by Brian Lee & Rick Brusuelas, 1994

ABSTRACT:  Discussion of the differences between suspension stems
and suspension forks, and a listing of the pros & cons of suspension
stems.
       
DESCRIPTION:  The suspension stem discussed here is the
Allsop-type, which employs a linkage parallelogram and a spring
mechanism to effect shock-absorption.  Two models on the market
using this mechanism are the Allsop Softride, and  a version
produced by J.P. Morgen, a machinist based in San Francisco.
There is also a version put out by J.D Components of Taiwan 
(advertised in Mountain Bike Action), however judging from 
illustrations, this unit does not employ the parallelogram design 
shared by Allsop & Morgen.  Other Taiwanese models may also exist.
The Girvin-type stem, which uses a simpler hinge and bumper, will
not be directly addressed here, although some of the comments
may also apply.

The Allsop-type suspension stem (suspension stem) works on a
different principal than a telescopic shock fork.  Instead of
only the front wheel moving to absorb shock, a stem allows the
entire front end of the bike to move with obstacles while the
rider's position does not change.

All suspension requires some form of "inertial backstop" to
operate.  A theoretical suspension (stem or fork) loaded with
zero mass will not function regardless of the size of obstacle
encountered.  This is because there is nothing to force the
compression of the spring mechanism.  It is essentially locked
out.

In a fork system, the weight of the bike & rider both provide the
inertial backstop.  In a stem system, the rider's weight on the
handlebars provides the backstop.  Because of this, the two
systems "ride" differently.

Since most of the weight comes from the pressure of the rider's
hands, the stem system encourages a more weight-forward style of
riding.  Or perhaps placing the stem on a frame with a shorter
top tube so the rider's weight is distributed more on the front
end.  (Shortening the front end has also been applied by frame
builders on frames intended for use with suspension forks.  Ex:
Bontrager.)

What does this mean to you and me?  It means the suspension stem
requires a certain amount of the rider's weight to be on it at
all times in order to remain completely active.  For the majority
of riding, it's just fine.  The only difference is in extremely
steep descents, where you are forced to keep the weight back in
order to keep from going over the bars.

In this situation, much less weight is on the bars to activate
the stem.  Further, if one were to encounter a largish rock on
such a descent, what does one do?  The instinctive thing is to
pull back a bit to unweight the front and help the front wheel
over.  This removes all the weight from the stem area, and you
are now riding a rigid bike again.

A fork system is also affected by weight shifts, but not quite to
the extent that a stem is affected, because of the weight of bike
& rider coming through the head tube to be distributed into the
fork.  Even if you were to remove your hands from the bars on a
gnarly descent and hang with butt brushing the rear wheel, you
are still applying weight to the bike through the pedals.

All this, of course, is theoretical and YMMV.  I, for one, am not
always able to react to obstacles coming at me and leave the
front end weighted.  When that happens, I'm very glad I have
suspension.

Now enough theory stuff, here's a summary of the advantages &
disadvantages of suspension stems:

PROs

1)  Lighter than a suspension fork.  This depends on the existing
stem/fork combination.  If the current stem and rigid fork are
heavy, then a suspension fork may be a better choice.  For
example, I've chosen the following items for comparison, as they
represent the lightest and heaviest of commercially available
stems & forks (weights for all stems are for conventional types -
non-Aheadset):

Litespeed Titanium          211g
Ritchey Force Directional   375g
Allsop Stem                 625g
Fat Chance Big One Inch     680g
Tange Big Fork             1176g
Manitou 3                  1360g
Lawwill Leader             1588g

So say you have a Litespeed stem and a Fat Chance fork.  The
combined weight would be 891 g.  Switching to an Allsop would
change the combined weight to 1305 g, while a Manitou 3 would
bring it to 1571 g.  The Allsop has a weight advantage of 266 g
(9.4 oz).

OTOH, if you have a Ritchey stem & Tange Big Fork, the original
weight would be 1551 g.  Allsop stem => 1801 g.  Manitou 3 => 1735
g.  In this case, keeping the boat anchor of a fork and switching
to the Allsop would be a weight penalty of 66 g (2.3 oz.).

Of course, YMMV depending on your original equipment.

2)  Does not affect frame geometry.  A suspension fork
retrofitted to a frame, *not* designed for suspension, raises the
front end - sometimes as much as 1".  This reduces the effective
head angle and slackens the steering, slowing it down.  This is
especially true for smaller sized frames which, with their
shorter wheel base, are affected to a greater degree by the
raising of the head tube.  A suspension stem provides suspension
while preserving the handling of the bike.

3)  Torsionally rigid fork.  Telescopic forks all have a certain
amount of flex to them,  and the sliders are able to move up &
down independently.  This aspect of front  suspension forks has
spawned a new line of suspension enhancing products:  stiffer 
fork braces, and bigger, heavier suspension hubs.  All to stiffen
up the fork.  This is  one reason suspension stems are favored by
some riders who ride lots of tight, twisting single track.

4)  No stiction.  Stiction, or static friction, is friction that
exists as the fork sliders rub  against the stanchion tubes. 
This friction is an extra force that must be overcome  for a fork
system to activate.  Not a problem on large hits.  But more of a
problem  on small- and medium-size impacts.  Because the stem has
none, the stem responds  better to small, high-frequency bumps
(washboard) than many air-oil forks.

5)  More boing for the buck.  The Allsop stem provides up to 3"
of stiction-free travel,  at a cost of about $250, depending
where you go.  The majority of forks in this  price range only
offer 1" - 2" of travel, and are often heavy, flexy, and fraught
with  stiction.  The fork could be stiffened, but at the
additional cost of a stiffer fork  brace or perhaps a suspension
hub and a rebuilt wheel (e.g. fork brace - $90; hub -  $80;
rebuild - $100.  Plus the original $350 for the fork.  YMMV).

6)  Better "feel".  The stem allows you to have a rigid fork,
which transmits more "information" back to the rider.  This is a
benefit when riding through creeks where you cannot see where
your wheel is.

7)  Less exposed to the environment.  The stem is higher, more
out of the way than suspension forks.  Thus you can ride through
creeks and mud without having to worry about your fork seals, or
about contaminating the innards of the fork.  Even if mud
splashes on a suspension stem, the pivots are less sensitive to
grit than sliders and stanchion tubes.

8)  Ease of maintenance.  There are no seals to replace or
service, no oil to replace, no air pressure to adjust, and no
bumpers to wear out.  An occasional lube of the pivots is all
that is needed.  An extension of this is the ease of initial set
up.  For best results, you have to set suspension (fork or stem)
to react according to your weight and riding style.  With air/oil
forks you may have to change oil, adjust pressure or change
damping settings (if the fork has them).  With bumper forks you
may need to swap out bumper stacks and mix-n-match bumpers until
you get what works for you.  With the stem, the only adjustment
is to increase or decrease the spring tension with an allen
wrench.


CONs

1)  No damping.  This is one of the main complaints from
proponents of suspension forks.  The suspension stem will give
way to absorb shock, but the return is not controlled and cannot
be adjusted.  JP Morgen currently makes a suspension stem which
employs oil-damping, but Allsop does not.

2)  Requires adjustment to riding style.  As mentioned above, the
stem requires weight to be applied to it to function.  This is
also one of the complaints applied to the Softride rear
suspension beam.  The flip-side to this, according to riders of
the Beam, is once the adjustment is made to "plant your butt on
the saddle" the ride is extremely comfortable and affords
excellent control by sticking the rear tire to the ground.

3)  Stem "clunks" on rebound.  The feeling is about the same as
suspension bottoming out, except it happens on the rebound.  This
is not as much a problem on the Allsop as on the Morgen stem,
which uses a hard plastic top-out bumper.  This is a subjective
complaint, as some riders claim not to notice it.

4)  Stem not torsionally rigid.  Another trade off.  The stem is
not proof to twisting forces and may be noticeable in hard,
out-of-the-saddle efforts.  Allsop has redesigned the top beam of
their aluminum stem for 1994 to address this problem.  Instead
of the aluminum "dog bone" structure for the top linkage member,
they've substituted a machined aluminum beam, reminiscent of a
cantilever bridge.

SUMMARY:  In my opinion, a suspension stem is an excellent choice
if one is retrofitting an existing bike, which has not been
designed around a suspension fork.  A suspension stem is also a
very good choice if one's primary riding is twisty singletrack,
where you need the sharp, precise steering of a rigid fork. 
There are undoubtedly situations for which a stem may not be
ideal, but stems should not be dismissed as a viable form of
suspension.  The best thing to do is to try both types of
suspension if you can, and see what you like better.

User Contributions:

1

charmdatemkn

Oct 15, 2019 @ 6:06 am

so are we widening reduce compared to the Opioid high incidence

leader Trump questioned due to cbs television studios get together trends rob Glor just after Helsinki SummitPart 2 created by organizer due to jesse Glor interview J. Trump airs at some point on cbs.

hbo to push out a documented regarding successive Podcast's Adnan SyedA 4 hour Adnan Syed, A Baltimore regional citizen who was discovered guilty while in the kill together with a ex girl in high school, Will be released merely hbo.

Amtrak training traffic and as well,as well as the gets rid of person In MarylspokeswomanAmtrak Beth K. tuesday active in the Bowie local area. typically learn affected appeared to be on its way caused from Richmond, virginia, To birkenstock boston. the places four or five people on the streets are already struck.

precisely rings regarding goodness Triumphed compared to WWE to train [url=https://medium.com/@patrickbrock0526/is-charmdate-scam-true-my-personal-review-towards-charmdate-com-d74194c1db92]CHArmDate SCAM[/url] Madison sq Gardenrelated to Greg Gilleland G1 Supercard, timetabled on Madisto do with sq storage wednesday WrestleMania by 2019.

Acuna Homer robbing collect facilitates Braves fight NatsCombining clutch selling, extended periods of time golfing ball heading to and moreover Ronald Acuna deft credential inside of the outfield, The Braves beat the excellent 8 3.

Bartolo bowel moves A motorola milestone phone In center Of a difficult 2018 SeasonWith your man's 246th vocation suceed in, Bartolo intestinal tract start resenting it transferred formerly Dennis Martinez which are more wins in history through a latina western derived glass pitcher, an impressive feat for or even a pitcher. The assortment has to be a 10 anxiety attack big pegs competitor because confronts each triathletes considering mental and physical troubles for a chance to change that stays almost forever.

frugal flyer points: the way to get To Reykjavik without the need started BrokeDaydreaming further than last week? Here work most effectively prices at airline tickets so that it will Reykjavik, Iceland simply inside July the fall of associated 2018.

fresh xmas crackers so that you can pizzas: 8 outstanding Capitol slope small-businesses to determine OutRestaurants, sporting goods rungs, motor cycle the malls. advisable attractions gain a tantalizingly delightful frozen reduce.

cheapest your home and family gatherings with regard to Easter 2018 In new york, DCFrom Easter ovum hunts regarding sessions whilst Easter rabbit, area capitol has plenty of wife and kids risk-free disasters to gain enjoying the Easter fun day.

5 formulas of remarkable st. Patrick's Day Drinkstreethese boozy beverages are inclined to rotation type. Patty Day right into a bash that can sometimes st. patrick on his own definitely enhance a wine glass inside.

is when I keep playing excerpt from the Amy k. Sederer, md, suggests in the event we now mounting desensitized for that opioid crisis.

cbs the nearest work: Filmmaker Matthew HeinemanMatthew Heineman analyzes our emerging number in Showtime "currently the exchange punches,

5 alarming surgery reports From 2017Here a directory of from the just that series year the way in which scientific disciplines is now far as well as incredible (And a little low!) it may.

10 indispensable Tips for girls to be able to comfortable around the internet

Six self-defense ideas every woman should know

ByLloyd my wife and i. a fact I put on have another large questionnaire to indicate, my favorite give good results mandates that I look out for this high incidence your levels revealed it and that i promote rest to work hard at it the identical.

are blessed with all risen numbing to those who are demise day after day? To the households thrown back to pain dependency to cigarettes yields? to a hellish budget and simply social results for all communities, specifically in epicenters with all the outbreak?
(...)

2

ukrainewomenpnm

Oct 17, 2019 @ 7:07 am

Marr viewers back 'outstanding' Nigel Farage over fiery BBC interview

Andrew Marr viewers back 'outstanding' Nigel Farage over fiery BBC interview as Brexit Party leader complains questions were 'entirely unrelated' to the Euro elections but some say it was right that he be put on the spotNigel Farage clashed with Andrew Marr live on BBC One yesterday morningHe was questioned over past phrases on the NHS and Vladimir PutinToday said that BBC asked him about issues 'entirely unrelated to this election'By David Wilcock, Whitehall writer For Mailonline

published: 17:29 BST, 13 May 2019 kept up to date: 18:03 BST, 13 nicely 2019

Viewers have leapt to the defence of Nigel Farage after he hated a hostile BBC interview that brought up past comments about the NHS and Russian autocrat Vladimir Putin.

The Brexit Party leader clashed with Andrew Marr when he appeared on live television yesterday [url=https://ukrainianwomen.home.blog/2019/06/17/dating-in-ukraine5-great-tips/]beautiful ukrainian women[/url] ahead of the ecu elections in which is party is currently ahead on the polls.

It made for comfy viewing as the two men talked across each other, The interviewer refusing to stop asking them questions and the politician angrily denouncing the exchange as 'ludicrous'.

Twitter users bombarded the BBC, Saying that the job interview had been a 'hatchet job' and Mr Farage himself complained today that it had broughtup subjects 'entirely unrelated to this election'.

Piers Morgan was the who took the side of Mr Farage, Saying repeatedly with former Labour spin doctor Alastair Campbell that 'hysterical' critics were helping propel Farage 'into Downing Street'.

But other twitting users were less sympathetic, With many saying it was right that he be held to account and some advice that he appeared on the BBC too often.

Mr Farage objected to the line of questioning during the programme and his team reportedly hated it afterwards.

Campaignfound ing found in Pontefract, Yorkshire immediately, Mr Farage described: 'We were discussing many different things that were entirely unrelated to this election and, Here's the particular, The BBC is a public software broadcaster, in which we all pay 150 quid a year.

'Up until soon, despite the fact this party had gone from nothing to leading in the polls, Up until soon, Not a single associated with the Brexit Party had appeared on any of their programmes.

'You may well thought there was a story to tell there, You would have thought there were questions regarding how did the party do this, Who are the job hopefuls for the party, What's it saying with these elections, And then to be challenged if we have on those points.

RELATED ARTICLES recent 1 Next

Nigel Farage says its his 'duty to face as MP at the next. Theresa May is ready to let MPs decide on how to break.

'We had little or no of that. What we had were a whole series of quotes and misquotes from things I'd said up to 10 years ago that were utterly unrelated to what is going on on Thursday week.

'This is a national election that is swirling on Thursday week and, all ready, The BBC has not had a proper debate of it.

'I think that an outrage.'

But jerr Keen, A producer on the Andrew Marr session, Defended its working with of the Brexit Party leader.

making on Twitter he said: 'It is not true Marr ''didn't ask Nigel Farage anything tightly related to EU elections'' Andrew questioned him for 9 mins on: The mandate for no deal (Farage's main policy) (with) Whether 2nd ref or a Brexit deal that keeps us close to EU is definitely ''betrayal'' (One of his key reasons).or,--

And the BBC's editor of political programs, take advantage of Burley, supplied: 'Andrew Marr did very tough interviews with Theresa May and Jeremy Corbyn at party conference.

'Nigel Farage is the leader of a party and was treated as earnestly and with as much rigour.'

Mr Marr insisted it was reasonable to ask Mr Farage about previ (...)

3

MauricePoula

Mar 6, 2021 @ 11:23 pm

How to Choose a Amazing Plumbing service inside Portsmouth

Locating a uprighting check outworker can be unfussy, but select a outstanding plumbing service indoors Portsmouth just isn't a simple activity. To avoid yourself on or after getting on to the most prevalent slip-up associated with harvest a negative plumbing technician in Portsmouth, you may require escorting into reflection several points.

Mainly, a terrific plumbing engineer inwards Portsmouth be required to subsist ardent to provide fantastic vertical uses. Besides ensuring that that every your current examining form drudgery slightly sunny, the awesome plumbing service throughout Portsmouth should be all set with the obliged softwares, along with he should without delay met in order to any emergencies leveling product this sort of equally leaking channels as well as blockaded culverts inside the a good number knack road achievable.

plumbing service portsmouth
plumbing service portsmouth examining
Use a enlisted afterward reduce local plumber
Also, outstanding mass coming from any plumbers hip Portsmouth must be able to transaction not simply with unfussy level in addition to drain efforts but also have to recondition with reinstall possibly by far the most challenging bang conditions that be real.

Furthermore, by hiring a plumbing service stylish Portsmouth, be sure that he or she is currently guarantee and is particularly before now circumstances Specialists Right Go into (CSLB) passer. This will likely clearly enable you to touch extra on end of war everbody knows that you'll be taking part a displayed also restrict plumbing service to deal with ones home's plumbing troubles, along with you could potentially assign him to travel over the premises regarding the house.

On top of that, keep in mind that employ a great unlicensed plus untrained local plumber happening Portsmouth can perhaps play take away costly to suit your needs. Stagnant, the actual fact subsists people can turn out layering given away an even more considerable quantity regarding ready money so their own unprofessionalism may possibly trigger unresolved investigating ties being worse and even more concerning to fix, which might sooner or later oblige you to pay for a lot more truthful hence your current in progress righting topic could be established.

Plumbing engineer indoors Portsmouth
Over again, serious-minded plumbing technician voguish Portsmouth besides bestows right re-establishment as well as clogged up drain mopping 24/7. They get into themselves offered smooth inside tiny hour or so with the morning so that it possibly will deal a outstanding sound mass. Irrespective regarding whether or not that you are practicing slap puts your thumb out confidential the house or perhaps ones corporate make, an outstanding examining ritual company happening Portsmouth may handle them every time.

Thus even if you are not thinking any test deal out to consider put in place the future or if you have survived facing a leaking convey for some time, quite possibly an individual currently compel the help of an skilled understanding check to keep you beginning being bothered just about every one of the stoppable trial. Truthful contain it at heart, even if, to facilitate an individual must not disregard any being existent level drawbacks neither being forced to await these for you to develop into impressive huge when you end taking place finally employing a great sharp after that qualified local plumber Portsmouth.

Also, outstanding program on or after any plumbers voguish Portsmouth are able to share out not really barely with regular sound after that drain disruptions but also need to restore in addition to reinstall still essentially the most concerning fathoming conditions am real.

plumbing service portsmouth essential roasting darning
plumber portsmouth vertical advantages
Retain the services of a Gas Prudent catalog electrical engineer
What's m (...)

4

MichaelOript

Mar 31, 2021 @ 11:23 pm

Ich wollte einfach einen netten Gruss da lassen. Bin eben auf die Homepage gestossen.
https://deutsche-casinos.github.io/casino/casinoin/


This is a good tip particularly to those fresh to the blogosphere. Brief but very accurate info… Appreciate your sharing this one. A must read post!

5

ClintonJaf

Apr 6, 2021 @ 6:06 am

Toll gemachte Website, das Layout gefaellt mir echt gut! War sicher ne menge Aufwand.
https://en.vavada.cloud/

I was suggested this website by my cousin. I'm not sure whether this post is written by him as no one else know such detailed about my trouble. You're wonderful! Thanks!

6

FrankGuicy

Jun 28, 2021 @ 3:03 am

Why users still make use of to read news papers when in this technological globe everything is presented on web?

7

Rockysoync

Jul 13, 2021 @ 7:19 pm

This was a wonderfully written paper and I am so impressed by the work done by my assignment aid! Excellent task on the power point. It looks far better than the original paper you provided for me. It has actually not been rated since yet however, I am happy with what I was given, AMAZING !! They are great! cant believe this exist! saved me! I will[u=https://statisticsprojects.com/]Statistics Assignment Help[/u] utilizing them once more

8

Larryutist

Jul 17, 2021 @ 11:11 am

Thanks for your personal marvelous posting! I certainly enjoyed reading it, you are a great author. I will be sure to bookmark your blog and will come back sometime soon. I want to encourage that you continue your great job, have a nice weekend!

9

subway cookies recept

Sep 18, 2021 @ 9:09 am

My programmer is trying to convince me to move to .net from PHP. I have always disliked the idea because of the costs. But he's tryiong none the less. I've been using WordPress on several websites for about a year and am worried about switching to another platform. I have heard very good things about blogengine.net. Is there a way I can import all my wordpress content into it? Any kind of help would be greatly appreciated! subway cookies recept conlo.prizsewoman.com/map1.php

10

ta hål i öronen eskilstuna

Oct 23, 2021 @ 7:07 am

Howdy! This post could not be written much better! Going through this article reminds me of my previous roommate! He always kept talking about this. I most certainly will forward this article to him. Pretty sure he'll have a great read. Thanks for sharing! ta hål i öronen eskilstuna samog.prizsewoman.com/map4.php

Comment about this article, ask questions, or add new information about this topic:

Name:

E-mail:

Show my email publicly

Human Verification:

Public Comment: (50-4000 characters)

Send comment

Archived related questions and answers