New owner... Vibrations.. And a question

[Cormanus]

Others have complained about vibrations in the 3-4K range, but not for some time.

[GoldOxide_imp]

After reading all the posts I am going to go out on a limb and suggest that Lazz's bike has a problem. I ride my 2014 Deluxe in the 70 mph to 85 mph range on our California freeways all the time and I have never noticed any unusual or excessive vibration. (I know this is not as fast as Lazz rides, but that the fastest I can tolerate for any length of time on an unfaired bike). I suggest finding another CB1100 Honda owner and swapping bikes for a ride to see if there is any difference in the two bikes.

Yeah, if possible, this is a practical idea worth exploring.

[j3gq_imp]

lazz, really sorry to hear about this problem. As others said, there could be many reasons. But you would certainly go from doing ALL the easy/cheap tests, before tackling more difficult/expensive solutions. May be taken the engine apart is the only solution - but it is certainly the last ever considered. Now this said - unless you park her in the dealers yard and he is willing to fix it for you (which I doubt) ... if it was my bike, and after all you did already, I would do the following:
- first ask the dealer to use his connections, and organize a ride on another CB for me, just to be sure (that you can feel the difference),
- you said it's rpm/s not speed, so go to that rpm range in third gear (not higher !), pull the clutch AND keep the throttle open so the rpm doesn't fall off, what happens ? same vibrations, or less, repeat until you are sure;
- it can be rpm/s and NOT be the engine, we need to know for sure, which is very difficult to say at high speed and rpm/s with your hands tortured;
- strap several accelero-meters (best the recording type) to places like fork, engine, tail etc. and get the frequency spectrum read-outs for each to compare. where is the problem located, what is just resonating, resonances, all objectively (your wrists may just be more sensitive than other body parts; have some one who knows these devices check the read-outs for you.
If you don't know how to do this, there may be guys at the race track or (if you are near water) the power boat guys who may be willing to help with this. If not, local mechanics department at the university.

[lazz_imp]

lazz, really sorry to hear about this problem. As others said, there could be many reasons. But you would certainly go from doing ALL the easy/cheap tests, before tackling more difficult/expensive solutions. May be taken the engine apart is the only solution - but it is certainly the last ever considered. Now this said - unless you park her in the dealers yard and he is willing to fix it for you (which I doubt) ... if it was my bike, and after all you did already, I would do the following:
- first ask the dealer to use his connections, and organize a ride on another CB for me, just to be sure (that you can feel the difference),
- you said it's rpm/s not speed, so go to that rpm range in third gear (not higher !), pull the clutch AND keep the throttle open so the rpm doesn't fall off, what happens ? same vibrations, or less, repeat until you are sure;
- it can be rpm/s and NOT be the engine, we need to know for sure, which is very difficult to say at high speed and rpm/s with your hands tortured;
- strap several accelero-meters (best the recording type) to places like fork, engine, tail etc. and get the frequency spectrum read-outs for each to compare. where is the problem located, what is just resonating, resonances, all objectively (your wrists may just be more sensitive than other body parts; have some one who knows these devices check the read-outs for you.
If you don't know how to do this, there may be guys at the race track or (if you are near water) the power boat guys who may be willing to help with this. If not, local mechanics department at the university.

Thanks for that

Will try pulling the clutch even though I'm 99 per cent certain its the motor, it can't hurt to have more info...

I got a very experienced motorcycle mechanic friend (40 years experience) to ride it today and another friend who has ridden only Japanese I4s for about 15 years, they were both amazed at how rough it was.

In the affected rev range the resonance is very very strong. A lot more than one might get from a loose or overtensioned exhaust.

It can be felt everywhere, the seat, pegs and the tank as well as the handlebars.

It is definitely rpm related and not vehicle speed related.

The accelero-meters road sounds really interesting. I'm less enthusiastic about that than I might otherwise be as I have a LOT of work on this year, so I just can't let this become too much of a project... I bought the Honda hoping to just turn the key and ride. (I have rebuilt a fair few engines and gearboxes, made custom wiring looms etc in my time so I'm no stranger to projects!!)

A question for everyone that has me stumped, how does the balance shaft adjuster actually work? It was easy to set, but I'm having a bit of trouble visualising what's going on inside the carnkcase when the adjustments are made. And the parts book is not too enlightening...

Thanks everyone

[j3gq_imp]

Do very well understand the “project“ problem. Is there a chance to simply return the bike to the dealer for a refund ? Politely Tell him about the bad press this will generate for him online and in town, and twist his arms a little ... offer to buy another one from him ... and turn it into a win-win ?
I am sure you thought about this too, but needed some moral support

[michael1954]

Hi everyone,

recently bought a CB1100EX 6speed that had just been run in.

I really like the bike in all respects and it seems perfect for my needs.

Except, on my bike, the constant vibrations/buzz in the midrange (from 3K to 5K) are intensely intrusive. To the extent that on a recent 3 hour run, my hands and feet were buzzing for several hours afterwards. I was wearing full riding gear.

I have been riding for 20 years, everything form old brits to racing ducatis with many guzzis in between and a fair few inline 4s. My daily round town ride up until now has been a 1970 Triumph twin and that causes me no problems in terms of vibration! (I mean the thumping vibration is there, but it is transient, unlike the constant buzz on my new honda) Heck, I've been using a 1960s guzzi police bike for the past 4 years for my long distance work.... So I don't believe I'm overly sensitive to vibrations.

I use a motorcycle as my primary mode of transport and ride far and often.

There are a few others who have complained about vibration on this forum and many who haven't, what I'm trying to figure out is whether my particular bike has a fault or if this is just a characteristic of the model.

Do you all just keep the revs under 3k?

Does anybody out there have a bike that is smooth between 3K and 5K?

Any info/data points gratefully appreciated

Ride safe,

Hi, and welcome. I replaced the bar end weights with heavier ones off Ebay. I had not really noticed that much vibrations, but the heavier weights helped with what little I felt.

[jtopiso_imp]

sounds like the balance shaft is 180deg out of phase...

[Lord Popgun]

Lazz, the balancer is a gear driven weight. The adjustment is for adjusting gear lash.

Jt, if it is out of phase, someone was having a bad day. It has an alignment mark on the weight and crankcase for proper installation. This can be seen in the service manual. Plus some other assembly details for putting the parts on the shaft, etc.

[Whoops]

Watch the second half of this video…

https://youtu.be/mEgQmyknW_4

Not having RLET’s is known to cause a rough vibration in certain parts of the bar ends though.

[lazz_imp]

Lazz, the balancer is a gear driven weight. The adjustment is for adjusting gear lash.

Jt, if it is out of phase, someone was having a bad day. It has an alignment mark on the weight and crankcase for proper installation. This can be seen in the service manual. Plus some other assembly details for putting the parts on the shaft, etc.

Thankyou!