How to combat rust on your forks where the mudguard mounts?

[John_S]

Hi All,

When cleaning my bike yesterday I noticed that I've got some rust on the forks at the point where the mudguards mount to the forks.

Now I use the bike all year around in all weathers for commuting and I do my very best to clean the bike as often as possible and I also do use protector treatments but it's obviously not worked here.

The bike is a Genesis Day One Alfine 8 2014 model and it has a steel fork:-

http://www.thebikelist.co.uk/genesis/day-one-alfine-8-2014

I'm guessing that this is maybe a vulnerable position where lots of salty water off the roads gathers around the mounting point from the mudguard to the fork.

Anyway now that there is some rust there I just wondered if anyone has any advice on the options of what I should do next? I'm not technical and so my apologies if these ideas are not on the right track but my initial thoughts were try to sand down the effected area to take off the surface rust and then treat again with a frame protector. However I guess that this may only cover up a deeper problem and not actually do away with the rust which may continue to spread.

I don't know if it's something that I need to take to someone who works on frames so that they can remove the forks and treat the effected area. Do they do something like blast frames/forks and then once okay they could be repainted?

Thanks for any thoughts & advice!

John

[Gattonero]

I assume that is very little rust and in a small area.
Once you clean and touch-up, leave it to dry as long as you can (a few days if possible) then just grease the threads and if you feel it's really a problem just spray some frame-protector or products like the Tectane Spray Wax, or Waxoyl, etc.
The eyelets/bosses are a "solid" piece so rust won't go through, or if it does then the rest of the bike would be severely ruined.

As prevention, is always a good idea to spray GT85 or similar in all the parts where water can be retained. If you have access to a compressor and an open, well-ventilated area, a regular wash +GT85 & blow-clean with an air gun (as long as you don't blow the water in :wink: ) is the perfect way to expel all the moisture

[PDQ Mobile]

After touching up with paint how about a small piece of mudflap type material as a washer between stay and fork.
Or a thin hardish plastic or polythene washer.
Use locktight (thread locker) on thread for security though.
Just a thought.

[gbnz]

Have to admit I'd just wipe it clean (At an extreme, a very light sand) and apply a bit of a paint. If it is serious, replacing the forks is a cheap and straightforward job

[Gattonero]

Have to admit I'd just wipe it clean (At an extreme, a very light sand) and apply a bit of a paint. If it is serious, replacing the forks is a cheap and straightforward job

By the time the bosses are so rusty to be "dangerous" I don;t want to think in what conditions must be the bike then!

[9494arnold]

Stainless steel bolts will help.

[Brucey]

you mean the eyes on the dropouts where the M5 screws go? The good news is that rust often looks a lot worse than it really is.

Do make sure that the threads in the eyes are not starting to corrode, else the bolts will seize up.

Obviously you can treat and repaint, but a good treatment that will hold the corrosion at bay during wintertime is to apply a little waxoyl to the area. This will stop if from getting any worse in the meantime, even if you plan to paint etc later on anyway.

My winter bike has lots of waxoyl on it....

cheers

[John_S]

Hi All,

Many thanks for all of the replies below which are much appreciated!


Hi Gattonero,

Yes it is quite a small area and so I'll clean and dry the area and give it a bit of a sand to hopefully get rid of any surface rust. At this point should I put some paint on first followed by frame protector or not paint and just put frame protector on? I've got some blue touch up car paint left over from a blue car that I once had and I've used that in other places on the frame such as on the chainstays where I've picked up stone chips on the paint work.

That's a good tip re: prevention and so in the future as well as using a frame protector although I don't own and air gun/compressor I'll make sure to use some GT85 to hopefully combat any water retention.


Hi PDQ Mobile,

Thanks for the that idea and I'm sure I've got something along the lines of that type of material that I could cut out and use in-between the stay and fork.


Hi gbnz,

Thanks for your message and I'm going to clean & give it a sand and hopefully keep it going because I'm hoping that it's not so bad as to necessitate a new fork.


Hi 9494arnold,

Thanks for your message and if I'm being honest I don't know whether or not the current bolt is stainless steel or not so maybe I should buy myself some new stainless steel bolts so that I know for sure.


Hi Brucey,

Thanks for your message and no the rust isn't at the dropouts it's up at the fork crown where the bolt goes through holding my dynamo light at the front of the fork and the mudguard at the back of the fork crown. At the moment the mounting point at the top of the mudguard is touching the fork crown and that's where the rust is. I do have some ACF-50 and I've used this to spray inside my frame but I've not used it around the crown of my forks before which in hindsight has probably been a mistake. However once I've cleaned & dried the area I will use ACF-50 around this area in the future.


Thanks all for your help!

John

[Brucey]

FWIW if the mudguard is touching and able to vibrate where it touches it will wear through pretty much any coating and will, in time, cause corrosion.

To stop this from happening you have basically two choices

1) adjust the mudguard so it cannot touch and rub or

2) fix something securely to the fork that the mudguard can rub against fairly harmlessly.

cheers

[Neilo]

I have a genesis Croix de Fer, which is a great bike, but I don't think that their painting/frame preparation is up to much. I have filiform rust under the paintwork in a few places, and rust bubbling the paint mostly around cable guides, with no scratches or scuffs to allow the rust in, so I assume that their bare frame preparation before painting was not good enough.
As for the mudguard mounts etc. As soon as I had the bike I pretty much took it apart and re-assembled everything using copper grease, A to allow ease of removal, and B to stop galvanic corrosion between the different metals of the bolts, BB bearings, stem bolts, steerer tube, brake caliper mounts, seat post, etc and the steel frame. I also replaced all the Bolts/cap screws I could with A4 stainless steel. Even the bolts mounting the brake discs to the hub, Don't try this at home kids, ,thread lock is normally recommended, .
My advice, copper grease, copper grease, copper grease.

[9494arnold]

Another thought, if you are out in all weathers it might be worth introducing rust inhibitor inside the fork blades, if you look closely, most steel frames have a hole in the blade where the brazing gasses escape (they are occasionally filled ) and you can get various spray preparations to utilise.

[John_S]

Hi Brucey,

Thanks for your message and I'll try one of those two options.


Hi Neilo,

Hindsight is a wonderful thing and looking back I wish that I'd done what you did by removing all of the bolts and the then reassembling with grease as well as replacing bolts with stainless steel ones. I now need to try and solve to immediate rust problem but at the same time I should be taking a more proactive preventative approach to this to stop anywhere else getting rusty over time.


Hi 9494arnold,

I do have some ACF-50 and whilst I had used this inside the frame before I've not previously used it on the forks, although looking back I wish I had of done. I will try it though going forward.


Thanks for all of the help and suggestions which are much appreciated!

John