Cycling UK Forum

Brucey wrote:

sreten wrote:
That is not a logical analysis....

I know I'm in a minority here....

But maybe I do things differently for good reason. For most riders the rear tyre sees half as much again or even double the loading vs the front.
To routinely use your more knackered tyre on the rear and subject it to such loads is basically asking for trouble.

-In the dry, less tread = more grip, not less... the grip argument is at least complicated, if not specious; bicycles are not the same as motor cars.


cheers

Hi,

Your still not making sense in terms of being logical. The front tyre you swap to the back
is not remotely knackered, compared to the state of the rear tyre you are replacing.

You always want the poorest tyre on the back as rear failure and slip due to grip
is much more recoverable than front failure or losing front grip, by a long way.

Your right in good conditions a worn tyre has more grip, but why did you choose
such a tyre in the first place ? For the poorer / the worst conditions, and a
worn tyre will be worse than a new one for those extreme conditions.

Rotating is very logical. Not doing it simply makes no sense. Your not saving
any tyre life, your wasting it. Your being pointlessly specious, indulgently.

rgds, sreten.

As stated rotating :
The front is 75% to 100%
The rear is 75% to near 0%
If you change the front goes from 75% to 100%, the rear near 0% to 75%

If you don't rotate :
fit a new rear, rear is 100%, front is 66% , that is not safe in the worst conditions.
Fit a new rear again, rear is 100%, front is 33% which is downright dangerous,
and TBH most people at this point would/should replace the the front tyre also.
Fit a new rear again you will need to replace the front if you already haven't,
i.e. you managed to near wear it out without it failing in some way first.

For the latter your bike is simply more dangerous to to you, as good rear grip
simply makes it easier to lose the front rather than the rear, that is not good.

Leaving the tyre on the front increases the chances of front tyre failure.
Rotating tyres deliberately reduces the chances of front tyre failure
by then inevitably increasing the chances of rear tyre failure.
That is what you want, if your sensible.

Brucey wrote:I

Similarly I question the logic of putting tyres that have seen front service already on the rear, and fitting a new tyre to the front. In some instances the tyre life is limited by the sidewall condition (eg flexing near the bead) and if there is any weakness (visible or not) in a used tyre my experience is that it will fail quickly on the rear where it might last much longer (and fail more progressively if it does so at all) if left on the front.

I realise that this flies in the face of accepted wisdom, but there is no 'one size fits all' approach here; I will act differently depending on the circumstances and the nature of the tyre condition/damage.

cheers

Hi,

That is not a logical analysis. The point of new tyre on the front and rotating the front to the back is
that it is almost impossible to wear out a front tyre and it will inevitably fail for some other reason
(some of which may not be pleasant) if just left on the front until it eventually fails.

Of course its not going to last as long on the back, that is the point. Lets say you get through a rear
tyre every two years. Say it implies a front every six years. Starting with two new tyres after 2 years
you need a new rear tyre. Rotating the tyres puts the best condition with the most grip tyre on the
front. The old front on the rear will probably now last about 1.3 years. Keep rinsing and repeating
and it will settle to to a new tyre every say 1.5 years. (can't be bothered to work out the exact number)

So your front tyre will never be be more than 1.5 years old and never be worn past 75%.
Your rear tyre you wear to 0% will be between 75% and 0% and 1.5 and 3 years old always.

When you fit a new tyre the rear jumps to 75% and the front back to 100% grip.

You always want more grip and less chance of failure on the front tyre, and
simplistically, the chances of a tyre failing are related to to the age of tyre.
(I freely admit the front is less onerous than the rear, so a 1.5 year old
front tyre can be treated as a roughly six month old rear tyre here.)

There is nothing logical about when you need a new rear tyre not rotating.
You are reducing the chances of being able to wear out your tyres before
failure. You are making your bike more dangerous to you. You will spend
more on tyres discarding still very usable front tyres usually. You will
spend more on tyres due to the front tyre failing before 6 years.

As a final point when rotating you only check the rear tyre wear.

rgds, sreten.

Hi,

If you've got plenty of clearance what is the point of going 650B ?
I think you overthinking this. Just fit the Silento's and give them a go.

rgds, sreten.

Hi,

The "Liteskin" sidewalls are really thin, about half the thickness
of standard Scwalbe sidewalls (one ply rather than two ply I think).

They roll better but are more vulnerable to damage. FWIW on
my folder I've got a liteskin Tracer on the rear (a trailer tyre)
and a (not liteskin) RoadCruiser on the front, the differences
in the walls are clearly apparent, the liteskin has no set curve.
No problems (or punctures) over 18 months of use.

rgds, sreten.

Hi,

The Land Cruisers are not ideal for roads.
They are ideal for mixed off road and road use.
The BA's already have a puncture protection belt.

Lots of cheap great choices :

Michelin City :
http://www.chainreactioncycles.com/mich ... -prod69985
The 1.85" reflex version looks good to me at £24 a pair delivered.

Schwalbe City Jet :
http://www.chainreactioncycles.com/schw ... -prod24629
The 1.95" gum wall is a bit slicker than the above, good at £26 a pair delivered.

Schwalbe Silento :
http://www.chainreactioncycles.com/schw ... -prod69454
Only in 1.75", maintains some offroad capability, good at £26 a pair delivered.

All have puncture protection, I'd go for the slickest and fattest.

rgds, sreten.

jqdsffjdsoge wrote:Does anyone know how/why I can cycle 120 miles a week, and still be puffed out walking up a flight of stairs?

Hi,

Power output, i.e. energy expended / time. For stairs the ratio is very high and does not need stamina.
For cycling the ratio is very low (try running for the length of one of your rides). Cycling is good for
the older as the amount of time involved can be high, building up your stamina and fitness.

However is you wan't to take on stairs, attack the hills on a ride and take it a bit easier on
the rest of the ride to allow you to recover. Work on your attack/recovery envelope, which
can be done with sprints on the flat,* but lends itself naturally to the hills on a route.

rgds, sreten.

* Past a certain age fast running and intermediate jogging works better than just
going a flat speed when running, especially if not that fit and wanting to build
up to your best flat speed for various distances.

Hi,

Most people assume flab is what they can see and feel around around their external
body, but in reality all your internal organs are also be surrounded by fat. If you are
fit and healthy, and not starving, there is no such thing as too much weight loss.

In fact you can go weight training to put on muscle and still lose fat, weight is
not the arbiter, fitness and a low body fat is, your weight depending on your
natural muscle bulk and the bulk you develop for your type of exercise.

rgds, sreten.

For the retired you will naturally lose muscle bulk as you age, replacing
this with fat to maintain body weight is not a good idea. Those who live
to a ripe old age inevitably are pretty skinny and frail relative to build.

Hi,

The width and height of of a tyre depends also on the width of the rim its fitted to.

The minuscule change in standover height is a very poor reason to choose your tyres.

rgds, sreten.

Hi,

Nothing makes much difference at low climbing
speeds except the right gearing and the engine,
and the total bike weight of course.

rgds, sreten.

Hi,

Put it on the back. Always have your best / newest tyre on the
front. Always rotate front to back when fitting a new tyre.

Yes I'd reuse it, it looks barely worn, and will look
a lot worse when its very worn but still usable.

Put in some glue if you wan't, the real issue is the
integrity of the carcass, not the rubber, easier
seen from the inside of the tyre than outside.

rgds, sreten.

Hi,

If the Silento's are good enough for the "offroad" sections they
will also be better than the Landcruisers for the on road sections.

Just pump them up once a week the day after the off road ride.

rgds, sreten.

Smaller wheels with wider tyres may foul the chainstays ....

mig wrote:great skill.

i wondered why the two wheels would be made differently..?

Hi,

Presumably the white sections are metal inserts. Presumably
a wooden rear wheel can't take the drive of the geared hub,
and the rear offset would make it look strange.

FWIW wooded rims were once very popular with tubular tyres
for racing, and the front wheel is so anachronistic, it would
be far better with tension spokes like the rear, rather than
the cartwheel style compression wooden spokes.

rgds, sreten.

Hi,

I've never broken a spoke but understand loose spokes can flex by being
taken out of tension as the wheel rotates and the flexing can break them.

I understand for a "typical" road bike and wheels the DS spokes should be
be thicker than the similar sized front and NDS spokes for better optimum
tension in the NDS. (Normal lacing, normal offsets, same rims).

Just saying as the original post mentions low tension, which breaks spokes.

rgds, sreten.

E.g 1.6mm spokes front and NDS, 2mm DS spokes should all ring at
at near the same frequency with the same cross 3 lacing and rims.
About G4 (about 390 Hz) for plain spokes, A4(440) for butted.
This sets tension to about 1/3 of the yield point of the spokes.

Hi,

Whatever, the purpose of the SFN, cap and washer is to set the static
preload,which is held by the clamp of the stem on the steering tube.
As someone said, some caps are plastic and can't hold squat.

I'm not one of the "many" people who need the SFN tight to prevent
the steering coming loose, and as I said that is not its intended job.

Some people fit an additional clamp under the stem clamp allowing
the stem height to be adjusted without re setting preload, the SFN
tightness is irrelevant here.



Probably not a good idea on a MTB ...., but it will
allow the stem to be not tight and twist in prang.

rgds, sreten.

Hi,

Triban 3 bashing is quite amusing, especially the wheels as the bike
costs about the same as a pair of what some consider decent wheels.

Yeah swap the wheels, why not ?

rgds, sreten.