Motorcycle Owners Club

Honda CG125 but also some universal motorcycle information

Honda CG125 Tyres

Tyre Pressure

Front Disc Brake model, Front 25 psi, Solo Rear 29 psi, Passenger Rear 33 psi.
Front Drum Brake model, Front 25 psi, Solo Rear 28 psi, Passenger Rear 32 psi
1976 to 1984 models = 17 inch rear wheel = 40 psi.

Always test tyre pressure with a stone cold tyre (leave overnight to cool).
Stay away from garage air pumps (they can substantially over or under inflate motorcycle tyres).
Large changes in outside temperature will change pressure in tyre.
Dependant on inner tube or valve, tyre will lose air dependant on ether length of time or mileage (or speed and mileage).

When is a Tyre Worn out

A tyre (tire) will wear out,
you will probably find the bike suddenly feels like it's riding on ice round corners and goes round like a lorry.
In old age, the tyre can suddenly lose its strength or collapse leaving the inner tube to take the weight;
this will also lead to very bad cornering.
The tyre manufacturers recommend you have 2 mm of tread left in order to grip a wet road.
I have often found tyres are worn out at 2 mm or just below, the tyres feel like you are riding on ice even in the dry.
But it will depend on the make and model (some designs of tyres may not show any signs even with no tread left).
In the UK the legal minimum tread depth is 1 mm.

How to mix Tyres

It's important that the front and rear tyres are designed to work together,
mixing different makes and models is a bad idea unless the manufacturer states they are designed to work together.
It's also a good idea to change both tyres at the same time (unless the front lasts twice the mileage of a rear),
since the old tyre affects how the new tyre runs in,
also tyres go round bends differently when they are new compared to worn
(you want both the front and rear tyres to go round a bend the same).

How to avoid falling off the bike with new Tyres

When you have new tyres, there is a manufacturing residue left on them that needs to be worn off.
The amount of residue and slipperiness depends on the tyre; the manufacturers advise you to run a new tyre in for 150 miles.
You must start off slowly, reduce your speed, acceleration, braking and cornering.
Slowly increase your speed, acceleration, braking and cornering during the 150 miles.
This running in time will also teach you how the new tyres corner and perform,
your old tyres at the end, are totally different, even if they are the same make and model,
since they are a different shape due to the unevenly worn parts of the tyre.
A tyre that runs in a straight line most of the time, wears more at that part than the cornering part.

Many people have dropped their bike on the first bend they come to on new tyres since they forgot about running in the tyre.
Even experienced riders with large expensive bikes have made the same mistake,
do not make the same mistake and be very careful for the first few miles
(I keep speed below 40mph and do not lean the bike on any bend for the first 5 miles).

Inner Tubes

I highly recommend you use a quality branded inner tube,
cheap unbranded / Chinese ones may cost far less but I personally would worry about the quality
(air loss or even a lethal blow out).
The inner tubes do not need to be replaced every time you change the tyres (but tyre manufacturers recommend you do),
it depends on age, if there is a problem the shop should tell you when they see them
(they will look for cracking, stretching and other ageing things).
I have been told by tyre fitters they have seen 10 to 20 year old inner tubes that have been used and are still fine
(that does not mean every inner tube is at that age).

Tyre Makes and Models

The quality, performance and safety of the tyres you buy are critical to your safety and enjoyment.
As well as how many miles they manage and many other things.
I very highly recommend you never use a low quality brand of tyre on any motorcycle.
There have been so many reports of people using Chinese brands and falling off as a result.

The Michelin Pilot Sporty was discontinued in 2014, in my opinion and others it was the very best tyre.
I have not read about anyone comparing the Michelin Pilot Sporty to the new Michelin Pilot Street (see below).
The Pilot Sporty was marketed by Michelin as a sports tyre, the Pilot Street is not marketed as a sports tyre.

Michelin Pilot Street tyre was launched on the 28th March 2013 in a Michelin press release.
The only review I have found is
People on forums with sports bike styled 125 and 250cc bikes seem to be happy with it.
Because the tyre is so new, not enough people have tried it yet, all I can assume for sure is it is not a bad tyre.
Michelin claim it is designed for high mileage and good wet performance.

Michelin City Pro tyre was launched on 15th June 2014.
The only information I have found is
The tyre at launch is only available in a few countries,
but will be available in many more countries later in 2014 / early 2015.

Metzeler ME 22 has been around for a very long time (at least since 2001), it is not a bad tyre.
Metzeler claim it is part of their Classic line and is designed for high mileage and good wet performance.

Mitas / Sava MC 7, I have not read about anyone who has used the tyre.
Mitas / Sava claim it is a sports tyre, but when I phoned them they claimed it uses a medium rubber compound.

Michelin M45 (I assume it will be discontinued in 2015), is designed for road as well as a little minor off road riding.
It is the best tyre if you go off road, it is also ok on the road.

The Continental ContiGO! from what I have read and heard appears to have poor grip,
everyone who has it seems to want a better safer tyre (especially in the wet). But they have all managed to put up with it.

A tyre I would never want on a bike again,
please see my Pirelli City Demon Tyre Review

The original Honda CG125 tyres are 2.75-18 Front and 90/90-18 Rear
(1976 to 1984 models used 2.50 -18 Front 3.00-17 Rear).

Honda CG125 Tyre Sizes and Brands (Michelin M45 not listed since I assume it will be discontinued in 2015).

2.75 - 18 Front tyre

Michelin Pilot Street

Michelin City Pro

Metzeler ME 22

Mitas / Sava MC 7

Continental ContiGO!

Pirelli City Demon

90/90 - 18 Rear tyre

Michelin Pilot Street

Michelin City Pro

Metzeler ME 22

Mitas / Sava MC 7

Pirelli City Demon

The Mitas / Sava rear tyre in the list above is not reinforced like the others
so the maximum weight (bike + rider) on the tyre is only rated at 195 kg compared with 230 kg.
Which probably means you cannot carry a passenger without overloading the tyre.

I advise against using a 3.00-18 rear tyre size, the bike's original tyres are 90/90-18 rear for a reason,
the tyre firms will tell you 3.00-18 is imperial and 90/90-18 is the metric equivalent, but that's not true.
The 90/90-18 can carry much more weight (do not use a 3.00-18 with a passenger unless you are both light),
230 kg (max bike + rider) compared to 200 kg.

The 90/90-18 is wider and lower than the 3.00-18, this effects the cornering abilities of the bike,
people who have tried the 3.00-18 report the bike is unstable going round bends (twitchy).
In the past it was not possible to get 90/90-18 rear in the UK,
so some people were so desperate to get a wider tyre than the 3.00-18 they fitted 3.25 or 3.50-18.

The 3.25 and 3.50 are wider than a 3.00 but they are also taller
(taller tyres will change the weight distribution of the bike so affect cornering).
I advise only to use a 90/90 tyre since it is the correct width and height,
90/90 is nearly as wide as 3.25, a tyre that is not wide enough or to wide will affect cornering.

3.00 - 18 Rear tyre

Metzeler ME 22

Mitas / Sava MC 7

Continental ContiGO!

Pirelli City Demon

3.25 - 18 Rear tyre

Metzeler ME 22

Mitas / Sava MC 7

Pirelli City Demon

3.50 - 18 Rear tyre

Metzeler ME 22

Mitas / Sava MC 7

Pirelli City Demon

How to find the best price for Tyres

Shop around for the best price for the tyres, some car tyre shops will supply and fit to loose wheels and some even to the bike,
they can sometimes (not always) be substantially cheaper than a motorcycle shop.
Some motorcycle shops can even charge a fortune to fit to loose wheels, so the message is simple, shop around.
Mail order is nearly always more expensive, since you need to pay someone to fit the tyres to the wheels,
many shops (especially car shops) do not charge to fit new tyres to loose wheels if they supply them.

It's often a lot cheaper for you to give the tyre shop the wheels loose,
they often charge a fortune to remove and put the wheels on to the bike.

A tyre shop needs to know which way round the wheels move when the bikes going forwards
(some wheels have the brake on the right but others are on the left).
That's because motorcycle tyres are directional,
make sure they have got the direction correct, look at both side walls of the tyre,
on one side there should be a direction arrow pointing in the direction the tyre will move when the bikes moving forwards.
If the tyre is universal fitment, it can have 2 arrows,
on one side of the tyre it will have an arrow and say front
and on the other side an arrow pointing in the opposite direction and say rear.
If the tyre is being fitted to the front wheel you need the arrow that has front next to it,
if it's a rear wheel you need the arrow that has rear next to it.

How to remove and install the wheels in the Bike

The Owner's Manual (you can manage without it) tells you everything except.

I found I did not have to loosen the rear wheel chain adjuster nuts,
I simply removed the rear wheel axle nut and slid the whole adjuster off the spindle and bike,
this meant I did not have to check the wheel alignment afterwards.

Both wheels have metal spacers on the wheels, some are partly inside the wheels, make sure you do not lose them.

It only takes one person to remove the wheels, I strongly advise it needs 2 people to put them back in again.

If you do not have the Owner's Manual, below are the basics.

Rear Wheel

Remove the rear brake adjuster nut (1) at the wheel end;
remove the brake rod (2) from the brake.

There's a rear brake arm (2) that stops the brake spinning with the wheel,
remove the small pin (3, you will probably damage it so buy a new one)
that stops the nut (4) from being removed at the brake end.
The small pin is called a Cotter pin, it's basically a piece of metal folded in half,
it goes through a hole near the end of the screw thread.
The 2 pieces that have gone through the hole are then separated
and folded up and around in opposite directions around the nut.

Remove the nut and pull the arm off the brake.

If you have a fully enclosed chain, you will have to remove the chain guard, see Enclosed Chain Guard

Remove the rear wheel axle nut
(might have a small pin to stop the nut being removed like the brake) on the right hand side of the bike.
The nut is normal type, anti clock wise to slacken, clockwise to tighten,
if you're not strong enough to slacken it, tap / hit the spanner with a hammer several times quickly,
if that fails get a longer spanner (to get more leverage).

Remove the right hand side chain adjuster

(diagram shows the left hand side, the right hand side is identical).

Put your foot under the wheel and remove the rear wheel axle and then remove the chain.

To reinstall the rear wheel, reverse the process, to setup the rear brake see Rear Brake in Brakes page.

Front Wheel

On the left hand side of the wheel there is a speedometer device
and a cable connecting it to the instrument panel,
remove the cable at the wheel end (there's probably a screw to remove).

If you have a front drum brake, remove the brake cable.

Remove the front wheel axle nut (might have a small pin to stop the nut being removed like the rear brake)
and slide the axle out (wheel will then fall out).
The nut is normal type, anti clock wise to slacken, clockwise to tighten,
if you're not strong enough to slacken it, tap / hit the spanner with a hammer several times quickly,
if that fails get a longer spanner (to get more leverage).

If you have a front disc brake, do not touch the front brake lever while the wheel is out of the bike.

When putting the front wheel back in,
look at the speedometer device and the left front fork,
they need to line up with each other.

The speedometer device has 2 metal pieces sticking out,
the left front fork has a single piece of metal sticking out,
put the fork metal sticking out in between the 2 metal pieces of the speedometer device.

If you have a front disc brake, you will need to use the brake lever a few times before the brake works.