Rockshox air....maintenance question.

[Dave7]

While riding my hardtail.....when hitting a bump or pothole.....there is a decided & quite loud crack.
Its intermittent but regular.
It seems to come from the top of the forks (sounds as though its the frame but I doubt it can be)
Forks are Rockshox.
I only do light off road e.g. farm tracks & Trans Penine.
I have done maybe 500 miles in the 18 months I bought it new.
Could it just need a service ? Or something more sinister ?

 

[Levo-Lon]

Loud crack? Id look at headset..
you can get a bit of noise from a fork but a bang is most likely a bearing or the spacers or the stem..

 

[Dave7]

Loud crack? Id look at headset..
you can get a bit of noise from a fork but a bang is most likely a bearing or the spacers or the stem..

Thanks.....it could well be from that area. Frustrating as it is loud and clear but I cant tell where its coming from
Any ideas how to check it out ??

 

[screenman]

Are they at the correct pressure, assuming they are pump up.

 

[Drago]

Going by Rockshox recommendations of 50 off road riding hours they're probably well overdue a service. Not an especially difficult job, lots of youtube guides.

 

[Dave7]

Are they at the correct pressure, assuming they are pump up.

I confess
I have no idea and not a clue how to check if they are.
Any advice appreciated.

 

[Dave7]

Going by Rockshox recommendations of 50 off road riding hours they're probably well overdue a service. Not an especially difficult job, lots of youtube guides.

Thanks.
My nickname is Mr Bean.....as I am useless with diy.
I will have a look at youtube and see if its something I can attempt.
Failing that I will pay for it.

 

[Jody]

I confess
I have no idea and not a clue how to check if they are.
Any advice appreciated.

Push the rubber ring on the stancion to the bottom and then carefully mount your bike. Stand in the position you would assume if going down hill at pace and then carefully get back off your bike. The ring should have moved about 20-25 % of the overall travel of your fork (depening on how you like the forks to feel). If it goes to 30%+ you need more air in them. If it goes to less than 20% you will probably need to let some air out.

As to the OP, we could do with a bit more info as to when the crack occurs. Is on compression during a big hit or rebound after. Is it during multiple close occurring small bumps. Are you braking heavily when they do it. Reason for asking is it could be all sorts. Forks bottoming or topping out, worn or loose headset bearings, worn bushes in the lower (although not likely if they have done 500 miles from new), loose pads in the disc caliper, incorrect compression/ rebound settings etc

Assuming 10 mph average and you have done 500 miles they will be ready for a lower oil change but not desperate yet. That shouldnt really be causing any noises.

 

[Dave7]

Push the rubber ring on the stancion to the bottom and then carefully mount your bike. Stand in the position you would assume if going down hill at pace and then carefully get back off your bike. The ring should have moved about 20-25 % of the overall travel of your fork (depening on how you like the forks to feel). If it goes to 30%+ you need more air in them. If it goes to less than 20% you will probably need to let some air out.

As to the OP, we could do with a bit more info as to when the crack occurs. Is on compression during a big hit or rebound after. Is it during multiple close occurring small bumps. Are you braking heavily when they do it. Reason for asking is it could be all sorts. Forks bottoming or topping out, worn or loose headset bearings, worn bushes in the lower (although not likely if they have done 500 miles from new), loose pads in the disc caliper, incorrect compression/ rebound settings etc

Assuming 10 mph average and you have done 500 miles they will be ready for a lower oil change but not desperate yet. That shouldnt really be causing any noises.

I will try to answer your questions....please bear with me.
It happens on compression.
Doesnt have to be a big hit. Yesterday it also repeated quickly (3 times) as I went over some rough track although it wasnt as loud as when I hear a single crack.
Doesnt happen while braking or on rebound.
I have not checked oil or air in the 18 months I have had it.......as I "confessed"....I have no idea how to do that or how to top them up if needed.

 

[fossyant]

Could be that the preload washer for the bearings is dry. Mine always used to make a cracking noise when it was dry. Pop off the bar stem and then the spacers and cap. Pop out the compression washer (split ring), and give it a wipe. If there are black deposits on it, give it a quick scrub with sand paper or wire wool. Then check the steerer tube for similar marks. After time, these black marks cause the cracking and creaking noises. I scrub them off, regrease and re-assemble.

 

[fossyant]

It's basically aluminium deposits. It's quite common with pedals/cleats, like Look. If my cleats get black 'polished' marks on the contact points, you can bet they will creak. Get rid of them and all is OK.

I find I had to re-do my commuter every 6-12 months. Always the same issue - where the compression washer sits on the steerer, you'd get tiny micro movements which cause rub, and hence the marks build up over time.