Bonneville America Forums Forums Off Topic Discussion Forums Lounge That's why I do these things myself

Preparing for a big trip end of next week. New tyres needed..usually do these myself with the help of a friend with a tyre machine....but he's Ill so I went to a national chain advertising ride in ride out service.
Wish I hadn't..it took three of them an hour to get the back wheel in and I rode 59 miles home with an overtightened chain.
Readjusted this morning and now have a regular slight pulsing vibration through the boards at low speed under load.
My diagnosis is unevenly stretched chain....wheel is aligned OK and all running true.No broken rollers
Other diagnoses welcome

That's terrible! No comeback on the shop? I'm no help with diagnoses sorry.

What was the name of the shop? The three stooges? Sounds like three guys with no idea what they were doing left alone to puzzle it out the best they could.

I have had that pulsing for quite a while myself. I would be interested to hear what others think out that, too.

Hmmm, the pulsing is a new one to me and noticed only yesterday on the way home from the shop.
And checking the chain confirmed a major tight spot. As it only happens under load I assume it to be vibration as the tight spot passes over a sprocket.
No comeback on the shop...a chain of tyre shops by the name of Watling Tyres.

The pulsating is most likely a tune issue. Many with speedies and Americans EFI versions have it as soon as the exhaust and emissions are altered.
Aside from your other thread about the speed limiter, are you able to load a new tune in your bike?

I have worked half a dozen bikes with this problem. The owners are always amazed at the difference, like a new bike.

My pulsing is a vibration. It did it with new and old chains; dry and freshly sprayed.

I found early on that I have what feels like a vibration in the front at around 3k in the 30 to 40 mph range. I soon came to the conclusion it is the harmonics of the engine I am feeling at certain times. Once I get past that rpm-mph range it just fades away. It still catches me by surprise every now and then.

Thankfully it seems these clowns are only in Kent.
Myself, I get a bike shop to work on my bike.

.

Could be the change of tyres too.....was running Metzler 880's... now 888's.

I agree with you and it does sound like a tight spot in the chain ( just what you suggested). find the tight spot and check the side plates on the links. Those clowns might of bent the side plates by trying to roll the chain off sideways without slackening the axle. Who knows what else they did.

I'll take another look tomorrow......

Just been out and given it a thorough inspection.....yes a tight spot but I've seen worse. No damage to rollers or side plates.
What I did notice though is that my new tyres have a very slight line standing proud of the tread on the centre lines....looks like the marks from a mould process.....are they made like that?
It's possible that these lines are causing the vibes....very specific vibes...on acceleration between 25-30 mph.....then it's gone again.....
But also goes when I pull on the clutch lever and doesn't happen on deceleration...which suggests to me it's drive line related.....when the chains under stress.
Whatever, I'll live with it for now....it's got a 12 k service booked( cos I don't want to faff around checking valve clearances) at a trusted and competent Triumph shop ( Jack Lilleys).
They can have the unalloyed joy of changing the chain and sprockets at the same time...it's only money after all( sigh)

Well, after a day of checking....including wheel alignment, I concluded it is indeed a drive chain issue.
A call to Jack Lilley was cheering....'If you get it here( here, being 50 miles away) in the next hour we'll look at it BUT our currency is chocolate....bring a bar with you.'
I did and we jointly concluded I have a stiff chain link.
OK I can live with that assuming it'll last for my trip to Scotland next week.
Have to say I continue to be mightily impressed with Lilley's.
Helpful, knowledgeable and human.
These are the guys who wrote( without charge) the report on my Thunderbird LT which persuaded the factory that it needed a rebuild....and back then I wasn't even a customer of theirs.

Some of the fellows including myself ended up with a vibration under load after changing a tire. Mine ended up being the cush drive. I had installed some leather shims previously to tighten it up which worked for thousands of kilometers. A couple of years later, when I pulled the wheel apart to replace the tire, didn't get it back together right and ended up with a vibe.

I put 160,000 on a 02 america and other than 1st rear tire change. Learned to take tire off and have new tire put on at shop. This way I can grease Axel check cush drive and chain.

I've got a different thought. It seems to me it could be a warped rear sprocket. If the chain was way too tight and you rode it for a while, it could have got the sprocket hot enough to wear and tweak it out of round. Hence, it would only be noticeable under load. Together with a suspect, overstretched chain, I would bet that you will have to change sprocket, chain and front sprocket to get rid of it.

Hmm, that's another possibility. I'm waiting for delivery of a chain alignment tool...gizmo that clamps to the rear sprocket and runs a straight rod along the top chain run..... presumably if I do this at different points on the rear sprocket any run out would show up.
What makes cush rubbers my no1 suspect is that when the tyres were being fitted I glimpsed one of the' techicians' with a handful of cush rubbers.....I recall thinking that I didn't seem to remember needing to remove these last time I took out the wheel myself.

Well, the tool arrived lunchtime and I set it up.
And it gives different readings at different points on the rear sprocket.
I think therefore we have a diagnosis.......warped rear sprocket.
Presumably this sets up an harmonic resonance under some conditions of rotation and tension which transmits as a pulsing vibe.

I have a similar tool from Motion Pro. I personally would not bank on that giving you the correct reading you are looking for. You really should use a dial indicator, and measure run out. Take the chain off, attach the tool to the swingarm, and spin the wheel. Check it in a few different places. Maybe even check the hub too, to make sure the issue isn't somewhere else.

Granted, but a) it's got to be more accurate than the swinging arm fits and b) why the varying readings....?

You need something that can take readings to whole way around the sprocket without moving it. A dial indicator will do that. If you have to move your measuring devise at all, you will not get a true reading. Like said alignment tool.

Hah! Chicken dinner, chicken dinner, I probably got it right!