Strange noise and feel when bike hits 40mph

[MrXT]

As soon as my agility city goes over 40mph I get this strange vibration or grinding feeling coming from the bike, its hard to describe tho. The bike also doesn't go much faster than about 55mph. Any idea what the problem night be?

[Aceforever]

Hey mate, hope you manage to resolve the issue? Did you check the gear and engine oil?
I am starting to do a lot of it myself and feel confident in the following:
- Engine and Gear oil change
- Air Filter
- Headlight bulb

Gee, how disheartening to see no one got back to you since you posted 3rd Feb, 2016 (2xweeks now)?

[CROSSBOLT]

There may be a reason for the lack of response, Ace and it has nothing to do with MrXT. XT, I think 55 mph is pretty respectable for a 125. Vibration can be tires out of balance and grinding can be bearings or gears. Is it vibration or grinding? CVT belts, especially in the smaller bikes, go nuts at certain speeds and cause vibrations.

Karl

[Emil]

If it's a strong vibration I agree that it might be the tires(s). But your mention of grinding/vibration reminds me of when the dampening rubber piece of my kickstand came off.
The effect of it was so strong that I thought my engine or gear had a problem and it took me a while to figure out that the issue was nothing but a little rubber piece.
55 mph seems about right. I made it a few times above 60 - downhill and with tailwind...

[CROSSBOLT]

Never thought of that, Emil. Good suggestion.

Karl

[Aceforever]

There may be a reason for the lack of response, Ace and it has nothing to do with MrXT. XT...

No worries.

As soon as my agility city goes over 40mph I get this strange vibration or grinding feeling coming from the bike, its hard to describe tho. The bike also doesn't go much faster than about 55mph. Any idea what the problem night be?

Wish I could help. I use to have a similar symptom but it was only when I stop then go and it aggressively hop then drives normal at any speed.
I think its best to take it in the workshop my friend unless someone here knows the nuts and bolts?

Good luck, look forward to seeing it fix.