Front Wheel Speed-Sensor has become detached from the motorcycle

Hi All:

At the beginning of this riding season, I noticed that my 2001 ST 1100 would occasionally make a horrible grinding noise if I rolled it backwards. I went looking for the source of this noise, and it "appeared" to come from the front right brake caliper. Further investigation led to discovery that the speed-sensor for the front wheel was not attached to the bike at all (both fasteners were missing) and it was resting on the toothed ring. When the bike was moving forward, it did not make a sound, but when I rolled the bike backward, the toothed ring caught on the forward edge of the speed-sensor and made a racket.

I'm not exactly sure why the two fasteners came loose and disappeared, but I kind of suspect it happened when I had the front tire changed a few weeks ago. I had this work done 'on the road', not by my usual dealer.

For the time being, I have put a cable-tie through the lower of the two mounting points. This is holding the speed-sensor about 4 mm up above the toothed ring (more than the 1 mm gap I think Honda specifies). I don't know yet whether this will result in the ABS going out of service - I have not gone for a ride since I finished this jury-rig repair. Much to my surprise, the actual Hall-effect sensor is not damaged. It's certainly burnished nice and shiny, but it does not appear to have had any material ground away.

Below are pictures showing what I found, and where I put the cable-tie as a temporary fix.

What I found, with one of the two missing fasteners provisionally identified


The temporary fix until I can buy replacement fasteners


Using the parts list at Ron Ayers (the bike is a 2001 ST 1100 with ABS, purchased in Canada), I have been able to identify one of the missing fasteners as likely being 90106-MAJ-G40, a 6X25 flange socket bolt. But, I can't figure out what fastener (or perhaps a nut?) is used on the other attachment point in the upper left of the photo.

Can any one of you wizards out there let me know what (if anything) attaches to that upper, more rearward attachment point? Also, are there any washers, grommets, spacers, etc. needed in addition to the 6X25 bolt that goes in the hole where I put the cable-tie?

Many thanks (from a hotel in rural Portugal).

Michael

MM, see if you can spot the bits.... Roger

IMO are you only missing the 90106-MAJ-G40 6x25 bolt there (inserted from the inboard/wheel side BTW).
Appears the sensor bracket is simply slipped onto that pivot and held there by named bolt (marine lube on one, and thread-lock on the others seems in order though...)

Michael - There is a long bolt with a 'nose' that screws through the caliper bracket and the end of it goes through the 'smooth' hole on the ABS Sensor as an alignment device. Chances are the 'mechanic' did not pick up on this and just bolted the sensor on so it worked back and forth and the threaded bolt came out. (not at home or I'd show pictures). IIRC, you have to remove the front fender side bolts to properly get at the alignment bolt. IIRC, it's either a 5 or 6MM socket head. The arrow is the bolt I am talking about - notice the smooth 'nose' on the end. The part number is 90131-MAJ-G60. I'm pretty it's still there or you would be having caliper troubles. ;-)

Be sure to align the "nose" end of the bolt into the smooth hole before tightening the 6 x 25 bolt. After tightening the screw, give the wheel a spin to be sure the sensor clears the pulser ring.

IMO are you only missing the 90106-MAJ-G40 6x25 bolt there (inserted from the inboard/wheel side BTW).

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Mine is from the outside, A "US" bike, if it matters.

Ron said:

Mine is from the outside, A "US" bike, if it matters.

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Which is weird, cause all fiche (and Michael's photo) show the M6 bolt being inserted from the inboard side.
Sure its not a counter/securing nut you're looking at there?

Nope, the bolt we are talking about comes from the outside at the top. It secures the mounting bracket and the nose aligns the ABS sensor. It's that way on both of my ABSII ST1100s. Notice I had to unbolt the 'plastic' cover to get a picture.

Uncle Phil said:

Nope, the bolt we are talking about comes from the outside at the top.

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Yep, caught up now, Michael's pic tricked me by viewing through the rim, showing the inside of the RH fork leg & caliper; odd arrangement on fiche didn't help either.

jfheath said:

I don't think we are disagreeing, Phil. .

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I was trying to 'correct' Martin, not you! We posted about the same time. ;-)

Uncle Phil said:

I was trying to 'correct' Martin, not you! We posted about the same time. ;-)

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LOL! :lol:
I remember very thin guidance lines in older (hardcopy) fiches, clearly indicating where & how parts are put/slipped together, seems they omit those in newer/online drawings...

Yes, if you don't know that bolt aligns the sensor, you would never know it when you remove it (the sensor stays in place until you remove the lower bolt). A pretty typical mistake made by wrenches that are not familiar with ST1100 ABSII machines (and there ain't many that are familiar with them! ;-))

Hello again everyone:

Many, many thanks to all of you for the awesome assistance provided - the pictures, part numbers, and so forth.

I spent 3 hours today riding over 200 km to 3 different Honda dealers in the middle of Portugal, only to find them all closed. When I arrived at the third one and found them closed, I started to wonder "Gee, maybe it might be a holiday today in Portugal?" Sure enough, it's their national day (equivalent to July 4th).

Tomorrow, I'll go and get the bolt, and let you know how the install goes.

What I have learned in the meantime:

1) Fer' sure, the ABS & TCS lights go on when the speed-sensor is 4 mm above the toothed ring.

2) Those lights are awfully bright at night - I had to cover them up with paper before I could continue riding after dark.

3) I've only ever experienced the traction control system kicking in once in over 120,000 miles of riding - that was in Ireland, on a road covered with pea gravel. Well, sure enough (I think you can guess where this story is headed) tonight I was on a steep hill in a Portuguese city where they use those little square paving stones, and the road I was on had to be 300 years old... the stones were a little damp, and polished smooth as a baby's butt. I stopped halfway up the hill to geth my bearings, and when I started up again and put the lash to the moto, the back wheel broke loose and gave me a really wild ride - the rear end of the moto must have yawed 45? either side of centerline. My rear end puckered up so much I think I ripped the leather off the seat.

Moral of that story: You can be sure that on the one day out of 15 years that the TCS is inoperative, that'll be the day you need it.

Michael

You can dim the ABS warning light by pressing the ABS button, stops it blinking and dims it until the next key start cycle.

wjbertrand said:

You can dim the ABS warning light by pressing the ABS button, stops it blinking and dims it until the next key start cycle.

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That is correct only if the ABS warning activates (begins to blink as a result of a fault being detected) some time after the ignition has been turned on. If the ABS/TCS lights do not pass the initial built-in self test at the time the ignition is turned on, they will not blink but simply remain illuminated and cannot be dimmed.

Michael

Hi All:

I finally found a 6 x 25 bolt - at a chainsaw repair shop. I put a little Loctite on it, screwed it in, and everything is back to normal.

Once again, thanks to everyone who replied and provided information - it's really great to have this level of support when touring far away from home.

Michael