H: Hubs, Wheels and Tyres Tyres

[davidd]

"the resistance to turning the front wheel increases by the 4th power with wheel diameter increase"

Is this from a gyroscopic effect or increase in trail or something else?

I am sorry that I quoted the forces incorrectly, it is the square power not the 4th! Still quite an increase.

Here is Kevin Cameron's explanation and he seems to say that the larger the wheel, the more powerful the gyroscope:

https://www.cycleworld.com/how-has-motorcycle-steering-changed-over-years

David

 

[Tracey Tilley]

So, I went with 90/90 front in the end. Vintage Tyre Company sale, £341, for 4 tyres and 4 good quality tubes. I'll report back once they are on.

 

[Bill Thomas]

So, I went with 90/90 front in the end. Vintage Tyre Company sale, £341, for 4 tyres and 4 good quality tubes. I'll report back once they are on.

If the tube valve has 2 nuts, One should go on the inside of the rim, And one outside, If you have the outside one loose, You can see if the tyre moves. Cheers Bill.

 

[Tracey Tilley]

How about keeping on subject guys?
It was a reasonably simple question and you all managed to change to complete waffle about everything but my subject.

 

[flxible]

I went on the web and tried to find info', A lot of people say throw the second nut away and the other should be left loose on the outside, !! NOT GOOD.
The washer and one nut SHOULD be on the INSIDE, And the one on the outside should be left loose so you could see tyre creep !. Cheers Bill.

Hi Bill, I'm catching up on my forum reading-
I've found tube installation to be a topic of perennial discussion whenever bench racing gets around to tube type tires.
The variety of tube mounting methods employed by both shops and individuals seems widely varied.
So maybe 1 or 2 years ago the lack of agreement on method finally lead me to make inquiries at Avon, Michelin, and one other manufacturer I'm not recalling.
I posted the answers online somewhere, but I guess it wasn't here, as it didn't turn up in a search.
Anyway, they all had basically the same answer-
1- curved washer on valve stem, (to protect stem to tube interface) then valve stem through rim
2- first nut used to hold valve stem tight to rim during tire mounting
3- after tire mounting, first nut is loosened approx. 5-8mm distance from the rim
4- second nut used to lock first nut in place
5- valve cap installed
One of the manufacturers said this for observing if the tire shifts on the rim.
In my experience it seems most rims are knurled to grip the tire bead, but that said, I have one set of Vin rims that are smooth at the bead location (Radaelli) while the other set (Akront) is knurled.
One of the manufacturers also mentioned installation as you suggested- one nut under rim and one nut over rim; saying this method was for off road guys who were using low air pressure, I believe the idea was if the tire were to shift, the tube stayed with the rim, which I suppose assumes lots of talc in use.
I also recall racers used to run a nut up against the valve cap, in an effort to keep valve cap in place, this to (hopefully) keep air in tube if valve stem spring was weak, I have no idea how wide spread this tactic was, whether it worked, or if it's still employed?
Best-
George

 

[Bill Thomas]

Thanks George, I am a bit worried about 2, When I fit a tyre, I just put the nut on a few threads, I won't call it the outer nut, Or you will tell me off !!, Because I find when starting to fit the tyre from the other side, The valve will try to pop back into the tyre, So if we have tightened it right up, There will be one hell of a strain pulling on the valve ?.
If you had seen the way a valve flew out of a wheel, When I was taking my tyre off the other day, It had been on for many years, No trouble, You would want to fit a nut inside ?.
On the vintage Forum, A bloke said, " There was always a nut on the inside, Tight up on the valve, Push bikes and motor bikes ", I have just fitted a tube to a mountain bike with the rubber going all the way to valve cap, ie , No thread.
I love to do things right, But these things drive me Mad !.
I guess we will have to do what we think is best.
All The Best, Bill.

 

[Len Matthews]

So, Is nobody running 300/20 ? ribbed front , Why am I always different. Cheers Bill.

I am!

 

[Bill Thomas]

Hi Bill, I'm catching up on my forum reading-
I've found tube installation to be a topic of perennial discussion whenever bench racing gets around to tube type tires.
The variety of tube mounting methods employed by both shops and individuals seems widely varied.
So maybe 1 or 2 years ago the lack of agreement on method finally lead me to make inquiries at Avon, Michelin, and one other manufacturer I'm not recalling.
I posted the answers online somewhere, but I guess it wasn't here, as it didn't turn up in a search.
Anyway, they all had basically the same answer-
1- curved washer on valve stem, (to protect stem to tube interface) then valve stem through rim
2- first nut used to hold valve stem tight to rim during tire mounting
3- after tire mounting, first nut is loosened approx. 5-8mm distance from the rim
4- second nut used to lock first nut in place
5- valve cap installed
One of the manufacturers said this for observing if the tire shifts on the rim.
In my experience it seems most rims are knurled to grip the tire bead, but that said, I have one set of Vin rims that are smooth at the bead location (Radaelli) while the other set (Akront) is knurled.
One of the manufacturers also mentioned installation as you suggested- one nut under rim and one nut over rim; saying this method was for off road guys who were using low air pressure, I believe the idea was if the tire were to shift, the tube stayed with the rim, which I suppose assumes lots of talc in use.
I also recall racers used to run a nut up against the valve cap, in an effort to keep valve cap in place, this to (hopefully) keep air in tube if valve stem spring was weak, I have no idea how wide spread this tactic was, whether it worked, or if it's still employed?
Best-
George

Just looked at a new Mich' tube in a box, And on the outside a photo of the valve showing the lower nut firm onto the washer, With the other nut some way away.
Just my thoughts, Cheers Bill. P.S. Sorry Hugo. Bill.

 

[vibrac]

This is a question that is easily avoided by the manufacturer who give vague or no answers while every one else seems to have a different opinion. I worry more about the appearance of that steel washer that sits I suppose inside under the valve stem where did that come from? after all the furor about sticky labels on tyres I have no idear why that suddenly appeared. I just do it the way its always been done one nut against the rim after all it was OK in the days when tyre technology was not as good as now.
I also ride my modern trail bike in the lands end Trial 300 miles and I bet at least the second half is done at under 15lbs pressure, the only blowout I had was 2 years ago on the ride back from the trial when the extra heavy tube I had fitted for the first time burst and that was due to a tyre security rim clamp coming loose my fault for fitting it normally its OK with no clamps and standard tubes but at 40mph on a 280 lb bike I did not think it was a problem sit on the tank till it gets down to 3MPH fellow rider however said it was spectacular!

 

[flxible]

Just looked at a new Mich' tube in a box, And on the outside a photo of the valve showing the lower nut firm onto the washer, With the other nut some way away.
Just my thoughts, Cheers Bill. P.S. Sorry Hugo. Bill.

This image was sent with one manufacturer's placement instructions.
If the manufacturers don't agree within and without their organizations why/how they specify product use, I guess it's not surprising the end users are left wondering what they had in mind.
I'm not remembering when double nuts became standard, but I seem to remember tubes had just a single nut back in my largely misspent youth.
Perhaps double nutting has been in use long enough the current employees are now young enough that no one really recalls the original reasoning.
Or maybe the legal team is somehow justifying their job.
Best-
George