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R69s Tire Pressure

germancarguy
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R69s Tire Pressure

Post by germancarguy »

I have installed a set of Avon Roadrider MKII 100/90 X 18 (front) and Avon Roadrider MKII 110/90 X 18 (Rear) on my 1965 R69s. Does anyone have some insight into what the tire pressure should be.

Thanks
Paul
1962 R69s
2013 R1200GS

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schrader7032
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Re: R69s Tire Pressure

Post by schrader7032 »

I don't know about should be! But I run 32/36 F/R on my R69S.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

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jwonder
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Re: R69s Tire Pressure

Post by jwonder »

I run 32/34 (front/rear) on my R 69 S and all my vintage BMW motorcycles.
James Wonder
Vice President, Vintage BMW Motorcycle Owners
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Long Island, New York

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Micha
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Re: R69s Tire Pressure

Post by Micha »

How about an R51/3 ?
I go with 21/25, but maybe I should inflate more?
Michael Steinmann
R51/3 1952
Engine Nr. 529466

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Re: R69s Tire Pressure

Post by 808Airhead »

On my R69S & R60/2 I am running 25 front,28 rear, I am 230 lbs. It works for me as a solo rider. I have ridden with 28 front,32 rear before, just for fun I tried the owners manual recommended pressures and I liked it, the lower pressure seems more compliant, especially with the vintage-era suspension design. To each his own.
On my 2 plunger bikes, I was running similar higher than the factory pressures,25 front,30 rear. The bikes seemed very bouncy and when I changed them down to the factory recommended 22-25 psi the bikes were transformed, they rode so much better, smoother. I was shocked considering my size/weight but I understand why they wanted the low pressures,the suspension was very simple on those era bikes.
Thomas M.
R69S - R60/2 - R67/2 - R51/3 - R69

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Re: R69s Tire Pressure

Post by Tinkertimejeff »

32 PSI front and rear. You just have to keep it simple and safe. To low the tires can roll or shift on the rim and cause a sudden deflation. To high 40 psi or above will lead to a premature chicken strip wear out or not enough tread contact with the road.

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schrader7032
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Re: R69s Tire Pressure

Post by schrader7032 »

Five responses...five different answers! Everybody does what works for them!!
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

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Re: R69s Tire Pressure

Post by wa1nca »

Thanks Michael and Thomas
Never did look at factory spec's for the plungers
Always ran f/r 32-34
Always thought my r51/3 road hard mostly on dirt roads
Will lower tire pressure for next ride and try it on a dirt road
Tommy
Tommy Byrnes
54 R51/3, 55 R50/Velorex 560 sidecar, 64 R27, 68 R69US, 75 R75/6
Ashfield, Ma
USA

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schrader7032
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Re: R69s Tire Pressure

Post by schrader7032 »

One thing to consider is the contact patches. I'm running the 4.00x18 tire on the rear of my R69S so it has a bigger contact patch and "deserves" a higher pressure to accommodate that. I basically run the same pressures on my /7, with essentially the same tires (it has a 3.25x19 in front and 4.00x18 in rear)...while the weights are different, not enough to make a difference in my book. If you're running the 3.50 tires front and rear, I could see making a case for similar pressures.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

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Re: R69s Tire Pressure

Post by jwonder »

I did look into this somewhat seriously when I got my first vintage motorcycle. The published pressures in the owners manuals were for old design tires. With the new tire design (even bias ply tires are made differently) you need to run higher pressures to keep the sidewalls standing up to get good tire patches.

I spoke to Heidenau and to Metzler about this and they both concurred on higher pressures. They would not give me a specific number, but concurred that the owners manual pressures were way too low. I landed on f/r 32/34 after some testing. Not really sure it makes a huge difference from 29 to 36 though as long as your in that range!

Hope this helps.
James Wonder
Vice President, Vintage BMW Motorcycle Owners
2022 BMW Friend Of the Marque
Long Island, New York

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