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Hi folks,

so a 65 Cooper would have come out the factory with 7" brakes and narrow rear drums? is that correct?

redrobbo wrote: ↑Sat Feb 04, 2023 6:08 pm Hi folks,

so a 65 Cooper would have come out the factory with 7" brakes and narrow rear drums? is that correct?

Yes, that's correct.

Thanks Tweedy.

Ok, so is there a difference in front track width from 7" discs (since we cant get calipers anymore) to 7.5" discs set up?

Do you need wide drums with 7.5" set up?

My 65 had a small alloy spacer on the rear drums, not sure if original.
With out the spacer my wheels will rub thr radius arm.

The front track on the 7.5 set up is about an inch wider than drums/997/998 Cooper from memory. That’s why the offset on the S rims is different - the wheels place the tyres back under the arch. And I think rear track is narrower anyway.

The 'S' 7.5" disc set up does indeed widen the track at the front end over the 7" Cooper set up and also utilises different driveshafts, cv joints, drive flanges, steering arms. Also worth noting that the 'S' also used a larger master cylinder and of course a servo, I've run them in the past without the servo, but be prepared for a fairly firm shove needed on the pedal.

Onto the rear, the '65 998 Cooper essentially used the same drum brakes as the 850, with the non-spacered drum, this was tweaked in '67 I believe to a thicker faced drum to solve radius arm/inner wheel arch rub when using the Dunlop SP tyre.

When using 'S' brakes on the front I've always matched this up to 'S' drums on the rear with their built in spacer, to retain the balance with the geometry.

Rear tyre radius arm / inner arch 'rub' which can occur with modern rubber (particularly the Blockley's) I've found this can be worked around with thin spacer shims on the rear if the period correct narrow drums are wanted to be retained.

Hope this is helpful.

Thank you for all the replies guys, great info there.

I'll build the rear with narrow drums, fit the wheels and see how it looks.

If i need some thin spaces, can you recommend a set please?