Help with brake threads!

The metric version of car brake pipe unions is m10 x 1.00 mm, in practice the measured OD is 9.83 mm or 0.387 inch (just measured one)

The OD sounds about right - but the pitch doesn't. However m10 x 1.25 is used sometimes, and jap motorbikes tend to use unusual metric threads, so it might be that.

(there is a range of metric threads informally called Yamaha metric - m10 x

1.25 mm is in the range, as is m10 x 1.00 mmm)

Copper brake pipes are almost all still 3/16 imperial, even when the unions are metric. Cupro-nickel pipe can be better, especially for resistance to vibration - copper pipe can rapidly work harden if it being bent by vibration, and fail.

Steel pipe is available, but not used much. Braided stainless PTFE hose is the latest trick. Try fleaBay, but for hose get the connectors with the hose

- it's really hard and/or expensive to get them seperately.

Possibly a daft question, but since most karts now have a hydrauli system why not just use the piping from a kart?

The vibration on a kart is pretty severe and metal pipes don't las long. And the last thing you want to fail is a metal brake pipe goin into a corner.

The safety rules still require you to have a redundant connection fro foot pedal to master cylinder (usually a rod with a slightly slacke failsafe cable) but a single flexible braided brakehose back to the calipers.

has a pric list.

500mm of braided hose is £5.80

You fit master cylinders in the middle of the kart to protect them s you don't need enough to go from front to back

-- rss

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this thread:

Thread Dia/ Dia/ Pitch/ Pitch/ Core Core Depth/ Depth/ Name Inch mm TPI mm Dia/" Dia/mm Inch mm M10 Fine 0.3940 10.000 20.3 1.250 0.3330 8.467 0.0300 0.767

:-)

Mark Rand RTFM

Snip

This is for a home made kart and has not been designed for racing, but I do appreciate your comments. I have taken the front disk assembly from a Honda bike and modified the mountings to fit on a disk for the back axle.

It did come complete with a braided hose some several feet long which is to long for my application. I am using a cable from front to back of the kart and using it to operate the old hand level. The lever is now mounted

4 inches above the caliper and as such I only need about 8 or 9 inches of hose between the two. The whole assembly is inboard of the rear wheel on the chassis so hopefully is proteced.

I can fasten the hose for all its length every inch to stop vibration being a problem and I have the copper pipe and flaring tools hence the idea.

The problem I have is that the bike hose had banjo's at each end, and in my thoughts the joints could be unscrewed! All I did was to snap the banjo's with very little effort as they are made of aluminium.

I will seek advice from a bike shop during normal hours to see if I can get one made to the length required and that will save a lot of trouble.

The kart is simply a passtime to keep me occupied and give the kids some fun in the summer months on some local beach.

There is much to do yet, but if anyone is interested in viewing progress the you are welcome to view.

Cheers.

Adrian

Thanks Mark

M10 with a 1.25 mm pitch thread If all else fails then the I can buy a die for it, although for non standard threads it will cost a bit. I may be able to find what I want from a brake factors.

Cheers

Adrian

Snip

Thanks for the information.

Cheers

Adrian