Tire air pressure on a VL?

[harleytoprock]

There are really a lot of factors that determine the best tire pressure. 1. Bike and rider weight. More weight needs more pressure. 2. Size of tire. Skinnier tires need more pressure that fat tires. 3. Flex rate of side wall. Soft side wall, need more pressure. The flex rate can vary because of different manufacturing processes, different materials and quantity of plys.
If the tire is on the low psi side, advantages are better traction, less wheel hop and softer ride.
The disadvantages of low psi are mushy handling, premature tread wear, possible side wall or inner tube failure and some loss of power.
The ideal psi for your application is best determined by you, by experimenting with different pressures.

[Duda]

I have a 1936VLH with Cokers. A few years ago I put 25-28 lbs in the front to try it and there was marked difference in handling so I went back to the 18-20. It does not seem logical to run that low but that is where my bike likes to be. I am planning to try a set of K34 4.00x19 Heidenau. Does anyone have any experience with these on an old bike. Thanks

[Peter Cooke]

I just did a quick Google search on them and they get pretty good reviews. Also visited the Heidenau website and they are speed and load rated but couldn't find any info on recommended pressures.

[frichie68]

"snafalton
Junior Member

Join Date

Apr 2005

Location

NH, USA

Posts

15

I know Coker makes the tires (do they or is it outsourced?)"
My new 4.00x19 Cokers were made in Taiwan. Still putting the bike back together so haven't had a chance to try them yet.
Rich

[downunder vl]

Duda, I have also been looking at Heidenau K34's for my 35 VD. I have found the Coker Diamond pattern completely unsatisfactory, especially in the wet. I won't need new tyres (tires for you guys) for a while so I would appreciate a report on the Heidenau if you decide to go down that path or someone else has.
On the discussion. The outside diameter and the tyre depth to me is important because as was said earlier this is a component of a V models suspension, the only part at the rear for the bike and lower profile tyres reduce this. Currently I am running Mitas at 18 and 20 psi. I agree whole heartedly that when running at higher pressures, which I have done in the past the ride is very hard and the rear wheel does spend a large amount of it's life up in the air. When I did experiment with higher pressures I had other riders coming up to me and telling me so.
Another factor would be road condition. Our back roads here in Australia are probably not up to the US standard. If you spend more time on the motorway higher pressure would not be as noticeable.

[Peter Cooke]

Another factor would be road condition. Our back roads here in Australia are probably not up to the US standard.

If by probably you meant definitely then you've got that right.

How are the Mitas performing? I just did a quick comparison and the Heidenau K34's are speed rated to 124mph and load rated to 617lbs.
The Mitas H-02 are speed rated to 93mph and load rated to 761lbs.

Given that the tyre is an active part of the bikes rear suspension does this suggest that the Heidenau K34's would give a better ride, at the same air pressure, as a lower load rating suggests a slightly softer sidewall?

[harleytoprock]

Peter, I would say yes, the Heidenau k34 @ load rate of 617 lbs. would give a softer ride having a softer sidewall. In the past a had a heavy duty 6 ply tire that rode like it was filled with concrete. Even with low air pressure.

[Steve Slocombe]

I've just bought a pair of Heidenau K34 4.00 x 19 tyres for a 1932 VL I'm building. They have a similar tread pattern to the Cokers and the Goodyear/Firestone originals but are about half the price in Europe and speed/load rated as well. I'll let you know how they ride, and what those pesky AMCA judges think of them at our next National Meet.

[downunder vl]

Hey Peter. I want to see a video of a V model at 124mph. That would make Steve green with envy.

I have found the Mitas a good handling tyre in both wet and dry conditions. As they are a block pattern I have found them slightly noisy and like all block pattern tyres you can feel them on the road compared to the Firestone or Avon zig zag patterns. In Australia the Mitas are less than half the price of the Firestones and Avons with the Heidenau's in the middle.

Steve. I would be interested in a report on the Heideau's handling in both wet and dry conditions.

Peter. I noticed that you are from Australia also. Are you going to the Great Race?

[Duda]

On Saturday I put 22lbs in front and rear on my 36VLH. It handled surprisingly well, but the ride was harder and not comfortable on the rough spots. I am going back to 18-20 lbs. Heidenau. I was told about these by Mike Vils. He used them on his JD in the 2012 Cannonball. He said they performed well in all conditions and after over 3000 miles they still look new. I did not ask what pressure he was using. I am building a 1924 Deluxe for C2014 and bought 4x19 VL rims from Tom Feeser and plan to run the Heidenau tires. I sent the rims and hubs to Dave Moor in California to have him spoke. He was very fair and quick. I should see the wheels this week.

[Steve Slocombe]

Yes, 103 mph was all I could get out of my 34VL, while Harley made 104 mph in 1932 at Muroc Dry Lake - see the 1934 new model Enthusiast magazine. There is an earlier post on this forum from the late 1930s showing speeds about 115 mph being acheived by VLs in stock or stroker form. Now that my bike has been stroked, the 5:1 compression iron heads replaced with aluminium, and the seat post assembly replaced with a bobber I have hopes I can get closer to that Heidenau speed rating...

[Peter Cooke]

Peter. I noticed that you are from Australia also. Are you going to the Great Race?

If I do make it to the Great Race it'll be as a spectator only. Been living in Spain for 2 years, moving back to Melbourne next month, but unfortunately my 31V stills needs to be rebuilt. It's in my father's garage waiting patiently!

[downunder vl]

Peter. If you do get up there should be at least 3 vl's this year in the 120 or so bikes. There should be 2 from Victoria so it may be handy to have some contact with other close vl's for info on your upcoming work. One has has his for years and the other is a new acquisition that he has been raving about riding since it arrived. 31 is interesting. I don't know of another 31 here so far. Out of the 6 or 8 that I know about they are 34, 35 and 36.

[Peter Cooke]

Thanks for the heads up. I only know of 2 others in Vic (but don't know what year models) and both are long term owners. If 1 of them is the one you mention then counting the new acquisition and me makes a total of 4 in Vic. I'll bet there are plenty more under sheets in sheds around the country. The guy I bought mine from had a huge collection of vintage H-D's going back to a 1915 single and you'd never ever know just by looking at the building he kept them in. Which of course is exactly how he wanted it.
I'm using past tense as he passed away last year. I don't know what's happened to the collection.