Front suspension - when to use and when to lock out

[Paul Boyd]

On 10/08/2007 15:17, Roger Merriman said,

> no that would have been pre suspention,

Aye, but Overburys were still around making high quality rigid frames
when suspension appeared. In fact, it seems the shop is still around
http://www.overburyscycles.co.uk/ but I think they stopped making frames
years ago.

--
Paul Boyd
http://www.paul-boyd.co.uk/

 

[Paul Boyd]

On 10/08/2007 15:32, [email protected] said,
> If it's really steep locking the fork at full
> extension makes life harder by raising the front end (normally you
> have about 20% sag)

Don't lock it at full extension then!

--
Paul Boyd
http://www.paul-boyd.co.uk/

 

[Roger Merriman]

Paul Boyd <[email protected]> wrote:

> On 10/08/2007 15:17, Roger Merriman said,
>
> > no that would have been pre suspention,
>
> Aye, but Overburys were still around making high quality rigid frames
> when suspension appeared. In fact, it seems the shop is still around
> http://www.overburyscycles.co.uk/ but I think they stopped making frames
> years ago.

well it was only recently that i went from a fully rigid old steel frame
to a new aluminium hard tail so you can still use rigid certinaly for
mud plugging.

though the much better brakes which and suspention make for a faster
smoother ride. still have the mud tires fitted which i need to try on
the downs.

roger
--
www.rogermerriman.com

 

[Simon Brooke]

in message <[email protected]>,
Dundonald ('[email protected]') wrote:

> I've had a rigid bike for a long time and I'm recently testing out a
> bike with front shocks for the first time. I've asked around, done a
> bit of googling, to try understand when best to use the front shocks
> and when to lock them out. I might add that my I typically ride on
> off road tracks such as the TPT. The track I take to work is probably
> 80% off road track and 20% tarmac. Decent ascents and descents both
> ways of the journey. I noticed on the first run that with the front
> shock on, I'm bouncing as I'm putting the power down on a climb, so
> seemed to lose power, is that right?

I always lock both ends when on tarmac; usually lock the front (/not/ the
back) when climbing steep stuff off tarmac. The better you can train
yourself to spin perfect circles the less bob you'll get and consequently
the less power you'll lose to it, so it's worth learning to spin.

> So as I say I did a bit of research and what I understand so far is to
> lock out before hitting a climb and unlock on flat and descent. Is
> this right?

It depends. The more uneven the surface the more benefit you get out of
suspension. On really uneven climbs it may be worth leaving the suspension
active because the benefit you get from it will outweigh the loss from
pedal bob. Again, the better you can spin, the more often it will make
sense to leave it active.

> It just seems a bit of a pain locking and unlocking, especially if I'm
> on a track that I don't know, so possibly being surprised by a climb
> around a bend.

Do you have a lockout lever on your handlebars, or just a knob on the top
of the fork stantion? A lockout lever on the handlebars is a real benefit,
but can only be fitted for some models of fork.

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

Age equals angst multiplied by the speed of fright squared.
;; the Worlock

 

[Simon Brooke]

in message <[email protected]>, Ace
('[email protected]') wrote:

> On Fri, 10 Aug 2007 07:32:35 -0700, [email protected] wrote:
>
>>
>>Dundonald wrote:
>>
>>> So as I say I did a bit of research and what I understand so far is to
>>> lock out before hitting a climb and unlock on flat and descent. Is
>>> this right?
>>
>>Lockouts on shocks are generally evil things both front and rear.
>>With good suspension and a smooth pedalling/riding style it's rarely
>>necessary or desirable to lock them out.
>
> Rubbish. No matter how smooth you are there's still a significant loss
> of power due to suspension, particularly the rear.

There is loss of power, of course, but it is compensated by increase in
traction on loose surfaces, particularly uphill. Also, on uneven ground,
you have to put in enough power to lift the centre of mass of bike+rider
over every bump, and you don't get all that energy back on the other side.
Well tuned suspension reduces the movement of the centre of mass, so saves
energy.

But this is only on very uneven or loose surfaces, of course. On firm,
smooth surfaces there will be a net loss of power due to pedal
bob. 'Stable platform valves' and similar can reduce this, and are worth
having, but on really smooth surfaces - tarmac - it's worth locking even
these out.

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

;; I can't work yanks out......
;; Why do they frown upon sex yet relish violence?
;; Deep Fried Lettuce

 

[Simon Brooke]

in message <1i2mit7.mq2e8t1batwpdN%[email protected]>, Roger Merriman
('[email protected]') wrote:

> heh, yes i'd say so. bike suspention has been around maybe 10 years?

More than 100; and modern mountain bike suspension for 20 years. Bushido
were producing a full suspension mountain bike in 1987; RockShox started
mass production in 1989.

--
[email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/
Wannabe a Web designer?
<URL:http://userfriendly.org/cartoons/archives/97dec/19971206.html>

 

[[email protected]]

On 10 Aug, 15:49, Ace <[email protected]> wrote:

> >Lockouts on shocks are generally evil things both front and rear.
> >With good suspension and a smooth pedalling/riding style it's rarely
> >necessary or desirable to lock them out.
>
> Rubbish. No matter how smooth you are there's still a significant loss
> of power due to suspension, particularly the rear. I've been weak and
> feeble recently due to a broken back sustained last year, which
> necessitated a new full-suspension bike earlier this year mainly for
> comfort. So I've been using it almost exclusively on- and off-road and
> I can tell you with absolute certainty that having both front and rear
> locked out for road riding makes a huge difference to the speed and
> distance I can cycle.

I've been told by a bike manufacturer and a shock manufacturer that
lockouts put a lot of strain on the shocks and (on the rear) on the
bolts, resulting in shorter life if they're used regularly.
"Propedal" (Fox) type lockouts are better as they release if you hit
something hard (Rock Shox market this as 'floodgate'). My experience
would confirm that.

I've also never found a bike that really feels like a hardtail when
the suspension is locked out - theres something strange about the
feel . As i said, personally, i've never found the lockouts useful on
any of my bikes (single pivot and horst link 4 bar) or forks (Fox,
Rock Shox, Marchocchi). Your experience is obviously different.

 

[Peter Clinch]

Ace wrote:

> Rubbish. No matter how smooth you are there's still a significant loss
> of power due to suspension, particularly the rear. I've been weak and
> feeble recently due to a broken back sustained last year, which
> necessitated a new full-suspension bike earlier this year mainly for
> comfort. So I've been using it almost exclusively on- and off-road and
> I can tell you with absolute certainty that having both front and rear
> locked out for road riding makes a huge difference to the speed and
> distance I can cycle.

It depends on the bike design too. My full suspension bike doesn't have
lockouts, and I've never noticed a pogo effect to speak of. But there
again it's a recumbent with my pedal force a push along rather than down
and a rear sus setup designed and engineered /specifically/ to avoid
pedal bob. On anything but the best tarmac the sus not onlyt makes the
bike more comfortable but more efficient too (the primary reason to have
suspension).

If you need to rest your back and are riding on roads I would seriously
suggest you audition some 'bents. HP Velotechnik's "No Squat"
suspension is remarkably good at not bobbing.

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 protected] http://www.dundee.ac.uk/~pjclinch/

 

[Ace]

On Mon, 13 Aug 2007 16:08:14 +0100, Peter Clinch
<[email protected]> wrote:

>Ace wrote:
>
>> I've been weak and
>> feeble recently due to a broken back sustained last year, which
>> necessitated a new full-suspension bike earlier this year mainly for
>> comfort. So I've been using it almost exclusively on- and off-road and
>> I can tell you with absolute certainty that having both front and rear
>> locked out for road riding makes a huge difference to the speed and
>> distance I can cycle.

>If you need to rest your back and are riding on roads I would seriously
>suggest you audition some 'bents.

Waaah! <Makes sign of the diamond frame>

But seriously, I had the metalwork removed from my back six weeks ago
and am expecting a full, no-more-pain, recovery, so hopefully the
suspended MTB can be put to the use for which it was intended and I
can start re-using my Mercian for road work.

For sure, serious ongoing back problems are one (of the very few)
reasons I can think of where I'd agree that a recumbent might make
sense. I prefer to sit at a normal height, TYVM; I'm not one to bash
those who support them though, even if you can get a bit evangelical
at times

--
Ace in Alsace - brucedotrogers a.t rochedotcom