Front Wheel Shimmy trouble shooting.

[JLEECB]

I put magnesium wheels on my bike summer 2022 and have rode it pretty intermittently since then. Life as a UPS driver can be brutal. When I do ride it, there is a small front wheel shimmy with the front brake between 30 down to 15 mph. If I don’t apply front brake, there is no shimmy. I have a bunch of upgrades coming in from webike. While I’m at it, what’s the best way to attack this problem? Rotors? New pads? What’s the likely explanation.

[mvk24_imp]

Sounds like what it was like when my front rotor was warped.

I changed the rotors and the shimmy/pulsing went away when I used the front brake. For some reason I noticed it more at lower speeds also

2014 CB1100, 1981 KZ440 LTD, 1993 Yamaha XJ600 Seca, 1994 Yamaha XJ600 Seca

[pekingduck]

Curious what kind of wheels you put on, and if they or the discs were powder-coated.

[misterprofessionality]

Can confirm the similarities to a front brake rotor warpage. the warpage is very minor but is likely to very slowly increase with time, and the "shimmy" will slowly become more prominent. Be careful though and make sure you test the rotors because what very often happens is it isn't BOTH of them that will be warped, so you don't need to spend so much money to replace both of them. Get one good one that you know is straight and replace them one at a time.

[JLEECB]

I got the JB Power magtan rims. They were second hand from a forum member who was selling his bike and extra parts. The rotors are my original ones. The breaking power has always been good, but it’s always had that rubbing noise that many complain about. I’ll go through old forum posts, but is there good recommendations for aftermarket rotors? I’m not concerned with price, just quality. What about brake pads since it’ll all be apart anyways?
Picture of the bike at time of last major modification just for fun. https://imgur.com/gallery/myPaKnN

[mvk24_imp]

I got the JB Power magtan rims. They were second hand from a forum member who was selling his bike and extra parts. The rotors are my original ones. The breaking power has always been good, but it’s always had that rubbing noise that many complain about. I’ll go through old forum posts, but is there good recommendations for aftermarket rotors? I’m not concerned with price, just quality. What about brake pads since it’ll all be apart anyways?
Picture of the bike at time of last major modification just for fun. https://imgur.com/gallery/myPaKnN

I got cheap ones from China and they were not machined right and wouldn't even line up with the mounts (learned my lesson)

So I got the TRWs from France I believe. Worked great and front brake shimmy/pulsing went away. When I tested/measured the rotors I couldn't not find the warp at all but when I swapped to the new ones it stopped so it must have been a very subtle warp still caused the problem.
https://www.ebay.com/itm/124656136045?mk...media=COPY

Think I ended up sourcing them from a different website but I see them on ebay also like above.

2014 CB1100, 1981 KZ440 LTD, 1993 Yamaha XJ600 Seca, 1994 Yamaha XJ600 Seca