120mm Fork on Specialized Epic Feasible?

[Two-Stroke]

How well would a 120mm travel fork work on a 2015 model Specialized Epic?  Anyone who's tried this, or has seen it done?

 

Bought the bike 2nd hand last year after a few years on my trusty Scott hardtail and have been enjoying how nicely the Epic balances comfort of full suspension vs keeping a "racy feel".  I'm by no means a racing snake or trail machine, but I enjoy mixing up Jonkershoek/OakValley/Welvanpas in-between longer "dirty roady" type routes.  I find though that the 100mm travel upfront is a little lacking on some trails and reckon 120mm would make a big difference.  Buying a Spez Camber (or similar alternative brand model) not an option - because let's face it, bikes have become silly expensive, and I really like the Epic as a general purpose type bike.

 

How would going from 100 to 120mm affect the Epic?  The obvious points would be slightly slacker headtube angle, and slight increase in bike front height requiring saddle & stem adjustments.  Any risks or potential issues I might be missing?

[nolipoli]

Higher bottom bracket would also affect handling.

I played around with the concept of also adding an angleset which would slacken the HA even further. This has the benefit of bringing the bottom bracket down again, but also getting that longer front end to work better on the steeps.

[Bizkit031]

Sorry to tell you the Epic is not built as a general purpose bike that is what the Camber is.

[Paul Ruinaard]

Works beautifully. I ran a 130mm revelation for a long time, no issues. The truth is all the purists will gnash their teeth and talk about bb height and frames original intended use etc.

 

But it worked great.

 

Front end was raked out a little more so the bike was more stable.

 

The are many pictures in here of 100mm XC bikes running much longer forks, I think even Iwan Kemp's VIPA.

 

Add some nice fat tyres and rims while you are there, it makes the bike ride like a trail bike...

[Captain Fastbastard Mayhem]

Perfect. 120mm will be absolutely fine. Will slacken the head angle by about .5 degrees and raise the bb by about 7mm or so. But the added travel and slacker head angle will work beautifully

[Two-Stroke]

Ah nice, good feedback - thanks guys.  It's probably a gamble, and agreed that the purists will knash teeth but a change to any factory spec doesn't necessarily result in a worse off product (if done properly).

 

Should probably drop this in it's own topic thread, but next step is to see whether the 100mm fork can be increased to 120mm.  The previous owner fitted it when he first bought the bike -   It's a 2014 Rockshox SID XX/29" model.  Some quick Googling suggests that this fork can potentially be run as 100, 110, or 120mm configuration - and from the sag markings on the stanchion it looks like some of the scale is hidden below the wiper seal.  Guess this is a question for the suspension specialists, but hoping someone here might be able to offer some guidance before I start phoning around.  First thoughts which come to mind are that if it can be done, that a new airspring unit will be needed, but more importantly whether the SID design is strong enough to handle the leverage of stanchions extended 20mm further out of the lowers.

Edited July 4, 2016 by Diesel85

[the nerd]

Ah nice, good feedback - thanks guys.  It's probably a gamble, and agreed that the purists will knash teeth but a change to any factory spec doesn't necessarily result in a worse off product (if done properly).

 

Should probably drop this in it's own topic thread, but next step is to see whether the 100mm fork can be increased to 120mm.  The previous owner fitted it when he first bought the bike -   It's a 2014 Rockshox SID XX/29" model.  Some quick Googling suggests that this fork can potentially be run as 100, 110, or 120mm configuration - and from the sag markings on the stanchion it looks like some of the scale is hidden below the wiper seal.  Guess this is a question for the suspension specialists, but hoping someone here might be able to offer some guidance before I start phoning around.  First thoughts which come to mind are that if it can be done, that a new airspring unit will be needed, but more importantly whether the SID design is strong enough to handle the leverage of stanchions extended 20mm further out of the lowers.

 

Should be able to do.. Droo should be able to help you! 

[Paul Ruinaard]

Ah nice, good feedback - thanks guys.  It's probably a gamble, and agreed that the purists will knash teeth but a change to any factory spec doesn't necessarily result in a worse off product (if done properly).

 

Should probably drop this in it's own topic thread, but next step is to see whether the 100mm fork can be increased to 120mm.  The previous owner fitted it when he first bought the bike -   It's a 2014 Rockshox SID XX/29" model.  Some quick Googling suggests that this fork can potentially be run as 100, 110, or 120mm configuration - and from the sag markings on the stanchion it looks like some of the scale is hidden below the wiper seal.  Guess this is a question for the suspension specialists, but hoping someone here might be able to offer some guidance before I start phoning around.  First thoughts which come to mind are that if it can be done, that a new airspring unit will be needed, but more importantly whether the SID design is strong enough to handle the leverage of stanchions extended 20mm further out of the lowers.

Hmm - I have been through this. If its a SID A it cant be done. SID B it can be and should be able to be done easily.

 

Those air springs aren't common....

 

I had a SID A which couldn't be changed, so I put on the Revelation, through axle as well.

 

SID A had QR closure only, Sid B had 9mm and thmm TA - which is another way to tell.

 

Just change the way you pump it - negative first

[Odinson]

I'm just waiting for some random Hubber to barge in here and post: "Put a Pike on it, bru. Best vork eva!".

 

Oh and for Myles to suggest Magic Mary's for the rubber.

[nonky]

I'm just waiting for some random Hubber to barge in here and post: "Put a Pike on it, bru. Best vork eva!".

 

Oh and for Myles to suggest Magic Mary's for the rubber.

 

hahahahahhaahhaaaaaaaaaaaaa.........

[BaGearA]

Getting more travel will be nice but something else to consider is some frames are made to work with different travel suspension (up to 4 different travel settings) but some are made to just work with one set fork travel.

 

the epic is one of them and although it could work very nice you run the risk of putting far greater pressure on a place like the head tube than it was ever desinged to be taken.

 

And an epic frame costs a lot , you also won't be coverd by insurance as the bike was modified beyond what is recommeneded by the manufacturer .

 

If you can find success stories of people having done this with no problems over a period of time , by all means go for it.

 

And report back some feedback:)  

[Rocket-Boy]

I'm just waiting for some random Hubber to barge in here and post: "Put a Pike on it, bru. Best vork eva!".

 

Oh and for Myles to suggest Magic Mary's for the rubber.

Lol!

I think you have missed most of Myles' posts for a while, I doubt he would be recommending MM's though.

[Paul Ruinaard]

I'm just waiting for some random Hubber to barge in here and post: "Put a Pike on it, bru. Best vork eva!".

 

Oh and for Myles to suggest Magic Mary's for the rubber.

You Joke,

 

Before getting my Stumpy I had my Epic pimped to run a Revelation at 130mm and a set of Flow EX's running 2.3 inch Sticky Vee Rubber.

[Paul Ruinaard]

Getting more travel will be nice but something else to consider is some frames are made to work with different travel suspension (up to 4 different travel settings) but some are made to just work with one set fork travel.

 

the epic is one of them and although it could work very nice you run the risk of putting far greater pressure on a place like the head tube than it was ever desinged to be taken.

 

And an epic frame costs a lot , you also won't be coverd by insurance as the bike was modified beyond what is recommeneded by the manufacturer .

 

If you can find success stories of people having done this with no problems over a period of time , by all means go for it.

 

And report back some feedback:)  

I can report back. It works. Ran a 130mm Revelation on my bike.

[Spoke101]

I've done it and with a SID XX WC 2012 Dual Air so was just a spacer removal.

 

Found 110mm was the best compromise for racing but that's at the sharp end.

 

120mm was defiantly more fun and stable when hitting rock gardens at speed, climbing was a compromise but only on the really steep stuff where the bike was trying to pop wheelies.

 

For your fork you will need to buy a new 120mm air spring ±R1200.

 

I ride hard and did some enduro's on the bike as well as a few 4m gap jumps and all was fine, I am on the light side at 60kg though.

[Two-Stroke]

Hmm - I have been through this. If its a SID A it cant be done. SID B it can be and should be able to be done easily.

 

Those air springs aren't common....

 

I had a SID A which couldn't be changed, so I put on the Revelation, through axle as well.

 

SID A had QR closure only, Sid B had 9mm and thmm TA - which is another way to tell.

 

Just change the way you pump it - negative first

 

Hmm so the fork is a 2014 Rockshox SID XX 29" with 15mm thru axle.  Does that make it the SID B model?

It's a solo-air model so no option to pump negative vs positive chambers.  Only one pomp-plek on the fork

 

Getting more travel will be nice but something else to consider is some frames are made to work with different travel suspension (up to 4 different travel settings) but some are made to just work with one set fork travel.

 

the epic is one of them and although it could work very nice you run the risk of putting far greater pressure on a place like the head tube than it was ever desinged to be taken.

 

And an epic frame costs a lot , you also won't be coverd by insurance as the bike was modified beyond what is recommeneded by the manufacturer .

 

If you can find success stories of people having done this with no problems over a period of time , by all means go for it.

 

And report back some feedback:)  

 

Good point which was mentioned on a few of the MTBR forum topics I found.  Would an extra 20mm travel and associated minimal headtube angle change really inflict that much additional leverage on it - or should I say enough added leverage to compromise the headtube strength?

 

I've done it and with a SID XX WC 2012 Dual Air so was just a spacer removal.

 

Found 110mm was the best compromise for racing but that's at the sharp end.

 

120mm was defiantly more fun and stable when hitting rock gardens at speed, climbing was a compromise but only on the really steep stuff where the bike was trying to pop wheelies.

 

For your fork you will need to buy a new 120mm air spring ±R1200.

 

I ride hard and did some enduro's on the bike as well as a few 4m gap jumps and all was fine, I am on the light side at 60kg though.

Nice to know it worked - thanks.  Reckon your fork was probably quite different in design though i.e. 2012 vs 2014 and dual vs solo air.  Made me curious about whether my fork has a spacer installed - which if removed will give an extra 10mm without any modification needed.  Alternative would probably be the 120mm air spring unit I guess.