Front brake vibrations

[Alexandru.k_24]

Hi guys,

Ever since I got this bike (Svartpilen 701), one thing has been bothering me a bit! When braking moderately, when I almost come to a complete stop, at low speed(like 5km/h), for a very short period of time (like half of a second or maybe a second), a vibration in the front brake appears. It's not like the vibration from ovalized discs. The vibration occurs for a very short period of time and is at a high frequency, like a hum. It also doesn't happen all the time. I have already replaced the brake pads and brake disc and cleaned the brake caliper, but the problem did not solved. I have also replaced the brake fluid and vented the system. The wheel is perfectly balanced and also perfectly straight. The spokes are correctly tensioned. Basically everything is perfect but I still get that annoying vibration. I'm starting to think that this is normal behaviour for floating discs. Otherwise I can't explain this shit. Anyone else is experiencing this behaviour?
Thank you!

 

[Alexandru.k_24]

Hi guys! Yesterday I took some time to take care of my Svartpilen. I needed to replace the rear wheel bearings, because one of them had a little play. After that, I checked that all the bearings were operating smoothly, paying particular attention to the steering head bearings, as I had complained about vibrations in the front brake. Even is the steering head didn't had any play at all, I decided to check if the steering head screw is properly tightened to 12 Nm, as the repair manual says. Long story short, it wasn't. After tightened the steering head screw and went for a ride, to my surprise, all of the front brake vibrations that i've described in the first post, were gone. So you may want to retighten the steering head screw even if doesn't have any play, if you have weird front brake vibrations, for no obvious reasons.