Vintage BMW Motorcycle Owners

The continental rear 4.00 and metzler 3.50 tyres on my '66 R69S were old & hard. I have fitted new Heidenau K36s, 3.50 front and rear and I strongly recommend them; I chose them after reading Barrington and easy availability in UK. Confident road-holding, dry or wet, no trace of 'tracking' and they look the part. The old tyres were so hard I could not lift the 2nd bead to remove the tyre. I took them to a motorcycle tyre fitter and he also balanced the wheels which is probably worth doing although I don't bother on most old bikes.

Gossamer wrote: ↑

Tue Oct 12, 2021 10:34 am

have the H K34's as well.

Tires feel very stable but man you get near rain grooves and you're holding on for dear life.

I put on around 120 miles on Saturday. About 20 miles of that was highway speed with deep rain grooves in the concrete. Serious butt pucker moments even though I know I'm safe it's a very uneasy feeling.

What tire pressures are you running? I run 32 front and 34 rear and I have a little weave on rain grooves, but not violent or scary. If it was worse I would try different pressures.

34/36

On one section of road near my house, the rain grooves are no big deal, in another connecting section they're cut deeper/wider and it's hang on for dear life.

So depending where I'm at it's ehh no big deal or a completely miserable ride.

Also the southbound section I was on it was horrible, the northbound on my return there were none.

There doesn't seem to be a 'standard' on how/where/why they're cut in. But when my wife has followed behind she's commented at times that she can actually see the bike wiggle back and forth.

I'm glad I live in a "groove-free" zone! Never really had any issues like that going way back, even when running the stock Continentals on my /7.

I will agree that I feel the bikes handle best with the stock 3.50-18 tire size front and rear. My 66 R60 came to me with a 4.00-18 rear and I rode it that way for years. When I did change to the 3.50-18 front and rear I was impressed with how much better the bike handled. I have ridden with the Metzeler Block C and I have been very happy with them. I don’t have too many rain grooves here in Washington, however the DOT seems to like milling down the concrete roads and that does also create groves that do cause wandering. This thread caused me to look up new tires, perhaps the Heidenau K36 is a good option, it seems to be currently available in the 3.50-18 size. (It looks like a Metzeler ME77, which I have ridden on in my Airhead past). While the wheels are off, it’s a great time to perform a wheel bearing service and brake service.

After experiencing the Metzeler "Block C's" on 2 of my bikes and having another with the more modern,round profile Avons...I will never go back to "period correct" style tires. their profile is like a automobile tire being flat and square. The round profile tires handle so much better when leaning over and do not give a near death experience on rain grooves. So now my 2 Earls fork and 2 plunger bikes have Dunlop and Continental tires sourced from 1970's vintage applications (Japanese bikes) and are much more enjoyable to ride. The bikes,at first,seem more "tippy" side to side,but in the corners it is a revelation. Period correct is great for the concours judges,but for riding experience,try a modern,round profile if you actually ride your bikes.

My Metzler Block C tires are round profiles...not like a car at all. Is there another "Block" style for Metzlers...like K? I think there is a more flat profile tire that is typically used in a sidecar setup.

Correct Kurt-
Metzeler Block K is a square tread pattern, like a car tire; made for use on all corners of a sidecar rig.
And as far as I know, only available as a 4.00-18.
You can sorta see them in the pic to the left.>
Best-
George

Compared to the round style profile of more modern tires,even the Block C is "square"...especially when 1/2 worn. They are the original spec,but tire technology is so much better now. To each his own, but I am convinced, the truth is in the riding experience.

Coulda fooled me! These sure look like round profile tires:

https://www.metzeler.com/en-us/products/tires/block-c