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Thoughts on pull shock
What are your thoughts (pros and cons) on a pull shock, like that seen on Scott genius and Cannondale Jekyll?
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Pros:
* TALAS-like ability to stiffen up the rear end for climbing with the flick of a lever. Not sure what differences / advantages it provides over pedal platform, though. Those with them might be able to answer.
* Different, if you like your stuff to be different (as I do)
Cons:
Servicing the shock seals (a simple job on a regular compression shock) is not a DIY task. Means sending your shock away which adds significant cost and time (weeks) off the bike to a job that can be done at home in well under an hour with simple tools.
In principle, the idea is no more or less sound than a normal compression shock, if the extra complexity of the dual chamber system introduced by Peter Denk (the guy who introduced them first to Scott and then Cannondale) doesn't bother you. Personally, I prefer simplicity when I choose 'different'.
Best advice is to ride both and see what you think.
Bear in mind that you are testing setup as much as the bike, and a poor setup can make a good bike ride crap. My recent discovery that I've been running minimum rebound for who knows how long on my shock is a case in point - it's so much more settled when descending, and climbs so much better now that I'm running more appropriate damping.
So investing a little time in setting up the shocks at each end with pressures and rebound is worthwhile before you bound off into the wilds of the ... bike shop carpark
Run away.......!
Seriously though, the idea is good as the shock shaft is mainly protected within the shock body but in the grand scheme of things when they go wrong there aren't as many fix people to go to & if it's shafted (sorry) your replacement options are severely limited.
I speak through experience gained while trying to sort out a mate's Scott Genius.
On the third attempt (sent away to recommended Scott shock service people)the shock finally held oil & pressure... He quickly sold the frame!
What about minor leakage over time? Wouldn't the shock suck in dirt, rather than blowing out oil etc?
And what about negative air pressure causing things to boil. A long shot probably, but starting off with a negative main chamber which decompresses even more, even something that boils at hundreds of degrees will boil at much lower temp. Not hard to get a shock hot as on a 40 degree day.
Hmm. Knowing a bit about Boyles law etc I see your point but these shocks still have high positive pressure in both the neg & pos chambers like a conventional shock otherwise they wouldn't leak they would suck......
The chamber function is just reversed.
Eg. 90kg rider on a Ransom using an equaliser pull shock. Recommended pressure 400psi in both + & - chambers!!! Nuts!
http://assets.scott-sports.com.s3.amazonaws.com/...
I have a Genius RC10. The pull shock works great, and the ability for full lockout means you can ride it as a hard tail.
But ... When mine needed servicing it had to go to Sheppard in Vic (regular shock servicing guys can't do it as Scott only sells the seals to authorised repairers, which in Aus is only Sheppard as far as I've been told) it took 8 weeks to get done (apparently average time is 2 but they had a big backlog). It's 100% better post service and runs really well. Climbing is great (better than pro pedal on my RP23 on my Rumblefish), descending is good too, though a little stiff at times. Having two chambers to set adds complexity and you need to Mae sure you set them up in the right order.
Quirky, yes. Good, yes. Timely and expensive to service, yes. Choice is yours!
Positive pressure in the negative chamber... Ur right, it doesn't make sense
8 weeks is insane, considering I did a minor on a Fox for the 1st time in 30min.
The ability to get parts serviced, repaired or replaced, especially things like crash replacement warranties really factor into my buying choice.
TBO, it sounds like a complicated, expensive piece of kit that may or may not be what you are looking for, and only if you have a shorter travel bike.
The work well but what happens in 3 years time when they redesign, drop the pull shock in favour of an off the shelf standard shock and you're left with out any spare parts.... Kinda like what happen in the late nineties with Yeti the Lawwils, Schwinns and other Rad bikes that used pull shocks back in the day
In theory a pull shock gives the frame designer far more room to be creative and keep COG low but consider that the concept and technology has been around that long, If it was that good wouldn't it be picked up by manufacturers in a big way....
Scott have resigned the Genius with a regular shock for 2013.
Mine is the older TC shock (replaced in 09 by the equalizer). Still get parts no problem. The shocks for Scott are made by DT Swiss, so they supply parts - but I wouldn't guarantee they'll keep stock of spares forever.
As for short travel - yep, mine is 100mm, I think they biggest pull Scott did was 125mm
I think it was great in theory, but as you say, if it 'that good', why did only cannondale join in?
I did note fox make a pull shock (RTD2 or something), but odds on it wouldn't fit a Scott frame
I have 2007 Scott MC 40. The pull shock has been great on it and I have always had it serviced without issues. On my model they had 130mm travel on the rear shock. Later models were 150mm and the LT were 185mm. Current Genius LT are still pull shocks with 185mm travel.
At the end of the day it up to personal choice what bike you prefer and are happy to ride.
Evan