Posting some measured lane widths at crucial points where cyclists might get squeezed or otherwise experience problems. Please add any more points or sections where you have experienced problems.
I measure lanes when no cars anywhere around, can be dangerous otherwise. Can pace out or use a measure, but please be careful of the traffic.
Lanes are quite wide in general, but come down at intersections where a fifth lane has been fitted in on otherwise four lane sections ( or third lane on 2 lane sections, as at Glebe Pt Rd).
Kerbside lane along Wentworth Park (westbound) : 3.6 m, narrowing to 3.3 m at Wentworth Park Rd due to central median put in for cement truck entries and exits on waterfront. Total road width about 14.5 m to 15 m. If it wasn't for these central medians it would be possible to mark kerbside lanes of around 4 m, and could almost fit in bike lanes. Note that 3.6 m lanes are not recommended in Austroads guides for bicycles. Wide kerbside lanes should be 3.9 m or wider for comfortable sharing with motor vehicles.
Lane width up the hill westbound before Glebe Pt Rd: 5.1 m, narrowing to 3 m when right turn lane starts.
Lane width eastbound at Glebe Pt Rd: 4 m, widening to around 5 m near Talfourd St. Total road width about 10.4 m.
Lane width westbound between Glebe Pt Rd and Ross St: about 4m at Glebe Pt Rd, widening to 5 m generally, but 4.2 m at refuge at Woolley St, which is about 1.8 m wide.[note added in March 2017: the central refuge has been removed and replaced with a pedestrian crossing. Two small kerb extensions narrow the lane a bit, but still quite wide through the refuge]
Lane width eastbound is generally 5 m except approaching Glebe Pt Rd when it narrows to about 3 m due to right turn lane, and 4 m at the refuge. Total road width : about 10.4 m. Used to be a bike lane marked between Ross St and Glebe Pt Rd, can stil see remnants.
Similar for Ross St to Cross St. Parking is allowed out of peak though, so don't always get the benefit of the wide lane. [note added in 2017: a new wide refuge has been put in near Cross St. They have allowed for a future bike lane eastbound, but the westbound approach to the refuge is a classic squeeze, from 4.5 m to 3.5 m. Have asked for a relook at this, as it is quite dangerous if a car tries to overtake into the squeeze point.]
Cross St to Booth St is generally about 14.5 to 15 m, but kerbside lanes reduce because of several right turn lanes and painted medians. Kerbside lane westbound approaching Both St is only 2.8 m wide, due to the right turn lane. Cyclists obviously need to take the lane here, or use the adjacent footpath, which is 3.6 m wide, with no doorways. One right turn lane into the Trio development mid block appears to be redundant, or a bit of a luxury. Kerbside lane eastbound at Booth St is only 3.3 m, and is possibly the most likely squeeze point to cause problems for cyclists. (Agree or disagree?)
Booth St to Parramatta Rd: generally 14 to 15 m wide with generous kerbside lane, except eastbound lane on approach to Booth, where narrows to around 3.5 m due to a tapered (widens out as it approaches the intersection) central median. This is also a possible squeeze point for cyclists, as lane comes down from a wide 4.3 m just before the median starts. Motorists will still try to pass, even though lane is narrowing.