1983 Honda GL650

[artcjr]

I am wondering if anyone can provide me some feedback on questions I have re: this vintage bike. In early October I completed a 4560 mile cross country trip from RI to CA via southern route. At the start of the trip, the tires had about 3100 miles on them. At the end of the trip, the rear tire's tread was worn away completely, i.e. completely flat in the middle. Tread wear was noticeably more aggressive in the hot regions where temps were over 100F as, for the first half of the trip, wear appeared normal and minimal. What seemed odd to me was that tread wear on the rear tire was not symmetrical, i.e. tread depth (remaining) on the left outer edge of the tire was significantly more than what remained on the right edge. I took a photo of it and kept the old tire for reference. This bike has a shaft drive with "PRO LINK" rear suspension in lieu of two shocks. I do not see any adjustment in the rear suspension but am wondering if something may be out of alignment to account for this noticeable disparity in tire wear at the edges.

The other question I have is re: a spongy feeling to the two front discs. Purchased rebuild kit for the master cylinder and bled fom top to bottom and bottom to top, but still get a spongy feeling when depressing lever. What I notice though is that the original rubber hoses can be seen to flex upon applying pressure. I am wondering if I don't have it bled completely of air or if I should replace original OEM hoses with SS braided lines. Bike now has 23K miles on odometer.

[BuzZz]

Replace the front brake hoses with some braided stainless steel aftermarket ones. Rubber hoses are more prone to expanding under pressure and giving a mushy feel, and this only gets worse with age.

The tire wear could be from many factors. Crosswinds, load distribution, road crown, cornering preference (most people favor turning one direction over the other), engine torque (especially with a longitudinal crank arrangement), any number of factors. Unless the suspension/swingarm set-up is loose enough to move side to side by hand, the Prolink rearend is probably not one of them. I wouldn't sweat the tire wear unless it starts happening much faster.