FRONT BRAKE Update

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Ming
Posts: 647
Joined: 01 Aug 2014 16:32
Location: France
Location: Central France

Re: FRONT BRAKE Update

Post by Ming »

I think a Kanguro M/C has the smaller piston, certainly works well on my single disc, non-original (but still cherished) Strada. I seem to recall a discussion where a conclusion was that a 19 mm M/C was more suited to a twin disc set up than single disc. As for spares for Chinese copies, Ariete would most likely fit, though a complete new unit would probably be cheaper, too. :wink: :wink:
Seagreen
Posts: 75
Joined: 18 Jan 2018 21:18
Location: Cheltenham UK
Location: Cheltenham, Glos

Re: FRONT BRAKE Update

Post by Seagreen »

After reading a thread in the Tre e mezzo section of this forum I thought that I would see if fitting the Honda CBF125 master cylinder would improve the feel of the front brake on my 500 (currently very wooden). I ended up buying two from breakers because I thought that the first was possibly leaking within the piston/cylinder bore but the second was the same. At the same time I bought a mastercylinder seal kit. I have concluded though that the problem with the use of these 12.7mm diameter piston mastercylinders is that there is not sufficient stroke to move the two calipers without the handlebar lever coming almost to the bar. That said, action was certainly very light with lots of feel and I am sure that this mastercylinder would be an excellent alternative to the standard offering, on a single disc set up.

Therefore I have the following for sale:
2 off Nissin mastercylinders both in good condition), only one has the lever (gravel rash on the end ball) + mastercylinder seal kit (brand new)
All these could be yours for £40 + p&p ono.
See For Sale section of this forum.

Thanks,
Charles
Kamel
Posts: 124
Joined: 10 Feb 2020 22:31
Location: Zurich, Switzerland

Re: FRONT BRAKE Update

Post by Kamel »

This site has been very handy to me over the years. You can find the ideal master cylinder bore size to suit the calipers you are using.

https://web.archive.org/web/20070922085 ... linder.htm

I believe he is retiring, so it may be worth taking a screenshot of the chart if it's of any value to you.

Cheers,

Kamel.
Seagreen
Posts: 75
Joined: 18 Jan 2018 21:18
Location: Cheltenham UK
Location: Cheltenham, Glos

Re: FRONT BRAKE Update

Post by Seagreen »

Hi Kamel,

Thanks for the link but I am not sure that I agree with his recommendations about the optimal ratio but I will give it closer scrutiny to make sure i am misinterpreting the chart.
I have a twin disc set up and a 16mm m/cyl piston with calipers fitted with 38mm pistons (I think) so according to the chart that gives me a ratio of 11.28 which is a long way off the recommended ratio of 27.1, Even with the 1/2" mastercylinder from the Honda CBF125 that would only result in a ratio of 17.91 still on the commentators idea of wooden, it was in fact far from wooden in feel - felt good but I was concerned about the amount of movement of the lever, almost back to the handle bar.
Personally I would like to find a m/cylinder of c.14mm but they seem far and few between - I think Brembo used to make one (could have been 15?) but no longer but will keep looking.

Perhaps I have totally misunderstood the www.vintagebrake article?

Adios,
Charles
AntietamClassicCycle
Posts: 151
Joined: 15 Oct 2012 15:03
Location: Rohrersville, MD, US
Location: Rohrersville, MD, USA
Contact:

Re: FRONT BRAKE Update

Post by AntietamClassicCycle »

Seagreen wrote: 12 Apr 2021 19:59 I have a twin disc set up and a 16mm m/cyl piston with calipers fitted with 38mm pistons (I think) so according to the chart that gives me a ratio of 11.28 which is a long way off the recommended ratio of 27.1
With twin disks (and calipers) you have four pistons of 38 mm diameter, so with a 16 mm master cylinder, you have a 22.56:1 ratio according to the chart.
Seagreen
Posts: 75
Joined: 18 Jan 2018 21:18
Location: Cheltenham UK
Location: Cheltenham, Glos

Re: FRONT BRAKE Update

Post by Seagreen »

AntietamClassicCycle wrote: 13 Apr 2021 14:00
Seagreen wrote: 12 Apr 2021 19:59 I have a twin disc set up and a 16mm m/cyl piston with calipers fitted with 38mm pistons (I think) so according to the chart that gives me a ratio of 11.28 which is a long way off the recommended ratio of 27.1
With twin disks (and calipers) you have four pistons of 38 mm diameter, so with a 16 mm master cylinder, you have a 22.56:1 ratio according to the chart.
Hi Antietem, thanks for helping me out on that piston number - I should have noticed that ( ) = Number of ACTIVE pistons !!! Makes much more sense now so all I need to do is find a mastercylinder of 14-15mm diameter piston size - anyone know of one? This is a classic example of how good forums can be. Thnaks again,
Adios,
Charles
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