Double disc to single conversion

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Stubaker58
Posts: 72
Joined: 28 Apr 2019 21:02
Location: Felixstowe, Suffolk

Double disc to single conversion

Post by Stubaker58 »

Hi,
I know I’ve read somewhere on here that going from two to one disc is a fairly straightforward change and doesn’t have too much impact on the effectiveness of the brakes (but can’t find the post again). As my double disc set up needs refreshing I thought this might be a cost effective way forward.
Is it just a matter of removing the near side disc and calliper and replacing the hoses? What happens about the brake light switch which is in the splitter ‘box’? Any other pitfalls to watch out for?
Thanks
Stu
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Ming
Posts: 798
Joined: 01 Aug 2014 16:32
Location: France
Location: Central France

Re: Double disc to single conversion

Post by Ming »

I find a single disc perfectly adequate, especially with a smaller diameter M/C setup. The splitter can be blanked off or replaced with a single brake line. The hydraulic switch may be moveable to the M/C if there is room. The 'problem' is that the diameter of the speedo drives for single and twin disc set ups is different, so a double speedo drive does not look so neat on a single disc.
This is a spare
Double disc.JPG
Double disc.JPG (89.25 KiB) Viewed 4783 times

Larger diameter unit for single disc - disc attachment drillings in hub masked.
Single disc.JPG
Single disc.JPG (108.94 KiB) Viewed 4783 times

Double disc bike - the speedo drive does not cover the disc attachment.
D Disc + bolts.JPG
D Disc + bolts.JPG (117.09 KiB) Viewed 4783 times
Stubaker58
Posts: 72
Joined: 28 Apr 2019 21:02
Location: Felixstowe, Suffolk

Re: Double disc to single conversion

Post by Stubaker58 »

Thanks Ming, that’s very clear.

Can anyone tell me what the single disc bikes, presumably with a single hose(?), do for a front brake light switch?

Thanks,

Stuart
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Ming
Posts: 798
Joined: 01 Aug 2014 16:32
Location: France
Location: Central France

Re: Double disc to single conversion

Post by Ming »

Mine have a small push switch operated by the lever. If you have a splitter manifold on the bottom yoke you could use the spare side of that for a pressure switch.
3potjohn
Posts: 1243
Joined: 02 Jun 2007 13:58
Location: Devon

Re: Double disc to single conversion

Post by 3potjohn »

This is what I use they seem to last about 10 years. In my case on a Y reg Sport it screws into the rear of the brake lever mount. I have to file the tip very slightly to get it to operate at my desired sensitivity, otherwise it ttriggers only after a good squeeze of the lever. We are only talking a minute amount to adjust it. Guess a thin washer could do.Bit of heat shrink or suitable grommet doesn’t go amiss. I think a K75 set up is similar.
https://www.ebay.co.uk/itm/YAMAHA-YZF-R ... SwqfpZyNGH
dunk 1
Posts: 208
Joined: 25 Oct 2007 18:16
Location: cumbria

Re: Double disc to single conversion

Post by dunk 1 »

Venhill do a banjo bolt with built in pressure switch - Duncan
dunk
Stubaker58
Posts: 72
Joined: 28 Apr 2019 21:02
Location: Felixstowe, Suffolk

Re: Double disc to single conversion

Post by Stubaker58 »

Thanks Duncan, that looks favourite. I take it it will screw into the master cylinder leaving one hose from cylinder to Cali per.
dunk 1
Posts: 208
Joined: 25 Oct 2007 18:16
Location: cumbria

Re: Double disc to single conversion

Post by dunk 1 »

Yes it goes through the brake hose into the master cylinder with the wiring coming out of the top of the bolt - if that makes sense - I have one fitted but have to admit I haven't actually connected the wiring into the system yet (after some time fitted) - that's going to be part of my winter rebuild -however I have checked the function of the switch in situ with a beep tester and it seems to work fine - thanks - Duncan
dunk
Stubaker58
Posts: 72
Joined: 28 Apr 2019 21:02
Location: Felixstowe, Suffolk

Re: Double disc to single conversion

Post by Stubaker58 »

Mine has a splitter on the bottom yoke and there’s already a pressure switch on it so if I go single disc, single hose then the new switch can go on the cylinder and be connected onto the current wiring.
Should save a fair bit of cash and have an arguably better looking (not to mention lighter) bike.
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