Hi, I have A T120 model 2017, total milage currently 8000. After about 5000 miles I have experienced handlebar oscillation. With loose hands only at about 40 MPH. So bad that I would crash if not grabbing the handle bar. (I know I shouldn't drive with loose hands.) I read in other conversations that the cause would be the worn tires. So I replaced them allthough there still was enough profile with pirelli scorpion trail 2. (very nice tires) The oscillation was gone .. almost but not entirely. Now I can drive with loose hands but there is still oscilation, not dangerous anymore, but annoying. My dealer (not a triumph dealer) already checked bearings etc and could not find anything. I have replaced the fork springs by TEC forkspings and the shocks by YSS topline. Also placed a fork-brace from britisch customes. All feeling very well, the bike has become al lot more agile while cornering in the mountains. Does anyone have tips for me? Should I make the bike original and claim warrantee at Triumph or is this normal behavior? Thanks, Bert
I have a givi rack at the back, but there is nothing on it. I have chosen it because the original Triumph one is specified for only 3kg. I put a topcase on it if i go on travelling. I suppose this cannot be a cause with nothing on it. Could it? Anyway i need it when i have lugage.
If it's become more agile, it may be that the steering head angle has been increased (by raising the rear, dropping the front) which can cause issues if it's too much increase? Tyre pressures could also be a factor.
The YSS do have a setting screw to make the shock longer. But i have kept them on the minimum length So they should be the same as the stock length. Do you think I should try putting back the original ones?
Today i did more tests and also replaced the YSS chocks by the original ones. The oscillation occurs between 70 and 80 km/h. A lot of roads here have 80km/h speed limit, so i am often at this speed. The original shocks and the YSS are of the same length. The YSS springs are a lot softer, I can press them in about 10 millimetres by hand. The original shocks I can not press in at all. To make a long story short, with the original shocks I still get the oscillation.
Tires are quite new. So balance must be good. I have no equipment to test this. Before the new tires the oscillation was so bad that I would crash. With the new tires it is only annoying. Rack is still on. Could you elaborate more on why you think it could be rack related? I mean a few tubes of metal not much weight, Is hardly to believe that this has influence.
Yes its work and anyway i need it for my holiday soon. I will try to make time next week. I have my own business and it's very busy at the moment.
Another possibility is the tyre profile. A more triangular profile, normally like that to speed up direction changes, can cause the bike to be more prone to instability, whereas a flatter profile will be more stable. Also is the front wheel balanced properly and straight?
If have now the Pirelli Scorpion Trail 2, yes there are triangles. I asume the motor shop does the balancing and mounting right. I told them about my problem, so they should be extra carefully, they also checked the bearings. I have no tools to check the wheel balance. With the original tires, the shaking was a lot worse. For me the tension of the tires is unclear though. I hade these als on my triumph tiger, where the tension was 2.5 / 2.9 Bar. The bonneville manual says 2.2 / 2.5 Bar. Would this make any difference? I will remove the rack next week and let you know. But how could the rack have influence, any idea?
They're an on/off road, enduro road tyre according to the Pirelli website, seems an odd choice of tyre for a T120? Anyway, if you're using the pressures (from your Tiger) of 2.5/2.9 Bar on your T120 and the recommended pressure for a T120 is 2.2/2.5 Bar, I'd correct the pressures first before doing anything else.
The Pirelli Scorpion Trail is designed for adventure bikes that spend most time on the road but have off road capability. Maybe not the ideal choice for a T120. Tyres nearing the end of their life and squared off won't perform well, and might cause that oscillation, as would a wheel that's out of balance, I had similar problems on my Street Twin on the OEM Pirellis with around 6k mile in them, and a front wheel that had lost a balancing weight.
Yes I had this tire on nu tiger and i liked it. Never slipped in the rain. With the original triumph tire my rear wheel has slipped several times make me feeling unsafe in the wet. On the tiger I got 10000 miles with these. Also in other forums these tires where recommended.
Today i tried with the givi rack off. No difference at all. Set Tire pressure to 2.2 / 2.5 bar. No difference. Shocks original triumph. Tried various preloads on the shocks no difference.
Hi, Lot of chat there and great advice. But assuming your 2017 is in warranty,which you may have breached,I have same year bike with no stuff bolted on,it’s mint at any speed..personally,I would be right back to bonefide dealer and warranty..one other good reason is,good dealer let’s staff use bikes..so they know their shizzle..also just done Triumph factory tour and they are very professional in my experience so far...good luck...
Have you checked your spokes? Tap your spokes, they should all sound the same. The off sounding one will need to be tightened. Good luck.
My 17 T120 did the same thing. Happened around 45 mph. I picked up a piece of wire in the rear, so I replaced both tires with Avon Storms. Most of the shake was gone, but it wasn’t perfect. Dealer looked and rebalanced the front. Now I’d say it’s about 98.5% gone,maybe more. What’s odd is, when I was waiting for the tires to be mounted I took a 2018 T120 demo out. Front end felt fine. Oh well, the Avon Storms are much better than stock tires, so I guess it worked out.
Hi, I’m new to the forum and Triumphs. However I have been riding a good while. Ten years ago I rode a Honda Vtx 1300 that developed the same oscillation you describe. I also changed tires and had some improvement. LSS, I replaced the steering neck bearings and races with a higher quality aftermarket set and the problem went away for good. Hope this helps. BTW, the factory bearings showed no wear I could detect, seemed fine on inspection and fallaway testing. I read about the fix on a Honda forum.
