CBR650R Bike pulls right

[Hagen]

Hello everyone!

So I have had my '19 CBR 650R for some time now and noticed, that it won't drive straight without my hands on the bars.
This Issue persisted since i bought it and started to bother me recently,
when I had it in for maintenance and got a '21 650r as a replacement for the weekend, which drove (mostly) straight.

My dealer said that they did not notice anything and told me about uneven roads and water drainage, so i let some friends investigate, and confirm my issue.

It is not very noticable during normal riding, but really shows when i lean back and coast without hands. I have to correct my body position far to the left to make the bike drive straight. After that, it drives stable and can handle some corners by tilting as usual.

Now, I started checking alignments, loose bolts, fork play, repositioned the fork and rear wheel and could not alter the result whatsoever, everything seems fine. My last assumptions are unevenly worn tyres or a twisted swing arm (preowner did wheelies/stoppies).
I bought it with 16k km and am currently at 19k

I will do a tyre change in a while and have my hopes up, but I am not sure if this will solve the problem.

Has anyone else perceived this or heard of a solution?

 

[Brammers]

You've covered most things. Are the tyres a matching brand?

If they have different profiles all sorts of fun things will happen. I might have to let some of the resident experts have a go

 

[Hagen]

Yes, the tyres are Pirelly Angel GT 2, since 12k ( handle very good btw ).
They currently have about 2mm left and look rather evenly worn, maybe a little flat on the rear, thats my only concern.

 

[Cbat]

Are unconsciously leaning just slightly from the bike's CG? Leaning back from the bikes CG would accentuate any offset with your weight. Just a thought, try and shimmy slightly left on your seat and try again. Reaching for straws here.

 

[Hagen]

Well that's what I already have to do. If I sit conciously straight (arms straight against the bars, crotch to the tank etc.) and let off the bars, the bike wants to go off the road within 5 seconds.
If i only lean, I almost fall off the bike, so I sit a little to the left and it gets easier.
I have the vague feeling, that I have to correct less if I lean backwards and lay on the pillion seat, but I'm not sure about that. ( only on safe and empty roads of course, I'm not trying to kill anyone, I swear! )

I also have experience on other bikes and usually, I don't have to adjust to drive straight, so I guess it is not just my fault.

Thank you for your feedback so far!

 

[FogDucker]

You are a man. One side is always heavier
is your back wheel aligned with the front? it is hard to be seen with eyes. you need tools for it.

 

[Hagen]

I tried to align it, and even over exaggerated in both directions. It did not really change, for better or for worse.
I don't even know if it should change, because both wherls can just move Independent from each other.

 

[MrFritz86]

I was experiencing the same thing with the stock tires.
After I swapped them with Rosso III, the issue was gone.
Not sure if it was wheel alignment or the tires, but glad to find out it was fixed.

 

[Enrico]

My cb650f turned very easily so I don't think I would have wanted to take both hands off the handlebars anyway ( as I wouldn't with any bike ) I suspect a lot of bikes would pull to one side because of road camber for one thing !

 

[Madabtpr3]

I am having same issues even changed tyres and ex owner had installed aftermarket forks but don't know not able to sort out.

 

[Ajax_650]

Was it ever dropped or crashed? maybe bent frame

 

[Bran]

I'd go to a tyre issue after what you've checked. I know cars are different but have seen loads with tyre wall damage to the inner tyre wall due to speed humps. If the alignments good tyre drag can cause the issue