[jackalope]

Whilst laying a nest of corned back rattlers, I was perusing the latest edition of MBA...And surprise, surprise - they absolutely love the Santy VP Free (yes, the bike that won't be available to the average Joe til next Spring, in typical SC fashion - think Heckler)

Anyway, to my point - They mentioned in their 'Suspension Tips' that bikes with mulitple rear shock positions put undue amounts of stress on the shock when it's placed in the lowest and highest settings; due to increased leverage ratios I gather...To wit, I have a Marin Wolfridge frame that I use as my trail / light FR rig (my Bullit is now too portly for day to day excursions), and one of the reasons why I bought the frame was because of it's 4", 5", and 6" travel settings...Changing the travel setting is accomplished by simply opening the quick release and sliding the rear shock axel to which ever direction you wish...I do usually ride in the 5" setting, but I was sessioning some FR stunts this past weekend and rode for quite a while in the 6" setting (and have done so on other occasions as well)...Put the head tube adjustment at 69 degrees and had fun...So I'm wondering if there is any real truth to MBA's assertion? If so, why bother even offering this 'option' if it is known to create instant shock destruction? I know there are several other quality manufacturers that go this route as well...So far no problems for me, but I'm just curious....

 

[Curb Hucker]

Alright listen carefully "Do not, I repeat do not believe anything that you read in Mountain Bike Action" - Zaskar Rider

 

[jackalope]

^^^
Yes, I know - but the glossy pages make for such poor sh!t tickets...

Maybe I can use a few zip ties and wrap a few issues around my chain stay in place of a Lizzy Skin or old tube...Or wrap some around the lowers of my new Shiver instead of those tacky plastic shields...Damn, I'm a veritble Martha Stewart of old bike rags...Hell, the way things are going, our stock portfolios are starting to look remarkably similar :

 

[Repack]

MBA sucks.

In general, most good suspension is designed to work around a leverage ratrio of 3:1, or slightly higher. This means that a 2" stroke shock (the amount that it actually compresses by, not eye-to-eye overall length) would likely be on a bike w/ ~6-7" of travel. 3:1 is a "happy spot" because it allows a bike a reasonable amount of progression, without overwhelming the damper.
Also, the forces coming into a shock come at it along an arc. The point in the arc changes the effective leverage. The higher the leverage ration, the more the angle changes.
High leverage rations also make the shock work a lot harder. It is important to remember that a rear shock is a sealed unit. Resevoirs do provide a place for hot fluid to expand into, but you still do not want to overload the shock.
Higher leverage ratios require more preload, meaning that you could in theory have an easier time bottoming out your bike when set up w/ 6" than when set at 4".

Does this make any sense? I'm trying. Someone like dw should chime in.

 

[zedro]

ya, like was said above, the higher travel settings will put more load into the shock. However, as long as its designed for it, its an irrelevant point. Problems can arise when say it was originally designed around 4", and you mod the plates for 6" and use the same size shock/hardware/bearings.

I find the multiple travel setting trend kinda pointless for coil systems (TALAS is a diferent story). You can only optimize the coil and damper settings for one travel setting, the rest is a comprimise. If the suspension is designed and tuned right, the lower travel settings (assumed to be for heavy pedalling duties) would be redundant.

 

[RaID]

well yes increasing the leverage ratio on shocks is going to put extra stress on the shock

but youre never changin travel by more then 2"-3" at the wheel anyway
hence the compression ratio change isnt gonna be that great

anyway the shocks are designed to work well around the ratio of 3:1 which is what most bike are around, and their various wheel travel settings

its when you get ratios 4 and over for normal shocks that you have to start worrying but this wont happen unless you have custom linkages


in other words change the travel on your bike how you like, MBA wouldnt know a sheep from a goat

 

[thaflyinfatman]

Originally posted by RaID

MBA wouldnt know a sheep from a goat

Perhaps, but they sure do know the difference between a paying advertiser's test bike, and anything else!

 

[binary visions]

Who the heck is MBA to determine that, universally, changing shock positions will too much stress on a damper? Hell, my bike could have a 1:1 leverage ratio in the one position, and a 1:1.5 in the other position.

Every time I think they're as stupid as they can possibly be, they get a little stupider.

Someone should go to MBA and, as Milton would say, "set.. the building on fire..."

 

[jackalope]

Thanks - feeling much better now...Even found a new use for the old rag: plunger pad (thus, when you're finished unclogging the porceline throne, you don't have to put the business end of tha plunger back down on your spotless linoleum - just plop it down on the most recent edition of MBA instead)...

Although Zed makes an interesting point about the lower suspension settings (e.g. if you get a spring rate for your highest setting, it would not be ideal for the other settings)...That said, there's really not too much to optimizing a Vanilla R coil over IMHO...Just a few rebound clicks and maybe a pre-load adjustment...

 

[thaflyinfatman]

Originally posted by binary visions


Who the heck is MBA to determine that, universally, changing shock positions will too much stress on a damper? Hell, my bike could have a 1:1 leverage ratio in the one position, and a 1:1.5 in the other position.

Every time I think they're as stupid as they can possibly be, they get a little stupider.

Someone should go to MBA and, as Milton would say, "set.. the building on fire..."

I wholeheartedly agree. Worst magazine everrrr.

 

[Zaskar Rider]

Originally posted by ViolentVolante
Alright listen carefully "Do not, I repeat do not believe anything that you read in Mountain Bike Action" - Zaskar Rider

You beat me to it with my own quote hahaha