque) to make the rear axle "suck up" into the travel. When this is combined with the fully extended fork, it will shift the weight back dramatically and unload the front end. While I am a Specialized and Horst link/FSR fan, this is something that cannot be ignored and is easily reproducible.

    This is not meant to start any fights, nor am I picking on your results; this is merely criticism of the case you are presenting. Take it with a grain of salt if you wish.
    1997 Specialized Stumpy Pro
    1998 Specialized Allez Epic
    2007 Specialized Stumpy FSR Elite
    2010 Specialized Roubaix Expert

  9. #9
    Texan
    Reputation: Gary H's Avatar
    Join Date
    Dec 2006
    Posts
    1,345
    Quantitative data! No test report is complete without it!

  10. #10
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    Student Driver, you are absolutely right about my test(s) being completely subjective. That said, I have test ridden (12) 07 Specialized FSRs, (2) 08 FSRs to date in pursuit of purchasing a durable bike that fits me and my style of riding. With gearing, rear hubs, count of rear spokes and similar rims all being more or less equal and ignoring the drive train differences, all of the bikes I tested yesterday should peddle somewhat equally up a steep incline. They didn’t, the SJ Elite was the easiest, followed by the SJ Comp, followed by the Epic and last place goes to the FSR XC Comp. So that means that the only other factors involves are 1) the rear shocks, which were all locked-out, pivot placement-again the rear shocks were all locked-out and lastly frame flex induced by the drive-train-note I kept my tail planted on the seat during every climb. Frame flex is broken down into the pivots and surrounding frame material and the frame sections themselves-specifically the seat stays, which take the brunt of the load. My subjective tests basically confirmed that the 07 SJ with the beefiest asymmetrical stain stays and the largest double dropout bearings was the easiest to peddle up a steep incline because it has the stiffest rear triangle out of the bunch. The Epic has a less beefy asymmetrical chain stays than the SJs with single dropout bearings and the FSR XC has the smallest chain stays that are symmetrical with the smallest double dropout bearings. Where else can the peddle energy be going if it is not being absorbed by lateral frame flex in the rear triangle?

    Lastly, the frame geometry is what really blew my socks off-I was planning on buying the 06 Epic because it really seemed like the best bike for my type of riding-with 100mm of travel the Fox F100RL fork and the Fox Float R shock with adjustable brain (i.e. inertia valve) are completely locked-out. On paper the bike should have been the best climber out of the bunch with its steep seat tube, which is angled very close to the new 08 SJ’s at about 73.5 degrees (effective) and its flat handle bars; however it lost out to both SJs with their beefier chain-stays and dropout bearings.

    PS; thanks for the spelling check.

  11. #11
    Texan
    Reputation: Gary H's Avatar
    Join Date
    Dec 2006
    Posts
    1,345
    bwalton. Unless you can provide test data with measurements that are traceable with calibrated equipment in a lab environment, your comparing apples to oranges. When you write an "Engineering Test Report", it's imperative to include little things like "Traceability"

  12. #12
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    I am a Licensed Engineer, and agree with your scientific test method, which in an ideal world must be repeatable (hopefully in different environments) and statistically significant. However, as a bicycle consumer, I am not prepared to shell out thousands of dollars to a testing agency to prove my theory-this is a bicycle club not a science or engineering journal where professionals scrutinize theories and test results.

    As I mentioned in my previous posts, all of my test results are SUBJECTIVE-QUALITATIVE not quantitative and are solely based on the pedal force I felt through my legs while climbing the hill. Maintaining a somewhat consistent cadence in a pre-selected gear, some of the test bikes boggled down and required that I change gears in order to maintain my cadence up the hill while other bikes did not. One of the possible explanations for the different pedal forces between the bikes is frame flex.

    I rented a Gary Fisher HiFi on the Thanksgiving holiday and rode it up a very steep gravel road that I normally ride up on with my 04 SJ FSR and hands down the HiFi is much easier to pedal on an incline than my SJ. One of the reasons for this is because the HiF is not taxed with a drop-out pivot inline with the drive train like all of the Specialized Horse FSR designs are. The GF HiFi gives up some of the active suspension that the Specialized FSRs have and in its place yields a noticeably stiffer rear end that pedals like a hard tail.
    Last edited by bwalton; 12-03-2007 at 06:24 PM.

  13. #13
    banned
    Reputation:
    Join Date
    Mar 2004
    Posts
    477
    I think Student Driver must be an engineer of some sorts by his dialogue...

  14. #14
    mtbr member
    Reputation: kersh13's Avatar
    Join Date
    Sep 2007
    Posts
    272
    So I am looking at a new Epic myself and here's what I wanna know bwalton; you pumped the rear shocks all up to the same air pressure and used the same rebound setting and dampening settings and you liked the Stumpjumper best? My understanding was the same as you mentioned: that the Epic is the climbing-FS-bike to have.
    - Just livin' the dream -

  15. #15
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    Here is another point of reference to consider: hard tail pedal efficiency. It’s been so long since I have ridden a hard tail mountain bike that I have forgotten how easy or efficient they are to pedal-especially up a steep incline.
    So to get back to my test rides, what variable would cause one dual suspension bike to have better pedal efficiency than another dual suspension bike if both were locked-out?

    Remember, the four Specialized bikes I tested were all new, they all have very similar rear Shimano hubs, 32 spokes, heavy walled rims, HG-50 cassettes with the same gears, 30.9 mm seat posts, seats, main pivot bearings 6802 RS orientated behind the BB and chain ring gear ratios. The component differences between the bikes are as follows: Crank sets with their respective BBs-two pieced with outboard bearings vs. three pieced with a cartridge bearing, SRAM vs. Shimano chains, Shimano SP-505 vs. SP-520 pedals, all of the bikes weighed 30 pounds +/- one pound, all of the tires were pumped up the 45 psi, all of the rear shocks and front forks were adjusted to 25% sag and SRAM vs. Shimano rear derailleurs. None of these components other than the cranks would have any effect on peddle efficiency. The crank setup would have very little impact on the peddle efficiency because the relative stiffness between them is probably within 10% or less.

    Again this line of deductive thinking brings you back to the relative stiffness of the rear triangle as a major contributor to pedal efficiency. All I can say is that my hybrid road bike, with different gearing, tires and sized wheels can be peddled up a very steep hill at 10 MPH, while my SJ FSR travels up the same hill (fully locked-out) at 4 MPH and is noticeably harder to pedal as well.

  16. #16
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    kersh13, no one was more surprised by my findings then I was because I intended to purchase the Epic that day. After all it is advertised as a climber-race bike with hard tail pedal efficiency. I dialed all of the rebounds to the center settings on all of the rear shocks before I rode them up the hill. All of the bikes I tested pedaled quite efficiently on flat surfaces and slight inclines. They all felt stable down hill and felt very similar except when pedaled up the steep hill. It could be that my weight of 215 pounds coupled with my height of 6’-3”, which positions my saddle above the average height, puts addition stress on the rear suspension that may be maxing-out the frame components and causing them to flex beyond their design parameters.
    All I can say is test ride the Epic over as many different surfaces and slopes as the bike shop will allow-better yet find a shop that will rent one to you so you can try it on your trails. Remember you will ride a bike that fits you and that is tuned to match your trails more than a bike that is not.

  17. #17
    mtbr member
    Reputation: kersh13's Avatar
    Join Date
    Sep 2007
    Posts
    272
    I test rode one just this weekend and I really loved it. But I'm coming from a HT Stumpjumper so obviously the difference is night and day there. Too, where I'm from, is all the North Georgia Mountains XC riding so the amount of travel from a Stumpy FSR is a bit much for the type of terrain here. I was just wondering if you had used the same air pressure and everything from bike to bike. When I first got on the Epic, it felt entirely too plush for my likings. Until, one of my friends recommended that I change the rebound settings and that made all the difference. Just one click on that red rebound knob made a very, very noticeable change in the way the suspension reacted. Maybe if someone else knows this, but are the median settings on all these bikes going to react differently?
    - Just livin' the dream -

  18. #18
    Texan
    Reputation: Gary H's Avatar
    Join Date
    Dec 2006
    Posts
    1,345
    I'm not an engineer, but I am in engineering. I'm the guy who tells the engineers whats wrong with their designs. I'm a Lab Rat! So, help me through this. I dont understand how you concluded that bike "A" was harder to ride uphill because of rear triangle flex? Why not the weight of the different bikes as the major factor? Or one rotor was dragging on the pads etc? Or change in wind direction?

    Nothing wrong with a good "Feel by the seat of your pants" theory, but that would make it just a theory and not a true test that should be published IMO. You could be 100% correct, but without data to support your theory, it's just a theory and not a true test.

    Interesting stuff though!

  19. #19
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    Kersh13, my ride on Sunday was the second time tested the Epic Disc-the first time was in August on the way back home from a camping trip. The first time I rode the bike the rear end bobbed like a pogo stick because there was not enough air pressure in the shock. Last Sunday I made sure that the Mechanic aired up the shock correctly and the bike did not bob at all in the front or the rear-it felt like a hard tail with a locked-out fork. The Epic's shock and fork did not bob what so ever when I climbed the steep hill either, so it surprised me to learn that both of the SJ's, which felt softer when fully locked-out then the Epic, were noticeably easier to pedal up the hill. I tested all of the bikes back-to-back at least four times each. That is, I would ride the Epic up the hill on one run then the SJ Comp on a run, next the SJ Elite on one run and finally the FSR XC. Then I would start another round of runs. As far as the rebound adjustment goes, I dialed both the rear shock and fork to the middle settings on all of the bikes.

    I would recommend that you rent a Stumpjumper and a Gary Fisher HiFi, so you can get good feel for all three the bikes on your trail before you fork over $2K+.

  20. #20
    mtbr member
    Reputation: Student Driver's Avatar
    Join Date
    Jul 2006
    Posts
    1,246
    Quote Originally Posted by mtbikernc69
    I think Student Driver must be an engineer of some sorts by his dialogue...
    1997 Specialized Stumpy Pro
    1998 Specialized Allez Epic
    2007 Specialized Stumpy FSR Elite
    2010 Specialized Roubaix Expert

  21. #21
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    Gary H, as young engineering student I have three bits of advise for you 1) Study hard and don't blowout all of your brain cells at parties. 2) Relax when you are taking a test-remember its not life and death only one extra semester of retakes at worst. And 3) there is a different reality out there other then what your course work is exposing you to. Aside from the abstract world of language and theorems, a human being relies on his five primary senses to understand the world around him and any concept that is beyond the reaches of his senses must be related back to an actual experience (which at some level involved your senses). In other words, your core education will be dwarfed by real world experiences that you expose yourself to-and with that you will eventually develop a feel and much deeper understanding of the essence of your education. In less abstract terms, you will develop a feel for the mechanics behind the engineering principles and formulas that you are learning in school today. And that feel will transcend all the numbers and methodologies that you see today into a real understanding of how and why things work.

    So to get back on the subject, a number of members have posted that they can actually see their rear seat stays and chain stays laterally flex when their bike is mounted in a trainer and a friend is pedaling on the saddle. Specifically, I remember a few large Epic riders posting this observation on older frames. None of these observations are surprising given the eccentric chain load, which is transverse to the riders and suspension loads all acting on the rear axel and small frame section members and pivots that make up the rear triangle.

  22. #22
    Texan
    Reputation: Gary H's Avatar
    Join Date
    Dec 2006
    Posts
    1,345
    I'm not a young engineering student. I'm an old guy who works in an engineering lab. lol Testing is what I do for a living!
    Last edited by Gary H; 12-05-2007 at 03:50 AM.

  23. #23
    mtbr member
    Reputation:
    Join Date
    Dec 2007
    Posts
    38
    I'm new here, but this sounds weird. Where you testing mountian bikes for "climbing ability" on a 2% grade on pavement?

  24. #24
    mtbr member
    Reputation: Student Driver's Avatar
    Join Date
    Jul 2006
    Posts
    1,246
    Quote Originally Posted by xxforeverfallenxx
    I'm new here, but this sounds weird. Where you testing mountian bikes for "climbing ability" on a 2% grade on pavement?
    Yes, you're new however you are correct in that it's weird; this is a typical bwalton post with respect to Specialized bikes. You will get used to it though. To know bwalton is to think "what the hell just happened?" after reading one.

    j/k, but seriously, it's weird.
    1997 Specialized Stumpy Pro
    1998 Specialized Allez Epic
    2007 Specialized Stumpy FSR Elite
    2010 Specialized Roubaix Expert

  25. #25
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    Unfortunately, that was the steepest grade available in the bike shop’s area and I would like to amend my original estimate of 2% to about 3+% (i.e. 3’-0 of rise with 100’-0 of run or 2.3 degrees slope). The hill I tested the bikes on was approximately 500 yards long
    with total rise of about 50 feet. I can not find a bike shop in my area that rents 07 SJ FSR’s, so I can test it on my trails, which comprises of steep gravel roads and single track trails covered in clay with large out crops of rocks and grades in the upwards of 15%. I did however rent a Gary Fisher HiFi, which handled my trails very well.

  26. #26
    Texan
    Reputation: Gary H's Avatar
    Join Date
    Dec 2006
    Posts
    1,345
    Quote Originally Posted by bwalton
    Unfortunately, that was the steepest grade available in the bike shop’s area and I would like to amend my original estimate of 2% to about 3+% (i.e. 3’-0 of rise with 100’-0 of run or 2.3 degrees slope). The hill I tested the bikes on was approximately 500 yards long
    with total rise of about 50 feet. I can not find a bike shop in my area that rents 07 SJ FSR’s, so I can test it on my trails, which comprises of steep gravel roads and single track trails covered in clay with large out crops of rocks and grades in the upwards of 15%. I did however rent a Gary Fisher HiFi, which handled my trails very well.
    Your a P.E.?

  27. #27
    mtbr member
    Reputation:
    Join Date
    Dec 2007
    Posts
    38
    The more I read this, the stranger it gets! Where these "tests" performed all on the same day? Was there a proper warm up before each "test" what about recovery and average heart rate? What was your average time to complete each run? What tool was used to measure lateral flex in the swingarm? and where is the "data" that supports your findings? What was your average cadence, power output, ect. Are you buying a bike or just ridding all the bikes at your local dealer?

  28. #28
    I want to ride
    Reputation: pd406's Avatar
    Join Date
    May 2006
    Posts
    149
    WTF?

    That is the funniest post i've read. I feel sorry for that bike shop. How long have you been "testing" those bikes...

  29. #29
    Riding a bike
    Reputation: Matthew45454545454's Avatar
    Join Date
    May 2004
    Posts
    20
    Quote Originally Posted by Dusty Bottoms
    You lost me at "test road".

    For me it was "sidewalk"

  30. #30
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    All right here is my history with Specialized-I bought a 04 SJ FSR about 3 1/2 years ago. To date with about 2000 miles on the odometer, the bike has eaten through 3 sets of dropout bearings and 3 sets of shock link bearings and one set of main link bearings. My LBS sent me home with a set of bearings when the 4 dropouts and 4-shock link bearings froze after about 3 month of riding because the mechanic did not know how to replace the bearings. After I replaced the second set of bearings, I contacted Specialized who admitted that there was a problem with my frame but also said that they can not help me because I voided out my warranty when I swapped out the bearings (SOL). So much for customer loyalty.

    So before I buy another mountain bike-especially a Specialized dual suspension model-I want to make sure it is designed adequately to withstand my size and type of riding for many years and not fail after 3 months of riding like my 04 SJ did. Before I owned this 04 SJ, I would base my decision solely on the way the bike rode and not on the design of the pivots or how much lateral flex I felt in the rear triangle when pedaling up a steep grade.

  31. #31
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    Comparing the frame schematics of the 07 SJ, the 06 Epic and the 04 SJ (which has the same rear triangle as the 07 FSR XC) shown in the owner’s technical manuals, the main pivot housing look substantially stiffer on the 07 SJ and 06 Epic than it does on the 07 FSR XC. This is because both the 07 SJ and Epic have a boxed in pivot housing that is either forged into the back of the BB or welded all the way around the BB. The forged chain stay pivots and bearings (6802 RS) are mounted outboard of the BB pivot with an aluminum M15 bolt.

    The 07 FSR XC has two forged bearing flanges that ear out behind the BB and mounted on the inside these flanges is a forged chain stay pivot housing that the left and right stays are welded off to. The 6802 RS bearing are pressed into the BB pivot flanges and the whole assembly is tied together with a single M15 aluminum bolt. The 07 FSR XC BB pivot flanges and the seat stays look less beefy than the main pivot assemblies on the 07 SJ and 06 Epic’s, which are boxed into the BB.

  32. #32
    mtbr member
    Reputation:
    Join Date
    Dec 2007
    Posts
    38
    and did a 1/2 mile ride on a sidewalk give you your answer? This sounds like more a problem with your dealer than with your previous bike/ specialized. Also sounds like your last bike wasnt that bad at all, a couple of bearings over the course of 2000 miles. if your a larger guy ( like myself ) or ride hard that should be expected. What is the total list of bikes you've tried? ( other than the Fisher and Specialized ) if you are looking for simple, what about a single pivot ( Cannondale or Santa Cruz ) Isolate your price range ( why test a 07 FSR XC next to a SJ ELITE? ) in my opinion the simple fact that a bike might "feel" easier to pedal up a sidewalk says nothing about the bikes 1. actual swing arm stiffness 2. potential longevity of its components. This would be more a result of quality in suspension, wheels, and cranks.

  33. #33
    mtbr member
    Reputation:
    Join Date
    Dec 2007
    Posts
    38
    THAN WHY TEST RIDE A 07 FSR XC!!! it makes no sense! it has nowhere near the component spec, and a lesser quality frame. why even test ride it? all this "testing" and all you've come up with is that the better bike ( according to specialized ) is actually better........ duh

  34. #34
    mtbr member
    Reputation: his dudeness's Avatar
    Join Date
    May 2007
    Posts
    1,886
    Quote Originally Posted by bwalton
    All right here is my history with Specialized-I bought a 04 SJ FSR about 3 1/2 years ago. To date with about 2000 miles on the odometer, the bike has eaten through 3 sets of dropout bearings and 3 sets of shock link bearings and one set of main link bearings. My LBS sent me home with a set of bearings when the 4 dropouts and 4-shock link bearings froze after about 3 month of riding because the mechanic did not know how to replace the bearings. After I replaced the second set of bearings, I contacted Specialized who admitted that there was a problem with my frame but also said that they can not help me because I voided out my warranty when I swapped out the bearings (SOL). So much for customer loyalty.

    So before I buy another mountain bike-especially a Specialized dual suspension model-I want to make sure it is designed adequately to withstand my size and type of riding for many years and not fail after 3 months of riding like my 04 SJ did. Before I owned this 04 SJ, I would base my decision solely on the way the bike rode and not on the design of the pivots or how much lateral flex I felt in the rear triangle when pedaling up a steep grade.

    Ok dude, so I'm about to try and skew up your test results a bit here in a big way.
    1. Putting the same psi in the rear shocks on an epic vs a stumpy WILL NOT mean that both bikes are properly set to your weight. Set the rear shock psi by sag, not a guessed psi based roughly on your weight. Both bikes are different (design, geometry), both bikes are designed to ride different (all around vs. race), both bikes use different shocks made by different manufacturers, intended to work in different ways, and the manufacturer will state in their individual owners manuals how their shocks need to be set up. basically, to be set up to equal performance levels both shocks will need DIFFERENT psi levels in them.
    2. Why would you test the overall performance and stiffness of a full suspension bike with the suspension set at full lock out? If you want a more accurate measurement of their performance then you need to open the valves up a bit so the suspension can actuate... Especially on the epic since the valving needs to not be locked out if you want to get any sort of benefit from the Brain. I frequently climb steep hills and having the rear end not locked out gives you better traction (better traction translates into more foward momentum= you go faster)... and in that regard I'm pretty sure the Epic will outclimb the Stumpy.
    3. Testing a bike on a 2-3% graded and paved road is by no means a way of doing any sort of "real world" testing. I still consider a 2-3% grade as FLAT not a steep hill. Consider this for a moment as well, if the different bikes had different tires on them then your results would be skewed as well as the different tires probably have slightly different tread patterns and rubber compounds making them faster or slower rolling. In other words, an epic set up with fatter and stickier tires is going to pedal slower on pavement against a Stumpy set up with narrower and less sticky tires... The real question here then isn't how they perform on road but how they would perform offroad. I've had tires move really slowly on pavement, but throw them in the conditions they were made for and they'll be exceptionally fast.
    4. What is your height, weight, saddle position, saddle height, saddle position over the rear axle, handlebar position, cleat position? These are all critical factors to getting each different bike to perform well, the setup from one bike once again is probably not anywhere close to how the other bike is supposed to be set up... And you said that you basically set them all up identically.
    5. What was your torque output at the pedals? What cadence were you pedaling at, and was it the same throughout the testing? What was your wattage output at those cadence levels on the bikes? Did you shift gears on all the bikes, and if so did you shift to the same gear at the same point during your tests? Did you use a speedometer or a stopwatch to actually time your tests and provide yourself with data on stiffness versus efficiency? Do you realize that one leg is longer than the other? Do you realize that one leg is your dominant leg and therefore provides more power than the other? Were you sitting or standing for these tests and did you replicate the EXACT scenario when on each bike? To make your stiffness tests more accurate you need to take the rider out of the equation and put the frame on a machine to properly and accurately test frame stiffness. Any one of those questions that I posed will cause any of your data to be inaccurate unless you can honestly say you know the answers to all of them.
    6. Your complaint about having to replace bearings is simply something you're going to have to live with when you own a fully suspended bike. Most companies recommend that you replace your bearings every 4-6 months on your frame (Santa Cruz recommends every 4 months, I believe Specialized recommends every 6-12 months). If you've had your current bike for 3.5 years and have had to replace your bearings that many times I'd say you were doing exactly what most people on MTBR are doing. Simply put, no bearing is indestructable... they all will have some sort of torque and load put on them for their lifespan on your bike, if you want to replace your bearings less then get something like a Santa Cruz Bullit which essentially uses BB cups in a huge single pivot to make them last longer.
    7. All bikes need to be designed with flex in mind. With that considered, all bikes will be built for different reasons, therefore things like frame weight and tubing design and thickness must be factored into the design so that it can perform in the way it was meant to. The epic is designed for xc racing, the frameset might utilize thinner tubing so as to cut weight wherever it can. The Stumpy might very well be stiffer since it is designed as a longer travel (more travel means the frame should be beefier) trail bike, not a race bike. To make your test results accurate you will need to consider things like frame stiffness and how each frame is constructed. For example, a Carbon road bike is much stiffer than steel or titanium... in fact you can get it stiffer than Aluminum, and lighter too if you want to race. But take a hammer to it and then take a hammer to a steel or aluminum frame and see which one holds up better.
    8. Another fun tidbit about flex is that a little flex can help you corner better since the frame is able to absorb some of the shock that you inevitably put on the frame in a corner and then utilize the flex to pop you out of the corner faster, the same principle applies to bicycle suspension (which is another reason why you should test f/s bikes without being locked out.
    9. Last but not least, I wouldn't worry so much about getting the stiffest rear triangle on the market, or even the stiffest rear triangle between the three. Instead, I'd ponder on how stiff of a rear triangle I actually NEED for the type of riding that I am planning on doing. If you were going to race I'd say go the Epic route. If you were going to be a bit more abusive to your bike, if you ride technical and rocky terrain, if you encounter jumps or dropoffs along your trails then I'd go with the Stumpy.

    Ultimately, buy what works the best for you. If you're more comfortable on a Stumpy then buy it, we don't need a whole bunch of analysis to know that you liked the Stumpy better regardless of how stiff the rear end is. I'm not trying to prove you wrong or get you angry or anything, but you're test data is nowhere near being accurate since you have too many outside variables skewing everything. Once again, if you wanted to be accurate (and if you say your an engineer I'd hope that you would really want accuracy) then buy both bikes and set them up on a MTS frame machine to properly test for frame stiffness in a controlled and accurate environment. Or, just contact Specialized and see if you could get in touch with whoever does they're testing, I'm sure they can provide you with all the accuracy you want right down to the newton meter for both bikes.

  35. #35
    mtbr member
    Reputation:
    Join Date
    Dec 2007
    Posts
    38
    or if you are worried THAT MUCH about bearings and flex buy a hardtail!! bottom line moving parts break, if your not ok with that, get somthing with fewer moving parts.

  36. #36
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    Dude, here is a quick summary of the test bike(s) setup: Rear shocks 25% sag, rebound dialed to the middle setting, front fork(s) 25% sag with their rebounds turned to the middle setting, Tires all aired up to 45 psi-the SJs and FSR all had the same tires and the Epic had thinner tires with smaller knobs, all the saddle positions were in the same location and I wore my cleats on all the rides. And yes I agree that a 3% grade is mild, so I was very surprised by the results. And lastly, like I posted earlier, that all of my tests were SUBJECTIVE and I would be more than willing to run them again in a lavatory environment if I can convince members to make a donation to me so I can retain a certified testing lab to conduct these tests. I would say I need about $8K to $10K to get started. Otherwise we can keep this discussion limited to pedal pressure felt through the legs and registered by the brain and we all know when it gets harder to pedal because we normally shift down to maintain our cadence, which is what I did on the test run. Furthermore, review the OEM equipment on these four bikes and you will see that components like rear wheels, hubs, spoke count and cranks are all very similar (i.e. within a few percentage points in stiffness to one another). So why is one bike model noticeably harder to pedal up a smooth surfaced hill than another when they are locked-out?

  37. #37
    mtbr member
    Reputation:
    Join Date
    Dec 2007
    Posts
    38
    yes, lets get $8-10K so you can test bikes in a "lavatory" ( I tested a few bikes in the lastest isssue of MTBA just a few minutes ago in the lavatory ) YOU ARE MISSING THE POINT OF WHAT EVERYONE IS SAYING, LET ME MAKE THIS CLEAR!!!! YOU HAVE NOT "TESTED' THE SWINGARM STIFFNES!!!!! YOU ARE NOT FEELING THE SWINGARM OR BEARINGS OR LINKAGE!!!!!! YOU ARE NOT! FLEXING THE REAR TRIANGLE ON A 3% GRADE UNLESS YOU ARE A PRO TOUR CALIBER BIKE RACER!!!!! WHY ARE YOU TESTING A FULL SUSPENSION BIKE LOCKED OUT!!!

    now I remember why I left retail...........

  38. #38
    mtbr member
    Reputation:
    Join Date
    Dec 2007
    Posts
    38
    Sorry if I seem a little upset by all this, but I've come to MTBR.com as a source for info when buying my last 3 bikes and I hate to see such misleading, wrong or crazy logic passed off as fact. At least rename you post " My opinion on what is feels like to ride a $2800 mountian bike on a sidewalk"

  39. #39
    mtbr member
    Reputation:
    Join Date
    Dec 2006
    Posts
    290
    Wow, what an amazing thread. I wanted to respond, but didn't know where to start. "his dudeness" did a good job. I think somewhere between guys that buy a bike based on color-matched components, and bwalton's seemingly logical but subjective over anal-ysis is where most of us are. But the extremes keep it entertaining.

  40. #40
    Riding a bike
    Reputation: Matthew45454545454's Avatar
    Join Date
    May 2004
    Posts
    20
    Quote Originally Posted by bwalton
    I would be more than willing to run them again in a lavatory

    First a sidewalk, now a toilet? Come on now...

    Please post your lavatory test results, I myself have been looking for a new toilet and am a big dumper much like yourself.

    My lady has been testing this one for me:



  41. #41
    mtbr member
    Reputation:
    Join Date
    Sep 2007
    Posts
    1,746
    is anyone else absolutely lost at this stage?

  42. #42
    memento mori
    Reputation:
    Join Date
    Feb 2004
    Posts
    374
    Sounds like bike-geek overload.IMO my epic is the best climbing bike I've ever owned(fully since '94).I'm 5'11" 175lb expert race level in New England conditions.I run a low gear of 29-32 and feel no frame flex.If flex and durability is that big a problem then get a hard tail.All frames eventually fail.Specialized's warranty rules.

  43. #43
    mtbr member
    Reputation: his dudeness's Avatar
    Join Date
    May 2007
    Posts
    1,886
    Bwalton:

    Did you ever stop to measure how tall the tires are? Some tires are higher volume than others, and therefore a 2.1 from one company may be slightly wider, narrower, taller, shorter, etc than another tire. Regardless of whether or not you had the tires at the same psi, the taller tires will have more squish (due to their highter volume) which could just possibly be percieved as frame flex in your mind due to how it caused the bike to feel. This would also provide an excellent explanation for why one bike pedaled faster than the other.

    And then of course there's the "gription" factor for the tires... Did you test for tire grip?

    Seriously dude, if you are so concerned with the rear triangle stiffness on Stumpy's vs. Epics, just save your dough for a 08 Stumpy. The rear triangle is pretty much the stiffest and strongest that Specialized has EVER made, I've seen them handle 25 foot road gaps under a smooth rider. I think it'll be more than enough for you.

  44. #44
    mtbr member
    Reputation: Student Driver's Avatar
    Join Date
    Jul 2006
    Posts
    1,246
    Quote Originally Posted by his dudeness
    Bwalton:

    Did you ever stop to measure how tall the tires are? Some tires are higher volume than others, and therefore a 2.1 from one company may be slightly wider, narrower, taller, shorter, etc than another tire. Regardless of whether or not you had the tires at the same psi, the taller tires will have more squish (due to their highter volume) which could just possibly be percieved as frame flex in your mind due to how it caused the bike to feel. This would also provide an excellent explanation for why one bike pedaled faster than the other.

    And then of course there's the "gription" factor for the tires... Did you test for tire grip?

    Seriously dude, if you are so concerned with the rear triangle stiffness on Stumpy's vs. Epics, just save your dough for a 08 Stumpy. The rear triangle is pretty much the stiffest and strongest that Specialized has EVER made, I've seen them handle 25 foot road gaps under a smooth rider. I think it'll be more than enough for you.
    Actually, I've recommended a Turner in the past, but maybe a Ventanna is in the works at this point? Both are legendary for lateral stiffness, but my 07 has been fine for me and my 230lbs. Also, did anybody cover wheel build differences and its effect on perceived lateral stiffness of the system (overall bicycle assembly)? Crappy wheel build can make a bike feel like the frame is cracked (along with hub body stiffness and overall clamping force of the retention system chosen [err, skewer ]).
    1997 Specialized Stumpy Pro
    1998 Specialized Allez Epic
    2007 Specialized Stumpy FSR Elite
    2010 Specialized Roubaix Expert

  45. #45
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    I guess I have been pretty lucky so far because I have never encountered an online club member, like xxforeverfallenxx, who is so uptight and angry about a stranger’s opinion about a consumer product. The postings on this club are chalk full of opinions on all sorts of products. Fox vs. Manitou, Shimano vs. SRAM, Hope vs. Avid, Specialized body geometry saddles vs. Terry saddles (ha-ha)-the list goes on and on. My previous posting about my bike have generated very interesting answers and stories that have helped me understand the equipment and the sport better. And that is what keeps me coming back to this club are the members who share their experiences and knowledge in a thoughtful and courteous manner-hopefully I have passed on useful information to other members along the way as well.

    So to get back on track-my test rides made no sense at all, so I am simply trying to explain the differences in the feel of the bikes by comparing their respective components and frame designs. What I have not introduced into this discussion is quality control. The quality control or should I say lack thereof, from the manufacturing of the bike and components to the final assembly and adjustment at the bike shop. Does anybody have any stories about QC issues?

    Lastly, can any member verify my subjective findings, by testing riding the same bikes (at their LBS) up a steep hill? Remember to lock-out the front forks and rear shocks before you assend.

  46. #46
    mtbr member
    Reputation:
    Join Date
    Sep 2007
    Posts
    1,746
    i cant believe i weighed myself today and im down to 130 pounds, i was 145 when i started biking seriously again which at just over 5 foot 8 was a good weight for me, i really dont need to be losing any weight but it keeps coming off,

    back on topic though, put the brand new epic through its paces today, i wanted to find out if its as good a climber as they say, tried 2 technical steep rocky climbs that i used to do on my XC, the epic was noticably better going up and coming back down, im comfortable with the seat level with the bars on the epic and i still get a good xc pedal stroke, that was something i couldnt get on the XC i had to have the seat waay over the bars to achieve it, thats an extra perk for me as i thought the epic would be lousy going down, its actually much better than the XC

    they had a new 08 SJ comp in the shop today its the first time ive seen one, i picked it up and it was noticably heavier than my epic comp, i thought both would be similar weights now but not so,

    my epic will be shedding some weight this week, XTR cassette and front derailer plus XT crank and phenom sl seat are going on, hopefully itll make it over 26 pounds, as it is its over 27, still though it feels very light when riding it, im loving it so far

  47. #47
    mtbr member
    Reputation:
    Join Date
    Dec 2006
    Posts
    290
    bwalton,

    Try this to eliminate quite a few subjective variables: Clamp the bike frame up in the air to something solid (yes, could be tricky to do without marring the frame..), rig up a solidly fixed pointer (think trueing a wheel), and pull sideways on the rear triangle at axle with a spring scale. Have a helper measure deflection to pointer (with caliper, feeler gauge etc). Repeat at same spring scale reading on other frames (you'll need to experiment to find a scale reading giving measurable deflection on most frames). Of course you should test many frames of each model to get a meaning result...

  48. #48
    mtbr member
    Reputation: his dudeness's Avatar
    Join Date
    May 2007
    Posts
    1,886
    Quote Originally Posted by bwalton
    I guess I have been pretty lucky so far because I have never encountered an online club member, like xxforeverfallenxx, who is so uptight and angry about a stranger’s opinion about a consumer product. The postings on this club are chalk full of opinions on all sorts of products. Fox vs. Manitou, Shimano vs. SRAM, Hope vs. Avid, Specialized body geometry saddles vs. Terry saddles (ha-ha)-the list goes on and on. My previous posting about my bike have generated very interesting answers and stories that have helped me understand the equipment and the sport better. And that is what keeps me coming back to this club are the members who share their experiences and knowledge in a thoughtful and courteous manner-hopefully I have passed on useful information to other members along the way as well.

    So to get back on track-my test rides made no sense at all, so I am simply trying to explain the differences in the feel of the bikes by comparing their respective components and frame designs. What I have not introduced into this discussion is quality control. The quality control or should I say lack thereof, from the manufacturing of the bike and components to the final assembly and adjustment at the bike shop. Does anybody have any stories about QC issues?

    Lastly, can any member verify my subjective findings, by testing riding the same bikes (at their LBS) up a steep hill? Remember to lock-out the front forks and rear shocks before you assend.

    Well you came to the right place to get info, a lot of people on here (me included) consider opinions as fact so take everything we say with a huge grain of salt. In the end only you can pick the right bike for you, we're more than happy to provide input though.


    I'd perform your tests since I have a whole fleet of Specialized bikes to borrow and ride, hell I'd even perform them in the dirt to test it in it's intended envornment. I would politely refuse to perform these tests with the suspension locked out... to me that is absolutely ridiculous. Test a full suspension bike the way it was intended to be tested, with the suspension set up properly for each bike and with it active. Unfortunately I wont be able to perform said tests... I spend too much time riding the sh!t out of my Pitch. It's plush, its frame is super tough, and it descends like a bat outta hell. I say scrap the Stumpy vs Epic debate, buy a Pitch, and never have to worry.

  49. #49
    mtbr member
    Reputation: bwalton's Avatar
    Join Date
    May 2006
    Posts
    631
    In a past post I read, an Epic owner mounted his bike in a trainer and watch the rear chain stays and seat stays flex from side to side as another rider pedaled in the saddle. It would be interesting to see how much flex would occur when the rear suspension is traveling over a rough surface while the drive train is being loaded by the riders pedal strokes.

  50. #50
    mtbr member
    Reputation:
    Join Date
    Dec 2007
    Posts
    38
    1350 miles combined on my Tarmac Expert and FSR XC comp this year. I'm 6' 225 ride hard and long miles on both bikes. I have pretty limited time in my life and if its a choice between riding and measuring how much flex my swing arm MIGHT have if I was riding. I take Riding everytime! By the way I have over 450mi on the FSR XC not one squeak out of the shock or linkage

Members who have read this thread: 0

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •