Suspension Stem

[DarkNewt]

Hiya,
yep, I have been looking for a softride one! Incidentally I saw a suspension cartridge small online with a built in lockout lever and now I can't find it lol, my plan was to replace the cartridge in a softride or similar and have the lockout!

[MikeDee]

The Softride stem is way better than the Girven. Softride used a parallelogram linkage so the bars stayed in the same plane (didn't arc). I've used both in the day. The Softride was flexy in torsion though, and the bushings creaked, but it worked well. Team Ritchey won on it. There was a high end one made by J P Morgan (not the Wall Street company).

I can't understand why suspension forks and stems aren't used in Paris Roubaix. They were once for a couple of years. Maybe they were banned.

[Brucey]

...I can't understand why suspension forks and stems aren't used in Paris Roubaix. They were once for a couple of years. Maybe they were banned.

well the pave sections don't add up to a very high percentage of the whole race; if they were longer then there would be more advantage to suspension. As it is, forks are heavy, unaerodynamic, take time to adjust riding style to suit (if it is possible which it mightn't be in every case) and don't (partly because the actual suspension quality achieved is not very good) actually fix the #1 problem on the pave which is falling off. Obviously they don't do anything for the rear wheel, either.

Stems might have more going for them, provided they don't do any of the usual things that suspension stems do. I think that the TransX idea of simple, with limited movement is perhaps the way ahead, but what works for a leisure cyclist may not do for racing. If someone attacks in P-R , they will be putting out x2 or x3 the power of a (flat out) leisure rider and x5 or x10 the steady state power output. If there is the slightest hint that a stem is moving in an unhelpful fashion that gives a lower efficiency, it'll be in the bin, quick as lightning.

If such devices had no downside of any kind on smooth roads, and were demonstrably quicker on bumpy bits, they would have something going for them. As it is, the primary benefit appears to be comfort; the added discomfort of a bumpier road is, for a racer, just a (temporarily in P-R) added drop in an ocean of pain, and its association with a reduction in speed -for a well-motivated racer- is less immediately obvious.

cheers

[DarkNewt]

Hi All,

thanks for the great comments so far! I have come across a video for a suspsension wheel below, and while I wouldn't consider the wheel he does make a point about suspension forks and stems only giving suspension in one plane interesting.

I really think for a touring bike that a suspension stem, with lockout would be a good addition, it's a pity there's no voting option on the forum that would be fun.

Newt

[southerly]

As someone who is currently overhauling a Cannondale Silk Path from 1999, not used for some years (a long story) which comes with the Headshock suspension system, it really does make a difference. The travel is only 25mm/1inch but get a rough road or one remade with big granite chips or worse cobblestones and you will know just how effective a bit of suspension is.

It's a shame that Cannondale have a world patent on headtube suspension because it is way,way better than suspension forks. At the price quoted for a suspension stem I would look for a s/hand Cannondale, their off road bikes had a lot more suspension than the Silk Path.

[Brucey]

the cannondale system is (when it is working) better than most suspension forks but that is because most suspension forks are complete rubbish instead of (perhaps) partial rubbish.

Heaven knows what cannondale patents actually say; the idea is as old as the hills so their 'worldwide patents' probably only protect some minor detail of the particular arrangement they use.

The cannondale system requires routine maintenance, which they could have greatly eased by simply adding a grease nipple or two. If the water gets into the bearings and the lube fails, the results are truly 'spectacular'.

The cannondale system has deep flaws in the way it has been implemented. If you own an older unit spare parts are now almost impossible to source should the damper go 'pop' which they do. Or the air spring develop a leak (which they do). Or one of a dozen other things that they do.

A meaningless anecdote; A couple of friends of mine went touring in Morocco a few years ago, on MTBs. Chum A took a recent cannondale with a headshok. The bike had seen light use only and was in good condition. Chum B used a steel-framed Marin and I helped him fit suspension forks to his machine before the trip. The forks in question were ones I'd worked on over several years until I'd got them 'just so'. I'd improved the seals, the lubrication, the travel, the springing, the friction in the bushings, the top-out characteristics and particularly the damping. My chum was initially sceptical; the forks looked just like they had done before I'd started, and I'd started with base model forks.

'Why are there no adjusters?' he asked.
'You don't need them' I answered. 'Ride it' I said.
He did.
'Why don't these feel like other sus forks?' he asked.
'What do you mean?'
'Well I can't feel the bumps...'
'Isn't that the idea...?'
'And they are not bobbing...'
'No, they shouldn't do if you pedal smoothly; that is how I designed it'.

So off he went. Chum A's headshock topped out repeatedly when climbing, variously leaked air and oil at different times and was a constant source of annoyance over two weeks. Chum B floated along quite happily on my modified forks. All he had to do was clean under the boots once every couple of days (dust eventually gets in through the vent holes). Nothing else.

Other folk have ridden these forks and they liked them too. Comments like 'transformed' and 'unbelievable' are often used. It is impossible to describe but is a bit like the difference between being in a Jag and a Morris Minor.

If I told you that the mods took months to work out but would have taken mere pennies to implement in production, it just shows you what a crock of rubbish you will find inside most suspension systems that are used on bicycles. To get anywhere near the same suspension quality you would need to spend a fortune, more or less.

There are plenty of mechanical arrangements that will allow sensible suspension movement for bicycles; it really doesn't matter if you have teles, a headshock, a leading link fork or whatever; within reason, any of these systems can be made to work well enough . The devil is in the detail, where you can 't see it, even if you can feel its effects. It is in the springing, the damping (especially the damping) and the friction in the seals, bushings, pivots etc. The end result is the difference between unreliable junk that barely moves even on big bumps, and something inherently simple and reliable that rides like a jag.

cheers

[DarkNewt]

Brucye every time I make some minor adjustment to the setup of my bike you make me feel like theres miles left to go! Similiar feeling I get when browsing Sheldon Brown's site!

[southerly]

Brucey,
I take your point but the fact remains that head tube suspension is the best idea. So if Cannondale hav'nt got a total monopoly on this form of suspension why is no one else doing any empirical research?

The difference that this system has over rigid forks on a rough road has to be experienced. The punishment meeted out with rigid forks is not funny. I remember riding through Rouen over the cobbles and ahead were 2 cycle tourists on conventional touring bikes - they were being bounced around all over the place, the PSI in their tires probably did'nt help. I just glided over the cobbles thanks to that 25mm of suspension. Suspension forks are great for m/bikes but not for cycles - agreed.

[Brucey]

If the headshock arrangement were an inherently superior way of packaging suspension I daresay it would be found on motorcycles etc too. If it were the ideal solution then I'd suppose that Cannondale would not have bothered to develop the 'lefty' afterwards, either.

An inherent issue with the headshock is that the bearings are under a very large cantilever loading, especially on the brakes. This (together with the need for some appreciable amount of travel) more or less prohibits short headtubes (with large wheels), so it is never going to be a one-size fits all solution, even if they made a decent spring/damper unit for it. It also has a somewhat higher unsprung weight than many other systems. Overall it isn't a bad compromise for certain applications; in 25mm form it rides a bit like an original moulton, IIRC.

BTW as well as early Moulton front suspension, some Giant models have had a short travel shock absorber hidden in the headtube, too [edit; 'Accend' and 'Enlight' models; see pic]. Not big sellers I think; no idea why...



cheers

[DarkNewt]

just a thought on this, I haven't really quantified the effect that riding on rough ground has in tiring my arms out etc.. but wouldn't it be interesting to do a test ride o/ver a specific patch of rough terrain until the arms really felt fatigued, first with suspension then without or vica versa. Measure the time it takes till you notice the fatigue in both cases.

Anyone up for it to compare results, I know our different suspension/bikes/weights are all very variable some may not have lockout so can't do it on the same bike, however a crude extrapolation could be drawn on roughly how effective suspension is as an average.. probably not enough people to draw anything worthwhile in terms of a conclusion but am going to have a go myself... for the sake of daydreaming.

[Brucey]

I used to ride the same (bumpy, half-offroad) route daily and at various times used a CX bike, a rigid MTB, a hardtail, a softtail, a couple of different XC type FS bikes. On that route the CX bike was fastest (in the dry) and the softail/FS bikes were the most comfy/least fatiguing. The softtail was my favourite because it was as fast as the hardtail but more comfy. The FS bikes required that I pedalled very much more smoothly to get the best out of them, which I found difficult when I was already a bit tired.

On good roads, there was little advantage to be had from front suspension. However if you have a riding position that throws much weight onto your hands then you should get more benefit from it. Given the choice though, I'd suggest sorting your riding position out over bothering with FS, every time.

cheers

[Sweep]

http://sunsetcyclery.com/brands/road-an ... 00-354.htm

I have one of these which i think may have the sort of suspension some of you are talking about.

If anyone is interested in buying it, let me know.

Would also be interested in anyone's opinons of it.

I have only ever seen one other.

[DarkNewt]

The bike or just the fork?

[mig]

didn't ernst colnago say that his frames didn't require suspension forks and the like for paris-roubaix? i.e the geometry and tube arrangements were sufficiently good.

i just don't like the idea of front suspension in any form, preferring the front end to be rock solid and a basis for my input into the bike. then again i'm a roadie at heart..!!

[southerly]

mig,
imagine trying to sell any m/bike or car that did'nt have suspension? You want rock solid why, do you like to punish your wrists and elbows. The 25mm of suspension at the front of my bike makes means it literally glides over a rough road whereas with a rigid front end a lot of your energy is kicked back at you so lessening control rather than enhancing it.

Brucey has a valid point about riding position but then you have to take into account the transferring of shock from wrists and elbows to the spine, especially true if you ride high pressure tyres, again a little suspension in the seat tube makes a difference. Rational suspension ideas are where cycle theory should be heading.

Certainly for performance riding suspension is a no-no, completely different for those who take their time - horses (or bikes) for courses as always.