Improving stock RZ350 brakes

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concours
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Location: Kensington, New Hampshire, USA

Re: Improving stock RZ350 brakes

#16 Post by concours » Tue Oct 08, 2013 9:07 am

I've been a big fan of EBC "HH" pads for street use, I see the FA81 shape pad needed for the front of my RZ350L is not available in the "HH" spec, but is made in the "R" spec, defined as sintered, but off-road specific.. any experiences?

Also, what are the OEM Yam pads supplied? Organic? Sintered?
WFO for 45 years
1984 RZ350
1973 Yamaha TX750
1975 Yamaha DT400
1974 Norton Commando 850
Triumph Tiger 1050
Triumph Rocket III

J.A.W.

Re: Improving stock RZ350 brakes

#17 Post by J.A.W. » Tue Oct 08, 2013 7:33 pm

OEM=Expensive..
Race-type metallic pads perform well, but wear down [pad & rotor] fast..

J.A.W.

Re: Improving stock RZ350 brakes

#18 Post by J.A.W. » Sun Oct 20, 2013 1:42 am

Concours, I 've found these products to be good value..

[ I don't run the single piston calipers though, I find them too 'wooden' feeling].

http://metalgear.com.au/view_model_deta ... l_id=10318" onclick="window.open(this.href);return false;

bryanaverill
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Re: Improving stock RZ350 brakes

#19 Post by bryanaverill » Mon Dec 16, 2013 9:26 pm

Well, I completely rebuilt the system including a meticulous rebuild of the master cylinder and calipers. I used braided stainless lines. The result was indistinguishable from the original system which was in fairly good shape. I still need to make 100% sure the system is properly bled but I have good technique and it's probably correct.

My opinion is that the calipers are very flxible compared to modern units. I can clearly see that a larger bore master cylinder would reduce lever motion but also increase the required lever force (such is the compromise). The result would be different but still bad, in my opinion. I'm not really into changing the brake light switch or mirror either. I could consider better calipers but that's not really the point of my bike. Too much cost for an old smoker.

I think I can still get an improvement with more agressive pads. Are race pads available? What mfg/part numbers?

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JonW
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Re: Improving stock RZ350 brakes

#20 Post by JonW » Mon Dec 16, 2013 9:50 pm

Bryan, have a look at Aarons bike, he fitted a new master which wasnt expensive and it works very very well now.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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pepsi
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Re: Improving stock RZ350 brakes

#21 Post by pepsi » Tue Dec 17, 2013 10:56 am

bryanaverill wrote:Well, I completely rebuilt the system including a meticulous rebuild of the master cylinder and calipers. I used braided stainless lines. The result was indistinguishable from the original system which was in fairly good shape. I still need to make 100% sure the system is properly bled but I have good technique and it's probably correct.

My opinion is that the calipers are very flxible compared to modern units. I can clearly see that a larger bore master cylinder would reduce lever motion but also increase the required lever force (such is the compromise). The result would be different but still bad, in my opinion. I'm not really into changing the brake light switch or mirror either. I could consider better calipers but that's not really the point of my bike. Too much cost for an old smoker.

I think I can still get an improvement with more agressive pads. Are race pads available? What mfg/part numbers?
I'm believe that I have arrived at almost the same weak caliper conclusion. I did get somewhat better results but at the cost of a spongy feel.You have the outcome a little backwards, the lever will move more with less effort.
KR Y&B stocker with cats

bryanaverill
Posts: 42
Joined: Mon May 13, 2013 3:20 pm

Re: Improving stock RZ350 brakes

#22 Post by bryanaverill » Tue Dec 17, 2013 5:29 pm

pepsi, you are right. I was thinking the stock master cylinder is 3/8" but it is actually 5/8". That means a 1/2" MC would have more lever motion than stock. This would be very very bad in my opinion. I want less lever motion AND less effort. Seems like the only way is better calipers. Maybe something from a newer FZR or FZS?

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JonW
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Re: Improving stock RZ350 brakes

#23 Post by JonW » Tue Dec 17, 2013 6:34 pm

bryanaverill wrote:That means a 1/2" MC would have more lever motion than stock.
Im not convinced about that, check out the hints and tips section and read the links I put about MCs as you maybe be onto a winner with a 1/2.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

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pepsi
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Re: Improving stock RZ350 brakes

#24 Post by pepsi » Tue Dec 17, 2013 7:17 pm

JonW wrote:
bryanaverill wrote:That means a 1/2" MC would have more lever motion than stock.
Im not convinced about that, check out the hints and tips section and read the links I put about MCs as you maybe be onto a winner with a 1/2.
I think it pretty much has to with the laws of physics and everything :smt037
KR Y&B stocker with cats

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JonW
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Re: Improving stock RZ350 brakes

#25 Post by JonW » Tue Dec 17, 2013 7:30 pm

Perhaps, but have you read the links? There is to be a lot more to the MC to piston relationship than you might think. If you want good brakes you shouldn't just substitute parts and hope for the best, do the research I say. Ive learnt a lot from my initial stabs at swapping parts, but doing the maths would have saved time and hassle.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

RuZty
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Re: Improving stock RZ350 brakes

#26 Post by RuZty » Wed Dec 18, 2013 7:47 am

There are 2 factors here, the hydraulic advantage of the cylinder and the leverage your hand has on it. A bigger cylinder will move more fluid with less travel, so quicker response maybe at the expense of feedback. The lever might have a different ratio to offset the effect of diameter if you are swapping the whole unit from another bike.

MaxHitZ
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Re: Improving stock RZ350 brakes

#27 Post by MaxHitZ » Wed Aug 06, 2014 12:23 pm

:smt006 Another dilemma over here, restoring an RZ250. With respect to the MC, the looking glass is broke, and needs a rebuild kit thrown at it. As i saw this add, made me think what other options i have.

90's model cbr's the go?, without the provision for the rear vision mirror but..

Any help be awesome thanks
'83 RZ250K (resto. project)
'92 NSR250MC21
'2000 KTM300EXC
'09 CBR600RR
'92 VFR400NC30

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aaronmvrider
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Re: Improving stock RZ350 brakes

#28 Post by aaronmvrider » Fri Aug 08, 2014 7:20 pm

purchase a sight glass kit... under $10
1 x 4mm stroker rz 375cc 1983
1 x 7mm stroker rz 443cc 1984 (under construction)
1 x rz 500
1 x mv agusta 1000

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aaronmvrider
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Re: Improving stock RZ350 brakes

#29 Post by aaronmvrider » Fri Aug 08, 2014 7:28 pm

prices have gone up...
i have this kit installed.. its an easy fit and mine hasnt had any leak issues

http://www.ebay.com.au/itm/83-84-rz350- ... a41&_uhb=1" onclick="window.open(this.href);return false;
1 x 4mm stroker rz 375cc 1983
1 x 7mm stroker rz 443cc 1984 (under construction)
1 x rz 500
1 x mv agusta 1000

MaxHitZ
Posts: 21
Joined: Mon Aug 04, 2014 12:47 pm
Location: Adelaide, Australia

Re: Improving stock RZ350 brakes

#30 Post by MaxHitZ » Sat Aug 09, 2014 8:24 am

Haha thanks guys, unfortunately the sight glass was the least of my concerns, my main interest is replacing the MC all-together.
'83 RZ250K (resto. project)
'92 NSR250MC21
'2000 KTM300EXC
'09 CBR600RR
'92 VFR400NC30

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