Fork Rebuild and Hyperpro Spring Installation

FYI – Here is my write-up on my fork rebuild. The rebuild followed advice on this forum, the Honda Service Manual, input from fellow bikers, and my own expertise (little of which I have). Terminology is based upon the Honda Service Manual. Parts total for rebuild was about $250 – not including any tool costs.Loosen the Upper and Lower Pinch Bolts while the tire is on the ground – they were VERY hard to break free – I used Harbor Freight EXTENDED box wrench with vise grip on one end to get the leverage I needed – did not remove plastic Front Cover. When I tightened these Pinch Bolts I used a Harbor Freight 3/8 Torque Wrench and Socket – had barely enough room – I needed to turn the forks this way and that way to get the socket on them. I feel better knowing that I have torqued the pinch bolts properly when riding at high speed! Next time I am going to see if I can break the Pinch Bolts using a 3/8 inch breaker bar as this would be so much easier than using the box wrench. I bought all the parts that I thought I would need for the rebuild – used them all. One of my Fork Tubes had heavy film of oil in it – the other was dry – but both tubes had the same amount of oil in the Bottom Case - guessing the oil seal on one fork tube was leaking a bit – after the rebuild both tube are nearly dry – you can not see any oil on the fork tubes unless you look real close. The Socket Bolt on the Bottom Case was easy to break free BUT the Fork Piston still spun in the case – the compression of the Fork Spring would not keep the Fork Piston from spinning. I had to whittle down a wooden garden handle (0.92 in diameter, 32 inch long, about 0.75 in diameter where it is whittled down to act as friction point in top of Fork Piston) and jam it down into the top of the Fork Piston to keep it from spinning. I held the Bottom Case upside down, inserted the garden handle up into the Fork Piston, put a vice grip on the end of the garden handle, stood on the vice grip, inserted the Front Axle into the axle hole, pushed down hard on the axle, then turned the Socket Bolt loose (and had to tighten it the same way). The impact wrench was useless in this whole process – other than initially breaking the Socket Bolt free. I know others have not had this issue – but I sure did! The manual says to REPLACE the Fork Piston IF it is REMOVED – I did not see the need for this and did not do this. I heated up the Socket Bolt with a propone torch to brush all the old locktite off of it. My fork oil looked disgusting – guessing that a lot of dust works its way into this oil. I surely (don't call be Shirley!) am going to install a fork gaiter – this saves on fork pits due to rocks, Stopper Seal, Oil Seal, and wear on fork tube assembly parts – cheap insurance – guessing that all fork assembly components would last a lifetime with proper fork gaiters/cleaning. The Fork Tube that had some weeping oil had some nearly invisible pits on the forward face near the top of tube that I could only see with a magnifying glass and feel with my finger nail – took some 1200 grit to them (thanks to this forum I would never have seen these). To remove the Fork Cap I put the Fork Tube in my steel vise with wood on jaws and hard rubber over the wood. I exerted pressure near the top of the fork tube and turned the fork cap – if the Fork Piston started to move in the vise I just tightened the vise a bit more. The Fork Cap is aluminum (I think) and is only lightly torqued onto the Fork Tube. Both Fork Springs went flying around my garage – along with the Stopper Ring – so be prepared for this – best to try and keep the parts from flying too far – or out of control. The Fork Tubes were a lot more `beefy' than I would have thought – doubt if you could damage them in a soft jaw vice setup. I replaced my OEM Fork Springs with Hyperpro Springs (about $170 including shipping). Getting the Fork Cap on by hand tools is pretty easy once you do it. I sat in my lawn chair, with fork assembly between my legs, used a tee-bar with socket (I tried using a regular ratchet wrench but could not keep the Fork Cap straight), got my weight atop the assembly, pushed down vertically, then turned the Fork Tube and Tee-Bar (loose – then tight) until the threads caught. I believe the Hyperpro Springs are under far less compressive force than the OEM springs as it was easy to undo the Fork Cap without the Hyperpro Spring shooting out. The Slider Bushing showed no wear – did not replace it. Both Fork Tube Bushings showed wear – replaced them. Replaced the Oil Seals and Dust Seals. Hyperpro provides a bit of grease to install between the Dust Seal and the Oil Seal – I am thinking that periodic cleaning/placement of lithium grease (no 2 or greater) in this area may extend the life of the Seals – what do you think? I did not see any serious wear on any part – so, if I had to do this rebuild over, I would try to replace the Dust Seal, Oil Seal, and Fork Tube Bushing WITHOUT removing the Socket Bolt (as this was the hardest part of this rebuild for me).
HyperPro Fork Spring (HPS) Musings: I had a slow speed wobble (still have) that I had hoped would be solved with HPS – not so, but HPS did help reduce the wobble. The really good news is that the HPS make the Swing (IMHO based on nearly 55,000 miles of Swing riding the past 2.5 years on varied roads and rides) handle so much better. Here is what I have observed: in the corners I can go 5+ mph faster without getting that soft feel, holds a line better, can lean over further, feel much safer; on the straights I can go 15+ mph down the same roads and feel less in the way of bumps; can go much faster and feel much more in control; better cross wind handling/stability; much better counter-steering at high speeds, just feels way more in control; much smoother ride, less in the way of bumps, far fewer road imperfections being transmitted to the handle bars; the HPS transform the entire suspension system into something vastly better; a much safer ride because the Swing handles so much better under high speed, steering at high speed, the front tire seem to spend more time on the pavement, and at mid-range speed (20-40 mph) you can dink and weave a lot better on the freeway with heavy traffic; when driving on longitudinal road surface changes (lateral road surface changes like deep grooves)there is far less in loss of control; the HPS are going to save significant wear and tear on my body, at 68 this matters - it matters at any age; and an item that I can not feel (better or worse) is better control during braking – guessing less dive and more control (but I can not say that I feel it). The one thing that surprised me was that I thought the HPS would be stiffer – in fact they are MUCH softer – at least with the initial travel – I have some thoughts on this. On a side by side comparison (with another Swing, same year less miles) when you pump the forks with HPS they are much softer and go up and down so much easier than the OEM springs. The Honda OEM springs have a two inch spacer – but the Hyperpro do not – the HPS are not preloaded and compressed as much as the OEM springs – this translates into the HPS being a lot softer to start – then they get harder farther down. I had at one time considered adding that 1" PVC spacer (for total 3" long spacer) as a means for a better ride. Now that I have experienced/analyzed HPS I am thinking that the 3"spacer will reduce sag and cut way down on the initial dive – but do nothing to significantly reduce the harshness of the ride in the manner that HPS can do. My only regret with HPS is not doing this 55,000 miles ago. If your Swing rides are short, you don't go more that a few thousand miles a year, your roads are smooth, and your pace is easy – then this upgrade may not be necessary for you – but for the rest of you this mod is a must! I might add that my HPS came with HPS fork oil SAE20 (look a lot more viscous than what was in my forks) – but I used (ended up draining the HPS fork oil for some reason that I can't remember and when to local HD dealer to get more fork oil because I did not want to order more HPS fork oil and endure the wait) Harley Davidson (HD) Screaming Eagle Heavy Duty fork oil – which looks less viscous than the HPS fork oil. I queried Hyperpro regarding HPS fork oil and here is what they said," The oil used on the Silverwing in combination with the Hyperpro springs is a Hyperpro oil – SAE 20. I do not have any more information. No, we are not using the same oil on all applications. We have it in 2.5, 5, 10, 20, 30, 40 and a GP5 for race applications and newer fork styles. Regards Klaus Huenecke at HPS"
Has anybody tried different fork oils with their HPS? Feel any difference.  I love my HPS with the HD Fork Oil, so unless someone gives me a reason to change I am going to stick with the HD Fork Oil.

Apparently you did not use Hyperpro oil in your replacement. Can you tell me what Oil and weight etc. you used and how full did you fill them.
Thank you for your input.

Did you go by the Honda Service Manual on how much oil to put in them?

DaveR wrote:

Did you go by the Honda Service Manual on how much oil to put in them?

I went by how far the oil needed to be from the bottom of the fork filling cap as stated in the Honda Service Manual - which is 3.8 inches down from the top of the Fork Tube. Which is the same dimension as stated in the Hyperpro instructions. I did not measure VOLUME of the fork oil.  Hope this helps.

Dimond, nice write up, thanks....

Thank you for your help. This is just what I was looking for.