Hawk/Enforcer Fork Valve upgrade. - Page 4

Thumper · 01-14-2022, 08:56 AM

Quote:

Originally Posted by Megadan

I have ended up at 10W as well. The rebound was a little too sluggish with 15W. The weight of the oil most directly impacts the rebound and low speed compression damping.

I always thought that the main benefit of the inverted shock is lower unsprung weight (the part attached to the front axle). Is this true, and the only real benefit?

One consequence of an inverted shock is that you can not drain an inverted shock as conveniently since the seal side is down-and this also means when the seal fails, the shock gets drained!

But all that aside, I am sure that the inverted shocks on my storm have the simple orifice holes in the damping rods style which have the problems MegaDan described (years ago!): 1) mushy low impact damping and nose dive braking effect, and 2) hard high impact response

If I measure the OD on my fork tubes, (the part attached to the wheel on my inverted forks) is this the key measurement to predict if the same PD238 fork valve will fit in them?

Maybe a Storm owner with the newer inverted forks knows if these fit?

Megadan · 01-14-2022, 09:32 PM

Quote:

Originally Posted by Thumper

I always thought that the main benefit of the inverted shock is lower unsprung weight (the part attached to the front axle). Is this true, and the only real benefit?

One consequence of an inverted shock is that you can not drain an inverted shock as conveniently since the seal side is down-and this also means when the seal fails, the shock gets drained!

But all that aside, I am sure that the inverted shocks on my storm have the simple orifice holes in the damping rods style which have the problems MegaDan described (years ago!): 1) mushy low impact damping and nose dive braking effect, and 2) hard high impact response

If I measure the OD on my fork tubes, (the part attached to the wheel on my inverted forks) is this the key measurement to predict if the same PD238 fork valve will fit in them?

Maybe a Storm owner with the newer inverted forks knows if these fit?

Technically speaking, if the inner fork tube is the same diameter and length, the inverted shocks will have a reduced unsprung weight. However, the outer fork on an inverted unit tends to be bigger, so it's a trade off of weight vs. unsprung. The other big benefit is actually rigidity of the forks themselves.

As far as where the valve would go. It's designed to regulate flow through the damping rods, so if your inverted forks do have a damping rod where the valve can be seated to, it could be made to work in theory. Most of the cheap chinese inverted forks are just slightly reworked standard forks turned on end.

Megadan · 01-14-2022, 09:34 PM

Quote:

Originally Posted by drstansbury@yahoo.

Dan thanks for telling us about this mod. The suspension is very much improved. The ride is so.much better. After I put the zx10r rear shock on I had to do something with the front. These fork valves are definitely the ticket. No more nose dive on braking or low speed trails but also no more harsh bouncing and jarring on the higher speed stuff. For the ease of modifying the front forks and low cost this is really a mod that should be more popular. They make the front forks react appropriately. Bike rides and handles like a motorcycle now!

I agree. Although I went a different route in terms of rear suspension, at the end of the day the fork valves, fork brace, and rear shock are probably the most significant upgrades to the bike in terms of overall riding capability and feel. If I sit on a standard Hawk and go back to my bike it doesn't feel anything close to the same bike.

drstansbury@yahoo. · 01-15-2022, 04:38 AM

Yea, I have to say I wish I would have done the suspension mods sooner. The bike is so much more enjoyable. It handles so much better on and off road and is so comfortable now I can ride.much longer distances without becoming fatigued. I love the engine mods and how the bike performs but to do it over again I'd definitely upgrade the suspension first. Definitely one of my favorite upgrades!

China Rider 27 · 03-07-2022, 02:06 PM

The time has come and I went after the HAWK front suspension and thought I would post up my experience as it is so far for others and this is the best place to put the post. Hats off to Megadan! The Mikes SX fork valve looked to me to be much the same as the YSS valves and my budget liked it.

Took the HAWK front end apart and drained the fork oil. WOW…pretty surprised to see how dirty it was as this bike has only 1146 miles on it and the factory oil was changed at build up to MAXIMA 15W. Where does all that black come from? Must be the scouring pressure of the fluid against that aluminum.

I think I messed up with the drilling of the Damper Rod. The instructions say 5/16 inch holes spaced 180 degrees lengthwise 10 mm apart. I thought that meant 10 mm distance on hole center and drilled the first hole that way. After looking at it, um…that looks to close and big! The instruction pictures make it appear much smaller but 5/16 in a 14mm rod looks huge and through both sides! I am all in now but ¼ inch I think would be better. Hope have not been fatally weakened. These instructions are for a Yamaha XS650 fork so I am wondering if those damper rods are larger. The second rod I spaced a little more. I believe they will be strong enough, and one thing is sure they will no longer impede oil flow.

*CAUTION: After some research, the 14 mm HAWK Damper rod should have holes drilled with a 1/4 inch or 6 mm bit.

I bought some aluminum rod 24 mm OD with a 16 mm ID and I turned down the outside diameter with sandpaper by hand and what a job. They also offer a 23 mm OD with 19 MM ID. I was going to do a rotary tool on the inside diameter too but I figured out to use a step drill to chamfer the inside to provide a recess to allow the valve to seat flush. I don’t have a lather or a drill press, but eventually towards the end of fabricating I figured out I could use a highspeed rotary tool on low speed with a sanding disc and tape to spin the aluminum rod against a piece of 100 grit sandpaper to take it down to 23.89 or so mm needed to fit in the fork tube. Use 100 grit if you do, finer stuff just takes forever.

Aluminum tubing:

https://www.amazon.com/uxcell-Alumin...s%2C250&sr=8-1

The HAWK came with a stock preload spacer of 35mm. This preload is pretty good for my weight, 175 lbs and 15 lbs of tools on the rear. The front (loaded with rider weight) SAG was 2.1 inch and I have never bottomed the front forks so this would be the target with the valves too. The valves measure 14mm so I decided to use a 10 mm valve adapter so I could have something on the other spring end as there is a good chance, I will be loading this bike and need to add more preload to the spring. So 14 mm plus 10 mm adapter leaves 11 mm for a preload spring spacer I made up of PVC for the total of 35 mm.

I want to clean out the inside of those forks and I am looking for a cleaner that would be friendly to those rubber seals. I thought about putting the bolt in the bottom and sloshing kerosene around but maybe there is a better idea?

Megadan · 03-07-2022, 02:56 PM

Excellent detail on the Mikes XS valves. I am glad somebody finally shared their experience in detail as far as installation.

As far as cleaning out the forks and not huring the rubber. Kerosene or WD40 (basically also kerosene) works pretty good. That's what I used.

China Rider 27 · 03-07-2022, 03:05 PM

I thought I might as well add to the discussion since I was doing it, the Team would take no less. Thinking maybe a quart of transmission fluid would also work maybe not as good as kerosene but better than nothing. Anyway, enough stalling I need to go clean some forks.

China Rider 27 · 03-14-2022, 02:03 PM

Fork valve install experience round 2. I decided to add some more pre load to the springs, after further considering the SAG numbers at 2.1. What I have gathered on the forum is the HAWK front suspension travel is about 6 inches and therefore the SAG should be roughly 30 percent of that or 1.8 inch. As I was at 2.1 inch I want to reduce that SAG to around 1.5 to 1.75 inch. I had ordered some of that 23 mm OD by 19 ID mm aluminum tubing and cut that using a hack saw and miter box. Good ole hack saw, man they work good and never go out of usefulness. I had cut the previous 24 mm tubing with a Miter cut off saw and a carbide blade, but eventually it started to chip the tubing and was not clean and had a tendency to grab it at the end and toss it. I straightened it up using Megadan’s suggested use of glass with sanding paper, 100 grit to get it straight and finished with 400 grit. If one was not inclined to do the fab work to get the valve adapter to more directly align in the tube, I think this 23 mm OD by 19 mm ID could work for both an adapter and spacers. Pix shows valve inserted into 23 mm OD tube.

There is a metal flange or adapter in the bottom of the fork that the damper rod fits into, it is loose in the tube, slides around, and must be aligned correctly in the bottom of the fork with the damper rod or the bolt will not reach the threads. Wiggle it around, slide this way that, to get it to fall into place and line up. When aligned properly the bolt sticks out about ¼ inch from the fork bottom ready to be threaded.

Having heard tale of using broom sticks to tighten the damper rod I came up with the idea to use a piece of 5/16 inch threaded rod to make a tool for tightening. The end has a bolt from a metal bike shipping frame head size 14 mm, a 8 mm nut threaded onto a 5/16 inch rod with 5/16 nut to tighten up and on the back end two 5/16 inch nuts. A piece of PVC was used to protect the inside of the fork tube. It appeared to work well but was not needed as the damper rod tightened and torqued with no spinning. A vise is very helpful here but you could use a table top.

The question is how much fork oil? I thought I would go low side and put in what the HAWK generally comes with or 160 ml. Looking at data on line, these valves need to be submerged in oil, I presume so there is no air space in the hydraulic action. After adding 160 ml of 10wt I fully extended the fork tube and the valve was visible, and after pumping the fork it looked like the oil level was around 1 ½ inch below the valve. I added 20 ml and it brought it up to just flush with the valve opening. I added 20 ml and the fork valve disappeared but the adjusting nut stem was visible so I added another 20 ml for a total of 220 ml which covered the valve completely. Another way to measure fork oil is to measure down from the fork top to the oil with the fork completed depressed without the spring. The 220 ml measures 9 inches or 228 mm from the fork top.

A picture of the aluminum stock gasket and a copper one I took off after torqueing to 17.46 NM or about 13 ft lbs. I had forgot the damper rod spring goes on the damper rod so I had to take it all apart again to fix it. That is a very light torque load and not necessarily the recommended assembly torque. The pix is meant to show how the washer seals by compression and why you need new washer gasket and 6 mm allen for bolts.

Spacer in fork tube atop the spring sticks out roughly 9-10 mm

Looking forward to ride testing!

Megadan · 03-14-2022, 02:45 PM

I guess I never considered the level issue with the valves installed with a spacer before. Funny enough, 220ml is about what I generally run in my forks anyway, so I guess it just worked out by chance. As long as the top of the valve is covered at full extension, it should work just fine though. As the bike sags and the forks compress from just being under its own weight or with the rider the level will come up anyway.

China Rider 27 · 03-14-2022, 04:23 PM

Yaa, I agree the oil level will come up when compressed so maybe 160 ml might work but I would not want to chance it. 180 and above would likely work. Funny how much volume the upper fork tube takes up when you extend it from fully compressed to extended, you can watch the oil level go down. That air space behind the fork matters too in some way. After compressing a fork on the floor awhile to see how it worked I loosened the cap to remove it and air escaped in a hiss!

03-07-2022, 02:06 PM	#50
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	MikesSX fork valve emulator install The time has come and I went after the HAWK front suspension and thought I would post up my experience as it is so far for others and this is the best place to put the post. Hats off to Megadan! The Mikes SX fork valve looked to me to be much the same as the YSS valves and my budget liked it. Took the HAWK front end apart and drained the fork oil. WOW…pretty surprised to see how dirty it was as this bike has only 1146 miles on it and the factory oil was changed at build up to MAXIMA 15W. Where does all that black come from? Must be the scouring pressure of the fluid against that aluminum. I think I messed up with the drilling of the Damper Rod. The instructions say 5/16 inch holes spaced 180 degrees lengthwise 10 mm apart. I thought that meant 10 mm distance on hole center and drilled the first hole that way. After looking at it, um…that looks to close and big! The instruction pictures make it appear much smaller but 5/16 in a 14mm rod looks huge and through both sides! I am all in now but ¼ inch I think would be better. Hope have not been fatally weakened. These instructions are for a Yamaha XS650 fork so I am wondering if those damper rods are larger. The second rod I spaced a little more. I believe they will be strong enough, and one thing is sure they will no longer impede oil flow. CAUTION: After some research, the 14 mm HAWK Damper rod should have holes drilled with a 1/4 inch or 6 mm bit. I bought some aluminum rod 24 mm OD with a 16 mm ID and I turned down the outside diameter with sandpaper by hand and what a job. They also offer a 23 mm OD with 19 MM ID. I was going to do a rotary tool on the inside diameter too but I figured out to use a step drill to chamfer the inside to provide a recess to allow the valve to seat flush. I don’t have a lather or a drill press, but eventually towards the end of fabricating I figured out I could use a highspeed rotary tool on low speed with a sanding disc and tape to spin the aluminum rod against a piece of 100 grit sandpaper to take it down to 23.89 or so mm needed to fit in the fork tube. Use 100 grit if you do, finer stuff just takes forever. Aluminum tubing: https://www.amazon.com/uxcell-Alumin...s%2C250&sr=8-1 The HAWK came with a stock preload spacer of 35mm. This preload is pretty good for my weight, 175 lbs and 15 lbs of tools on the rear. The front (loaded with rider weight) SAG was 2.1 inch and I have never bottomed the front forks so this would be the target with the valves too. The valves measure 14mm so I decided to use a 10 mm valve adapter so I could have something on the other spring end as there is a good chance, I will be loading this bike and need to add more preload to the spring. So 14 mm plus 10 mm adapter leaves 11 mm for a preload spring spacer I made up of PVC for the total of 35 mm. I want to clean out the inside of those forks and I am looking for a cleaner that would be friendly to those rubber seals. I thought about putting the bolt in the bottom and sloshing kerosene around but maybe there is a better idea? Last edited by China Rider 27; 03-11-2022 at 10:05 PM. Reason: Add CAUTION*
	2

03-07-2022, 02:56 PM	#51
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 7,976	Excellent detail on the Mikes XS valves. I am glad somebody finally shared their experience in detail as far as installation. As far as cleaning out the forks and not huring the rubber. Kerosene or WD40 (basically also kerosene) works pretty good. That's what I used. __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	1

03-14-2022, 02:03 PM	#53
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	Fork valve emulator HAWK Fork valve install experience round 2. I decided to add some more pre load to the springs, after further considering the SAG numbers at 2.1. What I have gathered on the forum is the HAWK front suspension travel is about 6 inches and therefore the SAG should be roughly 30 percent of that or 1.8 inch. As I was at 2.1 inch I want to reduce that SAG to around 1.5 to 1.75 inch. I had ordered some of that 23 mm OD by 19 ID mm aluminum tubing and cut that using a hack saw and miter box. Good ole hack saw, man they work good and never go out of usefulness. I had cut the previous 24 mm tubing with a Miter cut off saw and a carbide blade, but eventually it started to chip the tubing and was not clean and had a tendency to grab it at the end and toss it. I straightened it up using Megadan’s suggested use of glass with sanding paper, 100 grit to get it straight and finished with 400 grit. If one was not inclined to do the fab work to get the valve adapter to more directly align in the tube, I think this 23 mm OD by 19 mm ID could work for both an adapter and spacers. Pix shows valve inserted into 23 mm OD tube. There is a metal flange or adapter in the bottom of the fork that the damper rod fits into, it is loose in the tube, slides around, and must be aligned correctly in the bottom of the fork with the damper rod or the bolt will not reach the threads. Wiggle it around, slide this way that, to get it to fall into place and line up. When aligned properly the bolt sticks out about ¼ inch from the fork bottom ready to be threaded. Having heard tale of using broom sticks to tighten the damper rod I came up with the idea to use a piece of 5/16 inch threaded rod to make a tool for tightening. The end has a bolt from a metal bike shipping frame head size 14 mm, a 8 mm nut threaded onto a 5/16 inch rod with 5/16 nut to tighten up and on the back end two 5/16 inch nuts. A piece of PVC was used to protect the inside of the fork tube. It appeared to work well but was not needed as the damper rod tightened and torqued with no spinning. A vise is very helpful here but you could use a table top. The question is how much fork oil? I thought I would go low side and put in what the HAWK generally comes with or 160 ml. Looking at data on line, these valves need to be submerged in oil, I presume so there is no air space in the hydraulic action. After adding 160 ml of 10wt I fully extended the fork tube and the valve was visible, and after pumping the fork it looked like the oil level was around 1 ½ inch below the valve. I added 20 ml and it brought it up to just flush with the valve opening. I added 20 ml and the fork valve disappeared but the adjusting nut stem was visible so I added another 20 ml for a total of 220 ml which covered the valve completely. Another way to measure fork oil is to measure down from the fork top to the oil with the fork completed depressed without the spring. The 220 ml measures 9 inches or 228 mm from the fork top. A picture of the aluminum stock gasket and a copper one I took off after torqueing to 17.46 NM or about 13 ft lbs. I had forgot the damper rod spring goes on the damper rod so I had to take it all apart again to fix it. That is a very light torque load and not necessarily the recommended assembly torque. The pix is meant to show how the washer seals by compression and why you need new washer gasket and 6 mm allen for bolts. Spacer in fork tube atop the spring sticks out roughly 9-10 mm Looking forward to ride testing! Last edited by China Rider 27; 03-18-2022 at 10:04 PM.
	1

03-14-2022, 02:45 PM	#54
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 7,976	I guess I never considered the level issue with the valves installed with a spacer before. Funny enough, 220ml is about what I generally run in my forks anyway, so I guess it just worked out by chance. As long as the top of the valve is covered at full extension, it should work just fine though. As the bike sags and the forks compress from just being under its own weight or with the rider the level will come up anyway. __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	1

01-15-2022, 04:38 AM	#49
drstansbury@yahoo. Join Date: Dec 2019 Posts: 77	Yea, I have to say I wish I would have done the suspension mods sooner. The bike is so much more enjoyable. It handles so much better on and off road and is so comfortable now I can ride.much longer distances without becoming fatigued. I love the engine mods and how the bike performs but to do it over again I'd definitely upgrade the suspension first. Definitely one of my favorite upgrades!
	1

03-07-2022, 03:05 PM	#52
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	I thought I might as well add to the discussion since I was doing it, the Team would take no less. Thinking maybe a quart of transmission fluid would also work maybe not as good as kerosene but better than nothing. Anyway, enough stalling I need to go clean some forks.
	0

03-14-2022, 04:23 PM	#55
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	Yaa, I agree the oil level will come up when compressed so maybe 160 ml might work but I would not want to chance it. 180 and above would likely work. Funny how much volume the upper fork tube takes up when you extend it from fully compressed to extended, you can watch the oil level go down. That air space behind the fork matters too in some way. After compressing a fork on the floor awhile to see how it worked I loosened the cap to remove it and air escaped in a hiss!
	0