How do I determine if mine is working properly? The previous owner (po) told me he thought it was bad or going bad. All I can tell you is under medium to hard braking the front end shakes pretty bad. I thought this might be the rotors but they look pretty true. I do have the Honda shop manual just was wondering if anyone had done this repair? Little mention of anti-dive in the search.
About the Anti-Dive
- Thread starter docjones
- Start date
If you have shaking under braking, it is most likely one or both rotors are warped. You would also feel a pulsing in the brake lever. The anti dive mechanism, if not working, wouldn't cause this, but you would likely notice a much larger than normal compression of the forks under a hard brake. You would not be able to see a warp in a rotor. Just being warped out of shape by a few thousands of an inch could be noticeable by feel in the lever.
John OoSTerhuis
Life Is Good!
Good info from Mike and ForeST. I rebuilt my anti-dive like Mike when I found a piece of the piston's seal lip in the bottom of the left fork slider during a fork seals R&R. I recommend every high mileage ST1100 have its anti-dive disassembled and inspected, FWIW.
John :STOC: Ten Fifty-Eight
John :STOC: Ten Fifty-Eight
The antidive is intended to slow the fork dive under hard braking. As stated above, I doubt that would cause a front end shake under brakes, but a bent rotor certainly will. The disc runout can be checked with a dial indicator gauge clamped to the fork leg, maximum allowed in the spec is 0.3mm.
The antidive is activated by the left caliper swinging forward on its pivoted mount, which pushes a piston valve inside the fork leg and closes off the compression damping bypass. There is a spring holding the piston valve normally open, and while stiff you should be able to see some movement by pushing with your hand. There should be no external oil leaks.
The antidive is activated by the left caliper swinging forward on its pivoted mount, which pushes a piston valve inside the fork leg and closes off the compression damping bypass. There is a spring holding the piston valve normally open, and while stiff you should be able to see some movement by pushing with your hand. There should be no external oil leaks.
Wow, OK I was wrong. The right rotor (the one on the other side of the anti-dive mech.) is warped. So bad you can see it just by rotating the wheel. Am I crazy just to replace the one side or should I do both? I've never purchased anything on eBay before so can I really get quality rotors? The price on these things (the rotors) is crazy expensive. I need guidance.
If the other rotor looks in good shape and you are sure it isn't also warped, just replacing one should be OK, but also put in new pads all round. Can't comment on the quality of aftermarket.
Slydynbye
Will ride for Pie
Is there a chance the rotors are just slightly mis-mounted? ie not actually flat to the mating wheel surface.
Ya know Slydynbye, I guess there is that chance. I'll check that out. Take the wheel off, remove the rotor, maybe rotate it 180 degrees and put it back together with specified torque. Oh, and I did find some EBC rotors on ebay for around $105.00 each. That beats the heck out of $241.00 each for OEM rotors. Hey mcthorogood, how are those Delkevic rotors holding up? I assume you replaced the pads while you were in there? What brand of pads did you go with? Thanks for the help gentlemen (and I use that term loosely).
Slydynbye
Will ride for Pie
I'm pretty sure you shouldn't rotate them 180 as they are clearly marked for which surface is on the outside.
just out of interest how do you check your anti dive is working .when i got mine it hardly dived but now she seems to dive a lot more under braking .
thanks :bow1:
thanks :bow1:If your kidding Slydynbye your a funny guy. I was just talking about spinning the rotor 180 degrees. Still looking at new rotors. Still think the prices are way to high. What did you pay for yours mcthorogood if I might ask? Haven't seen that brand on ebay. A lot of the one for sale on ebay state they are for the VT1100 but say they will fit the ST1100. They are different part numbers on Hondas web site so how could that be?
STraymond
Site Supporter
John OoSTerhuis
Life Is Good!
When I did mine I replaced all but the big plate and its bolts (#5 and #6).
John
John
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STraymond
Site Supporter
When I did mine I replaced all but the big plate and its bolts (#5 and #6).
John
Thanks, John.
STraymond
Site Supporter
Ordered the 9 parts for a rebuild. Cost about $40 before shipping from Partzilla.
Hi ,
Is the anti dive significant to stop fork dip..My old vf400 had veriable antidive and it worked a treat.
My st 11 on the other hand , notice nothing it dips ..its done 30k so would not expect to strip it just yet..
CYYJ
Michael
I think it's kind of impossible for an average ST 1100 owner to make an objective evaluation of how well the anti-dive system is working, or whether it is working at all. I think the only way such an evaluation could be made would be to test ride your motorcycle, then immediately test-ride another ST 1100 that is known to have a fully-functional and properly operating anti-dive system. Even then, it would be tough because you would only have one or two seconds (during the application of forceful front wheel braking) to observe the effects of the anti-dive system.
I rebuild my anti-dive system every 10 years. It's not expensive or difficult to do, I just replace all the components that are subject to deterioration, and at the same time, thoroughly flush out the front fork system and replace any front fork components that are worn. Although I think the whole front fork system works better after this work is completed, it's still very difficult to describe what "before and after" is like, because several days pass between the last ride before the rebuild, and the first ride after all the work is done.
Michael
Thanks for that Micheal,
I suppose the other aspect is that the pan with its 700+ weight ain't going to sit pretty pulling up full on and is in no way the same as my first bike with anti dive , which I have to say you could notice immediately when adjusted from soft the hard .And less than half the weight of the pan.
Certainly going to look at a strip down at some point as it is a 19yr old ,so a wise move from what you say . No service history to say fork oils etc changed..
Pete.
CYYJ
Michael
In that case, you'll probably have to drill the old fork oil out
On a more serious note, it's a fairly easy task to tear the whole front fork system down and rebuild it from scratch. It's complex, in the sense that there are a lot of parts and a lot of steps to the process, but it's not difficult. Having said that, I think it is the kind of project best left for the wintertime when the bike is laid up, because that way you can complete the work over 3 or 4 days, and if you have to wait for parts to arrive, it won't cut into riding time.
I did a write-up explaining the whole fork rebuild process for a ST 1300, it is here: ST1300 Front Fork Overhaul: An Illustrated Bibliography The process for the ST 1100 is similar, although the ST 1100 has the anti-dive valve that the ST 1300 does not have.
Michael
ST1100Y
Site Supporter
I get frequent reminders that "it's there and operational"...
Like when diving into a hairpin a little ambitioned, hitting a bulge in the tarmac with applied brakes will cause a brief squeak caused by fork oil being driven through the smaller orifices...
I also think that a non operational anti-dive will cause a real spongy, deep diving front end during heavy braking...