Wheel bolt lengths on 33 and Sprint
Can anyone here please tell me the correct wheel bolt lengths used with Speedline 14" 8-hole alloy wheels on the Sprint, 13" 14-hole alloy wheels fitted to the Trofeo and Imola, and the 14" pressed steel wheels fitted to the 1.7 ie?
The Speedline wheels definitely use longer bolts than the Trofeo alloys, as they are thicker, plus there is a recess in the back of the wheel under the seat for the bolt.
The Trofeo alloys are also thicker than the steel wheels.
The Alfa manual just says that different bolt lengths are used for different wheels, but gives no actual lengths.
A tyre shop has managed to wreck most of a set each of long and short bolts with their air hammer and I want to get new ones, having managed to salvage the hub threads by carefully tapping them out.
I have no spare long bolts for the Speedline wheels, but there are two different shorter length bolts in my spares, so maybe the Trofeo alloys use slightly longer bolts than for steel wheels?
Today I plan to measure the depth of thread in the hubs beyond the wheel contact surface, but I have already noticed that, at the rear, the female threads, which are in the brake drum, start immediately next to the wheel, whereas at the front the threads in the hub start beyond the holes drilled in the brake discs, so should ideally need a longer bolt than at the rear.
So it seems the length of the bolts has to give enough engaged threads at the front but not be so long as to foul the brake mechanism at the rear.
Is it even possible Alfa used different length bolts at front and rear?
Nr. Carcassonne. '94 Trofeo 1.4 ie (F), '93 Imola 1.3/1.4 ie (now for breaking) (F), '91 1.7 ie (GB)(spare car), '86 Sprint 1.5 QV (F). '87 VW Syncro camper (F), '99 Fiat Seicento (F)
Last edited by Silversprint; 09-01-16 at 06:18.
Reason: To correct spelling