Which Banjo bolts for the brakes?

[Walterg]

Hi everyone,

I'm meaning to replace the banjo bolt that's screwed in my front brake cylinder but before I take it out I
need to know the threadsize. Does anyone know this? I know it's an M10 diameter bolt but I have to choose between
the 1.0 and 1.25 thread.

Thanks,
Walter

[docc]

It is 1.00mm pitch.

[gstallons]

Uhhhh , what is the reason for replacing the bolt ?

[p6x]

4 hours ago, Walterg said:

Hi everyone,

I'm meaning to replace the banjo bolt that's screwed in my front brake cylinder but before I take it out I
need to know the threadsize. Does anyone know this? I know it's an M10 diameter bolt but I have to choose between
the 1.0 and 1.25 thread.

Thanks,
Walter

You know that you can use a ruler to measure the distance between the top of two threads? 1 mm should be quite easy. The screw threads into a softer material, so it makes perfect sense to have a fine pitch.

 

[Speedfrog]

5 hours ago, Walterg said:

I'm meaning to replace the banjo bolt that's screwed in my front brake cylinder but before I take it out I need to know the threadsize.

 

1 hour ago, p6x said:

You know that you can use a ruler to measure the distance between the top of two threads? 1 mm should be quite easy. The screw threads into a softer material, so it makes perfect sense to have a fine pitch.

That would be very, very difficult, I'd venture to say quite an impossible task I recon  

[pete roper]

While the answer has been given thread gauges are very cheap and easy to acquire and always useful to have in the toolbox.

 

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p4432023.m570.l1311&_nkw=metric+thread+pitch+gauge&_sacat=0

[docc]

FWIW, I used the master cylinder I took off mySport a few years back and a thread gauge to find the 1.00mm pitch.

Having used "rulers" in the past to measure fasteners, and threaded holes, I must admit to being decidedly bad at it.

[audiomick]

23 hours ago, pete roper said:

...thread gauges are very cheap and easy to acquire...

Or buy a decent tap and die set. Everyone should have one of those, I reckon, and there is generally a set of thread gauges included.

[gstallons]

Bad...... I wouldn't even try. I have metric and standard thread gauges. Thread files and all kinds of other trinkets to help me . When you get older you become MORE unsure of yourself daily.

[Lucky Phil]

6 hours ago, gstallons said:

Bad...... I wouldn't even try. I have metric and standard thread gauges. Thread files and all kinds of other trinkets to help me . When you get older you become MORE unsure of yourself daily.

This is called the Dunning Kruger affect. 

[po18guy]

I just buy banjo bolts from RaceTi or RaceBoltUK. SS, Ti or even aluminium for lower stress applications. RaceBolt, in particular, delivered my order from the UK to the west coast USA in 7 calendar days from my mouse click. Incredible.

On 9/12/2024 at 3:36 PM, Speedfrog said:

 

That would be very, very difficult, I'd venture to say quite an impossible task I recon  

 

[p6x]

On 9/12/2024 at 5:36 PM, Speedfrog said:

That would be very, very difficult, I'd venture to say quite an impossible task I recon  

I do it all the time... the "pas" or "pitch" in English for a Metric thread is measured between two pitch either dip or tops.

As it is clearly said, a screw is characterized by its external diameter and its pitch.

M10 has either 1mm or 1.25mm. Using a graduated ruler on the screw that goes inside the banjo, you can determine the pitch.

Now explain to me what would be very difficult, so I can laugh too...

 

[audiomick]

Difficult in the sense of "measure" and "before I take it out"...

[Speedfrog]

18 hours ago, p6x said:

Now explain to me what would be very difficult, so I can laugh too...

The OP was seeking info on the correct size/pitch presumably to have the proper bolt on hand before dismantling his brakes . . . 

Nobody is denying the science of metric pitch measurement, but as we get in these very small dimensions and our eyesight is not what it used to be, you'd have a better chance finding the correct pitch with a pitch gauge than a ruler. A measurement with a 0.25 mm difference is pretty hard to discern with a naked eye. 

 

[Walterg]

Since I installed risers I need to extend or replace the front brakelines. One of the ideas was to attach two parallel lines on one double length bolt to the cylinder instead of the H- or T- setup.