Changing Tires

[Maz12]

Of the pictures posted and lord knows where  David finds them all the first ones look like they canm out of a Chinese container.  Seem to recall BMW ones are a bit over £100 each but they seem to go on forever. Compared to the types you find in a lot if cars these days which just tell you the pressure is down,  they are very sophisticated.  .

do the BMW ones not look like the ones in Daves pics then?
Are they similar in design,  dunno why but I thought they were in the .valve stem

[Levisp]

Do not know which method of balancing is best but for practical purposes static balancing works fine. Not all tyres come with balancing marks. If they do most tyre fitters fit the tyre so that the dots are aligned with the valve. If you have TMPS then the valve will definitely be the heaviest part of the wheel, so aligning the dots to the valve is correct. However if you do not have TMPS then the valve may not be the heavy point on the wheel. I put the wheel without tyre on the static balancer and mark the heavy point, then fit tyre to this point. This will reduce the amount of weights to balance the wheel and tyre. I do not have TMPS on my bike and have found the BMW wheels are not only light but are very well balanced. BMW also state in their workshop manual a max amount of weight to use for balancing which I think is 60 grams but I need to check this.


The sensors I had on my GS were the ones in Davids last pictures, the one piece black moulded module attached to the valve.

[Levisp]

Just checked my BMW workshop manual and it states:


Max weights for front or back wheel is 80 grams. (thats quite a lot)


Max imbalance for front wheel is 5 grams
Max imbalance for rear wheel is 45 grams


The surprise is the max permissible imbalance for the rear wheel. I certainly would not be happy with that amount of imbalance. I'm sure you would not feel anything while riding but the imbalance forces being transmitted to the final drive cannot be a good thing. A balanced rotating mass must be a better option for general wear. One reason I always balance both wheels and except no imbalance. The manual also shows the wheels being balanced with a static balancer. Interesting.

[David.]

My 2012 RT is now on it's third pair of tyres from new, the rear was Dynamically balanced & has 25g of weights on both the outer edges of the rim.

Not sure about the front, the bike is tucked away under a cover at the moment.

I don't recall there being any weights on either F or R Wheels from new, is this usually the case, if so, how do BMW achieve it.

[Levisp]

Sometimes you can be lucky. BMW wheels are very well balanced without tyres so if you get a well balanced tyre fitted you can be within the 5 gram imbalance limit for front and 45 gram limit for rear. In this case they would be no need to attach any balancing weights. Maybe BMW have a way of checking tyre balance and matching them to wheels to achieve a balanced result within their spec.

[Levisp]

I mentioned that I thought BMW wheels were well balanced but thats wheels without TPMS. I have always wondered why BMW do not fit a counter weight opposite the TPMS to bring the wheel back into balance. All that would be needed is a small flat weight attached to the inside of the wheel in the drop zone matching the weight of the TPMS. Job done.

[DaveCly]

Had a look at mine today, no weight on the back, but one on the front, seem to remember the tyre fitter saying back didn't need balancing?

[mbro]

Aaah, nothing beats the smell of fresh donuts... 


I spent some time in the garage last night, dismount the exhaust and rear wheel, valve stem, and then get out my custom tool that I meant intended to be my bead breaker.  Its a 2x4 on edge bolted to another short 2x4 that inserts into the trailer hitch receiver on my truck, with another 2x4 bolted to the long lever to push the bead off the rim.  EPIC fail...  The piece that pushes on the tire was mounted too far from the trailer hitch.  I drilled another hole, adjusted the mounting, and it was better, then the 2x4 inserted into the trailer hitch receiver split.  I retrieved my steel trailer hitch and bolted the long lever 2x4 to this, and tried it again, then split the long lever 2x4...  Back to the drawing board.  I used the old vice method of breaking the bead last night, and had another good idea last night on how to improve on my design...  I suppose this is how everything is made - try, fail, adjust, try, fail, adjust, try, succeed!  I'll get it yet.


I used lots of caution around the TPMS.  I'll do the front tire on Saturday.  The old rear tire (Michelin Pilot road 4) was very stiff - lots of heat cycles... 

[Levisp]

Had a look at mine today, no weight on the back, but one on the front, seem to remember the tyre fitter saying back didn't need balancing?

I hear this quite a lot and totally disagree. An out of balance rotating mass cannot be a good thing. I wonder if its a case of the tyre fitter not having the correct adaptor for the rear wheel to balance it.

[guest3074]

I hear this quite a lot and totally disagree. An out of balance rotating mass cannot be a good thing. I wonder if its a case of the tyre fitter not having the correct adaptor for the rear wheel to balance it.

I agree, never had a problem myself, always had the rear balanced.

[CWRoady]

Change my own and have been balancing with Counteract balancing beads instead of external weights for several years now. On my last change I was going to pre-balance the wheel before mounting the tire, but after adding more weight than I wanted, I removed them and went with beads again. Posting a pic of tpm sensor also. [attach=4][attach=5]

[Johnboy]

Change my own and have been balancing with Counteract balancing beads instead of external weights for several years now. On my last change I was going to pre-balance the wheel before mounting the tire, but after adding more weight than I wanted, I removed them and went with beads again. Posting a pic of tpm sensor also. [attach=4][attach=5]

Interesting you have the front wheel on the balancer for the pic, Is that adaptor on the ground forr the rear? and if so where can they be purchased?
Here's some pics of my home made balancer, not a million miles away from the off the shelf jobbie you have!

[CWRoady]

Looks like the same unit to me John . Balancer and adapters is from NoMar (and yes, that is the rear wheel adapter on the ground).

[Johnboy]

I almost started to look for NoMar and seen where your from, so started looking for a european equivilant, and found some interesting stuff on the DIY wheel balancing on this guy's site and it's a great source of info and ideas! http://www.largiader.com/balancer/ and found the adaptor at a reasonable price as well from Abbastands http://www.abbastands.co.uk/product-detail.asp?pid=51  :clap: