T160 T140 Disc rotor 4 bolt PCD ?

[Esmerela]

Hi

The po of my t160 has fitted Morris mags, I presume from a t140. The 19"front seems Okay, however 18"rear is a horrible mess t140 rear sprocket the chain alingment is way out , odd slection of spacers and washers even head race cone pushed in the speedo drivehub but no speedo drive ? and fitted on the LHS.
I am modifying 19" WM3 Morris mag front wheel from Sportster to fit , I have made new bearing carriers and the offset now matches a std wheel can some body help with the 4 sprocket /disc rotor bolt PCD.

 

[L.A.B.]

I have made new bearing carriers and the offset now matches a std wheel can some body help with the 4 sprocket /disc rotor bolt PCD.

Pitch Circle Diameter?
Well, I make that 3.4375".
Edit: If you can find a disc to measure then the T160 rear disc was the standard Triumph item. Late T140s also had LH Veglia speedo drives so there are two types of T140 rear disc hub, both different to the T160 rear hub.
Hopefully, you are aware that unlike the T140, the T160 rear hub bolts are 7/16" diameter except for the short (3/8") section through the disc, so the T160 sprocket holes are 7/16" and the T160 sprocket was dished to accommodate the LH speedo drive gearbox.

 

[Esmerela]

Pitch Circle Diameter?
Well, I make that 3.4375".
Edit: If you can find a disc to measure then the T160 rear disc was the standard Triumph item. Late T140s also had LH Veglia speedo drives so there are two types of T140 rear disc hub, both different to the T160 rear hub.
Hopefully, you are aware that unlike the T140, the T160 rear hub bolts are 7/16" diameter except for the short (3/8") section through the disc, so the T160 sprocket holes are 7/16" and the T160 sprocket was dished to accommodate the LH speedo drive gearbox.

L.A.B,

Many thanks for the Pitch Circle Diameter information and for pointing out the the increased diameter of the T160 rear hub bolts. The 18"rear Morris mag that the bike came with used 4 x 3/8 UNC Allen bolts either side to secure disc and rear sprocket to to the wheel. The wheel was fitted with the Smith's speedo drive ring installed on the RH disc / bearing carrier, and not as stated previously to the LHS.