917 - RSR Brake Calipers

[mrg3.6]

Does anyone know what the differences (technical or otherwise) are between:

1) pre 73 917/RSR brake caliper and....
2) post 74 917/RSR brake caliper.

I am particularly interested to know whether both calipers are the same (side to side) width

Thx

Martin

[ret9191]

The 73 callipers are probably about the same size as the 74's but they do look different. Do a search under slide valve RSR and there are pictures of both. Armando has done a great job with this site.

[mrg3.6]

here are the two calipers

Appreciate the response.

From the photographs the 74 calipers looks to be wider than the 73 calipers - any idea on the respective widths (side to side)?

Thx

Martin

[OliveR]

Some pics of 3L RSR repro calipers

[mrg3.6]

Some pics of 3L RSR repro calipers

Hi Oliver,

Same question - how wide (side to side) are these calipers and are they an accurate copy of the originals?

Thx

Martin

[Flunder]

The wide versions used on the '74 were the so-called "long range" calipers of the 917 that held a deeper pad with more friction material for endurance racing.

[mrg3.6]

The wide versions used on the '74 were the so-called "endurance" racing calipers of the 917 caliper that held a deeper pad with more friction material.

Tom,

You don't happen to know what the 'exact dimension' is for the width of a '74 caliper do you - I am really struggling to get an answer on this one?

Thx

Martin

[boba]

I think there were 3 disks that could have been used 28, 32, and 35. There were also different pad thikness sprint vs endurance. The combination if the pads and disk was refered to as the stack height. There were different bridge peices which could be used to build dif caliper height. If you have a set of 930 calipers you can look at them and see what I am refering to as the pads were the same F&R but the disks were 28R and 32F and so the bridge peices are two different heights. 4mm diff.

I know this does not give you a specific answer to your question but it will help you understand why you will see variation. I will try to get you a measure off a R 73 RSR on Monday.

Hope this helps,

Bob

[mrg3.6]

I know this does not give you a specific answer to your question but it will help you understand why you will see variation. I will try to get you a measurement off a R 73 RSR on Monday. Bob

Bob,

Thx for your feedback - very useful.

I have just measured my front 930 calipers and they are approx 6 1/4" wide whilst I 'understand' that the 73 RSR caliper are the same?

Now my problem is that I need to know the dimensional impact of the 'endurance stacks' on a '74 caliper like the one below, so I can determine whether the stack offset can be physically accomodated behind standard 9" fuchs/RSR flares mounted on 73 bilstein front struts.



Martin

[Flieger]

Does anyone have a weight difference between the early and late fin designs?

Thanks