£1500 (£1700 and knock down maybe) budget... What you got ?

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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by mangocrazy »

A mate of mine had an FJ12 - he loved it. I think most 80s bikes had sub-par brakes (certainly by today's standards) as most were using sliding-caliper designs to avoid paying the patent fee for opposed-piston designs. Brembo used opposed-piston designs, but not many others did. Was that also around the time when asbestos could no longer be used in brake pads?
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Le_Fromage_Grande »

80s GSXRs and RGs had good brakes, even my 1979 GSX750 had pretty good brakes, Suzuki seemed to be the only Japanese manufacturer who could work out the right master cylinder / caliper combination, it took Yamaha until the Thundercat and Thunderace to get it right, I don't know when Honda and Kawasaki worked it out.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Bustaspoke »

Le_Fromage_Grande wrote: Sun Mar 12, 2023 10:46 am 80s GSXRs and RGs had good brakes, even my 1979 GSX750 had pretty good brakes, Suzuki seemed to be the only Japanese manufacturer who could work out the right master cylinder / caliper combination, it took Yamaha until the Thundercat and Thunderace to get it right, I don't know when Honda and Kawasaki worked it out.
My 2008 SV650 has crap sliding caliper front brakes,it was a bit of an eye opener when I got the bike home & had a good look at things,I thought they stopped fitting them sometime in the eighties :shock:
I'm sure mid 70's Yamaha TZ's & some RD's had opposed piston calipers At the time they were the best brakes around.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Gregor »

mangocrazy wrote: Sun Mar 12, 2023 10:41 am A mate of mine had an FJ12 - he loved it. I think most 80s bikes had sub-par brakes (certainly by today's standards) as most were using sliding-caliper designs to avoid paying the patent fee for opposed-piston designs. Brembo used opposed-piston designs, but not many others did. Was that also around the time when asbestos could no longer be used in brake pads?
Yep great bikes, should have kept it and upgraded to blue spots but it needed a new rear shock and carb diaphragms which were pricey and 2 up the centre stand would scrape the deck.

My K100 weighs about the same and has brembos which are way better, shame it doesn’t have the acceleration of the FJ.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by mangocrazy »

Bustaspoke wrote: Sun Mar 12, 2023 10:59 am I'm sure mid 70's Yamaha TZ's & some RD's had opposed piston calipers At the time they were the best brakes around.
I think TZs had opposed piston designs, but the first LCs (1980-1982) had sliding calipers. I seem to recall that YPVS models (1983 on) had opposed piston calipers, but I could well be wrong.

Interestingly (if you're a brake nerd) in a Wiki article it stated that radial calipers are no better than axial calipers and it's all just fashion. Beware trusting what you read in Wikipedia...

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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Bustaspoke »

mangocrazy wrote: Sun Mar 12, 2023 12:28 pm
Bustaspoke wrote: Sun Mar 12, 2023 10:59 am I'm sure mid 70's Yamaha TZ's & some RD's had opposed piston calipers At the time they were the best brakes around.
I think TZs had opposed piston designs, but the first LCs (1980-1982) had sliding calipers. I seem to recall that YPVS models (1983 on) had opposed piston calipers, but I could well be wrong.
I'm talking mid 70's aircooled RD's,maybe 1976.I was still at school but I can remember reading about them a few years later.I think the article said something about Yamaha going back to sliding calipers so as to avoid paying a fee to the patent owners every time they fitted them to a motorcycle.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by mangocrazy »

Bustaspoke wrote: Sun Mar 12, 2023 12:37 pm
mangocrazy wrote: Sun Mar 12, 2023 12:28 pm
Bustaspoke wrote: Sun Mar 12, 2023 10:59 am I'm sure mid 70's Yamaha TZ's & some RD's had opposed piston calipers At the time they were the best brakes around.
I think TZs had opposed piston designs, but the first LCs (1980-1982) had sliding calipers. I seem to recall that YPVS models (1983 on) had opposed piston calipers, but I could well be wrong.
I'm talking mid 70's aircooled RD's,maybe 1976.I was still at school but I can remember reading about them a few years later.I think the article said something about Yamaha going back to sliding calipers so as to avoid paying a fee to the patent owners every time they fitted them to a motorcycle.
Yup, that's it. Not sure if/when the patent expired, but it would have been a nice little earner. Blindingly obvious from today's point of view. Yamaha also had to pay Rotax a patent fee for their use of exhaust power valves in the YPVS models. I think Rotax still hold the patent for that. Doubtless why Suzuki went with an (arguably inferior) guillotine type power valve on their 2Ts...
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by ZRX61 »

MTFU & get an big old brutal hairy arsed Kaw.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Skub »

ZRX61 wrote: Sun Mar 12, 2023 5:06 pm MTFU & get an big old brutal hairy arsed Kaw.
Not many of those in that price range now,unless you include the ZZR11.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Le_Fromage_Grande »

A quick history as I know it of Yamaha brakes

First RDs had opposed piston calipers, these were good
RD 250 / 400E got sliding calipers, not good
LCs got sliding calipers, 250 had single disc, 350 twin disc, 350 has 5/8 master cylinder, 250 has 1/2 master cyinder, 350 brakes work better with 250 master cylinder.
The first YPVS has sliding calipers, 85 onwards had opposed calipers, which are better than the sliding calipers but not much, an 83 RG250 has much better brakes.
RD500 and 85-88 FZ 750s have the same calipers as 85 onwards YPVS, they're shit for a heavy, fast bike.
87 the FZRs come out and get 4 piston calipers, still with a 5/8 master cylinder, they work much better with a 14mm.
93 YZF750 gets 6 piston calipers, which are not great, due to a 5/8 master cylinder
96 Yamaha fit blue spot calipers and a 14mm master cylinder, finally a Yamaha has brakes to match it's performance.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by KungFooBob »

My race aircooled RD250 (1976) had a horrible pivoting thing that had pads with angled friction material, thin on one edge and thick on the other.

EDIT: like this...

https://www.ebay.co.uk/itm/195508957969 ... VCEALw_wcB

Image

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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Le_Fromage_Grande »

mangocrazy wrote: Sun Mar 12, 2023 12:47 pm
Bustaspoke wrote: Sun Mar 12, 2023 12:37 pm
mangocrazy wrote: Sun Mar 12, 2023 12:28 pm

I think TZs had opposed piston designs, but the first LCs (1980-1982) had sliding calipers. I seem to recall that YPVS models (1983 on) had opposed piston calipers, but I could well be wrong.
I'm talking mid 70's aircooled RD's,maybe 1976.I was still at school but I can remember reading about them a few years later.I think the article said something about Yamaha going back to sliding calipers so as to avoid paying a fee to the patent owners every time they fitted them to a motorcycle.
Yup, that's it. Not sure if/when the patent expired, but it would have been a nice little earner. Blindingly obvious from today's point of view. Yamaha also had to pay Rotax a patent fee for their use of exhaust power valves in the YPVS models. I think Rotax still hold the patent for that. Doubtless why Suzuki went with an (arguably inferior) guillotine type power valve on their 2Ts...
I don't think it's Rotax, my mate had an 84ish Rotax 250 engined Armstrong that didn't have power valves, I think the rotary power valve is a Yamaha invention, Suzuki and Honda initially had a valve that opened and closed a chamber to increase exhaust volume, Suzuki went to the 3 piece guillotine design and Honda stopped making road going two strokes.

Rotax used to make a 250 engine with an adjustable power valve that Yamaha copied, but that was about 25 years ago, basically the power valve had a damper that you could stiffen to make the valve open slower, making the bike easier to ride.

Now nearly every one uses a multi valve design that I first saw on Kawasakis - KIPS.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Le_Fromage_Grande »

Just to give some balance, the SRAD 750 proves that Suzuki are perfectly capable of fitting poor brakes to a bike in the name of fashion, the following 2000 - 2003 GSXR750s weren't great either.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by weeksy »

Le_Fromage_Grande wrote: Sun Mar 12, 2023 6:13 pm Just to give some balance, the SRAD 750 proves that Suzuki are perfectly capable of fitting poor brakes to a bike in the name of fashion, the following 2000 - 2003 GSXR750s weren't great either.
Couldn't disagree more. They were plenty fine for me into Mallory hairpin setting a respectable race lap time. Completely stock brakes as good as the Brembo P4s off 748R

ImageDSC_3520 by Steve Weeks, on Flickr
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by mangocrazy »

Le_Fromage_Grande wrote: Sun Mar 12, 2023 6:08 pm I don't think it's Rotax, my mate had an 84ish Rotax 250 engined Armstrong that didn't have power valves, I think the rotary power valve is a Yamaha invention, Suzuki and Honda initially had a valve that opened and closed a chamber to increase exhaust volume, Suzuki went to the 3 piece guillotine design and Honda stopped making road going two strokes.

Rotax used to make a 250 engine with an adjustable power valve that Yamaha copied, but that was about 25 years ago, basically the power valve had a damper that you could stiffen to make the valve open slower, making the bike easier to ride.

Now nearly every one uses a multi valve design that I first saw on Kawasakis - KIPS.
I'm basing my comments on conversations I had with Derek Chittenden about 25-30 years ago and unfortunately he's no longer around so I can't check with him. I've googled 'yamaha ypvs power valve patent' and whenever I do that it suggests 'yamaha ypvs rotax power valve patent', but I can't find any definitive statement as to who held the patent for the YPVS system. I'll keep searching...
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Le_Fromage_Grande »

weeksy wrote: Sun Mar 12, 2023 6:23 pm
Le_Fromage_Grande wrote: Sun Mar 12, 2023 6:13 pm Just to give some balance, the SRAD 750 proves that Suzuki are perfectly capable of fitting poor brakes to a bike in the name of fashion, the following 2000 - 2003 GSXR750s weren't great either.
Couldn't disagree more. They were plenty fine for me into Mallory hairpin setting a respectable race lap time. Completely stock brakes as good as the Brembo P4s off 748R

ImageDSC_3520 by Steve Weeks, on Flickr
I didn't like them on my 2002 one, it had done 2500ish miles when I bought it in 2003 so I assume it had the standard pads, I thought it lacked feel, and the brakes on the 98 R1 I had were better.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Mr. Dazzle »

mangocrazy wrote: Sun Mar 12, 2023 7:39 pm

I'm basing my comments on conversations I had with Derek Chittenden about 25-30 years ago and unfortunately he's no longer around so I can't check with him. I've googled 'yamaha ypvs power valve patent' and whenever I do that it suggests 'yamaha ypvs rotax power valve patent', but I can't find any definitive statement as to who held the patent for the YPVS system. I'll keep searching...
Patents are funny old beasts to be fair, I wouldn't imagine you'll ever find a patent for YPVS. You might find a patent for an incredibly specific abstract idea which if you squint at you can recognise as YPVS. But you gotta speak patentese first and have nothing better to do with your evenings ;)

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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by weeksy »

Aye, R1 calipers were always very highly regarded I agree.

But I didn't notice any issues
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by KungFooBob »

IIRC the original Bluespots from the Cat/Ace and developed on to the R1/6 where good because they were made from a single casting, not two halves bolted together, so they didn't 'flex'.

The blue spots unscrewed to get the pistons in/out.
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Re: £1500 (£1700 and knock down maybe) budget... What you got ?

Post by Mr. Dazzle »

KungFooBob wrote: Sun Mar 12, 2023 8:47 pm The blue spots unscrewed to get the pistons in/out.
You know....I've always assumed that to be the case, ever since forever, but I've never checked :D. That's why they have the flower shaped torxy drivey bit?