I’ve had a play with some 100mm SID’s and they seemed remarkably good, nothing like SID’s of old with their 28mm stanchions. Sorry, it’s been a few years since I really paid attention to most lightweight racer stuff, but to all intents and purposes the newer SID’s are supposedly a good all round trail fork too.

Which leads me to ask a question based upon some rumours I’ve heard… Have heard that the 120mm travel SID’s struggle to give up their full travel, no matter how they’re set up they get very firm after 100mm is what I heard. Now the 100mm set of SID world cups I was playing with were possibly the nicest set of 100mm forks I’ve ever tried, and you could get them to easily use all 100mm of travel, but what about the 120’s and the rumours I’ve heard?

Basically, I want a new 120mm travel fork, but I want to use all 120mm is why I’m asking…

Test Here

I have the RLT 120mm came with my specialized 2011 bike. Lovely fork and does the job very well. I have been looking after it though with lower leg services and a damper oil change. Fixed any issue I’ve had with them.
Rumour has it that rockshox never put the correct amount of oil in, so replace it as soon as you buy them. I’ve had to do this with 2010 rev race and these SID’s.
I’ll give 4/5 because my cable guide bolt snapped as the reviewed showed 🙁

To achieve full travel, you’ll be squashing the bottom-out bumper. All travel figures are for maximum travel, rather than likely travel achieved on most rides. So, if you are regularly achieving maximum travel on any fork, then you’re probbly battering them and jolly well have not got enough spring in them. Forks shoon’t really be battered right down to the bottom out bumper I woon’t have thought…

Air forks will ramp up towards he end of their stroke. Which helps stop them bottoming out frequently. So, I’d say getting close to within 10mm or so of maximum travel is fine. The only time I achieved maximum on my Rebas was cos I’d done them too soft. 40mm sag is a bit too much. Pumping them up a bit saw just over 100mm for most rides. Plenty.

If you really want all 120mm travel, then get a set of 130-140mm forks, innit?

S’a bit like brawdbaynd; ‘up to 120mm travel/10meg’. Up to. Not ‘will regularly give this every time’.

I say ‘up to’. I’m meant to have ‘up to 8 meg’, but have only ever had 4. 😥

can the travel be reduced to 100mm with spacers? RS make a 100mm model but not with a maxle.

To achieve full travel, you’ll be squashing the bottom-out bumper.

No bottom out bumper in Rockshox to speak of… So full travel should be able to be attained if you hit the fork hard enough (or its set up too softly) rather than it ramping up too much at the end of the stroke.

If you really want all 120mm travel, then get a set of 130-140mm forks, innit?

Not really, geometry is critical too, and frames are usually designed to work best with a fork of a specific axle to crown length. Also, almost every fork I’ve owned ever has at least been tunable to make sure you can (if required) get all of the available quoted travel. The 2 exceptions to this were a pair of 2007 Marzocchi 66SL’s that just wouldn’t give more than 160 of their quoted 180mm travel (they ramped up WAY too much), and a pair of 2001 Rockshox SID SL’s that wouldn’t give more than 65mm of their quoted 80mm for exactly the same reason.

Rumour has it that rockshox never put the correct amount of oil in, so replace it as soon as you buy them. I’ve had to do this with 2010 rev race and these SID’s.

This is often the case to be fair, and if that’s all it is, then I’ll not worry. Usually forks come with sub-par oil inside anyway, so it often pays to replace with good quality full synthetics fairly soon. I know Marzocchi used to underfill a lot of forks which meant they seemed too linear, similar to Maverick DUC32’s from the factory too.

can the travel be reduced to 100mm with spacers? RS make a 100mm model but not with a maxle.

Yup, they can be spaced down to 100mm with a spacer. The SID range is quoted as being 2 distinct forks, one optimised for 120/100mm of travel, and the other as 100/80mm of travel.

Adding negative air shortens the fork and thus reduces available travel, so you’ll never get 120mm unless you run no negative air at all.