suspension

enorehtonatey said:

I ride on roads, bumpy tracks, bumpy fields, muddy bumpy tracks and don't
percieve the bumps don't seem to be a problem . . . except that I sometimes
bend the rear axle bolt . . . would rear suspension stop that from
happening??

Possibly. Possibly not.

Quoted message said:

Does suspension need much maintenance? or replacement after a few years?

Possibly.

Quoted message said:

Does it add much to overall weight??

Yes.

Quoted message said:

Does it use energy - ie make the whole process less energy efficient.

Yes.

Quoted message said:

I'm
fairly sure that seat post suspension would do that, but what about front
and rear suspension??

To pad out the above rather terse answers: :-)

A seat post will ease the ride on the bum - but if you know you're on
bumpy ground you're probably not sitting down anyway. Front
suspension will ease the ride on the hands/arms. I shouldn't think
either will prevent you bending the rear axle bolt.

Cheap suspension will be very heavy, very hard to properly adjust, may
well be made of cheese, and almost certainly won't come with a lockout -
so on flat smooth road you'll be bobbing up and down like a yo-yo (and
this will be absorbing your pedalling energy). Very much more so with
rear than with front.

I'll leave it to those who know more than I to talk about rear suspension.

R.

enorehtonatey said:

I ride on roads, bumpy tracks, bumpy fields, muddy bumpy tracks and don't
perceive the bumps don't seem to be a problem . . . except that I sometimes
bend the rear axle bolt . . . would rear suspension stop that from
happening??

Rear suspension means a full sus bike, and those cost serious money if
they're done properly. We're talking getting on for 4 figures for
anything worthwhile.

Quoted message said:

Does suspension need much maintenance? or replacement after a few years?

Some degree of maintenance certainly possible, but not necessarily much.
Could just be clean and grease once a year.

Quoted message said:

Does it add much to overall weight??

Something, certainly. How much will depend on implementation. As with
most things in cycling you can throw money at it to get the weight down.

Quoted message said:

Does it use energy - ie make the whole process less energy efficient.

It depends what you're doing. Climbing on a smoothish track, suspension
will tend to pogo which wastes energy. Better suspension can be locked
out so you can prevent this, but again we're talking more money.
However, over rough ground, especially at speed, suspension *saves* an
enormous amount of energy. On a rigid bike, if the front wheel hits a
root the wheel, frame and rider all have to be moved up over it, and the
energy for that comes from your forward speed. With suspension, only
the wheel and lower fork have to move up, you lose less energy from
forward motion and you go faster with less effort because suspension
makes the bike *more* efficient. Suspension for MTBs was introduced
more for efficiency than for comfort, and its use has picked up since
people started winning races *because* they had suspension.

In my first paragraph I noted "done properly". That certainly applies
to the previous paragraph too. Crappy suspension will just go "boing"
and bounce you about. It's meant to look like good suspension but isn't
engineered to act like it. That will almost certainly waste more energy
than you put in. You don't need to spend an arm and a leg for some
basically okay front forks, especially if they come on the bike, but I'd
personally be a bit suspicious of bargain basement prices. I'll not
suggest a price point myself, I'm not enough in touch with the MTB
market to give a good idea of where the [censored] stops, but someone here
should hopefully be able to give you an idea.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

in message <[email hidden]>, enorehtonatey

(') said:

I posted yesterday asking where I could buy a mountain bike. I was sure
I did not want suspension, but a few people have recommended it and
made me wonder if I should reconsider.

I ride on roads, bumpy tracks, bumpy fields, muddy bumpy tracks and
don't
percieve the bumps don't seem to be a problem . . . except that I
sometimes bend the rear axle bolt . . . would rear suspension stop that
from happening??

Does suspension need much maintenance? or replacement after a few
years?

Does it add much to overall weight??

Does it use energy - ie make the whole process less energy efficient.
I'm fairly sure that seat post suspension would do that, but what about
front and rear suspension??

The very best full suspension bikes don't weigh very much more than rigid
bikes. But they are /very/ much more expensive. Anything under about
£1500 is going to be noticeably heavy. Furthermore, cheap rear
suspension really does bob on flat surfaces, and that does rob you of
power. Also, suspension components do need maintenance, and good ones
which are high precision engineering used in a hostile environment need
relatively expensive maintenance. Expect to have shocks serviced and
possibly some bushes replaced every couple of years. You /can/ service
most makes yourself, but if you don't feel competent the usual costs is
about £30-£50.

On rough terrain a good suspended bike is significantly more energy
efficient than an unsuspended one, but on smooth surfaces even a good
one is likely to be less energy efficient.

Rear suspension - even cheap and nasty rear suspension - should stop you
bending axles.

I would honestly suggest you try a reasonably good hard tail and a
reasonably good full suspension bike, before you buy. I don't know where
you are in the country but some mountain biking centres will hire you a
bike for the day, and this is a good way of finding out what they're
like before you commit yourself to spending a lot of money.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Wise man with foot in mouth use opportunity to clean toes.
;; the Worlock

"Peter Clinch" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

enorehtonatey said:

I ride on roads, bumpy tracks, bumpy fields, muddy bumpy tracks and don't
perceive the bumps don't seem to be a problem . . . except that I
sometimes
bend the rear axle bolt . . . would rear suspension stop that from
happening??

Rear suspension means a full sus bike, and those cost serious money if
they're done properly. We're talking getting on for 4 figures for
anything worthwhile.

Quoted message said:

Does suspension need much maintenance? or replacement after a few years?

Some degree of maintenance certainly possible, but not necessarily much.
Could just be clean and grease once a year.

Quoted message said:

Does it add much to overall weight??

Something, certainly. How much will depend on implementation. As with
most things in cycling you can throw money at it to get the weight down.

Quoted message said:

Does it use energy - ie make the whole process less energy efficient.

It depends what you're doing. Climbing on a smoothish track, suspension
will tend to pogo which wastes energy. Better suspension can be locked
out so you can prevent this, but again we're talking more money. However,
over rough ground, especially at speed, suspension *saves* an enormous
amount of energy. On a rigid bike, if the front wheel hits a root the
wheel, frame and rider all have to be moved up over it, and the energy for
that comes from your forward speed. With suspension, only the wheel and
lower fork have to move up, you lose less energy from forward motion and
you go faster with less effort because suspension makes the bike *more*
efficient. Suspension for MTBs was introduced more for efficiency than
for comfort, and its use has picked up since people started winning races
*because* they had suspension.

In my first paragraph I noted "done properly". That certainly applies to
the previous paragraph too. Crappy suspension will just go "boing" and
bounce you about. It's meant to look like good suspension but isn't
engineered to act like it. That will almost certainly waste more energy
than you put in. You don't need to spend an arm and a leg for some
basically okay front forks, especially if they come on the bike, but I'd
personally be a bit suspicious of bargain basement prices.

This is all very useful. Thanks.

Quite a few of the bikes I'm looking at have
"Suntour XC60 suspension fork"

Is this any good??

"enorehtonatey" <[email hidden]> wrote in message
news:[email hidden]...

..

Quoted message said:

Quite a few of the bikes I'm looking at have
"Suntour XC60 suspension fork"

Is this any good??

or this one:

Fork: Spinner R-1 hydraulic, 100mm Travel w/Magnesium lowers, Preload
adjustment & lock out

in message <[email hidden]>, enorehtonatey

(') said:

"Peter Clinch" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

enorehtonatey said:

I ride on roads, bumpy tracks, bumpy fields, muddy bumpy tracks and
don't
perceive the bumps don't seem to be a problem . . . except that I
sometimes
bend the rear axle bolt . . . would rear suspension stop that from
happening??

Rear suspension means a full sus bike, and those cost serious money if
they're done properly. We're talking getting on for 4 figures for
anything worthwhile.

Quoted message said:

Does suspension need much maintenance? or replacement after a few
years?

Some degree of maintenance certainly possible, but not necessarily
much. Could just be clean and grease once a year.

Quoted message said:

Does it add much to overall weight??

Something, certainly. How much will depend on implementation. As
with most things in cycling you can throw money at it to get the
weight down.

Quoted message said:

Does it use energy - ie make the whole process less energy efficient.

It depends what you're doing. Climbing on a smoothish track,
suspension
will tend to pogo which wastes energy. Better suspension can be
locked out so you can prevent this, but again we're talking more
money. However, over rough ground, especially at speed, suspension
*saves* an enormous
amount of energy. On a rigid bike, if the front wheel hits a root the
wheel, frame and rider all have to be moved up over it, and the energy
for
that comes from your forward speed. With suspension, only the wheel
and lower fork have to move up, you lose less energy from forward
motion and you go faster with less effort because suspension makes the
bike *more*
efficient. Suspension for MTBs was introduced more for efficiency
than for comfort, and its use has picked up since people started
winning races *because* they had suspension.

In my first paragraph I noted "done properly". That certainly applies
to
the previous paragraph too. Crappy suspension will just go "boing"
and
bounce you about. It's meant to look like good suspension but isn't
engineered to act like it. That will almost certainly waste more
energy
than you put in. You don't need to spend an arm and a leg for some
basically okay front forks, especially if they come on the bike, but
I'd personally be a bit suspicious of bargain basement prices.

This is all very useful. Thanks.

Quite a few of the bikes I'm looking at have
"Suntour XC60 suspension fork"

Is this any good??

Quick summary: not very, but not completely horrible. It is, if I recall
correctly, a steel sprung, elastomer damped fork, significantly better
than the elastomer-only ones - but check I'm right before you buy.

There are four basic suspension technologies used on bikes, although most
suspension systems are hybrids using more than one.

(i) 'Elastomer' is a springy plastic. It's very cheap, and as well as
being springy also has damping properties, so makes reasonable
suspension on its own. But it doesn't work nearly as well in cold
conditions and may get to soft in warm ones, and it gets much less
springy with age. Springyness and damping can only be tuned by changing
the elastomers for a different grade. Elastomer may be described as a
number of other things, for example 'closed cell urethane'. Elastomer
suspension is the cheapest, but not completely appalling.

(ii) Oil is an incompressible fluid. It doesn't bounce but does damp. It
cannot be used for suspension by itself. Oil is the damping medium in
most good suspension units. Oil damped suspension can be tuned by using
a different weight of oil, and by adjusting the size of the apertures
through which it flows (usually just by turning a knob).

(iii) Metal springs, usually steel. They bounce but don't damp;
consequently if they're to be any good they must be used in conjunction
with a damping medium, usually oil but sometimes elastomer. Spring/oil
units are the strongest and often used on downhill bikes but are
significantly heavier than air/oil units. Spring suspension units can be
tuned to some extent by adjusting the preload on the spring, but major
tuning can only be done by replacing the spring with another of a
different grade. Some cheap units have springs only with no damping;
these are really bad.

(iv) Air is a compressible fluid and is very light. It bounces well but
it doesn't damp particularly well; consequently it's usually used in
conjunction with a damping medium, usually oil. It's the easiest
technology to tune - just pump more air in or let some out. It's also
the lightest, which means it's the preferred choice of cross country
riders. Because even the smallest leak makes an air unit unusable, the
engineering is extremely precise and these units tend to be expensive.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
;; This email may contain confidential or otherwise privileged
;; information, though, quite frankly, if you're not the intended
;; recipient and you've got nothing better to do than read other
;; folks' emails then I'm glad to have brightened up your sad little
;; life a tiny bit.

Simon Brooke said:

(i) 'Elastomer' is a springy plastic. It's very cheap

It's potentially very cheap, with lower grade elastomers. More
specialised flavours will have price tags measured in Real Money, like
the Meks Carbon forks for 20" wheels (high grade elastomer combined with
steel springs).
The Meks aren't much of a concern for the OP, of course, but this is
simply a note to say the word "elastomer" doesn't necessarily equate to
"rubbish".

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

enorehtonatey said:

I ride on roads, bumpy tracks, bumpy fields, muddy bumpy tracks and don't
percieve the bumps don't seem to be a problem . . . except that I sometimes
bend the rear axle bolt . . .

Do you have a freewheel , or or a cassette freehub on your rear wheel?(see http://sheldonbrown.com/freewheels.html for more)
Freewheel leaves a longer part of the axle unsupported than a cassette freehub, so you might want to look into that as well.

enorehtonatey said:

except that I sometimes bend the rear axle bolt

This happened to me three times, at which point I switched from the
old-style freewheel rear to a casette hub, since when I haven't had any
problems. (The freewheel holds the axle at one end and at the middle;
the casette holds the axle at each end)

--
Keith Willoughby http://flat222.org/keith/
Ceci n'est pas une sig

"enorehtonatey" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I posted yesterday asking where I could buy a mountain bike. I was sure I
did not want suspension, but a few people have recommended it and made me
wonder if I should reconsider.

I ride on roads, bumpy tracks, bumpy fields, muddy bumpy tracks and don't
percieve the bumps don't seem to be a problem . . . except that I
sometimes
bend the rear axle bolt . . . would rear suspension stop that from
happening??

Does suspension need much maintenance? or replacement after a few years?

Does it add much to overall weight??

Does it use energy - ie make the whole process less energy efficient. I'm
fairly sure that seat post suspension would do that, but what about front
and rear suspension??

With advice received here in mind I've finally ordered:

http://tinyurl.com/8e3tm

Thanks for your help

"enorehtonatey" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

With advice received here in mind I've finally ordered:

http://tinyurl.com/8e3tm

(but with V brakes)

"dabac" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

enorehtonatey said:

I ride on roads, bumpy tracks, bumpy fields, muddy bumpy tracks and
don't
percieve the bumps don't seem to be a problem . . . except that I
sometimes
bend the rear axle bolt . . .

Do you have a freewheel , or or a cassette freehub on your rear
wheel?(see http://sheldonbrown.com/freewheels.html for more)
Freewheel leaves a longer part of the axle unsupported than a cassette
freehub, so you might want to look into that as well.

--
dabac

"dabac" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

enorehtonatey said:

I ride on roads, bumpy tracks, bumpy fields, muddy bumpy tracks and
don't
percieve the bumps don't seem to be a problem . . . except that I
sometimes
bend the rear axle bolt . . .

Do you have a freewheel , or or a cassette freehub on your rear
wheel?(see http://sheldonbrown.com/freewheels.html for more)
Freewheel leaves a longer part of the axle unsupported than a cassette
freehub, so you might want to look into that as well.

Going by that page it was a freewheel and I've never had a cassette, in
fact, I recall being told in the local bike shop that cassettes cost more
and had no advantages, so this is interesting and I see the bike I've orered
has a cassette so hopefully I won't be needing to hammer axle bolts any
more.

Keith Willoughby said:

enorehtonatey said:

except that I sometimes bend the rear axle bolt

This happened to me three times, at which point I switched from the
old-style freewheel rear to a casette hub, since when I haven't had any
problems. (The freewheel holds the axle at one end and at the middle;
the casette holds the axle at each end)

Is it straightforward to change over? I think the axle on CrapBike
has gone again under my grate wate, and as the freewheel is starting
to look like it needs replacing anyway, would the LBS be able to
replace it with a cassette on the same wheel?

Peter Clinch said:

I'll not suggest a price point myself, I'm not enough in
touch with the MTB market to give a good idea of where the [censored]
stops, but someone here should hopefully be able to give you an idea.

The Marzocchi MX Comp can be had for £130. Which makes it the cheapest
suspension fork worth buying...

"enorehtonatey" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"enorehtonatey" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

With advice received here in mind I've finally ordered:

http://tinyurl.com/8e3tm

(but with V brakes)

how much did you pay for it?

On Tue, 12 Jul 2005 15:30:28 +0100, audrey <[email hidden]>
wrote:

<snip>

Quoted message said:

Is it straightforward to change over? I think the axle on CrapBike
has gone again under my grate wate, and as the freewheel is starting
to look like it needs replacing anyway, would the LBS be able to
replace it with a cassette on the same wheel?

Not as far as I know - with a cassette, the freehub has all the
internal gubbins, you just fit the appropriate sprockets onto it. So,
it'll mean at least a new hub, and bearing in mind the cost of
re-building wheels, a complete rear wheel may work out cheaper.

Of course, in these days of total internationall standardisation,
Campy & Shimano cogs are not (again, as far as I know)
interchangeable.

Tony

PS I'm over 16 stone, and have had no troubles with either Campy or
Shimano (on different bikes).

HTIOSA

audrey said:

Is it straightforward to change over?

Not really. The distinction between frewheel and freehub is fairly fundamental to the design of the hub. I can't think of a way to achieve this change without replacing the hub and rebuilding the wheel. Still, lacing up a wheel isn't as hard as many like to think so why don't give it a shot?

"enorehtonatey" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Going by that page it was a freewheel and I've never had a cassette, in
fact, I recall being told in the local bike shop that cassettes cost more
and had no advantages..

Lying gitbags. Were they trying to sell you a bike with a freewheel by any
chance?

Not even Steven Scharf claims that freewheels are better! Here are a couple
of advantages of cassette hubs:

They aren't tightened by pedalling, so it's possible to take one off a
tandem wheel without using a really big lever (BTDT).

They've got stronger axles due to the bearing placement. (Shimano mainly
wins here).

You can get them - freewheels pretty much stop at 7 speed. (I know there
were some 8s, but they were pretty rare).

cheers,
clive