Wheel Balancing

[rjp996 1,091]

I had some vibration at high speed from my front wheel post a tyre change, so I had the wheel off and re-balanced (tyre place had made a total hash and put the weight on the already heavy side...).

 

Anyhow my question is whilst I have my balance out, I was going to do the rear as well - and that got me thinking if it would be better to balance the wheel with the sprocket and crush drive on the wheel as that would include all the rotating mass... ?? does anyone else balance with sprocket on.

 

 

[911767 148]

I'd say yes.

[DaveM59 1,605]

Keep as much of the rotating mass as possible.

[Slowboy 20,560]

It's only the tyre that's out of balance, the rest of it, having been made of homogeneous materials of finely toleranced sizing should be near as a gnats to balanced anyway. Never had an issue that needed the whole lot done. Personally I would fret too much over needing the whole assembly, just get the wheel and tyre done as usual.

[DaveM59 1,605]

You are correct, but why remove bits unnecessarily as you are risking a sheared bolt or other damage when it isn't necessary for the job in hand? Being close to the hub they wouldn't make much of a difference even if not so accurately made.

[rjp996 1,091]

i will give it a go at the weekend - balance the wheel and tyre and then see if the crush drive and sprocket make any diff and report back on any additional weights

[Mike5100 2,061]

I seem to remember some people discovered out of true sprockets on early bikes and this was causing a rhythmic thrumming which I felt myself on a demo bike

That would throw the balance out presumably

[DaveM59 1,605]

Possibly but static balancing really only detects the heaviest point on the circumference and you add weight opposite until the wheel has no particular point it favours stopping when you let it spin down. Slight wobbles or eccentricity is probably not accounted for as it would be on a dynamic balancer like that used on car wheels, although bike wheels can be done on this type of equipment, it seems to be very little improved in results.

[Tex 36,817]

For what it's worth, we balance the race bike wheels without the cush drive and sprocket.

[DaveM59 1,605]

On the rear you can probably get away with a less than perfect balance and the worst that will happen is a feeling of oscillation through the saddle, but on the front it is important to be pretty well set up or you get instability and bar shaking and all sorts of funny behaviour. Every bike is different and tolerance to imperfections differs between riders and of course the age of the bike, wear and tear etc.

I would imagine for racing it needs to be perfect on both wheels at all times, the limits to which you are pushing is far greater and consistency is also needed with every wheel set used. You can be a bit less critical for road use at legal speeds. Tex do you static or dynamically balance racing wheels?

My X9 shakes and thrashes about when I rev it on the centre stand, you would think the rear wheel was miles out of balance, but it is only a few grammes out, plus the tyre is ever so slightly oval (scooter tyres are often poorly made) but when ridden on the road it feels fine even at high speeds. Revolving in free space without any form of damping emphasises any imbalance, but weight it down and it's fine.

Edited June 13, 2016 by DaveM59

[Tex 36,817]

Dave, static balance with lots of patience. It's by far the most time consuming bit of tyre changing. With six bikes out in the same race we try to stagger the tyre changes so all twelve wheels don't need tyres/balancing at once.

[Griff 1,556]

My Tech always balances the tyres static with sprockets and any other loose bits removed. I have never had a problem after his work. However, last year I went to a local dealer who was selling the new Trail Smart tyres just after they were introduced to the market. He had already fitted a pair  a few weeks previously but I was off to France on the Triumph and I felt that the partly used rear tyre might not make the entire journey. He used one of these new fangled dynamic balancing machines. I left the shop that day and proceeded across country on backroads to my home. All seemed well.

 

Fast forward to the point where I exited the ferry en Cherbourg. Wife on the back, fully loaded, Gps pointing the way and we were heading for an overnight just south of Paris. Life was good !  Then we entered the first motorway. Great to give the bike its legs and make good progress, so I accelerated to the speed limit which is something in the region of 80mph. Something was very wrong. The bike was vibrating badly at speeds over about 70mph, really badly. The Wife could feel it too. I slowed to under 70 to be safe and pulled over asap. I was convinced that there were chunks coming off the back tyre it was that bad. I could see the front and it seemed fine on the move with no vibration on the forks, so the back was suspect. Inspection showed nothing wrong with the tyre so I now suspected balancing. Anyway I proceeded albeit at a much reduced rate of progress.  

 

 I eventually made it to my first main destination just south of Switzerland in Les Gets. Now I had time to email the shop and query the issue. I remembered that their tech had taken an inordinately long time to fit the tyre when he did so. I also remember that when questioned if there was anything wrong he said that he had a problem balancing one side but that it was eventually ok. In the email I reminded him of this conversation but he insisted that there was no problem. Not so, as far as I was concerned. He offered no help other than to suggest that I try riding the bike without the Wife on board !!!    "Leave Her in France" I asked. No response to that.

 

I eventually texted my own Tech. He told me to pull off the balance weights that had been stuck on by the shop. I did so after getting a spare set at a shop in Les Gets. That made a big difference while not solving the problem completely, but I could now travel at proper speeds.

 

Lesson learned. Firstly the Shop tech did not know how to operate the dynamic balancer properly, either that or the machine was faulty. Secondly I had not properly speed tested the new tyre at motorway speeds prior to embarking to France, as I had gone home across backroads. Lastly, my trusty Tech will be utilised for all further tyre changes. Indeed he refitted the part used tyre when I returned and it is perfect, statically balanced.      

Edited June 14, 2016 by Griff

[DaveM59 1,605]

I had a mobile fitter do a tyre for me once and his van was rigged with all the tools for doing car tyres but he wanted to dynamically balance the wheel as he had all the bits to attach to adapt the machine for bike wheels but had never used them. He spent about an hour messing about before he was happy and I stood and watched. There is more to it with the adaptors fitted, the machine not only needs to know the rim width but the adaptor type used and the extra offset on the rim because of the adaptor spacer and it also needed three or four spins without making any changes before it registered a position to add weight. The guy did it like a car wheel with weights on both sides, and they were not at the same point on the rim when finished either as you might expect. It performed faultlessly on the bike.

I'm guessing if you don't feed the correct rim data into the machine it doesn't balance as accurately.

 

The weights on my NC now are clipped to the ridge that runs centrally on the rim between the spokes and look very much like those clipped to car steel rims, but when I do them on my static balance jig I use stick on ones and try to hide them behind the spokes even if I end up with a clump behind 2 adjacent spokes rather than one midway between them but an eyesore.

[ontwowheels 19]

Hope this isn't a thread hijack; I've recently started changing my own tyres but don't have a home balancing solution. I don't want to spend a fortune, nor do I have the means to machine parts. I've heard about beads that can be put inside the wheel but am not too keen for various reasons. I've also seen a youtube video of a guy who places his wheel on a large steel ball such that the axle hole in the wheel is vertical and resting on the ball. The heavy side of the wheel then settles lower than the light side. Has anyone tried this or have any thoughts? I'm not after perfection - I currently don't have any means of balancing and have only ever had an indication of vibes at m'way speeds. I'm thinking even a fairly crude solution might suffice.

[Tex 36,817]

Something like this is more than good enough, is very affordable and will last a lifetime.

https://www.manomano.co.uk/mechanic-tools/professional-motorcycle-wheel-balancing-stand-red-527103?g=1&referer_id=537135&gclid=Cj0KEQjwnIm7BRDSs42KxLS8-6YBEiQAfDWP6CFFpWLf7Ld3SZqAlE3VjNqIbqXR7tpr_5_ON8IbKr0aAiSJ8P8HAQ

[outrunner 4,457]

Something like this is more than good enough, is very affordable and will last a lifetime.

https://www.manomano.co.uk/mechanic-tools/professional-motorcycle-wheel-balancing-stand-red-527103?g=1&referer_id=537135&gclid=Cj0KEQjwnIm7BRDSs42KxLS8-6YBEiQAfDWP6CFFpWLf7Ld3SZqAlE3VjNqIbqXR7tpr_5_ON8IbKr0aAiSJ8P8HAQ

I have one like that and also use it to build spoked wheels on some of my projects.

 

 

Andy.

[Guest GBH]

I had some vibration at high speed from my front wheel post a tyre change, so I had the wheel off and re-balanced (tyre place had made a total hash and put the weight on the already heavy side...).

 

Anyhow my question is whilst I have my balance out, I was going to do the rear as well - and that got me thinking if it would be better to balance the wheel with the sprocket and crush drive on the wheel as that would include all the rotating mass... ?? does anyone else balance with sprocket on.

 

And what about the chain since it rotates as well? Personally I think you are taking this too far.

 

Some tyre stations can balance car wheels on the car for the same reason if some of the other rotating parts are out but you then have to mark the wheel to the studs during removal etc.