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Brake Link Front/Rear

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Brian UK View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 27 Jun 2018 at 08:57
If the brakes have been delinked, the front master cylinder is operating both disc callipers, so it needs to be a larger diameter than standard not smaller.
Check what you actually have before looking for change.
Brian.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote StevieG Quote  Post ReplyReply Direct Link To This Post Posted: 27 Jun 2018 at 13:49
Just remember depending on what model you have, the front brake lever usually activates the cylinder via a cable. I don’t think it’s a good idea to rely on a cable to do all your front braking. Having one front disc connected to the rear is also a  fail safe feature.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote iansoady Quote  Post ReplyReply Direct Link To This Post Posted: 27 Jun 2018 at 17:19
No sooner the word....


TBH it's still a bit wooden and the reach is too much so I may remove a bit from the end of the lever that contacts the piston.

If yours has been delinked and the front master cylinder is working both front discs I wouldn't have thought you'd need to reduce the master cylinder size - if anything it should be increased - as you're effectively doubling the leverage.

<edit> sorry Brian posted before I saw your similar reply. </edit>
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rumpith Quote  Post ReplyReply Direct Link To This Post Posted: 27 Jun 2018 at 17:30
Thanks for that, Big smileThumbs Up 

It would seem I'm looking for a 15mm piston. All the Japanese ones seem to be 14mm or 15.8mm.

When I get in tonight I'm going to check whats on the bike as its none standard. Based on what I've been reading today and the advice being given I now think the one on the bike is too small, as there is a lot of travel when nothing happens and then it comes on quite strong.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GC888 Quote  Post ReplyReply Direct Link To This Post Posted: 01 Jul 2018 at 18:55
Originally posted by Rumpith Rumpith wrote:

Thanks for that, Big smileThumbs Up 

It would seem I'm looking for a 15mm piston. All the Japanese ones seem to be 14mm or 15.8mm.

When I get in tonight I'm going to check whats on the bike as its none standard. Based on what I've been reading today and the advice being given I now think the one on the bike is too small, as there is a lot of travel when nothing happens and then it comes on quite strong.

If its strong at the end then it doesn't sound like a master cylinder problem, as that would be good or bad throughout the range? 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rumpith Quote  Post ReplyReply Direct Link To This Post Posted: 01 Jul 2018 at 20:38
The bike is new to me and needs a bit of work doing to it before i can get it on the road. I'm not in a position to ride it again until this work is done so I will have to leave as is for now. The front brake is a Nissin 5/8 which equates to 15.8mm so may actually be fine, it just didn't feel too great when riding it though it did pull the bike up well if given a hard tug.

I'll let you know how i get on once I've done a bit of work to the bike and get it out on the road. First thing is to replace the 28 year old back tyre and the 18 year old front.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GC888 Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 2018 at 08:11
Originally posted by Rumpith Rumpith wrote:

The bike is new to me and needs a bit of work doing to it before i can get it on the road. I'm not in a position to ride it again until this work is done so I will have to leave as is for now. The front brake is a Nissin 5/8 which equates to 15.8mm so may actually be fine, it just didn't feel too great when riding it though it did pull the bike up well if given a hard tug.

I'll let you know how i get on once I've done a bit of work to the bike and get it out on the road. First thing is to replace the 28 year old back tyre and the 18 year old front.

I had a play on a new Kawasaki a couple of weeks ago the front brake was so 'grabby' until I got used to it, still not sure I liked it over a more progressive action. But was a lot better than the drum on my Montessa that will only stop when you feel like your bending the lever !!    
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ianboydsnr Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 2018 at 09:22
I just don’t see that, I regularly ride both my convert and fazer 1000, and switch between the different brakes easily, the convert has no engine braking so the brakes are harder used.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 03 Jul 2018 at 14:45
Both my V50s had linked brakes with both being very good to use, but on both bikes the front brake could best be described as `wooden`/ `crap`, with so much effort needed on such a wide reach on the lever. There is no comparison between the Guzzis and my Fazer with the latter having great `feel` and tremendous stopping power, but I suppose that`s down to advances in technology.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rapheal Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jul 2018 at 16:05
A friends BMW has linked braking, and I gather some Hondas do as well
must be a reason its come back ?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jul 2018 at 19:00
Both my X10 scooters had linked, where the left lever for rear brake did the front too, *IF* you press harder, so if for any reason you wanted rear only and if you then press harder (for more braking effort) the front would grab as well. Got to be quite a PITA TBH.



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Post Options Post Options   Thanks (0) Thanks(0)   Quote telegraphroad Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jul 2018 at 20:01
A PO delinked the brakes on my Monza and did a very professional job. I know it's a personal preference but I appreciate the increased flexibility to operate front and rear independently. The bike responds really well to a little rear trail braking into corners and the front action is  ery progressive and powerful. OTOH my Honda VFR has linked brakes but they are somewhat more sophisticated in that the rear braking force is directly proportional to front wheel braking effort (road friction effect) rather than lever force, and the rear brake pedal has an in built delay before the front is actuated. This lets you trail brake on the rear only with light pedal pressure but also to use the pedal alone in traffic. Hard braking on the front lever brings the rear almost to the point of slipping so hard stops are front lever only.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jul 2018 at 21:25
Strangely enough, my 1990 Spada III had all that too.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rumpith Quote  Post ReplyReply Direct Link To This Post Posted: 08 Jul 2018 at 05:16
What master cylinder did he use on the front to get such good results?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rumpith Quote  Post ReplyReply Direct Link To This Post Posted: 23 Sep 2018 at 09:27
Right a bit of an update.

I swapped the front master cylinder for another Nissin one but this was off a GSX600 and only had a 14mm piston as opposed to the 5/8" (15.9mm) that was on the bike when I got it.  This is much better with a bit more travel and power. Its not as good as it could be though and still needs a bit of a tug on the lever to get the bike stopping as good as I think it can. I think a 13mm piston would be better still. 

Remembering how good the brakes were on my wifes original V50 of 1980 I would say the best thing to do if you are thinking of delinking the brakes, is leave them alone. However, if you feel you have to delink them I would try a 13 or 14mm piston master cylinder. Any bigger is too big in my experience, giving a very dead feeling lever with little travel, which needs a very strong pull to get the brakes working well.
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