Raising forks internally?

Discussion in 'The Garage' started by shinyribs, Feb 13, 2018.

  1. shinyribs

    shinyribs doesn't care

    Joined:
    Sep 24, 2011
    Oddometer:
    1,547
    Location:
    The South
    I've got a bike with conventional damper rod forks. Everything about the suspension and brakes work fine for me, so I don't need a fork swap. I would like to lift the bike about 1", though.

    What's the best way to go about this?

    Not sure about fork leg extender caps, but also not sure they're a bad idea, either. With extenders in mind, the bike in question is a FZ07. Sub 400lbs wet ,primarily used for paved mountain twisties, but thinking about a little scrambler action. So, not looking to slam the forks off-road.

    Any ideas?
    #1
  2. sanjoh

    sanjoh Purveyor of Light

    Joined:
    Feb 13, 2007
    Oddometer:
    6,360
    Location:
    Mountains of Central Florida:)
    How much does the front sag with rider?

    Perhaps increased preload? PVC "spacers" are quick and cheap to try.
    #2
  3. shinyribs

    shinyribs doesn't care

    Joined:
    Sep 24, 2011
    Oddometer:
    1,547
    Location:
    The South
    The spring rate and sag numbers are good to go, so I don't want to make any adjustments there. I just want to lift the bike some. I appreciate the suggestion, though.
    #3
  4. YamRZ350

    YamRZ350 Been here awhile

    Joined:
    Jul 18, 2010
    Oddometer:
    117
    Location:
    Pittsburgh PA
    I don't know that you would get an inch out of it, but if the forks use top out springs, you could shorten them for some extra length. Be careful though, you have to make sure the inner tube still has enough contact with the outer tube bushings. Probably not an issue, but something to check.
    #4
    shinyribs likes this.
  5. Crisis management

    Crisis management Latte riders FTW!

    Joined:
    Feb 14, 2007
    Oddometer:
    1,836
    Location:
    New Zealand
    The simplest option will be fork extender caps, you retain the same suspension travel and action and gain some ground clearance, I assume you are lifting the rear the same to maintain geometry?
    I'm not sure you actually need to do this tho unless it's for a visual effect, I've thrashed a variety of road bikes in light off road conditions and never needed more suspension movement or ground clearance, unless you are planning on big hits or landings you are unlikely to bottom the suspension. If you are liable to bottom your suspension then what you are proposing is not going to help.
    #5
    sieg likes this.
  6. shinyribs

    shinyribs doesn't care

    Joined:
    Sep 24, 2011
    Oddometer:
    1,547
    Location:
    The South

    I've thought about ditching the top out springs since I've heard some forks come with just a thick o-ring instead, but was hoping to hear from someone that had done this. But yeah, it'd be tough to gain an inch from that. Thanks for the input, and I'll definitely keep an eye on the bushing locations.
    #6
  7. shinyribs

    shinyribs doesn't care

    Joined:
    Sep 24, 2011
    Oddometer:
    1,547
    Location:
    The South
    Yes, the rear will come up to match. And no, I don't really NEED to do this, but I think I'd enjoy it. I'm kind of big for a FZ07. I raised the seat height an inch already. Contemplated dropping the footpegs, but don't want to give up cornering clearance since these bikes drag pegs easily already. If I can raise the whole bike 1" I can drop my footpegs to match, and add a light skidplate ( more of rock protection really, though the sump is pretty exposed on these bikes) without giving up any current ground clearance. So, the combination of my 1" taller seat that I have now + 1" of raised bike/dropped pegs should make for a pretty comfy, roomy bike for me. I don't want to raise the seat height any more as I think that (1) the seat will end up getting too unstable (2) I don't want my own weight any higher on the bike (240lbs geared up).

    Bottoming and travel isn't a concern. Like you said, street bikes can take more thrashing than some realize.

    It all sounds more elaborate/expensive than it really is. It cost me $20 to redo my seat. A new dogbone to raise the rear is gonna run me about $20-30 in parts. Just need a good solution for the forks. Will likely get this all accomplished for well under $100. And of course, it will all be completely reversible. I've just never tried to raise/lengthen forks before.
    #7
  8. Andyvh1959

    Andyvh1959 Cheesehead Klompen

    Joined:
    Feb 16, 2012
    Oddometer:
    2,420
    Location:
    Da frozen tundra eh? 1.5 mile west of Lambeau
    Increase the pre-load/reduce the sag. You can add spacers at the top of the fork springs to reduce the sag when you sit on the bike. The spacer could be as simple as a section of steel pipe, or like we did years ago, use VolksWagon valve springs on top of the fork springs.
    #8
  9. shinyribs

    shinyribs doesn't care

    Joined:
    Sep 24, 2011
    Oddometer:
    1,547
    Location:
    The South
    Sag is already where it's supposed to be.
    #9
  10. foxtrapper

    foxtrapper Long timer

    Joined:
    Sep 6, 2011
    Oddometer:
    2,266
    Since you mention sag being where it's supposed to be, I question your question about raising the fork internally. Without extensive modifications, the range of motion is set in the fork. All you can do is move around within that range. Spacers under the top cap will lift the bike, reducing sag. You'll top out more, but have more compression and the raised bike.

    You can get a pretty good idea if you like it with a bit of PVC pipe acting as a spacer. Yes, it will get squashed in time. But it's cheap and easy, which makes it pretty much perfect for experimentation.

    Depending on the bike, you may have a smidge of room to raise drop the fork tubes down in the triple trees.
    #10
  11. Flipflop

    Flipflop Been here awhile

    Joined:
    Mar 18, 2009
    Oddometer:
    377
    Location:
    NC
    Can you go up in diameter on your tires and wheels?
    #11
  12. shinyribs

    shinyribs doesn't care

    Joined:
    Sep 24, 2011
    Oddometer:
    1,547
    Location:
    The South
    I'm afraid not. Wanna stick with 17's anyway. Fender clearance issues, too. Also, another pair of wheels would blow the budget through the roof. Frank's Forks could whip me up some custom tubes cheaper than new tires and wheels would cost.

    Making some progress on this idea with help from some guys in another forum. One guy has given me some info on some different stanchions that can be swapped in to FZ 07 lowers. R3 tubes/damper rods will give me 15mm. SV650 is roughly the same amount of lift. There's also a few years of ZX6 forks that can swapped in to my lowers that will give 35mm of lift, AND will update me to cartridges at the same time. Not sure about that route as I'm already happy with my suspension, but nonetheless, I'll update here if I end up with any usable info.

    Also, sag needs to be where it's supposed to be. My current sag is spot on. There's no way I can gain a full inch of ride height from preload alone, and I'd be taking two steps back if I did. Proper sag is very important to suspension function. My sag is currently fine.

    Thanks all for the input!
    #12
  13. victor441

    victor441 Long timer

    Joined:
    Jul 27, 2009
    Oddometer:
    1,783
    Location:
    Sonoma, Calif.
    Swapping in longer damper rods MIGHT work, FWIW it is a common thing on Sportsters which have used Showa forks for years. Often people will install Roadster damper rods in an Iron, 48, etc. to lift the front end about 2 inches and get more travel.
    #13
    shinyribs likes this.
  14. Salsa

    Salsa Been here awhile

    Joined:
    Dec 12, 2006
    Oddometer:
    972
    Location:
    Arizona, Alaska, Kalifornia
    I have always cut them and added to the middle and I can get any length that is feasable. Or make a whole new inside.

    in one case, I cut the slider and added 2" plus 2" inside.

    Don
    #14