DR650 - Front Fork Help Needed

[ManDownUnder]

Re the wear done on hard objects (in this case a fork leg). Soft materials in constant rubbing contacts are well known to cause wear on even the hardest of material - it's a well known phenominon which I can attest to from my days as a fitter. You can't use teflon as a bush for a hardened steel sheft to revolve in for instance.

It will reliably wear the harder material away, often with surprisingly little wear on the softer one.

[Robert Taylor]

Re the wear done on hard objects (in this case a fork leg). Soft materials in constant rubbing contacts are well known to cause wear on even the hardest of material - it's a well known phenominon which I can attest to from my days as a fitter. You can't use teflon as a bush for a hardened steel sheft to revolve in for instance.

It will reliably wear the harder material away, often with surprisingly little wear on the softer one.

That is exactly right, another often seen example is the wear that occurs on the distance collar behind front sprockets, often assisted / accelerated by grit ingress. The seal lips of the counter sprocket seal will long term wear appreciable grooves in the hardened steel surface.

It is always easy to often think the worst of dealers, we are ordinary everyday human beings like everyone else!

[paulj]

Well I'd like to think that it was 'fair wear and tear' - but a) wasn't there when they were sent down, b) aluminum left wearing long term like that doesn't leave pristine clean metal, c) there are grind marks within the cut itself (see attachment) - I doubt that a rubber brake hose or plastic covered speedo cable could do that. Also there is still a ragged edge to the cut and bits of scarf left there. Surely a rub mark would be smoother and the metal contaminated to some extent by dirt/oil? If anyone can shoot a pic of their wear marks that may put paid to my whinging.

Furthermore if I had seen anything like this during my infrequent and rudimentary maintenance schedule (ahem) I would have sorted it or at best noted it when they were taken off.

I see what is being suggested - that the hose/cable rubs these into the metal - the brake cable is about right for position but the speedo cable is way lower and should not have left a single deep scour. There is not sign of rub or wear on the cable/hose (this could be possible from what you say).

Now - forks are 960mm unloaded - as best I could push the front up - top cap to bottom - but again, it probably won't be the repairer - I'll have explained it carefully in the wrong language or some such other.

[merv]

paulj you measured those forks yet? As I said earlier going by your pics I reckon they haven't been shortened.

As for the marks are they exactly where the cable and brake hose fit? That would tell the story.

[NordieBoy]

Mine was marked here by the brake line.
Before I changed to braided.

I don't like the grind marks in your 1st pic though

[merv]

OK so you've updated your post with the measurement and they are 960mm, that means they have not repositioned the spacers so if you paid for that sorry but you need to go have words with them.

Did you download the workshop manual?

[NordieBoy]

Just had a thought.
If the marks on the fork legs looked dodgy they may have cleaned them out with a rotary wire brush?
I know I did this on a set of KX125 forks.
Could explain how a mark like mine got to be a mark like yours.

But you would think they'd tell you this - and charge you.

[warewolf]

do you really think the cable has done that and then would the other one be the brake hose? Seems a bit amazing if it was. You'd soon confirm because the cable and brake hose would fit right beside the marks when you put it all back together.

Those marks look exactly the same as the ones left in the similar-looking forks of my DR-Z250. Made by speedo cable etc. Due to rider sag, the cable may not sit where you observe it when the bike is unladen.

That is exactly right, another often seen example is the wear that occurs on the distance collar behind front sprockets, often assisted / accelerated by grit ingress. The seal lips of the counter sprocket seal will long term wear appreciable grooves in the hardened steel surface.

Routinely seen in wheel spacers, grooved by the wheel bearing seals - something more people are likely to see than behind the front sprocket! That groove in the spacer where the seal lip sits? That's not there on a new spacer.

b) aluminum left wearing long term like that doesn't leave pristine clean metal, c) there are grind marks within the cut itself (see attachment) - I doubt that a rubber brake hose or plastic covered speedo cable could do that. Also there is still a ragged edge to the cut and bits of scarf left there. Surely a rub mark would be smoother and the metal contaminated to some extent by dirt/oil?
...
I see what is being suggested - that the hose/cable rubs these into the metal - the brake cable is about right for position but the speedo cable is way lower and should not have left a single deep scour. There is not sign of rub or wear on the cable/hose (this could be possible from what you say).

Your stated b) is incorrect, it does look exactly like that in my experience. But I can't explain c) grind marks. If you clean them there is nary a mark on the plastic part, and no permanent detritus on the tidy groove in the forks.

Re: position, see my comment above about rider sag. Might be relevant, depending on attachment points, angle of attack, how the tube curves as the forks compress, etc.

As for the marks are they exactly where the cable and brake hose fit? That would tell the story.

Indeed, put it all together and get back to us.

[warewolf]

Likewise I was too lazy to reverse the spacer on the back shock too when we lowered it on the mounting bolt, but all that mod does is reposition the bump stop to prevent too much travel.

Possibly it also maintains the distance between the bottom anchor and the wider part of the base of the spring, to avoid it contacting parts of the linkage.

[NordieBoy]

Possibly it also maintains the distance between the bottom anchor and the wider part of the base of the spring, to avoid it contacting parts of the linkage.

Nah, just total travel.

[paulj]

Yeah - I think you're right guys ... and I apologise for the slanging off of the mechanic - the marks are too coincident with the position of the cables, although you might have noted, I routed the brake cable round the wrong side of the fork! LOL.

Must be age - I didn't note this when cleaning off the forks with soapy water - DUH! Perhaps they cleaned them in a proper bath which highlighted the marks?

I have been emailed the cost but they won't send the invoice until I've paid! Strange.

So thanks again - been a good experience and I'll drop the forks in the clamps meantime.

Back to sorting the broken stud and fitting the jet kit etc. (and spitting out crow feathers).

[merv]

However did they claim to have repositioned the fork spacers to do the lowering because that is the bit I'm saying looks like they never did?

[NordieBoy]

Looks like they may have cleaned up the marks with a dremel and wire brush.

Usually you pay on receipt of the invoice?