Whatever happened to the fork oil drain screws?

[ohiorider]

There has to be a reason forks no longer have the small screws (plugs) on the fork legs that made it so easy to drain fork oil.  The R100GS I bought 28 years ago, and still ride, has these drains.  But I don't recall any bike I've owned since then having these. However, back a few years and bikes ago, I had the dealer perform some of these tasks, so I may not have noticed whether they had the plugs or not.

Neither of my Guzzis had them, nor did the 2003 T100 Bonnie or the 2000 W650.  Nor does the 2014 CB1100.

Anyone thought about whatever happened to the fork drain screws?

[Huzo]

I thought of putting some in mine, but opt to just whip them out and drain/flush.

[oldbike54]

 Bob , it might just have become the industry standard as most bikes now have cartridge forks that must be disassembled to service .

 Dusty

[severely]

They went away about the same time people stopped servicing their own bikes and suspension.

[guzziart]

Hi Bob,

My '08 Wing has zero info on the fork routine maintenance.  ZZ & I ran down to Barber Motorsports the first week I bought the bike.  When I got home after our trip I decided to install Progressive fork springs in and switch to tapered roller bearings in the steering head.  Anyway, I had fully removed the forks and figured I'd change the oil too.  I was surprised at how filthy the fork oil was considering I had purchased the bike brand new and it now had about 2K miles on it.  Anyway, I've been changing fork oil on it since at about the 20K interval.

I think if the bikes today came with fork oil drains I'd change it more frequently but unless you remove the lower leg to clean out the sludge inside (collects at the bottom), fresh oil will just get contaminated in short order.  I suppose it can't be all that bad...I've not had to replace fork bushings on any of my junkers yet!

Have a great weekend!

Art

[bodine99]

There has to be a reason forks no longer have the small screws (plugs) on the fork legs that made it so easy to drain fork oil.  The R100GS I bought 28 years ago, and still ride, has these drains.  But I don't recall any bike I've owned since then having these. However, back a few years and bikes ago, I had the dealer perform some of these tasks, so I may not have noticed whether they had the plugs or not.

Neither of my Guzzis had them, nor did the 2003 T100 Bonnie or the 2000 W650.  Nor does the 2014 CB1100.

Anyone thought about whatever happened to the fork drain screws?

Went the way of Zerk fittings

[Two Checks]

They got lost in all the beans being counted.

[LowRyter]

If they ain't leaking, they're fine. 

Take apart a functioning fork because the oil is a little dirty? OK, when it needs seals and bushings time to go right ahead.

OK, shoot me.     

[slopokes]

They eliminated the fork drain screws about the same time as the centerstand...but you can buy back the centerstand— 💸🤑

[yogidozer]

OK, this will ruffle some feathers 
Where did the fork drains go?
The same place points and condensers went.
Computers are trouble free, until they're not, and you're stuck who knows where, and you forgot your laptop 
Spare points, condensers, feeler gauge takes up less room than a pack of cigarettes.
Fuel injection? Same thing, yet carb. on older Guzzi's got better mileage, didn't they?
Self canceling turn signals, for those that can't remember your thumb is holding a button down.
And now you need a light on the speedo to tell you...HEY, your thumb is holding a button down
And another thing on the speedo to tell you, you're in 3rd. gear.
Ok, my rant is over

[Antietam Classic Cycle]

It's one part cost savings and one part planned obsolescence mixed together. It cost $1 per unit to drill and tap a hole, then thread in a screw!  Huge cost saving by not doing that! Then, if the fork oil is rarely or never changed, then the forks will wear out much more quickly and make the bike not worth fixing. New bike sale! 

[Ncdan]

If they ain't leaking, they're fine. 

Take apart a functioning fork because the oil is a little dirty? OK, when it needs seals and bushings time to go right ahead.

OK, shoot me.     

I’m in full agreement with you Sir. It’s a sealed unit that builds little to no excessive heat. Leave it alone until the seals start leaking and change it when fixing the seals. I always changed the primary oil in the FLHT every other oil change. I always felt a little ignorant draining out pure clear red fluid with no adverse smell ( like heat effected) it accomplished nothing except maybe making one feel better.

[yogidozer]

I’m in full agreement with you Sir. It’s a sealed unit that builds little to no excessive heat. Leave it alone until the seals start leaking and change it when fixing the seals. I always changed the primary oil in the FLHT every other oil change. I always felt a little ignorant draining out pure clear red fluid with no adverse smell ( like heat effected) it accomplished nothing except maybe making one feel better.

You are doing the right thing. If you were to find metal bits in the oil, you could likely prevent a major problem.

[TN Mark]

If they ain't leaking, they're fine. 

Take apart a functioning fork because the oil is a little dirty? OK, when it needs seals and bushings time to go right ahead.

OK, shoot me.     

Do you use that same philosophy with transmission fluid, a radiator on a liquid cooled system,  brake fluid, rear differential oil or engine oil? Just leave them alone until they start to leak thereby ignoring any maintenance schedule? 

[Greenman]

They were removed because people didn't tighten enough or forgot the seal / oring on assembly and then crashed when oil leaked onto their tyres or brakes. Making it a safety issue. So because of this safety issue we no longer have the convience of drain screws on forks. And yes im still pissed at this.

[Chuck in Indiana]

If they ain't leaking, they're fine. 

Take apart a functioning fork because the oil is a little dirty? OK, when it needs seals and bushings time to go right ahead.

OK, shoot me.     

<Cocking hammer> And why is the fork oil a little dirty? There is really no entry point for dirt to get in there. Hmmm. Maybe it's from metal particles that have worn from use, and are suspended in the oil. I wonder if they are abrasive and cause even more wear?
Maybe that first oil change is over rated?  "There's no need to change the oil, boy.. they put it in at the fact try."
 

[Old Jock]

With ya

In defence Ohilins (on a Duc 1098) state it's because oil volume on later cartridge upside down forks are far more sensitve to oil volume.

Given that you never know how much old oil you left in there and how much you got out, over time yoou could end up making signifcant changes to the dampng charactersitics

It annoys me but really it's not such a big deal to whip them out turn them upside down

[Huzo]

<Cocking hammer> And why is the fork oil a little dirty? There is really no entry point for dirt to get in there. Hmmm. Maybe it's from metal particles that have worn from use, and are suspended in the oil. I wonder if they are abrasive and cause even more wear?
Maybe that first oil change is over rated?  "There's no need to change the oil, boy.. they put it in at the fact try."
 

Aluminium oxide Chuck ?
You know, that black stain you dread to see on the rivet heads of your plane...

[Ncdan]

How many folks here change the rear end lube in you cars and trucks? I’ve never in any vehicle I’ve ever owned and 100k miles later they are fine. Not all but some vehicle fluid charges at the  intervals we do they are completely unnecessary. However if it gives one the feeling of accomplishment and well being, by all means carry on:)

[LowRyter]

Do you use that same philosophy with transmission fluid, a radiator on a liquid cooled system,  brake fluid, rear differential oil or engine oil? Just leave them alone until they start to leak thereby ignoring any maintenance schedule?

no

[TN Mark]

no

 

[LowRyter]

But many of those items now have extended service life .....such as manual transmission fluid for life and 100K for coolant.  So "no" is practically "yes".

[normzone]

<Cocking hammer> And why is the fork oil a little dirty? There is really no entry point for dirt to get in there. Hmmm. Maybe it's from metal particles that have worn from use, and are suspended in the oil. I wonder if they are abrasive and cause even more wear?
Maybe that first oil change is over rated?  "There's no need to change the oil, boy.. they put it in at the fact try."

I'm a little bit concerned about the hammer cocking, but since I didn't hear the peep sight flip up and get adjusted for windage, only a little bit 

[Chuck in Indiana]

I'm a little bit concerned about the hammer cocking, but since I didn't hear the peep sight flip up and get adjusted for windage, only a little bit 

He *said* Ok shoot me.. <shrug>

[TodkaVonic]

Having just used a 1/8" drill bit to penetrate the sludge and debris at the bottom of my ambo forks so the drain holes would function and I could change out the fork oil, I'm getting a kick outta this discussion.

[Antietam Classic Cycle]

Having just used a 1/8" drill bit to penetrate the sludge and debris at the bottom of my ambo forks so the drain holes would function and I could change out the fork oil, I'm getting a kick outta this discussion.

 

[normzone]

He *said* Ok shoot me.. <shrug>

I understand that, but now the conversation is about range.

I have VERY high expectations of you, [Chuck].

[nealwp]

My Bassa has a drain at the bottom of the fork but the procedure is to remover the fork and drain it from the top. Fork oil needs to be kept really clean or dirt in the oil can cause the seal to leak.

[Ncdan]

My Bassa has a drain at the bottom of the fork but the procedure is to remover the fork and drain it from the top. Fork oil needs to be kept really clean or dirt in the oil can cause the seal to leak.

I’m just curious and hope this is a reasonable question. How can dirt get into a sealed system. When draining fork oil several times in the past years on road bikes I have never observed dirt in any form come out of a fork.

[ohiorider]

OK.  Dirty, clean or in-between.  Wasn't the reason for posting.

I posted the initial post because I have modified the Honda CB1100's damping rods (6 holes in them instead of 4) and installed RaceTech valving.  For those of you who know anything about these valves, compression damping is managed by (1) assuring the valves come with the correct number of bleed holes in them, and (2) setting the valves to 'blow by' upon hitting bumps at various rates.  On the Honda (and most bikes) it is possible to remove the valve to tweak its setting by simply lifting the front tire off the ground, removing fork caps, spacers, and springs. then removing the valve with a 'grabber' tool inserted into the fork.  Race Tech states that fork oil wt will not affect compression damping, since damper rods have been modified with additional (and slightly larger) holes.  With lighter fork springs and previous tweaks of the RT valves, I'm happy with the softer compression rate and ride.

Rebound damping with Race Tech valves, on the other hand, is totally managed by fork oil weight.  So, to achieve desired rebound damping using Race Tech valves, it is necessary to tweak by changing the fork oil.  I started with very light, am now at 10 wt, and need additional rebound damping, so it'll require another one or two removals of the forks to change the oil for the damping rate I want.  Drains would make this a simple task.  Instead, it's a PITA.

That's my story and I'm sticking to it.

Bob

Here's the link to RTG valve installation and tuning instructions.
https://racetech.com/download/InstructPDF/IP%20FEGV%20S%20Emulator-STREET.pdf