Tire air pressure on a VL?

[Jim]

As the Title says... what do you recommended for Tire Pressure on my VL? I am using Coker Diamond Tread Tires. The original Riders Hand Book says: for the 4.50 - 16 Front and 18 rear and for the 4.00 tire - 18 Front and 20 Rear. Is that air pressure STILL correct to use in a modern Coker Tire? Sorry, I don't know for sure what air pressure is in the tires now on my VL.

[Steve Slocombe]

Dear Jim, I'd like to know too, as I'm running pressures close to 30 psi front and rear on the Cokers on my newly rebuilt bikes. I just don't feel comfortable running under 20, even though riders today are more than the 150 pounds of the 1930s. I also found out Cokers are not speed rated, so don't like to run them soft.

[bselph]

I have run 28psi in the front and rear on my 19" Cokers for about 4K miles with no issues.

[Jim]

I checked the air in the tires this AM and found they have 25 PSI in them. Seem OK, and then again... I only go about 45-50 as my top speeds. That isn't what I would call "High Speed".

[Sargehere]

In the "Old Days," (pre-WWII) tires were built far stiffer, with thicker sidewalls, than modern tires are. That's the reason for the listed low, low tire pressures. All those ultra-low, old-time recommended tire pressures are out-the-window. I also run modern pressures, about 28-30 lbs, in my modern Cokers.

[Jim]

In the "Old Days," (pre-WWII) tires were built far stiffer, with thicker sidewalls, than modern tires are. That's the reason for the listed low, low tire pressures. All those ultra-low, old-time recommended tire pressures are out-the-window. I also run modern pressures, about 28-30 lbs, in my modern Cokers.

That is a really good explanation of tire pressure. I guess I will pump up my tires a couple pounds from 25 psi to 28-30psi. ;^)

[Panuckle]

That is a really good explanation of tire pressure. I guess I will pump up my tires a couple pounds from 25 psi to 28-30psi. ;^)

Couple points to make here regarding tire pressure.Been running Coker/Firestone all noneskid replicas on a 38 el ,16psi front 18 psi rear.This is my third set .The tires are run untill they're worn out ,no issues at all.If Coker thought the tire pressures should be run higher than whats recommended in your riders handbook ,the information would surely would have clearly been provided.
The drop-center rims were designed to keep tires on the riims at lower psi's.This provided a cushier, SAFER ride.High tire pressure greatly affects the handling .Your tires will spend more time airborne and thats not a good thing,especially when cornering at high speed.
Oh one more point ,tire wear increases Greatly with high PSI's. JMO

[harleytoprock]

Panuckle, I have to disagree that tire wear increases with high psi. With low psi there is more rolling friction which will result in fast wear. Low psi can also result in side wall failure due to increase flexing. Tread cupping is another problem from low psi. The ideal psi is not high or low. I think 28 psi is ideal for a modern constructed tire like the coker repops.

[1934VL]

I just called Coker and they recommend 28 - 30psi

[Chris Haynes]

Just follow any rigid frame bike on the freeway that is running 30+ PSI in its tires. You will notice that the tire spends a lot of time off the ground. Follow the factory rated instructions or use the old rule of hand of 1 pound for each inch of the rim.

[snafalton]

Remember that the tire is part of the active suspension. The VL was designed with a limited travel spring front suspension and no rear suspension. The pogo stick seat post and tire sidewalls were it. If 1930's sidewalls can flex safely then 2013 sidewalls with modern rubber compounds and fiber strengths can too. There were no such thing as high pressure tires back then so 18psi isn't "low" per se. I run 18-20psi on Cokers on the VL and it handles OK for an old VL plus the tread is wearing evenly.

[1934VL]

I told Coker the bike in question was a 34 VL. They recommended "based on their tire design" 28-30. I wish I could get a straight answer as well. I wasn't even concerned with it. I just happened to be browsing these posts for things that may apply to me and here I am. Personally, I've been running 18 & 20 (factory recommendation) and not had a problem. I run city and highway speeds and haven't noticed anything. The only time I've ever noticed a thing was when pressure was too low and slow steering was mushy.

[Jim]

I told Coker the bike in question was a 34 VL. They recommended "based on their tire design" 28-30. I wish I could get a straight answer as well. I wasn't even concerned with it. I just happened to be browsing these posts for things that may apply to me and here I am. Personally, I've been running 18 & 20 (factory recommendation) and not had a problem. I run city and highway speeds and haven't noticed anything. The only time I've ever noticed a thing was when pressure was too low and slow steering was mushy.

That was a good idea calling COKER, however, I had emailed them near the end of Sept. for the info and they told me something different. Here is the response I got from my email:

Coker Tires said":

James,
I have researched and found most classic cycle owners are running between 35 and 45 psi depending on what works best for them. As this is not definite I would suggest maybe checking with other owners, clubs, or forums to see what a general census would be before testing the limits on pressure.

Thank you
Richard Stephens"

So.... in "MY" conclusion, The whole thing tells me that you should run the amount of air in your tire with what you most feel comfortable with and had the best luck with.

[Chris Haynes]

Try putting 35 lbs in your tires. Then take a ride on the highway and have a friend follow and see how much time your tire is off the ground. Then do the same with the manufacturers suggested amount and repeat.

[snafalton]

I know Coker makes the tires (do they or is it outsourced?) but do the people answering questions on their behalf actually use their 4.00x19 tires? I suspect not. So recommendations of pressure are subject to experience. I'm not in the shop so I can't check for myself but the tires should be made to a load rating spec and DOT approved. I wouldn't run my VL with 30psi in the tires because it isn't spec for these bikes and as Chris noted you would spend a lot of time in the air as opposed to glued to the road.