2002 ABS error after changing front tire?

2002 ABS.

Getting ready for a trip, and took the bike into work today to test a few upgrades. New Michelin Commander front (130-70-18) and rear (160-70/17), Hyperlights, rewired GPS mount, etc. I have been using the rear Commander (same size) for the last 2 tire changes. First time using the front Commander.

I pulled the wheels myself and had the shop change the tires. Changed wheel bearings while I was at it, as they were a bit loosey goosey, and the bike was developing a wobble at speed around corners.

Good news is that the bearings solved the cornering problem. Riding into work this am (50 miles) all was ok, but I noticed the speedo was off. Indicated 85 was actually about 88 per the GPS. It was just the opposite b4 the front tire change - the indicated was always slightly less than the GPS. Other than that, no problems.

Coming home tonight I'm thinking, "great, all is working well" when the ABS error codes started flashing - 2 lights, adjacent. $#%&! I wish I would have thought to count the pattern. Note that this was after about 75 miles on the new tire.

I just hit the reset (?) button a few times, and the lights (2) stopped flashing, but stayed on. Pulled off the freeway, and turned the ST off. Counted to 30. Turned it on, and all is right with the world - no codes. Rode the 5 miles further home, no problems still.

I did not stop to measure the front tire height, but it has to be a bit taller (as evidenced by the speedo error) than what I had on there previously - a BT45 rear in the same size, 130-70/18. The only reason I changed it after maybe 5000 miles was odd looking stress cracks and the start of severe cupping.

So, a couple questions:

1. If this was an error caused by tire size, why did it take 75 miles to throw an error?
2. If it IS caused by tire size, is it normal for the error to go away when the key is turned off?
3. Assuming it is a tire size error, and it takes awhile to "see" the error, can I assume that a couple thousand miles of wear may correct it?

And the biggest question: will I do any damage if the abs error code lights up when I'm 1000 miles into a 3000 mile trip, and just ignore it? I'm ok with no abs (as long as I'm aware of it), but I'd rather not cause any damage that I later have to fix.

TIA

George had some problems with his ABS https://www.st-owners.com/forums/showthread.php?113437-ABS-II-Help-Needed!!!&highlight=

My brother had his BT45 tire cracked real bad on his ST1300 with a sidecar. Not sure why his cracked so bad.

Thanks Mike. I'll check out his thread.

As an update, as soon as I departed home this am it started flashing again.
No codes; just a continuous flashing, maybe slightly less than a 1 second interval.
The ABS button did not reset it to steady on; multiple activations had no effect.
But hitting the TCS switch made it go solid red.

Did some hard braking tests today coming in, not quite to the point of activating the ABS. All seemed to be normal, at least as far as I went.

Just curious, as the stock front tire size is a very common size, why did you mount a different size tire in the first place?

As a guess, there's a chance that the tire size would be irrelevant to the ABS operation, if it only monitors for wheel slip. If it also monitors something about front wheel rotation relative to rear wheel rotation, then the size may make a difference. The TCS system probably monitors that condition, so the fault you see when you turn on TCS may be caused by the tire size.

Probably not the tire size, though I did wonder about the 130. Check your battery terminal connections because if they are loose, they can cause the ABS to do funny things. I juts had similar problem with my 02 ABSII - flashing light for a while. I sort of wiped the sensors on each wheel, made sure the battery terminals were tight and clean and the problem went away for now. Also, check the positioning of the front sensor. On the ABSII, one of the allen bolts is a 'locator' to make sure the sensor is in the correct position.

dwalby - I went with the 130/70-18, as it's the closest that Michelin makes in the Commander II line to the ABS 120/70-18. This was also the same size tire as before, the BT45 rear on the front. And I did that because I only get about 10000 on a front tire. I'm hoping the Commander II on the front will get me an improvement equal (or so) to that of the Commander II on the rear. I would only get 5-6k on various flavors of rears. I am getting almost 12-15k with the Commander II. First impressions after 200 miles is that its a great combo.

UP - Thanks for the info. I'll check that out tonight. Interestingly, I did pull/replace the battery just b4 the warning lights started; had to get to the tail light wiring to get some slack to wire in the Hyper Lights. But I am (almost) positive I tightened the terminals. I always use the screwdriver first, then follow up with a 10mm open wrench.

Oddly enough, while the ABS warnings came on this am, my afternoon commute was without red lights emanating from the dash... weird stuff.

Thanks all. Still planning on departing on a Tucson-Big Bear-Big Sur-Tahoe-Death Valley trip in the am, ABS or not...YIPPEE!

The ABS flashing does not affect the braking other than the ABS doesn't work. If push comes to shove and the light comes back on, a piece of black tape or remove the ABS fuse should remove the 'irritant' until you have time to fuss with it.