Isn’t always the way, I upgrade to a new rig – Specialized Stumpjumper ’03 hardtail - fitted with a good pair of forks (Rock Shox Pilot XC/SL 03) which give me capable & dependable service of 3 yrs through all sorts of trouble & strife, but eventually a fork seal goes & it’s time to take them to the LBS for a service. Then the troubles begin.
No problem at the time, the Local Bike Shop knows of a bloke who specialises in bike forks – especially Rock Shox of which they are - & send them on. A week later they return resplendent with new seals & oil.
I fit them on again & do a MTB event the following week. The action feels alittle fast so I utilize the only adjusting knob I’ve got for rebound damping at the base of the right fork leg & turn them slightly to firm them up, and ride again. I find that turning the knob doesn’t give the sort of change I previously felt, but I can’t be sure, it’s been 3 weeks since I rode the bike last in similar conditions so I carry on.
That evening back home I check out the adjusting knob & find that previously I was able to turn it clock & counter-clockwise through it’s 1/3 of a turn range in a smooth action. Now I distinctly feel a notchy action, as if there are 3 to 4 notches between full fast & full slow action. The first thought I have is that the rebound mechanism has jammed & the adjuster rod/shaft has spun out or gouged through the plastic damping mech which is what is giving this notchy feel with apparent no change.
Due to work & play commitments another week goes by without addressing my fork issues & I’m fronting up to another event 8hr endurance XC event on the MTB. During the course of this event I start experiencing another funny thing from my forks. On big hits the damping works, but on little hits while it’s at the top of it’s travel – climbing seated over rough terrain for example – there is no damping, the fork is springing back at full speed. This also occurs while cornering - exiting corners - which makes the steering vague & very unpredictable, I started getting abit of arm pump which I haven’t felt since I was MXing.
So more than a month after getting the forks serviced and over 20hrs offroad riding time I’m standing in the shed looking at my Stumpjumper wondering how rocking into the Local Bike Shop with my forks in hand & dissatisfaction all over my face will go.
My leaky fork seals was never this bad.
Like any regular person faced with the prospect of a useless confrontation with a LBS where I get most of my parts/accessories from, I opt to fix it myself.
www.Rockshox.com/ Gets me the exploded diagrams & service instructions for my Rock Shox Pilot XC/SL 03 forks, so off I go.
I suppose the biggest thing about doing something for the first time correctly, is not so much what to do, because the instructions are pretty straightforward, but how to do it – the feel. Things like to know how tight to do up the bolts/nuts, how hard to push the rods through the oil seals etc, especially when you have a combination of alloy & plastic components. Oh yeah, also having the tools required goes a long way, but sometimes you can ‘get by’ without the specialised tools by improvisation.
Of course there are things like pulling the lower forks out without taking into account the remaining damping oil as it pours all over the floor & remembering to ‘grease-up’ the seals & shafts before reinsertion.
But after ½ an hour the suspect HC2 Rebound Damping shaft (part #11.4307.393.000) is successfully retrieved.
Inspection of the rebound damper did show that the plastic inner damping assembly had gouged as a result of the damping adjustment knob shaft being turned beyond the allowable range which was 1/3 of a turn. With the fork fully assembled & fitted to the bike it’s not possible to rotate the damping adjustment knob beyond the 3rd of a turn as the fork’s front axel mount on one side & the protruding skewer on the other restricts movement beyond this 3rd of a turn. Hmm.
Luckily the LBS can supply a replacement (@ $59.59) which arrives the following day.
Assembly always takes longer than disassembly , but surprising not so much in this example. Measuring out the replacement 5wt damping oil (did you know that cc is the same measurement as ml ?) which I had left over when I previously purchased for my motorcycle fork, took the longest. Unfortunately I didn’t have anything small enough to get the 30cc & 20cc amounts I needed so I used some cooking utensils from the kitchen to meter out the amounts (it’s OK, I’ve washed them well afterwards, my fiancée - she’ll never know).
I did notice that even though I did spill a considerable amount of damping oil in the disassembly, there seemed to be a very small amount removed compared to how much I was replacing as directed by the instructions.
With the fork assembled but before I fitted it to the bike, I exercised the fork through it’s action on various damping settings & it feels great, fast is fast & slow is slow. Didn’t get enough time to ride test it, but the weekly evening Dirt Criterium MTB event at the Westgate park (Melbourne metro Aust) is next Thursday so we’ll see how we go then.
No problem at the time, the Local Bike Shop knows of a bloke who specialises in bike forks – especially Rock Shox of which they are - & send them on. A week later they return resplendent with new seals & oil.
I fit them on again & do a MTB event the following week. The action feels alittle fast so I utilize the only adjusting knob I’ve got for rebound damping at the base of the right fork leg & turn them slightly to firm them up, and ride again. I find that turning the knob doesn’t give the sort of change I previously felt, but I can’t be sure, it’s been 3 weeks since I rode the bike last in similar conditions so I carry on.
That evening back home I check out the adjusting knob & find that previously I was able to turn it clock & counter-clockwise through it’s 1/3 of a turn range in a smooth action. Now I distinctly feel a notchy action, as if there are 3 to 4 notches between full fast & full slow action. The first thought I have is that the rebound mechanism has jammed & the adjuster rod/shaft has spun out or gouged through the plastic damping mech which is what is giving this notchy feel with apparent no change.
Due to work & play commitments another week goes by without addressing my fork issues & I’m fronting up to another event 8hr endurance XC event on the MTB. During the course of this event I start experiencing another funny thing from my forks. On big hits the damping works, but on little hits while it’s at the top of it’s travel – climbing seated over rough terrain for example – there is no damping, the fork is springing back at full speed. This also occurs while cornering - exiting corners - which makes the steering vague & very unpredictable, I started getting abit of arm pump which I haven’t felt since I was MXing.
So more than a month after getting the forks serviced and over 20hrs offroad riding time I’m standing in the shed looking at my Stumpjumper wondering how rocking into the Local Bike Shop with my forks in hand & dissatisfaction all over my face will go.
My leaky fork seals was never this bad.
Like any regular person faced with the prospect of a useless confrontation with a LBS where I get most of my parts/accessories from, I opt to fix it myself.
www.Rockshox.com/ Gets me the exploded diagrams & service instructions for my Rock Shox Pilot XC/SL 03 forks, so off I go.
I suppose the biggest thing about doing something for the first time correctly, is not so much what to do, because the instructions are pretty straightforward, but how to do it – the feel. Things like to know how tight to do up the bolts/nuts, how hard to push the rods through the oil seals etc, especially when you have a combination of alloy & plastic components. Oh yeah, also having the tools required goes a long way, but sometimes you can ‘get by’ without the specialised tools by improvisation.
Of course there are things like pulling the lower forks out without taking into account the remaining damping oil as it pours all over the floor & remembering to ‘grease-up’ the seals & shafts before reinsertion.
But after ½ an hour the suspect HC2 Rebound Damping shaft (part #11.4307.393.000) is successfully retrieved.
Inspection of the rebound damper did show that the plastic inner damping assembly had gouged as a result of the damping adjustment knob shaft being turned beyond the allowable range which was 1/3 of a turn. With the fork fully assembled & fitted to the bike it’s not possible to rotate the damping adjustment knob beyond the 3rd of a turn as the fork’s front axel mount on one side & the protruding skewer on the other restricts movement beyond this 3rd of a turn. Hmm.
Luckily the LBS can supply a replacement (@ $59.59) which arrives the following day.
Assembly always takes longer than disassembly , but surprising not so much in this example. Measuring out the replacement 5wt damping oil (did you know that cc is the same measurement as ml ?) which I had left over when I previously purchased for my motorcycle fork, took the longest. Unfortunately I didn’t have anything small enough to get the 30cc & 20cc amounts I needed so I used some cooking utensils from the kitchen to meter out the amounts (it’s OK, I’ve washed them well afterwards, my fiancée - she’ll never know).
I did notice that even though I did spill a considerable amount of damping oil in the disassembly, there seemed to be a very small amount removed compared to how much I was replacing as directed by the instructions.
With the fork assembled but before I fitted it to the bike, I exercised the fork through it’s action on various damping settings & it feels great, fast is fast & slow is slow. Didn’t get enough time to ride test it, but the weekly evening Dirt Criterium MTB event at the Westgate park (Melbourne metro Aust) is next Thursday so we’ll see how we go then.
