Minor juddering from disc braked wheel

[Mars]

I've had my Whyte Portabello for about 1500 miles now, and recently noticed when braking that the front wheel very lightly judders. I believe I have traced this to the spokes flexing very slightly - I am a heavy bastid (~100Kg) and I tend to tow a child trailer so I am putting a reasonable amount of strain through the disc brake and spokes.

Does my analysis sound likely?... and if so, would a minor tensioning of the spokes (say 1/4 turn each) resolve this do you think?

I know you might say "go visit your LBS" and I might yet but I like to do things myself, so if it's an easy fix, I would like to have a go.

[robpearson]

i felt something very similar a while back, i eventually identified it to having changed tyres...

[OneDs]

It might just be some contaminated pads or them not sitting in the calliper correctly, I'd take them out give them and your disc's a clean with some meths and then rebed them in 10 to 20 quick stops from 20mph.

[itsnotarace]

Spoke tension would not cause brake juddering. Warped disc, or brake residue build up, or incorrectly fitted pads

[Mars]

Thanks. I haven't changed tyres and two replies advising me to check pads - I'll do just that. Appreciate it..!!

[Pablo16v]

As itsnotarace said it might be a warped disc. Turn the bike upside down, spin the wheel, and look closely at the disc spinning between the pads.......if the disc is warped you'll be able to see it move from side to side ever so slightly.

[Ironballs]

A warped disc can usually be cured by tweaking with an adjustable wrench - if that's the problem. Juddering is often dirty discs

[Mars]

It's definitely not warped, you can clearly see the spacing between the disc and the caliper housing. Plus, the juddering (it really is quite minor) is several times per revolution.

Now that two people have commented about contaminated discs/pads I will give them a once over with some suitably oil-free spirit.

[robsti]

Could be the wheel has lost tension ! This happened to me when I was towing a tagalong!

[Mars]

robsti said:

Could be the wheel has lost tension ! This happened to me when I was towing a tagalong!

Thanks. I really think there is something in this. The front brake particularly gets a bit of a pounding, even at the relatively low speeds we travel. All that energy is directed through the spokes. It wouldn't surprise me if they needed a bit of tensioning. It is still fairly new and you tend to expect to tweek things here and there, no?

[BliarOut]

Loose headstock?

[Mars]

BliarOut said:

Loose headstock?

Another good suggestion thanks. I had recently changed my stem when I noticed the issue. I have checked movement with the forks and there is none but it's something I will reconsider when I have another play with it (tomorrow night).

Thanks.

[johnnyboy666]

Working on the idea of headset issues, Suspension fork bushings could be a suspect.

[Mars]

johnnyboy666 said:

Working on the idea of headset issues, Suspension fork bushings could be a suspect.

I have no sus - I am looking to buy a sus fork to "try" but haven't yet.

It's the bigger one.