UKC

I know there are loads of videos and website guides on how to do this, this is more a "has anyone else tried doing this as a complete beginner and had reasonably successful results?" sort of request.

I've got Hunt 4 Season Gravel wheels and they've been fantastic over the last three years, super reliable after about 10k kms on them, strong even when I've ridden rather more MTB terrain on the bike than its designed for, and until very recently have stayed true. But the front definitely has a bend in it now and I think it might be slightly distorting the brake rotor as I'm getting very slight brake rubbing noises which I've not had before.

I've had to twice take the bike in to a bike mechanic this year for jobs I couldn't do myself, something I've not needed to do in decades, so I sort of think I should try and sort this one out myself if possible!

So are there any successful have-a-go bike wheel truing heroes out there who reckon I can probably do it?

For what it's worth and with no knowledge on how he did it my dad managed to true many a wheel when I was younger and "ghosting" your bike was the in thing to to do. (Countryside not public areas) all I remember is It came with lots of swearing and hard work, ultimately with the wheel never being completely true. I think YouTube videos will give you the best advice but ultimately I don't think it will ever end up properly "true" however you may make it straight enough to ride on for a while. 

The hub is a small solid lump of metal compared to the rim so I don't think a bent rim can distort a hub and therefore indirectly distort the rotor attached to the hub. Use  adjustable spanner to grip rotor and gently tweak back into shape.

Once rotor not rubbing, ignore kink in wheel   

Watch some YouTube videos (GCN, Park Tools?) to get the idea of wheel truing.

Assuming rim is only slight bent (side to side), centred on the most distorted bit of rim, tighten appropriate spoke by half a turn, loosen the two adjacent spokes going to other side of hub by a quarter turn and see if it's an improvement. Refer back to videos if you need to do more over more spokes but basically small tweaks of balanced tighten/loosen 

That sort of process worked for me and I'm fairly  inept

I have built several wheels in the past, and lost count the number times I have trued wonky wheels. I have even rescued several pretzled MTB wheels back into a useable state (although these require bashing on the ground first to get vaguely straight, before attacking with a spoke key - not a recommended tactic for the beginner wheel fixer!)

People think spoke tension is this dark art that only gurus manage to master, but the truth is that it's not that hard. I don't really understand scooba2cv's comment - there is no 'hard work' involved in wheel truing. But I will acknowledge that it requires patience. And of course, like anything, the more you do it, the better you get at it.

Without repeating the endless amount of information on t'internet, my tips for a newbie would be:

1. A truing stand helps but it is an expensive luxury which is not necessary. I have built arrow straight wheels without one, that have stayed straight through many years of abuse.
2. be double-triple sure that your spoke key is the correct size for the nipples. I have rounded nipples in the past by being impatient and using a slightly too-big key.
3. Take your time. Make adjustments very slowly, quarter turn by quarter turn. Always spin the wheel after every adjustment to view the effect. Adjust one spoke at a time. 
4. Squeeze the spokes after adjusting them, to encourage them to adjust to the their new tension (you'll hear a ping-ping sound as they do).

It really isn't that hard. But you won't find that out unless you try!

PS I agree with elsewhere's comment, there is no reason why an out of true wheel would have any effect on a disc rotor. Before taking an adjustable to the rotor though, see if you can adjust the caliper to remove the rubbing sound.

Yeah, it's straightforward - just do as Alun says. I'm just an amateur bike fiddler but I've managed to completely rebuild a rear wheel to replace a hub in a couple of hours with only < 0.5mm of wobble at the end. Spoke tension is straightforward, I find flicking each spoke and listening to the note of the "ping" is enough to get it right - also helps identify how even the tension is, and whether there are any rogue loose spokes. 

I also agree that truing your wheel won't fix rotor rub.

This is all really good advice.

If you want to borrow a truing stand for a few weeks let me know Toby, I am heading up to the Snake Pass tomorrow and will be going past you probably on the way home.

Ill third this, the rim and the rotor are very unrelated. Time for a new rotor I suspect!

I've trued bike wheels in the past, and have built one set of wheels at a time when I was unemployed & had plenty of time. Its not physically difficult but can be very frustrating. Its also a useful skill if you are touring & have wheel problems.

But that was back before the likes of youtube & the web and I learnt as I went along using the advice in 'Richard's Bicycle Book' (which at the time was practically the bible for bike related stuff) and another book simply called 'The Bicycle Wheel' which Google tells me was by Jobst Brandt. I think the second was borrowed from the local library.

Although not really difficult, I suspect its a skill thats most easily learnt by being shown by an expert - do you know anyone who can give you a lesson ?

Upend the bike. Tape something like an allen key to the fork level with the rim and just brushing the kink as you rotate the wheel. Tweek the nipples as suggested above, when happy remove the wheel and press down on the rim with a hand on each side. This will cause little 'pings'as the spokes 'relax''. Check again in the forks. Use a seat stay if it's the rear wheel. In the óld days' cantilever brakes made the job easier.

Thanks everyone very much. I will give it go. I'm sure Park or GCN etc will cover this, but is it generally better to do it with the tyre off the wheel? Or does it not matter that much?

I've generally always done everything on my bikes myself for decades, but this year had a problem with the back hydraulic brake on my gravel bike, that I couldn't work out. So took it to a local bike mechanic (hat tip to Michael at Peak Bike Services in South Sheffield - recommended for anyone in the area needing a friendly and honest bike tech). It turned out to be more complex than he thought and ended up with the shifter and caliper needing replacing. Then a few months later the rear shifter/front brake stopped working, just worn out from 5 years hard use. Michael replaced that with a matching Tiagra one to the one changed back in May, but found that the calipers on the bike were Tiagra-level but non-series (from 2017) and Shimano had changed the hose sizes since then, so I had to get a new brake caliper as well! Hoping the bike will do another 5 years of solid service now, but I have spent a reasonable amount of money on it/supporting a local small business - hence why I want to give the wheel truing a go myself. So good to hear its unlikely to take me an entire Saturday, as I'm starting to see the benefits of paying a pro to do things and allowing you to enjoy your free time!  

Thanks to all for pointing this out. It had crossed my mind but there was such a distinct ping ping ping noise when I got the bike back, which I identified as coming from the rotor/caliper, which hadn't been there before, that with the new brake and pads, it must now be clipping the rotor. But of course the rotor could have been bent slightly totally separately to the kind in the rim.

How often do people think rotors need changing? The brakes on this bike have always been excellent, so beyond changing worn out pads, it's never really crossed my mind to change the rotors. The rotor in question is newer though because I bought a centre lock one when I got the wheels three years ago. They did have a conversion kit to use 5 bolt old ones with the Hunt centre lock hubs, but it was wider and touched the front fork. The centre lock rotor resolved this, but it means that one is 3 years old whilst the back is original so 5 years. 

If you decide to go a bit further down the rabbit hole of wheel truing and then on to building then I'd recommend Roger Musson's online PDF guide. Downloadable for a few £ and very very useful. THere are plans in there for a wheel jig also - which is cheap to make and excellent. I've used this jig and the guide to build probably a dozen sets of wheels now. Some of which have been truly hammered but are as true now as the day they came off the jig.

https://www.wheelpro.co.uk/wheelbuilding/book.php

Okay with the tyre on for a rough & ready job (straight enough to ride). For a really accurate retrue you want the tyre off, as well as removing the bead tension from the equation the tricky bit tends to be getting it radially true as well as side-to-side and that's easier to gauge on a bare rim.

When they're getting a bit thin! There'll be a manufacturers spec for min thickness but look for a distinct "step" developing at the edge of the braking track. Depends on usage obviously, on an MTB three years in gritty conditions could certainly be enough.

If it's an alloy wheel that's seen some action and has its fair share of dings, don't fret over it being super true; just let it be the shape it wants to be (within reason) don't fight it.  Dings on the rim can also be straightened out with an adjustable spanner - do it on all my wheels, even the gravel bike (probably get more dings on the gravel wheels than the enduro bike, lol).

I do wheel tweaking with the tyre on - its the whole system I'm interested in getting right (but again without being obsessive).

I've got a truing stand in the garage if you are passing - happy to show you how I would tweak your wheel. 

The rim won't be effecting the disk, unless your hub is made of butter.

I tweaked plenty of bent MTB/Gravel disks with an adjustable spanner when they've got really bad; else just ease off the bite point a bit (if your brakes allow this), or push the pistons back in (carefully) to re-set them. 

Worn pads are a great wide to hide a rotor with a small warp! 

I think every three years is reasonable, depending on conditions of course! Clean, dry roads, without long descents, I'd expect a bit longer. But IIRC you ride quite a bit of gravel and in the winter? In which case 3 years isn't bad for a rotor I don't think! My gravel bike rotors have only survived a couple of years. General rule is when they get too thin, pitted, or warped - and I guess you fall into the latter. 

When I were a lad, living in Weston-super-Mare and riding with Weston Wheelers the local bike shop was owned by Les Wilkins, who was renowned for his wheel-building skills. To get the spokes to the right tension he used a tuning fork.

I always though one of the biggest advantages of disc brakes was that you could keep riding on buckled wheels and at it's worst when you can feel the wobble or the tyre is hitting the forks/chainstays even the biggest punter like myself could do enough with a spoke key to get things going again.

For big bends I recommend using a bit of brute force between spoke adjustments, if you put the axle of the wheel on a block of wood and put your whole weight on the wheel you can help things along. Also, depending the quality of the spokes and nipples, you may want to prepare the wheel by lubing up all the nipples the night before you plan to do the job. The Mavic wheels I have on my commuter bike have been abused and the nipples are made of something with the physical properties of cheese so even with the correct size key you squash and round the nipples.

As elliptic said: when they're getting "a bit thin".  All my rotors (all Shimano) have the same minimum thickness figure ("Min TH=1.5") laser marked somewhere around the 6-bolt circle or centre lock.  Easy enough to check with a digital caliper.

You do have a digital caliper, don't you?

(And FWIW, WRT bent discs, I stumped up for the Park Tool disc straightening tool after one too many frustrating attempts with an adjustable spanner that kept slipping out of position.  Call me picky but I prefer to use a tool designed for the actual job in hand...)

Nope, I have a very nice, old school analogue one. And every time I get out of its case I also have to Google "how do you use a Vernier caliper?" 😆