Exactly a year since I started riding my 2001 ST1100 (non ABS), my wife and I were on a ride out for the weekend, when suddenly the front end started giving a light "thunk-thunk" sound that was too loud to ignore. Tried wheeling it backward and forward, could not see anything visibly touching anything to cause the sound, and at that speed it sounded more like a brushing than a hitting sound. Was about 40 miles from home when the sound started, so decided to ride home really slowly and hope I got there without mishap.
The sound was periodic with wheel rotation, and got louder and more noticeable (physically) about a couple of miles in. At one point it started sounding like a "whack-whack" sound, and then before I could react it started shaking the handle violently as of something was hitting something physically (but the sound was not metallic). And then... silence. The sound and vibes stopped, and I coasted to a stop a few hundred metres ahead. The only sign that something had gone terribly wrong was oil spurting downward from bottom end of the left fork/left brake calipers (it was hard to tell as both were splattered with fresh oil). I tried walking back to spot anything that might have fallen off, but I didn't spot anything (or maybe I didn't walk far enough). 5 minutes later, oil was still dripping, but at a slower rate. Didn't wait longer as it was getting dark, rode home slowly, not using the front brakes (in case it was brake fluid that was leaking - but the level in the reservoir didn't seem to be going down).
Back home, this is what the left fork looked like:
Waited till today morning, so that some of the oil could dry and I could possibly locate the problem better:
Took it to the mechanic who had last done my brakes a few months ago, and he confirmed it's fork oil that was leaking. He said it wouldn't be a quick job, and checked online for the parts that could be at fault (I didn't check which site, but it wasn't Honda), and they mostly showed unavailable or on backorder. Mechanic's verdict: it might be better to salvage parts off another ST1100 if possible, else I'm looking at my wheels sitting in his garage for a couple of weeks while he identifies the problem, gets parts shipped and fits them - a situation I'd rather avoid.
Some more observations, in case they help:
So my questions are:
The sound was periodic with wheel rotation, and got louder and more noticeable (physically) about a couple of miles in. At one point it started sounding like a "whack-whack" sound, and then before I could react it started shaking the handle violently as of something was hitting something physically (but the sound was not metallic). And then... silence. The sound and vibes stopped, and I coasted to a stop a few hundred metres ahead. The only sign that something had gone terribly wrong was oil spurting downward from bottom end of the left fork/left brake calipers (it was hard to tell as both were splattered with fresh oil). I tried walking back to spot anything that might have fallen off, but I didn't spot anything (or maybe I didn't walk far enough). 5 minutes later, oil was still dripping, but at a slower rate. Didn't wait longer as it was getting dark, rode home slowly, not using the front brakes (in case it was brake fluid that was leaking - but the level in the reservoir didn't seem to be going down).
Back home, this is what the left fork looked like:
Waited till today morning, so that some of the oil could dry and I could possibly locate the problem better:
Took it to the mechanic who had last done my brakes a few months ago, and he confirmed it's fork oil that was leaking. He said it wouldn't be a quick job, and checked online for the parts that could be at fault (I didn't check which site, but it wasn't Honda), and they mostly showed unavailable or on backorder. Mechanic's verdict: it might be better to salvage parts off another ST1100 if possible, else I'm looking at my wheels sitting in his garage for a couple of weeks while he identifies the problem, gets parts shipped and fits them - a situation I'd rather avoid.
Some more observations, in case they help:
- The brakes were serviced in mid January as they were binding. After the service, things were much better than before, but when wheeling the bike backward to park, it felt like there was more resistance than before - I wasn't sure if that was true or my imagination, as I started parking in reverse so I can roll out forward, after the brake binding incident. But last night, the bike was absolutely free when rolling backward - I was even able to wheel backward while astride, while it normally required me to get off and use the parking handle and still getting breathless in the process.
- I noticed over the last few weeks that there was a slight squeaking sound (in time with wheel rotation) when I'd start moving after a few days of the bike sitting still. I put it down to the brakes not having retracted smoothly and taking some time to get pushed back into position when rolling. The squeaking died after a minute or so which seemed to fit my theory.
- I noticed over the last couple of rides that the squeaking sound was louder when turning. Again no squeaking after a minute or so of riding.
- Parked last night after the incident, I checked that nothing from the fork was in contact with the wheel/disc rotor.
- Oil still dripping over 18 hours later, although much slower.
- I collected a couple of drops of oil last night to check the colour. Seemed clear, slight red tint:
So my questions are:
- Anything I should do right now to prevent anything going further wrong? I'm not planing to ride again until fixed, unless it's to the mechanic.
- What could have gone wrong?
- Anything more I can do to investigate (visually/without doing anything to make it impossible to ride to the mechanic)
- Best reference for what parts would be involved? (I have the Honda workshop manual and the Haynes one, although Haynes says '90 to '97, I think it still applies)
- I have a friend who knows someone who deals in scrapyard stuff, is that a worthwhile direction to pursue for this problem?
- I have a decent set of tools, but don't have much experience - should I attempt the job myself or trust the mechanic with my bike (and my money )
- If I choose to do it myself, what consumables would I need to replace (besides the parts etc in (3))? Do I need specialized tools for something like this?