Topic: Front brake line Single or double flare? degree? Anyone know?

[J.Webster Designs]

Hey guys,

Just wondering if anyone knows the specifics of the front steel brake line going into the front caliper. I do not have an original line that I can take a look at.

Need to know if the original front steel line is a single or double flare and what degree the flare is.

Any help would be appreciated!

Cheers!

Justin

[slikwilli420]

I've done some investigating on different flares and applications. I seem to recall a double flare for our lines, since they were 45 degree flares. The double flare is used when there is no backing piece (like a tube sleeve) for added strength. Now that so much is -AN flares, which are 37 degrees, we need to be careful not to mix and match without the right adapter. Because the 37 degree -AN flare uses a tube sleeve under the nut, there is no need for a double flare.

[J.Webster Designs]

So original CB750 front hard lines were 45 degree double flare? Anyone else confirm this?

[mystic_1]

"Japanese Inverted Flare" is what Russell calls it.

Their item 641471 is an adapter from this to AN-3:


At one point, I made up a custom hard line by using SAE tubing, transferring the fittings from an old stock hardline, and flaring it with a standard flaring tool (45 degrees?).  It sealed up fine and I ran that line for many years.

So, somewhere pretty close to 45 degrees 

mystic_1

[J.Webster Designs]

Thanks Slik and Mystic for the info!

[GritCity750]

Thanks Slik and Mystic for the info!

I double flared (45 degree) my stainless hardlines and they turned out dead-on to the original ones