Hyperpro progressive fork springs

I fitted Hyperpro progressive springs/20w folk oil to my SV650 and thought I’d post a short summary of what was involved….in the off chance someone either a) gives a **** or b) is thinking of doing the same. (Child’s play to you seasoned pros but possibly useful for other wannabe DIYers).

There seems to be two ways to change the springs:
1) The lazy way which avoids removing the front wheel and involves siphoning the old fluid out of the fork, presumably leaving some surplus plus all the crud still in the fork.
2) The long way, which is what’s described below.

Disassembly:

• With the rear of the bike on the paddock stand, front wheel on the ground:
• Note the amount of fork tube protruding above the top fork clamp.
• Loosen the top fork clamp.
• Undo the speed sensor and brake hose clamps.
• Remove the front mudguard.
• Remove the brake callipers.
• Loosen the axle pinch bolts and front axle.
• Remove the handlebars (I did this because I only have a 22mm socket, not spanner, so needed the access to the fork caps).
• Loosen the fork caps.
• Jack the front of the bike up using the engine as a jack point. (NB if you don’t get the jack dead centre the bike is prone to tipping…I had to readjust after a near disaster!)
• Remove the front axle and front wheel.
• Loosen the lower fork clamp bolts and slide the forks out.

Fork spring installation:

• Do the forks one at a time:
• Fully remove the fork caps
• Lift out the preload bush, the washer and the spring
• Tip the oil into a container and pump the fork to fully drain it of old oil. (I left it sitting upside down on a rag for 5 mins to fully empty.
• Before putting in the new spring fully compress the fork and add oil (Hyperpro 20w) to 165mm below the top of the fork tube.
• Pump the fork to clear any air from the oil and recheck the level.
• Add the new Hyperpro spring (the close coils to the top), washer and preload bush.
• Hand tighten the fork cap.
• (I lifted the dust seal and greased the fork inner but not essential)

Reassembly:

• Slide the forks back up through the clamps and hand tighten.
• Refit the front wheel.
• Adjust the forks to the same height above the top fork clamp as before. Tighten the fork clamp bolts (23Nm) and the fork caps (23Nm).
• Let the front down off the jack.
• Tighten the front axle (65Nm) and refit the brake callipers (39Nm).
• Replace the speed sensor and brake hose clamps.
• Replace the front mudguard.
• Replace the handlebars (23Nm).
• Compress the forks a few times then tighten the front axle pinch bolts (23Nm).

Job done! It’s made a big difference. Much less saggy and doesn’t dive under braking like it used to. Still to take it for a proper test but seems like a well worthwhile upgrade.

Here a few photos (excuse the mess but I left washing it until I was finished!)


Callipers and mudguard off:


Handlebars off for access to fork caps:


Forks out:


One SV minus front end:


Fork tube, cap and preload bush:


Shiny new progressive springs in a box:


Shiny new progressive springs inside a pair of manky old forks:


Back together again:

That's so cool doing the work in your livingroom, I wish the wife would let me bring the bike in the house so I don't get cold working on it

Originally Posted by BILLY

That's so cool doing the work in your livingroom, I wish the wife would let me bring the bike in the house so I don't get cold working on it

He he.... I wish! I borrowed my cousin's garage which he, for some reason, saw fit to carpet!

It looks like there's underlay under that carpet and there's skirting boards as well!!! How posh

Does your missus know you've ruined her best pink sheets?

JohnH

Originally Posted by ejohnh

Does your missus know you've ruined her best pink sheets?

JohnH

What you on about? They went straight back on the bed