DCR Radial Callipers

[roger]

Hi all.

A question/information request:

I have a pair of DCR mono-block radial callipers (part of an Ohlins MotoGP front-end). The callipers:

1: Are very finely engineered (I’d say more so than the Brembo equivalents – which I also have a set of).

2. Are relatively light, which makes me wonder if the bodies are of some material other than a grade of Aluminium billet.

3: Have a gold coated surface finish (which is similar to the gold coating applied to the Mg:Al fork bottoms… a surface protective finish applied to many Magnesium Alloy aircraft components).

Does anyone know anything about said callipers?

Thanks in advance of any feedback.

Regards,

Roger.

[roger]

Hello Larry,

I should be able to 'fish-out and de-bag' the callipers over this weekend, so I'll let you know their individual weight in due course.

How do I attach an image from one of my desk-top folders to these posts?

In the mean time, the below link shows DCR's fitted to an R7, the only image of the callipers that I've ever been able to find on the internet.

[/img]http://www.r7-world.com/Immagini/Owners ... 07.JPG[img]

Regards,

Roger.[/img]

[roger]

Ok, I've just tried to open the ink given in my previous post... not working, so go to this:

http://www.r7-world.com/Pagine/Owners.htm

Look at the 3rd of the R7's listed (by John aka Factory); the last image shows DCR's.

As said, it's the only image/thing I've been able to find regarding DCR's on the internet.

Regards,

Roger.

[roger]

Weight, single DCR Radial Calliper, complete (with pads, etc., fluid filled and with fluid retention cap/seal):

984g

(via Avery Weightronix mod. FX141 scales).

Regards,

Roger.

[Busy Little Shop]

Roger... the tags for posting photos is you have it back wards
as [/img]

[roger]

Ok Larry, many appreciative thanks.

Given the info you've kindly supplied, I agree that in all probability the DCR's are a grade of billet Aluminium.

I think the (psychological) reason they seemed significantly lighter (to me), compared to the equivalent Brembo's, may be because of how 'unfussy' the DCR's appear.

One thing's for sure, they're a real rarity... but why?... they're very finely engineered. Not sure if the pistions are Ti - but given the calliper weight I think they must be; furthermore the pads are sintered and in pairs per side so I believe they're probably orientated towards race rather than road use.

The rarity is a mystery! Could it be that they weren't much good (hope not, obviously), or they were significanly more expensive than Brembo equivalents, or just the market capture inertia enjoyed by Brembo.

I 'hate apparent mysteries', being of the school of belief that there's an answer to everything... thus an insomniac by default!

As originally requested, any (other) information appreciated and gratefully received.

Renewed thanks to Larry, and regards to all,

Roger.

[Busy Little Shop]

Ok Larry, many appreciative thanks.
Roger.

You're welcome Roger... its safe to say that any billet *radial* caliper will out
perform the stock cast *blade* Nissin... what I noticed after making the
switch was more stopping power and more feel...

DCR's pistons could be aluminum or titanium or even stainless steel... there
is no way to tell unless you pop one out and scrutinized it..

[roger]

Thanks Larry.

If the piston material wasn't observably obvious, I could perform a density (mass vs fluid displacement) test; but I'm not proposing to until/unless piston removal is necessitated for maintenance.

Hopefully (and in the fullness of time) I'll be able to add to your info/feedback - and any such might also confirm the piston material.

Thanks again,

Roger.