How to: ND4's fork upgrade mod.... 15 bucks, worlds better! - Page 2
Close
Login to Your Account
Honda Grom Forum

How to: ND4's fork upgrade mod.... 15 bucks, worlds better!

This is a discussion on How to: ND4's fork upgrade mod.... 15 bucks, worlds better! within the Grom How-To's and Guides forums, part of the Honda Grom Forums category; Thanks for the clear explanation and the pics! I wonder how much of the difference you feel can be attributed to the thicker oil and ...

Page 2 of 37 FirstFirst 1 2 3 4 12 ... LastLast
Results 11 to 20 of 363
Like Tree92Likes

Thread: How to: ND4's fork upgrade mod.... 15 bucks, worlds better!

  1. #11
    Senior Member
    is making bad decisions and
    scaring children
     
    kzam's Avatar
    Member #
    4884
    Join Date
    Feb 2015
    Location
    Portland, OR
    Posts
    326
    Thanks for the clear explanation and the pics!

    I wonder how much of the difference you feel can be attributed to the thicker oil and how much is due to the longer damper rod.

  2. #12
    Senior Member
    is making bad decisions and
    scaring children
     
    kzam's Avatar
    Member #
    4884
    Join Date
    Feb 2015
    Location
    Portland, OR
    Posts
    326
    Quote Originally Posted by nd4spdbh View Post

    Here is the stock rubber bottom out bumper over the new spacer (2 thin rubber washers went between the top cap and stock rubber bumper). Note how there is a little extra of the spacer sticking out. The stock bottom out washer slides over this and gets held in place by the M8 washer purchased above)
    Attachment 24978

    And this is the final product that gets screwed back on the damper rod. Yes the silver M8 washer is much larger than the stock circlip used to hold the bottom out washer, but its not an issue, the inner diameter of the stock lower fork tube that this assembly goes down into is PLENTY big enough for this washer to clear. In essence the spacer and silver m8 washer are sandwiched between the stock top cap and the top of the stock damper rod.

    Attachment 24979
    Am I understanding this correctly? It looks like your stock rubber bottom-out bumper is no longer able to absorb a bump (if you were to bottom out) because the spacer is taller than the bumper. You mentioned the RaceTech internals lengthen the rod by 20mm (0.787 inches) so maybe that's what those guys intended- lengthen the damper rod as far as they could while still taking advantage of the bumper in case of a serious bottoming-out.

    I think it would it be possible to use a slightly shorter spacer or to put some washers UNDER the bumper rubber (to raise it up a bit more) and you would retain the functionality of the bumper.

    Either way, you've certainly piqued my interest. I want to take mine apart now and take a closer look.

  3. #13
    Senior Member
    This user has no status.
     

    Member #
    6719
    Join Date
    Dec 2015
    Posts
    2,369
    Quote Originally Posted by kzam View Post
    Am I understanding this correctly? It looks like your stock rubber bottom-out bumper is no longer able to absorb a bump (if you were to bottom out) because the spacer is taller than the bumper. You mentioned the RaceTech internals lengthen the rod by 20mm (0.787 inches) so maybe that's what those guys intended- lengthen the damper rod as far as they could while still taking advantage of the bumper in case of a serious bottoming-out.

    I think it would it be possible to use a slightly shorter spacer or to put some washers UNDER the bumper rubber (to raise it up a bit more) and you would retain the functionality of the bumper.

    Either way, you've certainly piqued my interest. I want to take mine apart now and take a closer look.

    If you opened up the forks and looked at the inner tube it becomes super clear. The big washer slides over the spacer and can float up and down, The small silver washer i have put in place between the spacer and stock damper rod had a diameter thats smaller than the inner diameter of the lower fork tube. When the suspension comes up to bottom out the small silver washer goes inside of the lower fork tube (there is plenty of clearance). The top of the lower fork tube makes contact with the big washer and because the big washer can slide up and down on the spacer (the same way it could on the stock damper rod) the stock rubber bumper and two thin extra rubber washer can be compressed.

  4. Remove Advertisements
    HondaGrom.net
    Advertisements
     

  5. #14
    Senior Member
    is UK Gromin'!
     

    Member #
    5057
    Join Date
    Mar 2015
    Location
    Scotland, UK
    Odometer
    2200
    Posts
    139
    I guess you done this for both fork legs or is damping+compression controlled just on one side?
    Our lord who art in minibikes
    GROM be thy name
    Bring us this day our new top speed
    And forgive those who can't wheelie
    For thyne is the kingdom, no power but all glory,
    On earth as it is in turn seven
    For ever and ever, braaaap!

  6. #15
    Senior Member
    This user has no status.
     
    chaddington's Avatar
    Member #
    3437
    Join Date
    Jul 2014
    Location
    Austin, TX
    Posts
    752
    Quote Originally Posted by Twed View Post
    I guess you done this for both fork legs or is damping+compression controlled just on one side?
    Both fork legs.

    Quote Originally Posted by kzam View Post
    I wonder how much of the difference you feel can be attributed to the thicker oil and how much is due to the longer damper rod.
    I put in 30W fork oil and didn't change anything mechanically. I haven't bottomed out since and I'm not a light guy - 230lb/105kg.

  7. #16
    Senior Member
    This user has no status.
     

    Member #
    6719
    Join Date
    Dec 2015
    Posts
    2,369
    Quote Originally Posted by Twed View Post
    I guess you done this for both fork legs or is damping+compression controlled just on one side?

    Most definitely both fork legs. Cant have one leg with more travel than the other!!!


    FYI still zero issues with my extended fork setup. Rides great, does much better off road, and overall makes me much happier!

  8. #17
    Senior Member
    is gearing up for winter
     

    Member #
    6726
    Join Date
    Dec 2015
    Posts
    2,132
    Ive been waiting to do this for a while, but ofc couldnt find M8x50 socket head cap screws, only hex head. Thoughts on if this will work? Possible interference with the socket when tightening in the fork cap. I guess i could always turn the cap on the lathe and take out a bit of matl so the socket would fit.
    I could also buy them from mcmaster carr and have them tomorrow, but $5 a bolt is a little steep.

  9. #18
    Senior Member
    This user has no status.
     

    Member #
    6719
    Join Date
    Dec 2015
    Posts
    2,369
    Quote Originally Posted by turpinator View Post
    Ive been waiting to do this for a while, but ofc couldnt find M8x50 socket head cap screws, only hex head. Thoughts on if this will work? Possible interference with the socket when tightening in the fork cap. I guess i could always turn the cap on the lathe and take out a bit of matl so the socket would fit.
    I could also buy them from mcmaster carr and have them tomorrow, but $5 a bolt is a little steep.
    I dont see why the hex heads would cause any issues. I went with the cap heads so i could possibly use the stock black beauty caps that latch into the center of the cap heads.... but that didnt end up working as the head on the ones i got were taller. Also i figured why not as the hardware store i go to had them.


    I would take a cap off a stock fork and inner rod and take that with you to the hardware store, then you will be able to see if it causes any issues. But so long as the copper crush washer that goes in between the head and cap itself can seat properly it doesnt matter.

  10. #19
    Senior Member
    is Old Farts Society president.
     
    Mainjet2001's Avatar
    Member #
    1023
    Join Date
    Sep 2013
    Location
    Huntington Beach (Surf City, So Cal)
    Odometer
    2083
    Posts
    598
    Quote Originally Posted by nd4spdbh View Post
    Obviously this how two is at your own risk, I did measurements and tests and the 1inch spacer should work without issue. I did make sure that i filled the forks with the proper amount of oil so as not to run out of room when the suspension cycles.

    Did some more riding on the grom today including some off roading, never bottomed once!



    Attachment 25072
    Hmmm...hills in Yorba Linda?
    Some people try to turn back their odometers.
    Not me; I want people to know 'why' I look this way.
    I've traveled a long way, and some of the roads were not paved.




  11. #20
    Senior Member
    This user has no status.
     

    Member #
    6719
    Join Date
    Dec 2015
    Posts
    2,369
    Quote Originally Posted by Mainjet2001 View Post
    Hmmm...hills in Yorba Linda?
    Nope different spot. But I have been known to play on all the diet roads in the Santa Monica mtns. Zuma motorway is fun!

Page 2 of 37 FirstFirst 1 2 3 4 12 ... LastLast

Sponsored Links

Posting Permissions

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

Similar Threads

  1. ABS upgrade
    By Vampiere in forum Grom Talk
    Replies: 12
    Last Post: 03-08-2018, 01:03 PM
  2. Replies: 1
    Last Post: 10-13-2014, 08:24 PM
  3. Honda Grom speedo Healer 70 bucks on ebay
    By Limp1144 in forum Grom Performance
    Replies: 2
    Last Post: 08-31-2014, 07:48 PM
  4. I have $600 bucks burning a hole
    By TrukstopCale in forum Grom Performance
    Replies: 4
    Last Post: 04-16-2014, 06:26 PM
  5. Replies: 6
    Last Post: 11-07-2013, 07:47 PM

Search tags for this page

fork mod
,

grom fork mod

,
grom fork upgrade
,

honda grom fork mod

,
honda grom fork upgrade
,
honda grom forks
,
honda grom front fork mod
,
nd4s fork mod
Click on a term to search for related topics.