Rear Spring length and Weave

oldnewR3T

.040 Over
Joined
Apr 28, 2016
Messages
53
Location
Carlisle, MA
Ride
2013 Triumph R3T
Gents,

Hoping to get your opinion on my 2013 Touring's behavior. Last year I had a nasty death wobble, and thanks to good inputs from this site, narrowed it down to steering head bearing adjustment, which cured the problem and confirmed that Touring's are not allergic to white walls. No hands solid as a rock at low speed, and never the violent front end shake again. Unfortunately I did not totally control the experiment, because I also installed Progressive springs in the front while having it apart. These are much better handling than the mushy stock, but now I have a weave creeping in over 80 mph, and you know we didn't buy these bikes to stay below 80. It's controllable as I progress beyond 100, but not comfortable, becoming more noticeable if I decelerate rapidly. I'm thinking the new fork springs might have changed the trail due to the stiffer spring elongating the front suspension, thus adding some high speed instability? I am planning to add upgraded rear shocks, and to compensate I'm thinking of adding an inch of length to those shocks. I think the normal Touring rear shock length is 13"? Running Avon cobras and tire pressures are perfect, tubes fitted to triple tees spot on, no unusual loading or weight issues.
Not sure where to look next so appreciate your thoughts.
thanks, steve
 
What size tires are you running? What to you pressurize them to?

I noticed a weave creeping around 160mph in when my rear was low, and you're absolutely right, it gets a lot worse when you chop throttle.

A few things can contribute on a touring, do you have a windshield fitted?

When you notice it, are you sitting stark upright or pitching your upper body forward?
 
OK. I'm going to add my two cents worth. First off adjusting the steering head bearings is kind of a joke if the bearings and races are worn out. May seem right but it ain't. You will still have a wobble. Tire pressure is OK and windshield factors are nice variable but Bottom line is bearings and races. Races shot bearings will not set properly. Bearings being over-tighten will destroy the races and guess what? WOBBLE. Bearings greased incorrectly guess what ? Worn and WOBBLE. If your making drastic changes to what the Manuel recommends to adjusting the head stock good chance that something is worn out. Tear it apart and replace. Problem solve. Stock bearings are not greased properly. Some kind of slimy goo used. I had a wobble for a long time. Around 25,000 miles replaced with new bearings and races. Used Lucas green marine quality grease on bearings. Packed the bearings using the old hand and palm method. Now at 56,000 miles no issues.
 
What size tires are you running? What to you pressurize them to?

I noticed a weave creeping around 160mph in when my rear was low, and you're absolutely right, it gets a lot worse when you chop throttle.

A few things can contribute on a touring, do you have a windshield fitted?

When you notice it, are you sitting stark upright or pitching your upper body forward?

Appreciate you guys jumping in so quickly.
Sonny, When I adjusted the head bearings, I did check for any crack or roughness in the races. They appeared clean and smooth to my untrained eye. The grease was very thing and I did repack them, but again, it is no longer wobble that I have, rather weave. The front end feels solid. What I have now is a lower frequency undulation of the entire bike at what I consider speed, which is quite a bit slower than Claviger's reference points:).

Claviger, to your point, I have to come clean with other variables injected during the process. I also changed the front to tire to a Cobra Chrome AV 91 150/80R16 which I keep at 38psi. The back is a slightly older Cobra AV72 180/70R16 kept at 40 psi. I did play around with tire pressures +/- a couple of psi and don't feel a difference.

I have also played around with leaning forward and sitting back. No noticeable difference. I usually ride upright or sitting back due to too many spinal surgeries, hence the choice of a Touring. Additionally, I have replaced the stock windshield with about a 2 inch extension around all sides, but I have the problem with the stock windshield and taking it off altogether.
 
Interesting because I always ran 34 lbs front and every front tire I had scalloped within 1000-1500 miles, and I had the weave/death wobble over 110 mph. Raised the front tire to 38 lbs (and rear to 42), current tire over 3000 and no scallop, had no death wobble. I picked up my bike yesterday from getting a new tire on rear and my mechanic mentioned he put front tire back down to 34 lbs per manual, got the death wobble on the way home. Airing it up this morning before we leave for a ride, we'll see. And yes, not really a wobble, feels like a slow rotation back and forth around the longitudinal axis of the bike.
 
Never tried going as low as 34 on the front, but the unsettling thing about this wobble is the fact that I never had it when first picking up the bike used. I was cosmetically neglected, but solid up to 125, even with metzlers. Those tires did cup after a couple thousand miles, but cobras hold up well and frankly handle better.
 
Its a touring triumph built that wobble into the to make it more harleyish :D it s.ooths out once you pushing momentum has leveled out. Right before your breathing hard :D
Makes me a more aware rider for sure, but still would like to have my rock solid rocket back again. Occasionally rent Road Kings when traveling and you expect that kind of behavior at speed, but not on R3.
 
Ok, in all honesty when I was running front and rear Avon's, I got weave at speed often, however, as @sonny mentions, while I had tightened the headstock bearings down, they were already warped so tightening helped but not for long.

The bearing race can wear unevenly, which you won't necessarily be able to see or feel, but once compressed results in a little "slop" allowing the bike to flex at the bearing more than it should.

Replacing them is really not bad, nor expensive.

What I would suggest before going to that, is remove your screen and take the bike out, to at least see if that's the item triggering the weave.
 
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