Tyre sliding around under straight line acceleration.

[roboR]

So as per topic, getting a bit more comfortable with my bike (2012 CBR600F) and the tyre slides out under hard acceleration. Not flat out acceleration, just anything a bit brisk.

Tyres are in good condition, and are Bridgestone S20 evo's so they shouldn't be a problem. I'm guessing it's the walley behind the controls (me)?

However it just seems a bit odd as I really don't feel like I'm accelerating that harshly, and it really seems to spin out quite a bit. Any other possibilities or I'm just an idiot?

Tyre pressure I should add is the correct manual (and bridgestone) stated 36/42. However I do live in Gibraltar where it's 30+ degrees and road temps are hot. Could this be making that temp too much perhaps?

[roboR]

Haha thanks! It's my first bike and I've had it since around October last year. Was getting more and more comfortable on it... and since summer have been getting less and less comfortable. Is there a method for dropping pressures? Like should I do 34/40 or less?

[roboR]

Ok thanks will try that. It's weird as I would have thought the front would lift before the back slid out.

[roboR]

Girlfriend was walking past (hadn't seen her and wasn't showing off lol) and literally messaged me straight away saying that I drove past her fast and the back was swinging from side to side

And yeah, normal tarmac and not aware of any loose gravel. Clutch was totally out already. I had gone alongside a bus so was in first going slowly, clutch out totally, once I got past it I began to give it some revs (quite a lot, but nothing crazy) and that happened.

I'll drop it down sometime and take it for a spin, and then check pressures once warm. I'm guessing for road use I'd like them to be around that 36/42 but hot?

[roboR]

Also thanks for all the help! I lurk this forum ALL the time since I got my bike but never post. I'll get some pics up in the pic a day thread etc to say hi

Edit: I should add that I mentioned this to a friend and he said that there's building works alongisde where I was so it's possibly it was dusty etc and I didn't notice. Just never had this before until summer hit, and suddenly it seems to happen to me every few days.

Edited by roboR on Saturday 18th July 18:02

[roboR]

Jazoli said:

Measure your pressures cold as they will always vary when warm, use 36 for the rear tyre, I lived abroad for quite a few years and ran lower rear pressures because of the very slippery road surfaces everywhere, and didn't die once, or have any unintentional wheelspin, on a 135bhp bike, never mind a 95bhp 600

Hey MCN says 101bhp haha. Gotta be triple digits haha. Thanks though will definitely try lower pressures.

[roboR]

barker22 said:

Maybe she's trying to tell you to lose some weight

epic haha. She did ask me to join her gym the other day...

[roboR]

Since there seems to be a load of different opinions I'm just going to take it to a garage this week and get it looked at. Another friend said my chain could be loose. I don't think it's the frame since it's only been dropped once and that was stationary (stepped in some oil), never crashed.

Going to take it to a friends garage and see what it is. At least it makes me feel it's not me being super ham fisted or something. Thanks everyone

[roboR]

Biker's Nemesis said:

Just say you're awesome like the rest on here as to the reason why your tyres is sliding.

Oh of course that must be it, I'm backing it in... on the straights

drdel said:

You'll need grip on the rear if you want to wheelie. If the backend feels loose I'd check your rear suspension bushes and the shocker.

Well doing a wheelie isn't my goal, just brisk acceleration. Although a wheelie would still be preferable to the back sliding out!

[roboR]

civiclegend said:

Its the tarmac, highly polished, sun-abused and rarely resurfaced. Greece is the same, you can get squirly on a 125 cc step-through if you gas it coming out of a corner too hard, absolutely hopeless, and a nightmare if it rains. Alway remember seeing a guy riding a ZX12 on Rhodes, and you could hear the rear refusing to hook up on that polished surface. Lower pressures will help, but realistically just take it easy on the lean angle, especially combined with lots of throttle.

Happens to me on the straights

[roboR]

CypSIdders said:

Any news on this, OP?

Sadly been so busy with work I've not had a change to take the bike in! I've been doing the European thing and borrowed my mums 125cc scooter for the time being!

Next week I'm going to take it round (hopefully Monday morning).

[roboR]

UPDATE

So it went to the garage fella this morning. He confirmed bearings, chain and tyre wear is all fine. He said it's... tyre pressures.

Well strictly speaking he said it could be a few others things also but running on 36/42 in Gibraltar is too high. He comes well recommended from bikers here (owned 47 CBR's, had his garage for 15+ years etc) so I'm going to go with what he said.

He booked me in for next Wednesday for a proper check on the full bike. In the meantime he charged me nothing for looking at it quickly, and he dropped my pressures to what he recommends (30 front and 35 rear). He told me to drive it around till next week and if it seems fine to call up and cancel the booking. If it keeps happening then to come in and have his mechanics check everything.

Seems almost too good to be true, but since he didn't charge me anything and told me to cancel the booking if it rides fine the rest of the week then he's definitely being honest with what he thinks it is at least.

None of his mechanics batted an eyelid at lowering the pressure so I guess it might be fairly common here.

TL/DR: High tyre pressure and I can't ride a bike very well.

Edit: Kinda funny also that he said around corners it could be because of the chicken strips Said you can see I've been out to the edges a few times, but mainly ride around the middle few inches

I said I'd just got the bike pretty recently (Dec/Jan) and was building up more confidence, then summer hit and I started sliding everywhere so became like a granny hah.

Edited by roboR on Wednesday 29th July 12:56

[roboR]

moanthebairns said:

so we had, loose chain, chain lube, shockwaves from the Pompeii eruption, aftermarket levers, dust on the road from halley's comet, brakes binding, bent frame, the glare from the Aurora Borealis glazing the pads....

And basically I'm a noob

[roboR]

Deranged Granny said:

With the bike being newish and in good nick, it was only ever going to be down to pressures. They make such a massive difference.

Yeah. He told me that while it is the recommended pressure it is also the 'max' pressure as on my bike it's the same pressure they recommend for fully laden with a pillion passenger so not ideal.

I've asked about tyre pressures before on another forum and was told to go by the book, which is I guess the 'right' answer to say, but hopefully now my problems will have gone away. Going to let it warm up and then thrash it in first gear somewhere in a straight line and pray it doesn't slip out. In winter when I first got it and was getting used to it I got fairly confident (in a straight line that is ) and would apply a lot of throttle in first (ie. coming through a toll booth) and I'd feel the front get light and lift up a tiny bit before I changed gear. It felt awesome. But now the past few months it would just spin without even feeling like I was really flat out.

[roboR]

sc0tt said:

Im impressed that the tyre breaks traction before the front end comes up.

I'm not! I'd much rather wheelie than slide everywhere

[roboR]

sc0tt said:

Yes most obviously. But hot Tarmac in this case.

It's fairly hot here: http://www.mirror.co.uk/news/weird-news/watch-woma...

Edit: Just realised that's exactly what you meant doh. Yeah it might have been the road, or me being an idiot. I guess I need more experience in any case.

[roboR]

Insulted by loon, guess that makes me a proper bb member now lol.

Gibraltar is entirely slow town driving, we have a max speed limit of 50kph. if you can get to the edge here you'd have to be driving pretty dangerously. I work most weekends but when I get one off I go to Spain where there are awesome roads. That is why I've gone do the edge a few times, but mainly drive in the middle. Also I'm a stty noob. l
And I said I drove like a granny after it started slipping all the time.

Oh and it's definitely very side to side, I'm not imagining it.

As for ham fisted, yup probably likely. I've said many times I'm a noob to all this, hence asking on here and the garage. All gotta start somewhere. Thanks for all the advice given everyone.

[roboR]

Guess I didn't explain it well. I got the bike Jan time. Started driving and loving it, going to Spain and driving there, which is where I'd go low(ish). In gib I don't go low at all, hence middle is most used as its just stop start town driving. The spinning out started happening around 6-8 weeks ago. First on a roundabout, but then on the straights three times, all doing the same thing, fast acceleration in first. Once it started happening it made me drive like a granny as I thought there was a problem with the bike. Once I've been told its me as an idiot I've relaxed a bit and will use it more again. Basically I was gaining more and more confidence until this started happening. Sorry for errors, typing on my phone.

[roboR]

Oh and I should add (to appease further questioning) that near the edge means half a cm away. And when I say I've relaxed since being told the bike is fine I don't mean I've gone crazy. I've realised how rubbish I am, so trying to learn more and take it slowly.

Edited by roboR on Thursday 30th July 09:01

[roboR]

CaptainSlow said:

If you're going for long spirited rides in hot temps on hot roads I still think your pressures are too high. I was running F32/R30 on track a couple of weeks ago and run about 36 or 38 on the rear throughout the year on road.

Hi thanks! Yeah the garage recommended 30 front and 35 rear so I'll go with that for now and see. The bike is infinitely better than I'll ever be, but having it happen so often really knocked my confidence.