Author Topic: Fork Rebuild - Police 2000 non ABS - Sonic Springs.  (Read 6814 times)

Offline Piet

  • Sr. Member
  • ****
  • Posts: 278
  • Thanked: 27 times
  • Caroline Springs, Victoria.
Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« on: December 25, 2014, 10:50:30 PM »
Leaking seals - meant it was a good time to rebuild the forks with new bush, seals, dust covers and fresh oil.
After stripping them down, and cleaning the bits & pieces I thought I would take a few photo's to show the differences in the internals.
The first thing to notice is that the fork stanchion are different lengths for Left & Right sides.  This first photo has the bottom of the forks level (the wide angle lens might make it look as if they are not level but they are)  Notice that the LH fork is shorter.  Left is 614mm and the RH is 633mm.



The bases are the same for the comparison.



The top difference highlighted.



The base of each fork tube is also different.  In this next shot.  Left is Left fork, Right is Right.  The RH fork has a trapped washer fairly close to the base.  The Left has 4 tabs much deeper within the stanchion.





Comparison of the lower halves of the forks.  The front one is the RH fork casing.





Taking a look inside shows internal differences.  Left is LH fork.



I tried to get a clearer look inside.
RH Fork



LH Fork



Now looking at the internals starting from the bottom and working up.  The left hand fork internal are towards the front.
The bolts are what goes up from the bottom down at the front axel.



The next shot shows the sonic springs.  You might note I have a flat washer between the spring and the internals of the RH fork.  This is simply to make sure the spring sits square on the internal.



The top end of the internals.  I use flat washers where the springs meet the spacers.  Again where the spacer meets the top cap.  The LH fork (front of image) simply compresses to screw the top cap in to the fork stanchion.  The RH has a slider washer or bush.  You have to compress the spring sufficiently to slide the washer under the nut at the top of the damper unit.  With the sonic springs and the preload I have set, its fairly tough and needs two people.  One to compress the spring and another to slide the washer and slide bush/washer in place.  I actually swapped the spacer and the spring around.  I slid the spacer down the damper shaft first and then placed the spring on top of the spacer on the RH fork assay because I could not compress it otherwise.



If any one is interested,  My RH spacer length is 104mm and the LH spacer length is 185mm.  This gives the same level of preload on the fork springs.

From this point on its simply reassemble with new bush, new seals and new dust covers.  I assembled them and just left the top caps off.  I added the oil from the top.  I used the information from Yorkies post where he kindly tells us the oil capacity in the LH fork is 385cc and 435cc for the RH fork.  http://ozstoc.com/index.php?topic=4244.0

PLEASE NOTE:  When filling the RH fork assembled like this ... do it slowly.  It can easily come up and overflow the stanchion because it is slow in dribbling down into the fork.

« Last Edit: December 25, 2014, 10:58:45 PM by Piet »
Rides:
ST1100P 2004 Darkside
VTX1800C 2008 V&H pipes (sold)
 

Offline Totgas

  • Legendary Member
  • *****
  • Posts: 757
  • Thanked: 83 times
  • Everything is improved with "Flashing lights"
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #1 on: December 26, 2014, 12:21:25 AM »
Excellent write up and pictures. Thanks Heaps
I acknowledge hardworking Australians not matter who they are or where they come from. All those who have contributed to this wonderful country deserve an equal share of gratitude for their contributions. To single any group of individuals out for special homage only denigrates the rest of us.
 

Offline Abe

  • Legendary "1000 Club" Member
  • *****
  • Posts: 1780
  • Thanked: 165 times
  • 4D Gang Member
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #2 on: December 26, 2014, 05:16:17 AM »
Great write up and pictures for sure  ++
At my age " getting lucky" is remembering what I came in the room for ;)

:dred11     :wht13      Cheers Dave
Member of the 4 D Gang, no 5th wheel :'(
 

Offline Shiney

  • Dave
  • Global Moderator
  • UNBELIEVABLE "5000 Posts" Member
  • *****
  • Posts: 6415
  • Thanked: 2013 times
  • RTE Coordinator - Strathpine, QLD
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #3 on: December 27, 2014, 11:45:23 PM »
Awesome work mate, thanks for sharing it with us :thumbs
My Ride: 2011 ST1300  :wht13
OzSTOC #104   STOC# 8512   IBA # 59142
Find me in The Who's Who of OzSTOC!

I like shiney things :grin
One of the Dave, Dave, Dave and Duncan crew 8)
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #4 on: December 28, 2014, 03:56:09 PM »
Hi Piet,
         thanks for the clarity of description and pictures. Would you mind checking the fork tube thread and confirming the pitch (1.0,1.25, 1.5 mm etc)? While I have 41 mm tubes I think it should be the same pitch. I am try to track down fork caps that will fit.

Regards
          Garry
 

Offline Piet

  • Sr. Member
  • ****
  • Posts: 278
  • Thanked: 27 times
  • Caroline Springs, Victoria.
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #5 on: December 30, 2014, 07:59:10 PM »
Hi Garry,  Sorry for the delay in getting back to you.  I had already installed everything back on the bike by the time I saw the question.  I have ordered some fork gaiters and when I fit them I will check the thread pitch for you.
Rides:
ST1100P 2004 Darkside
VTX1800C 2008 V&H pipes (sold)
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #6 on: December 31, 2014, 08:55:26 AM »
Hi Piet,
          have you had a chance to think about the internal fork differences and the traxxion set-up? My summary:

1. The only difference in the internal fork legs seems to be for the TRAC which is on the LHS for your bike. I understand that the TRAC piston can be cut off. I thought that the TRAC was on the opposite side (RHS) for 96 and later models? I guess it may be different for police model?

2. The LHS (TRAC) fork tube is shorter and has 4 tabs much deeper within the stanchion. I assume this is for the damper rod oil lock piece. Can this be disassembled or do you think this may need to be filed flat for the AK-20?

3. The RHS (Cartridge) fork tube has 4 bent tabs close to the base. I do not think this will need to be filed as per the VFR800 example. The VFR had oil lock ring with no tabs and needed to be filed for improved flow. The AK-20 setup does not re-use the original lock pieces in the VFR example.

Overall the internal differences do not look too bad but I wonder why Honda made this thing so complicated and asymmetrical. 

Regards
         Garry

 
 

Offline Piet

  • Sr. Member
  • ****
  • Posts: 278
  • Thanked: 27 times
  • Caroline Springs, Victoria.
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #7 on: January 04, 2015, 04:12:23 PM »
Hi Garry,  To be honest I have not thought much more about it.  It is just too much money at this time.  I would like to give it a try but later.  The US$ to AU$ is really bad and because I have just fitted the Sonic springs as well at the Progressive 465 rear shock, the ride is pretty good at the moment.  I like the Sonic fork springs and the 465 shock is good even though I dont have much adjustment, and have no idea what setting its on.  I must have broken the adjuster I think.  Sometimes I would like to soften the rear shock just a little but its working fine.  Traxxion is in the back of my mind and later ... one day I will give it a try.  It sounds fantastic.

Rides:
ST1100P 2004 Darkside
VTX1800C 2008 V&H pipes (sold)
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #8 on: January 05, 2015, 08:29:19 AM »
Hi Piet,
        I guess it is just my way to continue analysing things until I act on a decision.

The conclusion I have reached on the existing forks is that other than the tabs inside the LHS tube it is possible to fit another HMAS cartridge to it. This is a lot cheaper than the AK-20 and is probably the way I will go. I am looking for a second hand set of cartridges with forkcaps and adjusters that will fit. I then will get them revalved to suit.

The interesting thing is that if I also found another ST1100 RHS fork tube I would replace the LHS and have the setup symmetrical (633mm).

Regards
           Garry
 

Offline Piet

  • Sr. Member
  • ****
  • Posts: 278
  • Thanked: 27 times
  • Caroline Springs, Victoria.
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #9 on: January 09, 2015, 06:33:43 AM »
Garry,  last night I fitted my new fork gaiters.  While I had the forks out I did remember to check the thread pitch.  The top caps are a 1.0 thread pitch.  Hope that helps.
Rides:
ST1100P 2004 Darkside
VTX1800C 2008 V&H pipes (sold)
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #10 on: January 09, 2015, 08:00:34 AM »
Hi Piet,
           that is good news and consistent with other Honda caps. I am also following up with traxxion for my model. I will share any additional information I can get.
Regards
          Garry

ps: I just noticed that your pictures of the forks & internals where taken the kitchen bench top. I hope your wife was pleased!
« Last Edit: January 09, 2015, 04:29:09 PM by Garry_Coates »
 

Offline muf

  • Newbie
  • *
  • Posts: 23
  • ST Legend
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #11 on: January 16, 2015, 12:58:07 PM »
Still don"t know what to do with my cycle suspension, it bottoms very easy both front and rear, attempted to purchase progressive front springs from the States today but was informed that the three outlets  I contacted do not ship to Australia, no doubt I am eager to receive any helpful information that may assist, the ST1100 has just clocked over 130,000 Klm so no doubt adjustments or replacements are required.

Regards
Muf
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #12 on: January 16, 2015, 05:18:40 PM »
Hi MUF,
         look up the racetech.com site to work out what spring rate you need. Buy them on ebay. Less than $170 in total shipped to Australia. Either straight or progressive rates.

eg: http://www.ebay.com.au/itm/Progressive-Fork-Spring-Kit-Pair-1991-2003-Honda-ST1100-11-1126-/201161323619?pt=Motorcycles_Parts_Accessories&hash=item2ed6263463 

Regards
        Garry
 

Offline Piet

  • Sr. Member
  • ****
  • Posts: 278
  • Thanked: 27 times
  • Caroline Springs, Victoria.
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #13 on: January 16, 2015, 06:59:37 PM »
Hi Muf,  I fully appreciate that each has differing opinions when it comes to fixed rate springs vs progressively would springs.  I chose fixed rate Sonic springs and am very happy with them.  My front end is working pretty well to be honest and I don't come anywhere near to bottoming out.  Garry found out (posted elsewhere) that std Honda progressive springs are .61 kg per mm of compression.  I am now running 1.2kg/mm.  Much better for my 105Kg on the 300kg ST11.

I tend to agree with this comment from the Sonic Website, (pure unadulterated marketing I know)
"One of the problems is that bikes, street bikes anyway, just donít have enough travel to take advantage of progressive rates. The soft initial portion gets blown right through, leaving a limited amount of travel for the stiffer portion to deal with. This results in less compliance, less traction and a harsher ride. Another issue is damping; Damping rates, particularly rebound damping, need to be matched to the spring rate. With a progressive (i.e. variable) rate, thatís impossible. Damping is always a compromise and a progressive rate just makes the balancing act that much more difficult. Adding to the problem is that modern forks actually have 2 spring mediums, the steel coil and the air trapped inside. The air is intrinsically a highly progressive spring. Adding a progressively wound steel spring to the mix is just making a bad situation worse."

For the rear,  a new shock would have you sorted I am sure.

Rides:
ST1100P 2004 Darkside
VTX1800C 2008 V&H pipes (sold)
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #14 on: January 16, 2015, 07:53:54 PM »
Hi Piet and Muf,
        I use both progressive and straight rate springs on different bikes and have not found a problem in real world use. Both ohlin and WP use them and recommend them in certain situations.

I think we should note that there is no such thing a straight rate spring anyway. It is only the middle 60% of travel that is straight. One thing I note of some straight rate suspension tuner fanatics is they seem to raise the oil level much higher than oem to get progression in the last 20%. I would do that only as a last resort.

I have been considering changing my ST1100's wp progressive springs (0.92 to 1.22 kg/mm) when I do my suspension upgrade. I will probably stay with them. 16 years of use and the SAG is the same.

I think progressive springs hide a multitude of sins on old bikes with outdated suspensions (eg ST1100). To be honest I can only tell the difference in the initial travel on my ST which is softer and I like.

I cannot see how in normal road use the front would blow through the initial travel if you have set the sag correctly without excessive pre-load.
 
To each his own.

Regards
        Garry
 

Offline Piet

  • Sr. Member
  • ****
  • Posts: 278
  • Thanked: 27 times
  • Caroline Springs, Victoria.
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #15 on: January 16, 2015, 08:28:41 PM »
Herein lies the beauty of such a forum because we are able to discuss the differences of opinions.

As an example.  When I read Garry's comment
"I cannot see how in normal road use the front would blow through the initial travel if you have set the sag correctly without excess pre-load." 
I find it hard to understand, because just a few lines earlier Garry comments he likes the softer initial travel.  Thats were travel is being eaten up.  Thats 100% fine, by the way.  To my understanding though the two comments are telling exactly the same story.

The next area that is confusing to me is "setting the sag correctly without excess preload."  As I understand it.  The preload is what sets the sag.  You can't have the preload excessive and the sag right.  The preload is the adjuster of sag height.  No preload then the weight will bear down on the spring compressing it until it balances.  It might well be a hefty percentage of the total travel.  So to raise it so that the sag is not so much, one has to preload the spring, compressing it.  As you add preload, the sag diminishes.  Thats a tiresome adjustment on the ST1100.  Install it and then measure.  Not happy ... then open up the fork and adjust the length of the spacer and reinstall.  Measure again and see what the result is.  In my case I have obtained 32mm of sag on the front end and that was what I was aiming for.  I got it first time and that was pure luck.  I tried to calculate it but I was off in my predictions, so took a bit of a guess and just lucked out.  The one thing that increasing preload also does is raise the ride height a bit as the sag diminishes.  Again front end ride height and sag are inseparably linked.  Just taking measurements from different points, but tied together regardless.
« Last Edit: January 16, 2015, 08:32:03 PM by Piet »
Rides:
ST1100P 2004 Darkside
VTX1800C 2008 V&H pipes (sold)
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #16 on: January 16, 2015, 09:51:47 PM »
Hi Piet,
          good to hear from you. I suggest you read Race Tech's Suspension Bible on the relationship between sag, pre-load and spring rates.

Remember you can probably set the sag to be 33 mm with the oem spring (0.61kg/mm) if you add enough pre-load. That does not make it the correct spring rate.

A soft spring with excessive pre-load can make the initial travel harsh. Remember this is closing more of the coils. A stiffer spring which requires less pre-load can actually feel softer in the initial travel. Rear shocks have a recommended minimum spring length when pre-load is applied as guidance.

It is counter intuitive.

Have a great weekend. I am off riding the sand on Saturday. 

Regards
          Garry
« Last Edit: January 16, 2015, 10:00:26 PM by Garry_Coates »
 

Offline Piet

  • Sr. Member
  • ****
  • Posts: 278
  • Thanked: 27 times
  • Caroline Springs, Victoria.
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #17 on: January 17, 2015, 06:48:53 PM »
Hi Garry,  Your absolutly right.  I can see how getting the right spring rate is very important.  That opens up a another can of worms as I absorb this and think about the implications.

The info that only 60% of a fixed rate spring is linear.  Where do you obtain this info?  I am interested in this explanation as well.  At present I struggle to understand that aspect.  I can imagine that as compression approaches its maximum it will tighten up some, but am suprized that is close to 40%.
Rides:
ST1100P 2004 Darkside
VTX1800C 2008 V&H pipes (sold)
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #18 on: January 29, 2015, 08:23:37 PM »
"It is only the middle 60% of travel that is straight"

I remember reading it on a suspension tuner's website with accompanying graphs. Peter V...... Designs? Remember these things are only for guidance.

It is important to get the right spring rate(s) regardless of whether it is straight or progressive.

It is easy to blow through the travel of the oem spring because it is too soft (0.61kg/mm) not because it is straight or progressive.

Regards
           Garry
« Last Edit: January 29, 2015, 08:52:20 PM by Garry_Coates »
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #19 on: February 16, 2015, 07:33:36 AM »
Hi Piet,
           what fork gaiters did you end up getting? I am considering using them with the suspension upgrade.
Regards
         Garry
 

Offline Piet

  • Sr. Member
  • ****
  • Posts: 278
  • Thanked: 27 times
  • Caroline Springs, Victoria.
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #20 on: February 20, 2015, 02:24:11 PM »
Hi Garry,

Sorry havn't been on-line for ages.

I purchased the 45 x 60 x 250 if I recall correctly.  180 would be a better length but they did not have it.  http://www.pyramidparts.com.au/pages/motorcycle-fork-gaiters

Hope this helps.
Piet
Rides:
ST1100P 2004 Darkside
VTX1800C 2008 V&H pipes (sold)
 

Offline Garry_Coates

  • Full Member
  • ***
  • Posts: 111
  • Thanked: 13 times
  • ST1100 ABS/TCS (95), XR600R (99) and TXC310R (13)
Re: Fork Rebuild - Police 2000 non ABS - Sonic Springs.
« Reply #21 on: February 20, 2015, 05:20:19 PM »
Thanks Piet I have been looking for some in the 175 to 200mm range. I am going to try those originally for a DL650.

Regards
          Garry
« Last Edit: February 21, 2015, 05:19:38 PM by Garry_Coates »