Corsa III 190/55 and 'hooked'!

R5vmille

Joined Jul 2009

94 Posts | 0+

Dorchester, Dorset

Discussion Starter
• Sep 9, 2009

• #1

I made some changes today, my 'hooked' airbox modification kit arrived today
:doug
so lunchtime today I put it on, a simple 20min job. It's a nice quality bid of kit and it all fitted perfectly.
While I was at it I changed my rear tyre for a Diablo Corsa III, 190/55. I did have a corsa 180/55 on there, but felt like i needed more stability/ confidence at greater lean angles, I read good things about the 190/55 size, that they're just as quick to turn with less chance of, or feeling like your running off the edge than on a 180/55.

So, I was looking forward to the ride home tonight! dry and sunny too for a change The hooked airbox... WOW what a great noise :biggrin and a performance improvement to boot. The tyre feels good at first impressions but I think I need to drop the forks in the yokes a bit (higher at the front) to compensate for the taller tyre? not sure how much :dunno any suggestions?

 

buffalo

Joined Mar 2009

169 Posts | 0+

newcastle, england

• Sep 9, 2009

• #2

why do you feel you need to make the bike higher at the front

 

R5vmille

Joined Jul 2009

94 Posts | 0+

Dorchester, Dorset

Discussion Starter
• Sep 9, 2009

• #3

I'm no expert here and I'm sure others will be able to confirm or correct me, but here goes..
because the 190/55 is a taller tyre than the 180/55 (the 55 is a percentage so therefore taller profile) so with standard fork height, the steering geometry has changed, and to put it back to standard, the front needs to be raised to match the difference between the height of a 190/55 vs 180/55, about 5mm by my calculations..

 

R5vmille

Joined Jul 2009

94 Posts | 0+

Dorchester, Dorset

Discussion Starter
• Sep 9, 2009

• #4

just thought, that's probably not what you were asking,
with the low front, the steering is too quick and on a constant corner at neutral throttle, it's trying to fall into the corner.
Is that what you meant?

 

J

jon_melson

Joined May 2009

279 Posts | 0+

• Sep 10, 2009

• #5

I run a 190/55 after swapping from a 180/55 and experienced no issues with the bike falling into the corner.

Apart from the additional grip, I didn't feel the bike really handled any differently.

Were you happy with the bike's set up before?

Most riders agree that bikes leave the factory with slack geometry anyway- most people raise rear ride height and drop the forks through the yokes if they're doing any serious track work.

It is preference though, and of course your weight will make a difference. I'm just under 15 stone so naturally find suspension too soft and rear ride height too low.

 

buffalo

Joined Mar 2009

169 Posts | 0+

newcastle, england

• Sep 10, 2009

• #6

yeh, if its steering to quick for your riding style compared to when it had the 180/55 on, best set it up, i just found mine handles better with a 190/55 plus the front lowered to 4 rings showing and the rear lifted by 5mm.

 

R5vmille

Joined Jul 2009

94 Posts | 0+

Dorchester, Dorset

Discussion Starter
• Sep 10, 2009

• #7

jon_melson said:

Were you happy with the bike's set up before?

.

Click to expand...

I raised the front 5mm today, and on the ride home the bike setup felt the same as it did on the 180/55 I guess it's nice being familiar again, The stability and feeling of grip is definitely improved at high lean angles and I'm more confident with it. Can't see any down sides to it really! I may experiment with lowering the front again if you guys find it good, I was a bit worried about making it tank slappy? :dunno

 

buffalo

Joined Mar 2009

169 Posts | 0+

newcastle, england

• Sep 10, 2009

• #8

if your happy with it bud, then its right for you:thumbup

 

1

1066RSV

• Sep 11, 2009

• #9

R5vmille said:

I'm no expert here and I'm sure others will be able to confirm or correct me, but here goes..
because the 190/55 is a taller tyre than the 180/55 (the 55 is a percentage so therefore taller profile) so with standard fork height, the steering geometry has changed, and to put it back to standard, the front needs to be raised to match the difference between the height of a 190/55 vs 180/55, about 5mm by my calculations..

Click to expand...

Yes 2.5mm it will make it higher at the rear.:thumbup
I know cos I have all the same as you except a Bridgestone 016 190/55.:thumbup

 

1

1066RSV

• Sep 11, 2009

• #10

R5vmille said:

I raised the front 5mm today, and on the ride home the bike setup felt the same as it did on the 180/55 I guess it's nice being familiar again, The stability and feeling of grip is definitely improved at high lean angles and I'm more confident with it. Can't see any down sides to it really! I may experiment with lowering the front again if you guys find it good, I was a bit worried about making it tank slappy? :dunno

Click to expand...

Now you will have raised the front by 2.5mm

 

J

jon_melson

Joined May 2009

279 Posts | 0+

• Sep 11, 2009

• #11

Na.... the front is still lower isn't it?

55% of 180 is 99mm, and 55% of 190 is 104.5mm.

So the sidewall is 5.5mm taller all the way around, hence rear wheel spindle is 5.5 mm further off the ground.
Lifting the front 5mm still leaves the front theoretically .5mm lower than before doesn't it?
God, I'm a sad little man. Sorry, I'm a bit anal sometimes!!! 190/55 still sounds like the ideal tyre to me, so best of luck to ya R5vmille.
Sounds like your bike is handling on the money!

 

R5vmille

Joined Jul 2009

94 Posts | 0+

Dorchester, Dorset

Discussion Starter
• Sep 11, 2009

• #12

1066RSV said:

Now you will have raised the front by 2.5mm

Click to expand...

by my calculations mate I make it,
180/55
sidewall height = 55% of 180mm = 99mm

190/55
sidewall height = 55% of 190mm = 104.5mm

a difference of 5.5mm in side wall height.

 

V

Vince

Joined Dec 2008

201 Posts | 0+

Cornwall

• Sep 11, 2009

• #13

Have a look at my thread,I whent from a 180/55 BT016 to a 190/55 BT016 & they measured 10mm difference,I lowered the rear 4mm & raised the front 1 ring,handleing was brilliant!