(Sensible) Advice Wanted - cornering and road camber

I've got my first bike since passing my DA course last May.

I got a '04 TW125 (trailway) because it was a very good deal and having been
using a Honda C90 for 3 years I decided it was time to get something with a
bit more in the way of tyre width, which I thought would give me more grip
and stability on shit roads.

I like it and it's rekindling the enjoyment I got when I was on the 500's
doing my test. But....road camber is affecting my ride especially on
corners, I am taking them a lot wider and possibly slower than when I was on
the C90. I am wondering if it's my riding skills having evaporated over the
last 8 months, or is it possible that the rather fat back tyre is having an
adverse effect and pulling me with the camber? Is it possible to have a tyre
that gives too much road contact and affects the ride?

Oh and before someone recommends a ninja or other large bike, I go 10 miles
a day to the train station in a 30 mph area, hence a smaller bike being
used.

Cheers,

Joe

 

joe says...

Check the tyre pressures and also wheel alignment to start with.

 

Not knowing what a TW125 looked like I had a google. A 180/80 tyre is
going to feel different to what you had on the C90. The front tyre also
looks pretty chunky.

My Morini has a really skinny front (90/90) tyre and I notice the
difference when I get on something more modern. IMHO I do reckon it is
possible for a bike to be 'over tyred' for its size and weight.

You may get used to it in time if you persevere with it. It will need
more 'input' than the C90. I can almost think the Morini round a bend.

A riding god/technical expert will be along shortly to say I am talking
bollocks.

--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

If I can contribute something here... I fitted an oversized tyre to the
front of the SOGS when it was all I had available at the time. It
affected cornering quite badly; sure, I got used to it and just put the
bugger round the bends anyway, but it wasn't pleasant and as soon as I
could I fitted the right size.

 

Good advice from Lozzo.

Tyre sizes are 130/80x18 Front and 180/80x14 rear according to
Bridgestone at http://snipurl.com/1900g - pressures given as F 1.5 and R
1.8 bars (1 bar is approx 14.5 psi)

Assuming they are the correct sizes, are they a matched pair? Are they a
good option for road use? Some trail tyres will give an odd or unsettling
feel to a novice.

I've not ridden this model but, as PF says, the bike probably requires a
lot more steering input than you are used to. I've ridden quite a few other
trail type bikes on the road and they need a firm push on the bars to get
them to turn in. On long sweeping corners, like roundabouts in towns, they
will need a fair bit of countersteering to keep them on track too.

 

It has been mentioned checking the alignment and tyre pressures, also, when
the rear tyre is mostly worn and squared off it can give an odd feeling.

I've ridden a few TW125s and they all feel a bit odd in corners. They need a
firm hand on the bars and react much better if you corner on a gently
rising throttle. Once you are used to the amount of steering you need
through the bars, they do corner quite well, in a squidgy, boingy vague
way.

 

Will check em out in daylight. Thanks for the tip.

Joe

 

Thanks for that. Now given I don't even know what 'a firm hand on the bars'
is, I reckon that means I need a trip to the bike school for a lesson.
Unless it means steering a bit more and being firm with it

Joe

 

The thing that has prompted me to ask here was today, coming down a
residential street towards a T junction which is a hill (so I am on the side
of the hill coming to where you go left down the hill or right up it). I
wanted to go right, did the usual, and found the camber of the road pulling
me to the left quite badly. So much so that when I came to the junction I
was at the left kerb at what would have looked like a nice controlled stop
if it wasn't for the righ indicator. Thankfully there was only a ginger
woman around 100m back so no harm or embarrassment caused.

I've got into the habit of easing off throttle when I experience the adverse
road camber, and this may have increased the pull, I'm not sure as I have
not tried to 'power out' of one before.

Joe

 

it's good etiquette to strip out people's "sigs" i.e. the part below the
"--" - a proper news client would do it for you....

Sounds like you are not positioning yourself at the T junction in a way
that will help entering the main road. In such situations I would
approach the T junction at an angle so that I was facing uphill
slightly. If you need to stop then put your right foot down as the
ground might be falling away on the left. When you pull away you will be
doing more of a hill start rather than turning a corner against a
camber: of course, if you can't get your left foot down then you would
need to be confident doing a hill start just using the front brake!

Bad practice: easing off the throttle will make the problem worse. AS MB
says, you need a good positive throttle as well as the correct steering
input.

 

If you ride your bike as well as you format your posts here, I'm not
surprised that you're having problems.

A 'firm hand' means that you deliberately put the little beast in to
the corner, don't just think about doing it - shove your inside
shoulder at the apex, shove the bars the right way and look where you
want to go. You should always corner on a positive throttle
(accelerating, then) as this will make the bike run around the line
you want rather than wandering wide.

I put a wider tyre on my RF900 - it takes a 170 section, but I put a
180 on it. The already vague turn-in characteristic became full-on
understeer and it needed effort to get round each corner. This is a
comparatively mild comparison to your very light, underpowered machine
with a fat, knobbly rear tyre.

Get some advice, get some lessons, get a real bike.

Learn to post correctly, learn to snip posts and sigs, get a sig sep.

Lessons for life, Joe.

 

From:

http://www.dooyoo.co.uk/motorcycle/yamaha-tw125/333005/


"Although I could reach the ground easily, I found that the combination of a
high centre of gravity, highish seat and wide bars made the TW125 difficult for
me. It felt really rather vague and wobbly, and the gearbox sometimes gave me a
few niggles, particularly when changing down into first gear. The TW lacks the
friendly low-speed control and low centre of gravity of the SR125, and
consequently isn't as learner-friendly. It's also rather heavier than the
SR125/DT125, making it comparatively sluggish in both speed and handling"


QED, Sell it.

 

Most bikes do. Technically, cornering is acceleration (change of
velocity, which is a vector quantity), and to accelerate you need to add
power. At least, that's what I'll tell the Judge if push comes to shove...

--
Ivan Reid, School of Engineering & Design, _____________ CMS Collaboration,
Brunel University. Ivan.Reid@[brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

 

Although to be fair, that's probably not sound advice when you're
coming up to a T junction.

 

try telling that to the scooter riders I was contending with last week

in Napoli

<fx beeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeep>

 

You've seen a TW125? A more cartoon-like bike is difficult to
imagine.

 

I guess that physics is not your best subject.

 

Using the patented Mavis Beacon "Hunt&Peck" Technique, Eiron

I guess that you're really rather stupid.

What did I win?

--
Wicked Uncle Nigel - Podium Placed Ducati Race Engineer as featured in
Performance Bikes and Fast Bikes

WS* GHPOTHUF#24 APOSTLE#14 DLC#1 COFF#20 BOTAFOT#150 HYPO#0(KoTL) IbW#41
SBS#39 OMF#6 Enfield 500 Curry House Racer "The Basmati Rice Burner",
Honda GL1000K2 (On its hols) Kawasaki ZN1300 Voyager "Oh, Oh, It's so big"
Suzuki TS250 "The Africa Single" Yamaha Vmax Honda ST1100 wiv trailer

 

Wicked said:

Being fair - he might be right. Ivan could be a nobel prize winning
flower arranger on the quiet.

A weekend of your choice with Ivan.

 

Using the patented Mavis Beacon "Hunt&Peck" Technique, Simes

True, true.

Oh. What's second prize?

--
Wicked Uncle Nigel - Podium Placed Ducati Race Engineer as featured in
Performance Bikes and Fast Bikes

WS* GHPOTHUF#24 APOSTLE#14 DLC#1 COFF#20 BOTAFOT#150 HYPO#0(KoTL) IbW#41
SBS#39 OMF#6 Enfield 500 Curry House Racer "The Basmati Rice Burner",
Honda GL1000K2 (On its hols) Kawasaki ZN1300 Voyager "Oh, Oh, It's so big"
Suzuki TS250 "The Africa Single" Yamaha Vmax Honda ST1100 wiv trailer