Mountain Bike Reviews Forum banner
Cancel

Perfect Epi Fork Length ?

2342 Views 36 Replies 11 Participants Last post by  yangpei, 
E
Just thought I'd post up some thoughts on experimenting with fork length on the Epiphany, and maybe get some feedback on what others are finding. I'd been running an 08 Fox Float with 140mm travel for a year, I had decided to go with the fixed travel Float as I didn't want any reliability issues with the Talas..and I'm more of the frame of mind to get the handling dialled for allround riding and leave it.

On its recent years service decided to get the mechanic to drop the fork by installing a travel spacer to 130mm (had to custom make one as fox only supply a 20mm spacer) - this was partly inspired by viewing the Ellsworth website which seems to indicate that the frame was designed for 120/130mm forks. To elaborate...the axle to crown length of my fox at 140mm was 513mm, and Ellsworth are suggesting a static fork length of (presummably the same thing as axel/crown?) 19.5 Inches or 495mm - My Fox dropped to 130mm now has a 503mm axel to crown - I've measured it accurately. This would suggest that a Fox at 120mm would be more spot on! They recommend a 5inch travel fork which would be 128mm...and I thought Fox were some of the lowest axel to crown for given travel!

Anyway, I'm shocked at what a difference to the handling just dropping by 10mm at the front has made, much bigger difference than was expecting for such a small change - though I admit that I am a bit like the Princess and The Pea when it comes to bike setup. The bike feels much sharper and racier and more stable steering. I had previously been getting some minor handling issues particularly on technical climbs where the slightest nudge at the front wheel had my wheel lifting and feet dabbing, as if I had too much weight rearward. I run a 10 degree 90mm stem set low with 5mm spacer, low rise bars and am 5'10" on a medium frame... and am conversant with adopting the bent arm and arse on nose of saddle type climbing posture. Also had similar issues with difficulty cornering on switchback climbs, and generally being nocked off balance too easily, I guess what you might call wheel-flop. Now with the front end down 10mm the weight balance allround and particularly climbing is spot on and I've just easily cruised up a climb that I struggled on last week.

So now the handling feels much further towards the racier end of the 'Trail' type bike, and think this type of handling best suits the light ('ish) nature of the frame, is this what Ellsworth intended? Running the front low is not without some drawbacks such as a slight loss of plushness on front and a steeper headangle which is noticed on steeper downhills. I'm really surprised if Ellsworth suggest 120mm as ideal as this would seem very steeply angled for a bike with over 5inches of rear travel, but maybe for certain types of terrain it works?

Just thought I'd throw it open to debate as it seems most people are fitting 140mm Fox's to these bikes when it seems strangely that Ells suggest an F120mm would be better suited....Though maybe because Fox and Rockshox dont make a 130mm fork now. What have people found to be the best compromise for fork length ?...where do you set the travel if you have adjustable travel?... should Ellsworths dimensions be taken with a pinch of salt (I've noticed a few typo errors etc. on the website before). Cheers.
See less See more
Reply
Save
Like
1 - 20 of 37 Posts
T
I might as well post up (again) with my thoughts. They pretty much agree with what you've learned. I'm also 5 10 on a medium Epi and a 90 by 5 degree stem. When i first bought the frame in 07, i put my old 02 Vanilla on it, set at 125mm and all was good (cept the fork was worn out). Then i finally got my hands on the previous model year's (06) Vanilla, which had 130mm travel, and this was great handling-wise but the fork had several issues (creaking crown, malfunctioning compression damper, clunking at the end of rebound). Fox replaced it under warranty with a Van 140. Nice fork, but i felt like crap on my Epi. Steering was slow and floppy, bike felt 'stilty', couldn't keep the front wheel planted on steep climbs. I was dismayed to learn that, for the first time since its inception, that the Vanilla's travel was no longer internally adjustable. STUPID!

anyway, I finally swapped the Van 140 for my U-turn Pike on my 'freeride' bike and all has been great ever since (except for the loss in front end stiffness on my other bike). I run the Pike (which is an awesome fork) generally at 120mm which is pretty much the same a-2-c as the Vanilla 130. Sometimes i will make it a little higher for extended technical downhills and i lower it for the really, really, really steep climbs that i love trying.

thumb
See less See more
Reply
Save
Like
road dirt
I run an 08 Talas on a large epi with a 110 stem. If I had to choose one setting it would be 120mm. Other than the 26" wheels it's pretty much the perfect bike at that setting.

I'm eyeing the Evolve like a fat man looks at a ham sandwich... :D
Reply
Save
Like
B
Magura Durin

This is good news. I was going to post a question about this early next year. I plan on buying an Epiphany in the spring. I really wanted to try a Magura Durin Marathon 120 mm fork on it, but almost every Epiphany I see has a 140mm Fox of some sort. My main concern was would this screw up the geometry, but it sounds like the Magura will be the better fork for that. So since someone has started this thread I might as well ask. Is anybody out there using the Magura Durin Marathon on there bike and how do you like it?
Reply
Save
Like
jimmy L
I'd agree that 10mm can and does make a difference. I've run the Rock Shox Revelation with U-Turn and experiemented with different lengths to find the sweet spot for racing and trail riding. I set the travel between 120-125 for Endurance and Marathon events which helps on the climbs and is a bit more twitchy for the XC style riding.

When out trail riding with mates I use all 130mm available and it rides great. The main thing with travel adjust is adapting your reaction to drops on decent as the shorter travel can bottom out causing a slight inbalance. On very steep climbs the 130 at front has drifted occassionally but I think that could be due to general fitness as it mostly never worries me now. I can't comment on the 140mm but I can't see any advantage for the terrian or type of riding I do.

I am also salivating over The Evolve which I think could be the perfect bike for around here.
Reply
Save
Like
baha_boater
I have a PIKE (air) on my LG Epi which is adjustable from 110MM to 140MM and also have found the 120MM > 125MM best for all around riding. As I just posted on another thread I swapped a Maverick SC32 125MM over from one of my other bikes this week just to see what it would feel like. The SC32 has a single throw climbing mode which reduces travel to 80MM and let me tell you the Epi climbs like a goat in that setting. I also felt the almost 1 lbs off the front end and was able to loft the wheel over roots with less effort. The axel to crown height on the Maverick fork must be a bit lower because I had to add about 3/4 " of spacers on beneath the same stem and bar I've always used with the PIKE.

Like most I have always thought that bigger was better and more was best, in this case I find the 125MM and lighter weight SC 32 makes my Epi track and climb better. As I mentioned in the other thread the only drawback seems to be reduced ground clearence so I have to be a bit more careful with the pedals over large roots etc...
See less See more
Reply
Save
Like
T
baha_boater said:
The axel to crown height on the Maverick fork must be a bit lower because I had to add about 3/4 " of spacers on beneath the same stem and bar I've always used with the PIKE.
Click to expand...
Doesn't that just mean that your steerer tube on the Maverick is a little longer?
Reply
Save
Like
baha_boater
My first thought as well but I don't think so... The steerer tube on the PIKE is cut to lenght and only had one small spacer under the stem and it fit/felt perfect. The steerer tube is longer on the Maverick SC 32 fork however when I put the same single spacer under the stem rest on top which is meaningless for this discussion the bar felt way to low or more correctly my weight or center on the bike felt like it was too far forward. Even with the PIKE cranked all the way down to 110MM it never felt that way. Unless I am brain dead (which is possible) the only thing that could acount for that is a difference in axel crown length of the forks. I had to put about 3/4" of spacers beneath the stem to get the same approximate fore aft weight distribution I am used to...... My Epi is at my buddies house I am headed over there later, I will measure both forks axel-crown lengths and let you know.....
Reply
Save
Like
T
baha_boater said:
My first thought as well but I don't think so... Unless I am brain dead (which is possible) the only thing that could acount for that is a difference in axel crown length of the forks.
Click to expand...
the other obvious possibility is a difference in preload/sag, which you wont notice until you're weight is on the bike. Zip tie on the stantion will figure that one out.
Reply
Save
Like
B
reply:

Hey guys:

You brought up a good point on the fork height; (EndOverend) I just replaced my Pike on the Epi with the Reba 120mm-Maxle lite and the geometry seems spot on for my riding style. I always had my Pike set on 115-125 anyway so I thought I'd go ahead and try the lighter Reba instead. The bike dropped about a pound in weight and seems snappier on the turns and uphill. Just installed a couple of days ago and liking it more and more than the Pike. Thanks for staring the thread, thought I was the only one crazy enough to try a 120mm on a 130mm bike. :D
Reply
Save
Like
K
BrooklineDr said:
Hey guys:

You brought up a good point on the fork height; (EndOverend) I just replaced my Pike on the Epi with the Reba 120mm-Maxle lite and the geometry seems spot on for my riding style. I always had my Pike set on 115-125 anyway so I thought I'd go ahead and try the lighter Reba instead. The bike dropped about a pound in weight and seems snappier on the turns and uphill. Just installed a couple of days ago and liking it more and more than the Pike. Thanks for staring the thread, thought I was the only one crazy enough to try a 120mm on a 130mm bike. :D
Click to expand...
I had a Fox 120 on an epiphany to start with to save weight and it gave the bike a quick snappy XC feel that I was looking for. I found a deal on a Fox TALAS and am trying it out right now. The 140 setting slows the handling down but notgrossly so. The bike still steer well and takes a lot more of the trail chop out but if I really wanted to go fast I'd drop it to the 120 setting.
Reply
Save
Like
baha_boater
Quick update: I've added two more rides on the 125MM SC32 and I have decided to keep it on my Epi over the PIKE (this is still a shock to me). I find the SC32 a better match for the frame, it seems to do just about everything a bit better (except ground clearence) and weighs almost a full pound less which is noticeable. I also like the single throw travel adjustment to 80MM for climbing vs the crank it down (4 or 5 turns) to 110MM on the PIKE. The last ride I went down some several steep rooty/rocky decents and found the 125MM of travel to be plenty. If the PIKE had a quicker (i.e. remote or single throw) travel adjustment it would be much closer because it's a great fork but as it stands not as good a fit for the frame and my riding style.area etc......
Reply
Save
Like
B
I've never seen a Mav SC32 on an Epi before, would you have any to post? Thanks
Reply
Save
Like
baha_boater
I have pictures

I took some pictures of the bike but mtbr would not accept the file size my camera spits out so I had to convert them to PDF format... They uploaded successfully so hopefully it will attach them to the post so you can view them. I have never included pics so this may be trail and error....

Due to the fact that the Maverick SC32 has a 24MM hub and the PIKE has the 20MM Maxel I had to swap the DT Swiss 4.2 wheel set off my Matic with the Crossmax XL set that was originally on the EPI. The DT wheels are a bit lighter anyway so I am just going to convert them to tubeless. I assure you I will NOT leave the blue Fire XC tires which were on my Matic on the EPI!! I need to order a Stans rim strip to convert the 4.2's to tubeless and I be able to move my Conti's back over.

I also added a picture of the Matic with the PIKE installed.. I have not even had a chance to ride it yet still working to perfect the setup on the Epi.

Attachments

Reply
Save
Like
E
BrooklineDr said:
Hey guys:

You brought up a good point on the fork height; (EndOverend) I just replaced my Pike on the Epi with the Reba 120mm-Maxle lite and the geometry seems spot on for my riding style. I always had my Pike set on 115-125 anyway so I thought I'd go ahead and try the lighter Reba instead. The bike dropped about a pound in weight and seems snappier on the turns and uphill. Just installed a couple of days ago and liking it more and more than the Pike. Thanks for staring the thread, thought I was the only one crazy enough to try a 120mm on a 130mm bike. :D
Click to expand...
Cheers BrooklineDr...I too thought I might be bonkers reducing my fork height, when most people and manufacturers seem to be bumping up travel. After more riding at 130mm Iit has re-inforced my conclusion that the lower fork makes a big difference to technical climbing. Now if my front wheel hits a bump on a steep climb the suspension seems to swallow it and the bike just pops over the obstacle in a very controlled manner with no wobble or wonder. At 140mm I always seemed to be nudged off to the side or backwards.

However, the sping rate of the Fox now doesn't feel as good at 130mm. I still don't seem to get anywhere near full travel which is I believe a common Fox air problem - even with running such low pressure that it feels mushy in mid-stroke....so now I'm wondering if I'd get the same results with fork set back at 140mm and instead run a 0 degree stem, loose all the spacers to dump the bars down low, and run an in-line post to steepen seat angle - as am thinking it may be down to weight distribution more than frame angles...
See less See more
Reply
Save
Like
baha_boater
Interesting

It will be interesting to hear how those changes impact handling, stability,comfort etc.

Fork (A/C) length affects head tube angle which affects trail which is a primary contributor to stability. Among other things, seat tube angle and bar height will affect fore-aft weight distribution and may increase sag (as Thumbies mentioned unless you increase the forks preload which will.... nevermind that is another discussion) also impacting trail affecting climbing stability but may also negativly impact handling on steep downhills. You could also experience upper body/wrist/arm fatigue due to the fact that you are using forward weight distribution to compensate for too little trail. Not to mention the inabilty to easily loft the front end over roots etc...

Which brings us back to the discussion on the various ways to impact straight line stability, tracking, climbing ability, etc. Or primarily what is the difference between increasing/decreasing the axel - crown length of the fork vs changing fore/aft weight distribution with bar height seat position etc. I suspect for AM/trail riding the way to get it right is to select a fork that has the minimum amount of travel you need for most riding conditions and setup around that.

What we need is someone who understands the engineereing around frame design and can explain the actual difference. I found a .xls tool to calculate trail that may be worth playing with for some........ http://www.anvilbikes.com/images/1064634020.xls
See less See more
Reply
Save
Like
B
Hey thanks for the pictures, I like the inverted fork very nice. You made a good point about longer travel forks. For my riding style, I prefer the shorter travel because it's efficient and usually less weight. I can clear pretty much anything that a 140mm fork can clear, probably not as fast but I can clear it. I have a 0 degree rise with 90mm length and it seems to work for me, a 110 may be a bit long for my reach but the front end is planted on the climbs. My new Reba feels plusher (maybe because it's new) than the Pike with about a pound in weight savings. --- The longer stem would probably spread your body weight better but might strain you back in the long run. BTW how much does your Epi wiegh in at? just curious. Inclued a pic of my pink Epi :thumbsup:
Reply
Save
Like
baha_boater
Good question... It weighs 25lbs even as it sits
Reply
Save
Like
baha_boater
25lbs
Reply
Save
Like
B
That's a light set up man. Mine weighs in at 26.4 lbs - I have a heaverier wheelset..mavic 819.
Reply
Save
Like
1 - 20 of 37 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Mountain Bike Reviews Forum
A forum community dedicated to Mountain Bike owners and enthusiasts. Come join the discussion about bike parts, components, deals, performance, modifications, classifieds, trails, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
General Discussion Downhill - Freeride California - Norcal Passion Shocks and Suspension
Top