Changing Tyres from a 60 to A 70

Hi all

Just a quick question. Just updated my bike with new Tyres. Went from a
60 to a 70. Should I drop my forks by 10 mm?

 

I once put a 70 profile tyre on the front of the CBR600 I had, and it made it very stable through
sweepers. Made it a little bit harder to tip into corners, but the difference was minimal, and I
quickly got used to it. I didn't bother with changing the fork height or suspension settings either.

 

would that be profile going from a 60 to a 70 ?

have you ridden it ???

why did you change the profile ???

 

Yes its seems ok, havn't leant it right over yet since still a little
green. I've read somewhere that it can change the handling of the bike and
was just wondering if this could be bad.

Didn't mean too, store just chucked them on, didn't realise until I got
home. Guess its my fault anyway because I didn't specify. I just said
"chuck some Dunlop 208 on her thanks" as they had a sale them ($385
installed) and I was blinded by the figure thinking hmm thats 1/2 a track
day price I have just saved and, hmm you know $100 could buy a nice set of
gloves ;-P.

 

I raised the forks through the clamps by 10mm when i went from a sixty to a
70
on my r6 and yes it makes a massive difference.

Handles so sweet now.

 

I went from a 60 profile to a 70 profile (free front tyre!) on my 1999
R6 and it turned into a tankslapping monster. I guess the weight was
shifted slightly back and the sharper profile didn't help.. nearly
ended up in the water on the way to Wiseman's Ferry one day. But you
didn't say what bike, and R6's are pretty knife-edge at the best of
times.

It'd only be 5mm anyway, not 10mm.

Agg

 

R6 I assume ?

Depends on how you ride it, if you ride like grandma don't worry about it !

By increasing the size of the tyre you've increased the rake a touch.
Dropping the rake by pushing the forks up through the triple clamp will
compensate for the change of geometry, as will raising the ride height.

Recognise that the "60" and "70" are percentages not mm and that's being
translated through an angle at the steering head (24.5degrees from
memory), so you can't simply say "move it 10mm to compensate" I'm sure
you could work it out precisely with trigonometry but I'm not about to
do so for you

Having pointed out that your conclusion to move 10mm seems to be based
on an incorrect assumption, it is actually about what I'd move it
initially Trial and error to get the right setup unless you know
someone who's raced one (try googling it might be on the 'net somewhere)
as I believe most of the racers use a 70 profile slick on the R6 instead
of the /60s as they're not available (where's Daron ?)

JL
--
Australian Financial Review 17 August 2004
"So far Howard's luck has survived a great deal: his move to dismiss
broken election pledges by distinguishing between "core" and "non-core"
promises; his retrospectively time-limited "never ever" pledge on the
goods and services tax; his vagueness about when he committed Australia
to war against Iraq; his shifting standards for ministerial conduct; his
demonising of asylum seekers as child killers; his tendency to blame
"advice" rather than to openly accept responsibility when things go wrong."
Will Howard's luck survive another election ? Do Australians not care
that their PM is a liar ?
http://www.johnhowardlies.com/

 

I'm here

R6's don't run slicks here or anywhere else in the world unless club racing.

You are correct in the 10% increase of width of the tyre. But it doesn't
equate to 10mm by a long shot.

There are many different ways to get around the "new" tyre is going to cause
drama syndrome. As has said before - it all depends on the rider, the types
of riding & the previous setup of the machine.

Pushing the forks through may work for some but others may want to drop them
through a couple more mm as they prefer the new setup.

change the tyre, ride it.. Push the forks through, ride it, drop the forks -
ride it..

Is the tyre the same compound & construction? Maybe a few clicks here &
there to adjust to the harder(or softer) sidewall. Bridgestones tend to have
a harder sidewall than Michelins but that mainly depends on the compound of
the tyre.

Basically - if what works for one rider, _may_ work for another. Thats why
motorcycles are such a personalised machine.

 

ooops

Forgot about the new Formula Xtreme Class in the USA.
They run slicks

 

Just a thought...be carefull if you stack it & the insurance dood knows
enough to look at the tyre. They love a non spec bike to get out of a claim.

 

Do you still have sufficient clearance between your tyre and mudguard? [1]

--
Conehead
[1] Put a 70 instead of a 60 on a ZZR600 then rode it on a clay road in the
wet. It was the very epitome of shitfulness.

Forks?! Fark.

 

Well I don't hear scrapping so I guess thats a good start. I think it will
be fine unless I go through mud

 

What bike is this for?

 

Yamaha 03 R6

 

Change your fork hight for sure
6-10 mm

Check this site out for info on r6s

http://r6messagenet.com/forums/

 

High speeds will make the tyre taller, possibly rubbing on the guard..
another issue I had on my R6 when playing with various tyres.

 

Well all I have just changed the forks height by 8 mm. I must say the
change in handling was very noticable. Seems that bike has alot more
confidence about it and is more happy to lean. Bike hasn't felt this good
since the original set of tyres. I am sure this was what was causing the
falling feel I had with the last set of tyres I had when lent over, I bet
they where 70s as well. Oh well. I'm off to a track day tommorow and will
tell you how it goes. May have to continue playing to get it 100% right

 

Shit!
That tyre's *huge*!
My postie bike only runs a 2.75 at each end...

Pat

 

Upgraded the front from the 2.50 eh Pat.

Theo

 

Standard size---but BTH's CT90 has "2 3/4" size tyres...

Pat