Tyre sliding around under straight line acceleration.

Tyre sliding around under straight line acceleration.

Author
Discussion

roboR

Original Poster:

199 posts

106 months

Saturday 18th July 2015
quotequote all
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?

moanthebairns

17,918 posts

197 months

Saturday 18th July 2015
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Yes. Reduce pressure


roboR

Original Poster:

199 posts

106 months

Saturday 18th July 2015
quotequote all
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?

moanthebairns

17,918 posts

197 months

Saturday 18th July 2015
quotequote all
Go out a spin. See what they are when hot.

They say tyres in the heat can go up as much as 15 percent.

So yeah that wouldnt be a million miles out.

roboR

Original Poster:

199 posts

106 months

Saturday 18th July 2015
quotequote all
Ok thanks will try that. It's weird as I would have thought the front would lift before the back slid out.

Jazoli

9,086 posts

249 months

Saturday 18th July 2015
quotequote all
Set your rear pressure to 36psi, that should fix it.

dean100yz

4,276 posts

183 months

Saturday 18th July 2015
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You'll be hard pushed to ever get a rear to spin in dry on a straight road

You bike has circa 100bhp. If its its revving up look at other area's like clutch slip etc

Tyre pressure at 32-42 wont make that much of a difference as mentioned earlier ideal pressure will get it handling better

Unless the ground is loose, wet or there is another underlying issue I would be very surprised that its wheel spin (Not doubting you but as you said you are new to it)

dean100yz

4,276 posts

183 months

Saturday 18th July 2015
quotequote all
Just read the last bit - given the road conditions I take that back. I have been abroad and on small island roads in Europe where they get shiny and real hot I have experienced similar.

Definitely dropping pressures I think would help. Its not something you really find in England

roboR

Original Poster:

199 posts

106 months

Saturday 18th July 2015
quotequote all
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 biggrin

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

Original Poster:

199 posts

106 months

Saturday 18th July 2015
quotequote all
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 biggrin

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

Jazoli

9,086 posts

249 months

Saturday 18th July 2015
quotequote all
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 smile

barker22

1,037 posts

166 months

Saturday 18th July 2015
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roboR said:
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 sidebiggrin
Maybe she's trying to tell you to lose some weight wink

roboR

Original Poster:

199 posts

106 months

Saturday 18th July 2015
quotequote all
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 smile
Hey MCN says 101bhp haha. Gotta be triple digits haha. Thanks though will definitely try lower pressures.

roboR

Original Poster:

199 posts

106 months

Saturday 18th July 2015
quotequote all
barker22 said:
Maybe she's trying to tell you to lose some weight wink
biggrin epic haha. She did ask me to join her gym the other day...

s3fella

10,524 posts

186 months

Sunday 19th July 2015
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Do you have aftermarket brake levers? Is your front brake binding?
I'm with otters that think it unlikely to be sliding about like that unless there is something real wrong. Even on a oiled dirt track I'm not sure it should swing side to side on a straight.

Fastdruid

8,623 posts

151 months

Sunday 19th July 2015
quotequote all
Something is wrong.

Standard tyre pressures shouldn't make that kind of difference until the the tyre gets hot, even at 30deg.

So either the roads are slippery or something is broken.

I suggest you check your rear damping.

A lack of damping will result in the tyre bouncing and losing traction.

Golgarth

380 posts

197 months

Sunday 19th July 2015
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Are you leaning hard over the front? Sit back and get some weight over the rear, unless the road is like glass I can't see how it would be weaving side to side?

Mastodon2

13,818 posts

164 months

Sunday 19th July 2015
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Is the frame straight?

moanthebairns

17,918 posts

197 months

Sunday 19th July 2015
quotequote all
He's in 30 degree heats, which means his tyre and road temp could be way higher.

Lower them. That's it. Probably

There's no need to go searching for the answer he knows it himself.

CypSIdders

842 posts

153 months

Sunday 19th July 2015
quotequote all
Having owned and ridden the same bike, on 36, 42 tyre pressures, in far war warmer conditions than the OP's, I've never experienced the poblems he's highlighted. I would say you can rule out tyre pressures as the cause!
Other than dust on the road, the only thing that caused wheelspin for me, was riding over those tarmac snakes that seem to be the norm for repairing cracked road surfaces, in hotter climes!