Tue Jun 07, 2022 5:49 am

Member
2008 MP3 250ie and 2009 MP3 Sport 500 (Gilera Fuoco)
Joined: 30 Mar 2022
Posts: 26
Location: WA, USA
 
Member
2008 MP3 250ie and 2009 MP3 Sport 500 (Gilera Fuoco)
Joined: 30 Mar 2022
Posts: 26
Location: WA, USA
Tue Jun 07, 2022 5:49 am linkquote
Anyone have bad needle bearings on the swing arm? Would you please describe the symptom to me?

I know that it was discussed before [topic140459.] The author said it feels like going over ice.

I seek more detailed description because mine did not exactly feel the same. It only wander/swerves (rear) at high speed, especially changing lanes or hitting a bump. It also trails the grooves on the road at high speed (60+ mph).

Checked the rear wheel and it was fine, no loose part. Checked the swing arm, well, I'm not sure because on center stand it feels solid (no side to side movement), but it doesn't rule out bad bearing right?
Tue Jun 07, 2022 12:08 pm

Hooked
2013 MP3 300ie
Joined: 24 Nov 2017
Posts: 100
Location: Netherlands
 
Hooked
2013 MP3 300ie
Joined: 24 Nov 2017
Posts: 100
Location: Netherlands
Tue Jun 07, 2022 12:08 pm linkquote
With the bike on the centerstand it's indeed hard to feel any play in the swingarm bearings. The weight of the engine and bike will keep both feet of the centerstand on the ground, that's why the rear wheel will feel solid, since it's connected to the engine and centerstand.

If the rear wheel feels solid when the bike is on the centerstand, and loose if it's only on tiltlock, then It's almost certainly the swingarm bearings as far as I can tell.

I bought my MP3 with worn out swingarm bearings, and it showed the same symptoms as yours, including the wandering at higher speeds.

You might want to fix this ASAP. If I'm not mistaken, someone on this forum experienced a serious case of tankslapper due to worn out swingarm bearings (might have been Maksor?).

By the way: you should check the front wheel bearings, steering head bearings and steering rod bearings as well, your problem might be related to those instead of (or in addition to) the swingarm bearings..
Wed Jun 08, 2022 8:40 am

Member
2008 MP3 250ie and 2009 MP3 Sport 500 (Gilera Fuoco)
Joined: 30 Mar 2022
Posts: 26
Location: WA, USA
 
Member
2008 MP3 250ie and 2009 MP3 Sport 500 (Gilera Fuoco)
Joined: 30 Mar 2022
Posts: 26
Location: WA, USA
Wed Jun 08, 2022 8:40 am linkquote
Thank you for the details. I am convinced that it is the swing arm symptoms.

The suspension head bearing notch would cause problem at all speed, if not less at high speed. I did have the steering head notch, and already replaced it.

Loose steering rod problem would be at high speed, and is easy to check. It's obvious when on tilt lock+center stand. So when the bike drop on one (locked) suspension, any play will be spotted. Anyway, eteering rod is nice and tight, the toe-in is small 0.1deg angle for highway speed. The left-right extreme (delta) steering angle differ <.5 Deg. I used the shim washer down to .1mm for this.

Thanks again, I know what to replace next
  DoubleGood Vespa Design  

All Content Copyright 2005-2022 by Modern Vespa. All Rights Reserved.

Modern Vespa is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.

Shop on Amazon Smile with Modern Vespa

[ Time: 0.0274s ][ Queries: 5 (0.0085s) ][ Debug on ][ 211 ][ Thing One ]