Strange 'bumping' while riding

[d3vi@nt]

Did a bit of work and the bike, and now I notice that when riding, I feel a series of three close-together bumps, followed by a few seconds of normal smoothness, then a repeat of the cycle. Seems to the most pronounced around 40mph. Doesn't seem to matter if I'm going in a straight line or leaned over. Also seems to happen while in gear, clutch lever in and coasting (not under power). I feel the bumps in the front end, but can't tell if that's where it's happening or just where it's being transmitted.

Now for the changes: I installed a 14t sprocket, and  I got new tires mounted, front and rear. I did the wheel removal/reinstall myself. I've rechecked torque, rear-wheel alignment, chain tension, etc. The ties seem to be free of defects. Everything else on the bike feels normal.

Any thoughts on what the issue could be?  I'm wondering if the front wheel didn't get balanced properly, but honestly I'm not sure.

As always, any advice is appreciated!

[Privateer]

i had a weird rumble when I got some new tires.  Took it back where I got the tires put on.  The balancing was just a tiny bit off.  Repositioned the weights and the rumble went away.


maybe?

[d3vi@nt]

It's weird -it's kinda like running over three small bumps in a row every three seconds.  I'm hoping it's just a balance issue...

Bummer is, I was trying to save some coin, so I bought my tires online. Then found that nobody in town would mount them unless purchased from them due to "liability issues".     Only place I could find to mount them is 50 miles away and they only mount/balance off the bike. So I'm hoping to find someone local who will just check the balance.

Thanks for the input.

[Privateer]

I bought my tires online. Then found that nobody in town would mount them unless purchased from them due to "liability issues".   

I find that more and more lately.  Not blaming anyone, they gotta make a buck and that's tough against internet retailers, but I have a feeling it has nothing to do with liability.

Hope you find the problem.

[Buckethead]

Bummer is, I was trying to save some coin, so I bought my tires online. Then found that nobody in town would mount them unless purchased from them due to "liability issues".     Only place I could find to mount them is 50 miles away and they only mount/balance off the bike. So I'm hoping to find someone local who will just check the balance.

Got a couple of jack stand and a piece of 1/4" all thread?

In the ghetto...

How to balance your motorcycle wheel

If you feel like saving some serious coin (over time) it might be worth looking into a No-Mar setup. You'll suddenly figure out who your motorcycle riding friends are, and you'll probably save a ton on beer.

If that's more involved than you want to get (or, like me, you don't have the space for one) it's worth calling around when ordering tires. Find the best deal you can online and then call local shops. In my experience, they'll match prices when they can, and even if they can't, they'll usually try to come close. If I have to pay an extra $20 to order a set of tires locally, I consider it the price of keeping my money local.

[Howie]

I would check the tire for out of round and make sure the wheel bearings are good.  Oh, how do the front brakes feel?

[Buckethead]

I would listen to Howie.

[d3vi@nt]

I would check the tire for out of round and make sure the wheel bearings are good.  Oh, how do the front brakes feel?

The front brakes feel the same as before. Just finished checking the rear tire and everything is fine side-to-side and up/down. The wheel alignment looks like it was off by 1mm to maybe 2mm at most. I wouldn't expect that to be the culprit though.

Getting read to check the front wheel now. Anything else to look for with the forks maybe, or something goofy with the chain?

Thanks all for the ideas so far. The wheel balancing vid gave me some options/ideas.

[Buckethead]

or something goofy with the chain?

How old is the chain? Any stiff spots?

[d3vi@nt]

How old is the chain? Any stiff spots?

I'm pretty sure it's the original. It had 4300 miles on it when I got it last year and now has 76xx on it. Looks to be in good shape, and the previous owner and I both take good care of it. Not much wet riding to speak of.  There are a few spots that are tighter than others -I checked the chain adjustment and decided it needed a little more slack due to those tight runs.

I'm going to give it a quick run, then check the front...

[stopintime]

I've decided to put my money on a chain/sprocket related issue

[ducpainter]

I've decided to put my money on a chain/sprocket related issue

safe bet 

[d3vi@nt]

I've decided to put my money on a chain/sprocket related issue

safe bet 

I gave it a little slack so the few tighter runs were within tolerance. I triple checked the rear alignment. Everything looked good.  Checked both front and rear for out of round and side-side wobble, but that all seemed good, too.  Went for a ride and same bump-bump-bump. 

The chain should theoretically be good for another few thousand miles, and it was fine before the tire change so I'm not sure what to think there.

Guess it's time to take it to the shop

[bond0087]

This is probably a long shot, but did you by chance put the cone shaped spacer in backwards? If you did, it causes similar symptoms, although I only felt them at low speed until I stopped and tried to figure out what the problem was.  Maybe I'm the only one dumb enough to do that, but when it's been a while between wheel removal and installation, it's easy to forget which way they go in.  I did that after I put new tires on.  I ended up having to install my online purchased tires myself, but not because no one would do it, because no one had time for several days and I wanted it done asap. It wasn't too bad, actually.  Anyway, just wanted to throw out a possible cheap/easy fix.

[Privateer]

This is probably a long shot, but did you by chance put the cone shaped spacer in backwards? ....  Maybe I'm the only one dumb enough to do that, but when it's been a while between wheel removal and installation, it's easy to forget which way they go in. 

the dealer did that to me, so no, you're not the only one dumb enough to do that.