Bonneville America Forums Forums Technical Forums General Tech surging feeling

I hope I can explain this feeling. When I am going 30-40 mph on the highway-when the semis have slowed down the nice flow-and I am in 2nd or 3rd gear I have a surging like feeling. Not an engine surge, the tach stays steady. But more like a rubbing feeling. Like on a revolution of some sort. My thoughts are bearings (23k miles on her), chain, rear wheel misalignment... It feels like it is right under my butt in the back half of the bike. As I am rolling along it is a pushing and pulling feel about every second at that speed. Will do it non stop until I accelerate.

This spring I put a new rear tire on, so I am thinking it may have started here. Did I get a bad balance? Bad alignment with the install? Rear sprocket rubbing. I don't notice is at any other speeds. Of course at 75-80 I may just be feeling more wind and road vibration to cover it all up.

Any thoughts and tips would be appreciated.

Thanks,
Brett

Sounds like chain to me? Just guessing you know not being there but I had that same experiance before and that's what it was or could be cush drive ? These bikes due tend to wear out the originals pretty quick ? But those are the two things I would ck first . It just sounds to me like you have a spot or two on that chain that is tight

Does it do it under power ? Knock it in neutral and see what it does. That will rule out engine. Bearings should be good at that mileage, bad bearings will make a grinding drone sorta noise and you can feel a vibration in the frame. A tire or sprocket that far out of alignment would really show. Brakes ? If the brakes be grabbing or rubbing the rotors will be disproportionately hot on a long run.

That's all I know. Maybe I fly up there and ride it

I'm with Newt. Sounds like a typical 'end-of-life' chain symptom. I'd give it a good look before I look a anything else.

Cool I'll check the chain. Also the neutral coasting at that speed is a great idea. So any specifics I'm looking for on the chain? I know the Cush drive is broken, the little connector pieces, but was still ok. Meaning it was solid still.

Survey your chain and check for a link that is tighter in relation to pivoting (following the sprocket radius) or excessive side flex throughout. But 23k? you got your money's worth with your chain and sprockets, time to replace anyway.

Chain... I'm thinking chain. The mileage and symptoms add up. It's due for a new chain anyway so throw one on and see how she feels.

What they said.

It was loose as I was looking at it last night. So 23k is good for a chain? How long do they usually last? Assuming the sprockets look ok do I have to replace those too at the same time? Is that usually recommended?

About 15 K is a good run for a set, they will go longer but they tend to get all shark finny.
Yup, always replace chain and sporkits together as a unit, they tend to wear into each other's eccentricities and if you replace one without the other you get premature wear as the one is trying so hard to wear into the other one and adjust to life.

now , Grasshopper, what can we learn from this metaphorical ramble ?

Adjust the chain. If it won't hold he adjustment very long, then it has stretched and it's time to replace it. You'll know.

If that's still the stock chain, it got to be about due.

Sprockets? Most likely okay, but they aren't that expensive, either.

Whose going yo replace the chain? You? Or a shop?

then it will be time to sing "you've lost that surging feeling".

Wade my OEM chain and sprockets went 23,000 with no lube and show no visible wear on the rear sprocket and only very slight wear on the front.

Wow I guess I did get a could life out of this one. It is the stock chain. So who is our favorite proprietor of chains and sprockets these days? And I will do it myself.

My 2 cents is since I got such good service out of the Triumph stock set that's what I got again.

So Hermys since your a PA guy?

Yep, been dealing with Hermy since when his mom and dad still ran the place.

Great. Looks like it will set me back about $170. Does that seem about right, and a good price?

I get something similar in second gear, 30mph, 3k rpm. It's a slow pulsing surge ... about one second apart. Is that the same you're feeling?

It doesn't seem to be fast enough to go along with wheel rotation. I'm only at 8.5k, chain is good.

I do a lot of highway riding. Would changing the sprockets benefit me in anyway? Bigger…smaller??

Thanks guys. I appreciate your help.