show us your car tyres on your hack, sidecar

[claude]

Originally Posted by BMWzenrider

I have not seen Richard-NL in this forum for a bit now...
Checking his posts, he has not posted anything since the 15th of November. That has been three weeks ago.

Anybody know his whereabouts? He has the best sidecar porn...

Yes Richard NL is missed for sure. We have comunicated and he is 'away' at this time but is looking forward to coming back as soon as he can.

[Abenteuerfahrer]

Have finally converted from the BMW OEM cast wheels and Tourances to Dauntless wheels and 165/15(VW) car tires after having Tourances eaten like candy on our way to Alaska and back.













On the sidecar....brake has yet to be mounted



Modified larger fender has yet to be painted..

[BMWzenrider]

Originally Posted by Abenteuerfahrer

Have finally converted from the BMW OEM cast wheels and Tourances to Dauntless wheels and 165/15(VW) car tires after having Tourances eaten like candy on our way to Alaska and back.

To be honest, I am a bit concerned about this setup...

I cannot tell from the photo because the resolution is not good enough, but PLEASE check to see if those were high-strength bolts supplied to attach the adapter to the stock hub...
You want at least a grade 10.9 fastener, preferably a grade 12.9.
Of course, even better would have been designing it to use the stock BMW wheel bolts...

Also, I do NOT like the idea of using plain flat faced socket head screws in place of a conical seat bolt or nut to attach a wheel adapter to a hub.
As you are applying power or braking to the rear wheel it could allow the adapter to shift back and forth on the hub.
If this starts happening, it will just continue to get worse as the parts wear against each other and the adapter bangs back and forth against the screws holding it on.

There is a reason that wheel bolts and nuts have conical seats!!!

You may well get away with it on the undriven and no brakes sidecar wheel, but I have strong foreboding about trying to contain over 100 horsepower over the long-term with the clamping pressure that can be generated just by the meager surface area under the heads of five socket head screws....

Why couldn't they have machined the mounting holes to accept the stock BMW wheel bolts? We already know that they are the correct strength for the application, and they have the conical seat needed to make sure things don't shift around under full power.

Just something to think about and discuss with your supplier.

[mickman]

Just fitted the first of SRK Engineering rear.Bathurst NSW whttp://i619.photobucket.com/albums/t...g?t=1260440893heel.http://i619.photobucket.com/albums/t...g?t=1260441028

[halflive]

To be honest, I am a bit concerned about this setup...

I cannot tell from the photo because the resolution is not good enough, but PLEASE check to see if those were high-strength bolts supplied to attach the adapter to the stock hub...
You want at least a grade 10.9 fastener, preferably a grade 12.9.
Of course, even better would have been designing it to use the stock BMW wheel bolts...

Also, I do NOT like the idea of using plain flat faced socket head screws in place of a conical seat bolt or nut to attach a wheel adapter to a hub.
As you are applying power or braking to the rear wheel it could allow the adapter to shift back and forth on the hub.
If this starts happening, it will just continue to get worse as the parts wear against each other and the adapter bangs back and forth against the screws holding it on.

There is a reason that wheel bolts and nuts have conical seats!!!

You may well get away with it on the undriven and no brakes sidecar wheel, but I have strong foreboding about trying to contain over 100 horsepower over the long-term with the clamping pressure that can be generated just by the meager surface area under the heads of five socket head screws....

Why couldn't they have machined the mounting holes to accept the stock BMW wheel bolts? We already know that they are the correct strength for the application, and they have the conical seat needed to make sure things don't shift around under full power.

Just something to think about and discuss with your supplier.

don't be scared. there are a lot of bolts installed.
European cars like the Smart fortwo and the older Citroen 2CV and Renault 4 use wheels with only 3 bolts. having stripped those wheel bolts i can tell you the ain't grade 10. these older cars where and are still used on very rough surfaces with full load. even today 2cv's and R4's are used in africa. 3 common steel bolts are enough.
you are right about those bolts being counter sinked for a reason. it is for centering the wheel and giving grip to stay torqued.
you can center the wheel with the hub, and lock the bolts with locktite.

[Paves]

I have this on the back - Michelin 135SR15


and this on the front - 130/90 15 Barracuda




The Barracuda's too wide and rubbing on the leading link on both sides. I'm going to replace it with a car tyre but can someone recommend one? The same as the back? (The back's a 135 but narrower than the 130 Barracuda (I've measured them)

[Bandit Bill]

Take one accident mangled stock Hannigan suspension/12" wheel setup (you can see from the inboard tire wear bar, how badly the leading swinging arm has been twisted), and cut away..



After a winter's worth of hack-sawing, filing, a little fiberglass work on the sidecar body, more than a few trips to the machine shop for final welding, and donor parts from an Asuna (Isuzu) Sunfire, and the weaksauce 12" trailer wheel has been magically converted into a 185/55R14 setup - finally some grip on the road so that i'm not spinning out when getting uber-aggressive in cornering. Swaybar and linkage not shown in photo. Shock shown in photo is place-holder only. Progressive Suspension unit used in it's place on final assembly.





A 'naked' photo, upon rollout after a long winter's work in Spring 2006. Suzuki Bandit has 185/55R15's on front and rear.

[BMWzenrider]

Originally Posted by halflive

don't be scared. there are a lot of bolts installed.
European cars like the Smart fortwo and the older Citroen 2CV and Renault 4 use wheels with only 3 bolts. having stripped those wheel bolts i can tell you the ain't grade 10. these older cars where and are still used on very rough surfaces with full load. even today 2cv's and R4's are used in africa. 3 common steel bolts are enough.
you are right about those bolts being counter sinked for a reason. it is for centering the wheel and giving grip to stay torqued.
you can center the wheel with the hub, and lock the bolts with locktite.

Ahhhh.... But just counting the number of wheel bolts only matters if they are the same diameter and pitch... Which they are NOT...

The two vehicles that you mentioned both use a 12mm-1.25 wheel bolt.
The BMW R1200 rear wheel hub only uses a 10mm-1.50 wheel bolt. BIG difference...

In fact, the tensile stress area for a M12-1.25 screw is 92.072mm^2.
Times three wheel bolts that gives a stress area of 276.2 square-mm.

A M10-1.50 screw has a tensile stress area of only 57.990mm^2.
Times 5 wheel bolts yeilds a stress area of 280.0 square-mm.

Nearly the IDENTICAL amount of material holding the wheels on in both cases...
Isn't that interesting???
It is almost like there is an optimum amount of metal required to hold a wheel on, and everyone designs to that, but not using the same number of bolts...

Loosing even one of the BMW wheel bolts, and then you are at a 20% detriment to the 3-bolt cars...

------------

And yes, as you pointed out, the conical seat used for lug nuts and wheel bolts does much more than properly align the wheel on the hub.
It provides crucial additional bearing surface for transfer of clamping forces and locking of the bolt/nut from loosening.

All metals will "creep" over time while under stress. High heat will accelerate the rate of creep in a metal.
Alluminum being soft and relatively weaker than steel, it will exhibit creep when used for a wheel or adapter plate at a faster rate than a steel wheel/adapter will. A larger bearing area, as provided by a conical seat, reduces the creep factor by spreading the load over a larger area/volume of material.
The small surface area under those plain cap screws will begin to lose compressive force over time as the metal creeps. As the comressive force is lost, the adapter is apt to start shifting back and forth under drive/braking forces. Once it starts shifting it will just get worse and worse till the bolts break or more likely, strip out of the aluminum flange on the final drive.

A tapered seat fastener will wedge and center the parts and prevent there from being any shifting even when the compressive force goes down towards zero.


If it loosens up and starts shifing while he is driving on it, it will take no time at all to shear off even hardened, high-strength bolts or strip the threads out of the aluminum flange that they are threaded into as it gets slammed back and forth under alternating power/braking/cornering forces.
Then he will lose an entire wheel, AGAIN, due to one of Jay's designs...

Kinda like here...
http://advrider.com/forums/showpost....&postcount=271

Jay has been known to have some designs that were not as well thought out or executed as some other builders.
I personally, as a Mechanical Engineer, happen to think that this is one of them.

[halflive]

being a mechanical engineer, you are right, in theory.
the reason i compared it to those cars is because these cars have a empty weigh about the weight of a loaded sidecar. with 4 people and a complet set of holiday gear those cars can easily weigh 1500kg. a co-worker of me once scraped the fenders of his 2cv loaded with wood and 4 men taking a round about.

giving these practical examples and never heard of a lost wheel or a bolt, i am convinced the 3x 12mm bolt design is already over engineered. for sure, it is fail save. having the same clamping force and tension spread over more bolts gives you more security. using high tensile bolts do not add more security in my opinion.

regular re-torquing and the use of lock tite wil give more security if you want to be sure the bolts won't free.

you are right about the stupid axle design. it happens to more sidecar axles. mostly a design with bearings in the wheel. it is a small axle with a lot of weight to carry on one side, thus bending.
the design with the fixed wheel and turning axle gives the bending like a train axle, giving extra fatique. then, at the flexing point of the axle making a sharp step is a major mistake.

[claude]

Half five wrote:
>>you are right about the stupid axle design. it happens to more sidecar axles. mostly a design with bearings in the wheel. it is a small axle with a lot of weight to carry on one side, thus bending.
the design with the fixed wheel and turning axle gives the bending like a train axle, giving extra fatique. then, at the flexing point of the axle making a sharp step is a major mistake.<<

With that being said ( I do agree) do you feel that a fixed wheel system with a larger axle and large radiuses at the transition points would be a good design?

[halflive]

Originally Posted by claude

With that being said ( I do agree) do you feel that a fixed wheel system with a larger axle and large radiuses at the transition points would be a good design?

i think you don't want any raduises at all. sometimes there is no other possibility, but it will always be a concentration of forces. a larger radius blends out those forces.
i like to use a fixed axle with a rotating wheel. preferable a wheel of a common type car, over here thats a VW Golf.
those axles are a very solid, being 50mm at the inner bearing and 25mm at the outer bearing. giving an idea what forces are build at the fixing point of the axle.
i think if you want to construct a swing arm with an rotating axle you have to make the axle 50mm (2") thick and make no steps, just a fixing plate for the wheel and disk.

[outfit]

[quote=Paves]I have this on the back - Michelin 135SR15

This tyre would'nt be my first choice. The sidewall's are paper thin.

Karl.

[Rockman]

Originally Posted by mickman

Just fitted the first of SRK Engineering rear.Bathurst NSW whttp://i619.photobucket.com/albums/t...g?t=1260440893heel.http://i619.photobucket.com/albums/t...g?t=1260441028

How do you find this wheel? They look ok but arent cheap and I'd want to be sure before spending $1700 odd. Phil

[BMWzenrider]

Originally Posted by halflive

being a mechanical engineer, you are right, in theory.
the reason i compared it to those cars is because these cars have a empty weigh about the weight of a loaded sidecar. with 4 people and a complet set of holiday gear those cars can easily weigh 1500kg. a co-worker of me once scraped the fenders of his 2cv loaded with wood and 4 men taking a round about.

giving these practical examples and never heard of a lost wheel or a bolt, i am convinced the 3x 12mm bolt design is already over engineered. for sure, it is fail save. having the same clamping force and tension spread over more bolts gives you more security. using high tensile bolts do not add more security in my opinion.

regular re-torquing and the use of lock tite wil give more security if you want to be sure the bolts won't free.

This will be my last reply on this topic, as I do not wish to beat this topic TO far into the ground... However...

You are again comparing apples to oranges, and then completely ignoring large sections of my reasoning.
My basic arguement (which you agreed with!) is that Jay should have designed the adapter to employ the original taper seat BMW wheel bolts to hold it to the final drive hub.
But you are clinging to the one small comment I made about whether the socket screws he provided were high-strength.

-----

You mention the weight and loading of the 2CV, but again, that is a 4-wheeled, relatively symetrically balanced vehicle.
A sidecar rig only has 3 wheels supporting its mass and the weight distribution is anything BUT symetrical.
As shown by my actual scale results above, up to 50% of the mass of a sidecar rig can be supported by the rear wheel of the bike versus only about 1/4 of the weight at each wheel of a car.
So, even if the car's loaded mass was twice that of a loaded sidecar, the load seen by the sidecar's rear wheel studs/bolts would be approximately the same as those of the car.

However, that is not the REAL issue, wheel loading and number of studs is just a distraction.

-----

The MAJOR problem with the Dauntless design is the use of non-tapered seat fasteners.

There is a very real possibility of the small clamping area under the heads of the (non-tapered seat) socket head screws not having sufficient force over time to keep the adapter from shifting under the over 100hp that this bike generates. (refering back to the design from Dauntless)

Even you agreed that this was an issue in your first reply:

Originally Posted by halflive

you are right about those bolts being counter sinked for a reason. it is for centering the wheel and giving grip to stay torqued.

You suggest regularly checking the torque of these fasteners and/or employing loctite.

Unfortunately for the end-user, these screws are blocked from access by the wheel that is mounted over the top of them, making regular inspection, even visually, impossible without first removing the wheel. Lack of access and ability to visually inspect these bolts makes it even more important that they be more secure and higher factor of safetly.
And incorrect selection of threadlocking compound can cause problems when the application is a steel fastener into an aluminum part.

----------

Basically, ALL of this could have been addressed by simply designing the adapter to use the existing wheel bolts. How hard would that have been?

They are self-aligning, keep the adapter/wheel from shifting while in use, self-retaining, resist creep and vibrational loosening, the right strength factor for the application, the correct fit tolerance for the mating threads (by design), and the stock tool kit comes with the correct wrench for them...

And lower parts cost to boot, since the bike owner already has them...
Why WOULDN'T you design it that way???

----------

You can look at the Dauntless adapter and see that it was done in the fastest/cheapest way possible.

There was no additional material removed to reduce unsprung mass.
There was no attempt to provide a hub-centric ring to align the wheel to the adapter.
He used cheaper fully threaded studs rather than piloted studs that may cost a few cents more apiece, but make starting the nut easier.

Everything was done to just the minimum possible standard, and nothing more (and in some cases less than minimum standards in my opinion).
It is not commercial quality work in my opinion.

-----------

As I said at the beginning of this reply; this will be my last public reply about this specific subject (the Dauntless R1200 automotive tire/wheel adapter).

I believe that my position has been stated quite clearly, and my reasons for my opinion well supported.

I was just trying to point out something that I feel is potentially dangerous based on my knowledge and experience in designing machinery with rotating components.
Take from it what you will.
Buy the Dauntless adapter as-is if you wish.
I thought that the point of this forum was to share knowledge, not to win arguements.

Over and out....

[DirtyDR]

Karl,
I got the Blizzak mounted on the GS and I have to admit I am surprized at how well it does in the snow. They sent a LM 18 instead of the W 60 but it works plenty good enough. I will go with a 165/80/15 come Spring but this will work for the little bit of riding I'll do on the GS in the Winter, that's what the Ural is for.