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I don´t get the driveside!

TheThereseTheTherese Posts: 34
edited September 2014 in MTB workshop & tech
Hello!

I been thinking long and hard about suspension (forks) and how it works ( I ride a Boxxer R2C2 by the way). The coil side is pretty clear. But the "driveside" is confusing. When I service the fork and remove the upper crown soo I can compress the diffrent legs independly there are almost no resistance to the movment at al on the damper side - while the coilside is hard and nice like it is when both legs are compressing.

What´s the point having a damper? This small experiment as mentioned above shows that the drive side ads almost noting to the equation compared to the coil. It might be a much better investment to buy the best oil and the best lube you can get rather than waste money on a charger damper.

Or am I wrong? Prove it to me =)

Cheers

Posts

  • Damping controls the spring... without it, the spring would just pogo.
  • Damping controls the spring... without it, the spring would just pogo.

    Hm. Yes I understand the idea. Have you tried to do the same experiment that I did? I feel that damping is more a hype - ok you might need it but can it really ad so much?

    What you can do your self: buy good seals and lube them, lube the spring etc must be more relavant than just "upgrading" a damper.
  • Once set, a springs is fixed. Seals and lube do nothing to control a spring.

    Its all about how much control you want... forks with rebound do well, but are set at middle park damping (note, they still have damping, its just fixed).
    Get a fork with fully adjustable damping and you can tune it to exactly how you want so it matches how you ride.

    The best fork I've ever used was a Rockshox Revalation with blackbox. Took me months to get set up "just so", but when I did....
    I actually swapped a motion control Rev for the blackbox version and the difference was astounding!
  • jimothy78jimothy78 Posts: 1,407
    When I service the fork and remove the upper crown soo I can compress the diffrent legs independly there are almost no resistance to the movment at al on the damper side - while the coilside is hard and nice like it is when both legs are compressing

    There shouldn't be much resistance if you're moving the damper side of the fork independantly (at least, it's not meant to push back like the spring side does, which might be why you feel like there's no resistance).

    However, you should notice that there's a limit to how quickly you can compress (and extend) it - that's what the damping is all about. Try increasing the amount of compression damping at the dial, and you'll notice that that speed limit becomes more restrictive (similarly, increasing the rebound damping will limit how quickly you can pull the rod back out).
  • TheThereseTheTherese Posts: 34
    edited September 2014
    Ok. Yes. You are off course right! When I think about it I also agree that using damper adjustments change the way the fork feels ( I ride Boxxer r2c2 and Pike (compression and rebound controll version - don´t like travel adjusts much)).


    How do you think about the charger damper upgrade vs the do it your self cluster ( oil level / oil quality / lube coil and seal / high quality seals like SKF or Racing Bros). What would be best money spend / performance ratio you recon?
  • jimothy78 wrote:
    When I service the fork and remove the upper crown soo I can compress the diffrent legs independly there are almost no resistance to the movment at al on the damper side - while the coilside is hard and nice like it is when both legs are compressing

    There shouldn't be much resistance if you're moving the damper side of the fork independantly (at least, it's not meant to push back like the spring side does, which might be why you feel like there's no resistance).

    However, you should notice that there's a limit to how quickly you can compress (and extend) it - that's what the damping is all about. Try increasing the amount of compression damping at the dial, and you'll notice that that speed limit becomes more restrictive (similarly, increasing the rebound damping will limit how quickly you can pull the rod back out).

    Ok. Yes. That sounds more like it. I never figured that test out (frist time doing service). The speed of the compression makes up for the flow of oil trough the damper right? Are there fixed holes or are there valves or both?

    Can I ask another question: from where does this resistance come on a Boxxer R2C2 (yes I know its from the damper) but how is it constructed and how can I increase the performance by my self if I wanted to. I know that MX racers work with something they call "shims" are there shims in the R2C2 damper as well?

    Thank´s
  • The RookieThe Rookie Posts: 27,757
    Depending on the damper, depends how complex it is, most have a valve so that, for example, the compression damper in rebound they has minimal effect, leaving it to the rebound damper, and vice versa.

    Most bike forks will have a lot less compression damping than rebound (the spring doing most the work), hence why lower level forks get away with just having a rebound damper and relying on the small effect that has in compression to be good enough.
  • benpinnickbenpinnick Posts: 4,148
    At low (relatively) speeds you wont feel much damping as the oil will flow through the port sufficently fast to feel like there is little resistance (unless your LSC is wound right in) - its only when you hammer it does the oil divert from the low speed port into the high speed stack as the low speed port gets overwhelmed, thats when you'd feel the damping.
    A Flock of Birds
    + some other bikes.
  • Thank´s guys! Soo damping is a cool thing. I agree. Still not sure if damping upgrade is the thing or if seals and lube and oil level / quality is the thing to go for. If one go from 5 wt to 2,5 wt that would change the way the damper work? I have a bit of "low support" in midstroke. Would adding a few (like 5-10 ml) in the outerleg on drive side take that dive away?
  • jimothy78jimothy78 Posts: 1,407
    TheTherese wrote:
    Thank´s guys! Soo damping is a cool thing. I agree. Still not sure if damping upgrade is the thing or if seals and lube and oil level / quality is the thing to go for. If one go from 5 wt to 2,5 wt that would change the way the damper work? I have a bit of "low support" in midstroke. Would adding a few (like 5-10 ml) in the outerleg on drive side take that dive away?

    The received wisdom is that oil levels in the damper circuits are critical - too much and you simply won't get full travel, as there's nowhere for it to go once it's run out of space, and it then acts like the lock-out has been switched on.

    You could experiment with oil viscosity if you like, but you may find that the best answer is to actually add a little oil to the air spring - by decreasing the available air volume, you increase the rate at which the pressure "ramps up" when compessed, so the forks stays sensitive at the first part of the compression, but then gets progressively firmer through the mid-to-late stages.
  • The RookieThe Rookie Posts: 27,757
    Adding heavier oil to the damper is only the same as increasing the damping.....just turn the dial a bit!
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