Rear wheel "wobble"

[Clinton1]

Hi,

 

As some of you may no doubt be aware from my posts on here, I recently bought a Silverback Phoenix from Leewees in Johannesburg. Now them being in Joburg is part of the issue as I have now noticed that I have quite a wobble on the rear wheel and can't just pop it back to them to take a look at.

 

It has obviously been like that since I got it but I only really noticed the other day when I had the bike on the rack and spun the back wheel. I stood behind and noticed it "wobbling" quite a bit from side to side. I have not ridden anything hardcore (as I can't!) and have limited my riding to the roads and the smooth paths at Giba.

 

So, now for my question, and I realise the answer may not be an easy one, but what am I probably looking at? I know the advice will probably be to take it to a shop but that will obviously cost and it will be nice to get an idea of what it might be first before I get taken for a ride

 

I have put a pen on the chainstay near the rear wheel, facing towards the rim, and spun the wheel and the rim touches the pen at some points but then at other times it may well be a few millimetres away from the pen tip. I'm obviously hoping it is not a buckled rim as there is no reason it should be unless I got it that way.

 

Any ideas? Is it something fairly simple? I've been doing a bit of reading on truing wheels and tightening spokes...

Edited December 5, 2011 by Clint_ZA

[Scoe]

It's more than likely just a truing issue... Take it in and let them do it... Most shops charge very little for this.

True it yourself if you know what you're doing, but be careful not to just tighten all the spokes - this can lead to overtightened spokes breaking andf could otherwise make the 'wobble' worse...

[Johan Bornman]

It's more than likely just a truing issue... Take it in and let them do it... Most shops charge very little for this.

True it yourself if you know what you're doing, but be careful not to just tighten all the spokes - this can lead to overtightened spokes breaking andf could otherwise make the 'wobble' worse...

 

You are talking through your nose. I'd like to see you break a spoke by tightening it at the nipple.

 

@OP - truing a wheel like that isn't as difficult as it sounds. Follow these steps:

 

1) Find the loose spokes. This should be easy. You should be able to feel them, spot them with your pencil test or hear them if you pluck the spokes. Remember, that the spokes on both sides are not at the same tension (unless you have a road bike front wheel). Compare side with sides, not with opposite sides.

2) Now for rule number one. ONLY TIGHTEN SPOKES. Yes, that's right. A spoke cannot tighten itself but it can loosen itself. Therefore you only tighten. Keep on tightening in small increments until the wheel runs true.

3) That wheel went out of true because the spokes did not have enough tension to start off with. If you are brave enough, you can now tighten all the spokes equally so that the wheel ends up with higher tension. I suggest one turn to each spoke and then maybe another turn to each spoke. Don't turn twice at once. You'll know when you reach maximum tension, since the spokes will start to turn with the nipple. If you can't see it, put a black permanenet marker mark on each spoke so that you can monitor whether it turns or now. If it turns, you overshoot the spoke spanner a little bit and then return. In other words, if you want a full turn, give it one and a quarter turn and then turn it back a quarter. The spoke will now be in the position you started and have no residual twist.

4) If the nipples make noises, it means you're nearing the maximum tension you can get into that wheel without lubricating the nipples. Unfortunately to do this, you have to loosen all the nipples until you can see thread, oil the spoke thread and nipple/rim interface, and start all over again. Dont go this far if you are not skilled in the process.

5) Once you have increased the tension of all the spokes equally, (i.e. turned the nipple say one turn on them all), your wheel will no longer be in the centre of the frame. The side with the slacker spokes (left on the back and right on the front)will be closer to the frame than the other side. You now have to put more thension on the opposite side - try 1/4 turn on each of that side's spokes first and see if it more or less in the middle. ON a MTB it doesn't have to be precise for what you're doing. A wheelbuilder can do it for you at a later stage. All you want to do now is get the bike going.

 

Need I say that you use an upside-down bicycle as a truing jig

 

I want to stress that there is NO way you can break a spoke by giving it too much tension. provided you don't allow the spokes to twist, you'll strip the nipples long before the spoke goes into plastic deformation.

[Clinton1]

 

5) Once you have increased the tension of all the spokes equally, (i.e. turned the nipple say one turn on them all), your wheel will no longer be in the centre of the frame. The side with the slacker spokes (left on the back and right on the front)will be closer to the frame than the other side. You now have to put more tension on the opposite side - try 1/4 turn on each of that side's spokes first and see if it more or less in the middle. ON a MTB it doesn't have to be precise for what you're doing. A wheelbuilder can do it for you at a later stage. All you want to do now is get the bike going.

 

Thanks for all that Johan. I had picked up bits of that on the internet but it was great to get it all in one place. I found point 5 particularly interesting as when I first noticed the wobble I was also concerned that the tyre seemed a lot closer to the frame on the one side than the other. You mentioning this definitely seems to indicate that it is a spoke tightening issue I have. When pushing two criss crossed spokes together some do have far more give than others, so these need tightening.

 

On the subject of doing it yourself, I do not have a spoke "wrench". How much would one cost, and would it be worth it? Or would it just be cheaper and easier to get a bike shop to do it for me?

[Johan Bornman]

Thanks for all that Johan. I had picked up bits of that on the internet but it was great to get it all in one place. I found point 5 particularly interesting as when I first noticed the wobble I was also concerned that the tyre seemed a lot closer to the frame on the one side than the other. You mentioning this definitely seems to indicate that it is a spoke tightening issue I have. When pushing two criss crossed spokes together some do have far more give than others, so these need tightening.

 

On the subject of doing it yourself, I do not have a spoke "wrench". How much would one cost, and would it be worth it? Or would it just be cheaper and easier to get a bike shop to do it for me?

 

Clint, your last question is directed at the wrong person. I'll never let a bike shop do it for me. At the very least you should try it first and then hand it over to someone else. Remeber, if it aint broke, fix it.

 

Tighten spokes so that the wheel runs true. Obviously you should pay attention to those that are obviously loose but thereafter you only worry about tension and trueness, not feel of individual spokes.

 

You want as much tension in those wheels as you can get without the spokes twisting so much that you cannot get more in there.

 

Buy yourself a nice spoke spanner. Get a Spokey (yellow) from CRC. But for now, but one of those crappy multi-side ones that cost a dime a dozen. They are good enough for the occasional wheel true but you don't want to do serious work with them because they slow you down and irritate your fingers.

 

You want a single-size spanner you can keep for life.

 

Something that very few bike mechanics know is that a perfectly true wheel cannot have even spoke tension and conversely, a wheel with even spoke tension cannot be perfectly true. This is due to imperfections in the rim.

 

Give it a go, it isn't difficult if you just think about what you're doing.