Soft MTB fork setup - pros/cons?

[NotSoBigBen]

I notice that many of the faster/better riders seem to run their forks pretty soft - are there any specific pros and or cons to doing this?

 

Will it make any difference to an untalented 'weekend warrior' such as myself that rides long 'non-technical' rides on the weekend and short stumbles through the Rietvlei Zoo Farm 'XC' course in the week?

[dirtrider]

Yes , your shock will bottom-out !!!

[NotSoBigBen]

Yes , your shock will bottom-out !!!

 

I thought 'if it doesn't bottom out now and then you not getting your moneys worth out of the fork'

[Agteros]

I thought 'if it doesn't bottom out now and then you not getting your moneys worth out of the fork'

You've gone from BigBen to LeanBen, so a softer shock setting might be in order

[Capricorn]

bottoming out because of what is the unspoken half of that overquoted catchphrase.

 

I love discussions about suspension settings. There is no real right or wrong. there are some fundamentals that apply, but on the whole, it's all very subjective. However, a certain objective coupled with a riding style will dictate a suspension setting that varies between riders by only a few clicks of the controls.

 

Firstly, what type of riding do you do?

What kind of fork do you have BB?

What are the controls u have on the fork, eg: compression (hi/lo), rebound (hi/lo)? NB hi/lo can be substituted by beginning stroke/ending stroke depending on the brand of fork.

 

At the two extremes, a rigid frame, and a super soft suspension: For pedalling, the former gives the best conversion of your leg efforts into motive force. The latter the worst as some of your leg efforts will be spent activating the suspension instead of driving the rear wheel.

 

sticking with rigid versus super soft: when rolling down a descent, the rigid at speed will require a lot of your human suspension to come into play to smooth out the bumps at speed. It's the most uncomfortable, most physically demanding, and probably the slowest as you will try to slow down just to able to stay on the bike.

On the other extreme: a super soft suspension is most comfortable as it soaks up the undulations on the ground. This could be the fastest as being more stable on the bike means you will be more confident and thus stay off the brakes more while still being able to gain more speed by pedalling if u so desire.

 

Cornering:

rigid means full conservation of the energy thru the corner.

super soft means losing some energy due to suspension activation (same as when pedalling hard), and thus requre you to choose line properly, riding smoothly, staying off the brakes (bigger balls), and/or pedalling like mad when exiting the corner just to gain back your speed.

 

I hope you follow where this is going: suspension is always a tradeoff between desirable bike handling characteristics. you have to determine what your objective is in the context of your riding style, and then setting up your suspension to play to your strengths. Sometimes, the ojective seems beyond your capabilities, but ifyou let the bike work for you, you will realise new performance boundaries. You just have to allow the bike to do it for you, as often you will find that a bike requires a minimum speed, above which the suspension really comes into it's own. Your bike will feel like a whole different animal. Just let it off it's leash...

 

oh and one last thing: the suspension starts from the rubber up

Edited March 26, 2012 by Capricorn

[TheV]

Hi BigBen,

 

Couple of quick comments on your post:-

 

So I guess you are referring to Sag? I say this because you mention you "noticed" other riders running their forks "soft"...

 

A "stiffer" spring (more air, or higher spring rate) will produce less sag, while a softer setting I will produce more sag.

 

Increasing sag typically produces a more comfortable ride and the suspension responds better to small bumps. Decreased sag typically makes the bike more firm and can improve your acceleration. Too much sag will make the shock bottom out too easily.

 

For the type of XC rides you are talking about, technically you would set up your forks according to your weight to have 15-20% sag. So if you want faster acceleration, or doing a longer ride over the weekend, I would say run at the lower 15%, when you get to stumble around rietvlei, on the normal XC route go for a 18-20% setting..

 

I personally run about in the middle of 20% and 25% (22.5) on Rietvlei when I run the blue routes and hit the rock garden, then you need it....

 

I also run my damping setting (rebound) pretty slow (about 50% setting) on Rietvlei - because you dont want to be bouncing around the place...

 

I dont usually mess around much with my sag often, i play around a lot initially when i get a new bike/forks, and after that I usually just adjust my rebound/damping settings for each trail, and i keep a note of how many clicks i go from low and keep it in my car...

 

Like the cap says above, it's a very personal setting, and it's affected by your style, balance and riding style, aggression, your bike, your tires, pressures, etc etc... Also, worth a mention, most forks take about 40 hours riding to run in, so you will have plenty time to play and adjust before you get it perfect for you..

Edited March 26, 2012 by TheV

[NotSoBigBen]

Mmmmm Cap, makes sense but difficult to somehow 'feel' what's good when you're as ham fisted as me on the bike ...

 

Lets take the example of my Epic that has a Fox Talas 32RL ...... I have been pumping it to 90PSI and the rebound is just 2 clicks toward slow from the mid setting.

 

As Heman mentioned I have however lost the weight of a small farm animal in the last couple of weeks and clearly this is also affecting it. I ride an XC course in the week that is not particularly hectic and then on weekends it's mostly long long rides with bits of technical/singletrack thrown in.

[TNT1]

Set your sag properly first. RTM. Then fiddle with rebound. I still say look to the forks for handling over comfort first.

[NotSoBigBen]

Set your sag properly first. RTM. Then fiddle with rebound. I still say look to the forks for handling over comfort first.

 

That's what I 'normally' do Bob but it seems to me that's not the rule for everyone ... are there different 'sag' rules for better/faster riders cause they sure as hell are not running the recommended!

[TNT1]

 

are there different 'sag' rules for better/faster riders cause they sure as hell are not running the recommended!

 

No. Setting sag is the same for everyone. What you see them running is a setup dialled in for race handling. But they would have started with sag first.

[Capricorn]

No. Setting sag is the same for everyone. What you see them running is a setup dialled in for race handling. But they would have started with sag first.

 

i tend to disagree: sag these days is not the cut and dried "follow the user manual recommendations". Guys who ride fast and hard, tend to run slightly less sag, ie let the fork sit up higher in it's travel. THis is very very useful for courses that are steep. Given the objective for XC, this will however, not be an overriding requirement compared to say, a downhill course.

 

I for instance, run my XC and DH forks high in their travel, and for my XC fork, the compression is 1-click off lockout. This stops something I personally dislike: excessive fork dive in corners and when going over obstacles. I run the rebound at the fork's middle setting, slightly on the slow side. Sometimes, if u set your rebound too fast, it makes the ride very skittish as the wheel is now forced to follow as much of the terrain as possible. If set slower, it allows alot of the rough to pass under the wheel before the wheel makes contact with the ground again. You have to set it not so slow though, that the fork 'packs up', that is, successive compressions causes the fork/shock to bottom out. So just slow enough to skip over some rough, but fast enough so you still get most of the travel. This is trial and error and often is terrain dependant.

 

Also, because I run such a stiff setup, I compensate somewhat by lowering the tyre pressure: the tradeoff is better traction, but more rolling resistance. For those running tubes, lowering the pressure increases teh risk of snake bites, and tyre pressure losses via burping on ghetto tubeless setups. UST compatible tyres+wheels should be pretty much immune to burps and of course snake bites.

Edited March 26, 2012 by Capricorn

[Capricorn]

Mmmmm Cap, makes sense but difficult to somehow 'feel' what's good when you're as ham fisted as me on the bike ...

 

Lets take the example of my Epic that has a Fox Talas 32RL ...... I have been pumping it to 90PSI and the rebound is just 2 clicks toward slow from the mid setting.

 

 

How does the bike behave at these settings? what would you prefer it do?

[Wyatt Earp]

Hey HoseMan, lekka name.

Yip that's why I run my fork so stiff.

Edited March 26, 2012 by HairySack

[Capricorn]

long non-tech stuff: if u want make good time, aka maximise your leg output into propelling you + bike: run your fork and shock stiffer. But u will sacrifice comfort as trail chatter will translate up thru the bike. Slightly softer tyre pressure can help with that though. The inverse is also true: higher tyre pressure, but softer suspension. Difference is though, pedal inefficiencies creep up due to software fork and shock settings. Not desirable. Padded grips and softer tyres are better options.

 

oh and rebound on the middle setting, but on the slower side.

Edited March 26, 2012 by Capricorn

[TNT1]

I run my fork so stiff.

 

me too. Oh, wait, it's a road bike...

 

Nevermind.

 

Ben, I'd suggest going past Russel Campbell racing one day. Dunno who else, since Alistair died, I don't have a good suspension guy for mtb's anymore.

[TNT1]

I don't have a good suspension guy for mtb's anymore.

 

Oh, wait, maybe the dangly hair, but I don't trust him...