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considering 120mm to 140mm fork upgrade

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asyluminc

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Discussion starter · #1 ·
Hey everyone,

My current fork is in need of replacement. I currently have a 120mm fork on an Ellsworh evolution (120mm rear). It has never given me any trouble at 120mm - is it worth it to go up to a 140mm? I think the steering may be slowed down a bit but are there any other negatives? I am certian somebody else has gone from 120 to 140 up front. What are your opinions?

Thanks.
 
#2 ·
X-Fusion Trace RL2...

Reasonably priced & solid performance.

Also adjustable (i.e. internally, travel can be changed - JIC you don't like 140)

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#3 ·
- Ensure the manufacturer supports that length - too long and the fork can put extra stress on the head tube and (in rare cases) cause catastrophic failure. It doesn't seem like much but it can put a lot more leverage on the head-tube/top-tube/down-tube junction. If manufacturer won't certify it, you may still be ok but you do so at your own risk. It will definitely fatigue the head tube junction faster, decreasing the life of the frame. Check frequently for stress cracks in the paint.

- Geometry wise, it will probably slack the head tube angle by around 1.5 degree and raise the bottom bracket by around .75 inch. The higher BB will have impacts like making the bike feel a little more precarious in technical climbs as well as ride higher in turns which can make the bike feel a tad less stable. But you'll have slightly better log clearance.

There is a geometry calculator here allowing you to plug in your numbers before/after and see the result:

geometryCalc
 
Discussion starter · #6 ·
eb1888 said:
What fork are you using? It's possible a better performing fork could get you what you want at 120 or 130.
Click to expand...
I currently have 120 millimeter Fox f29. I want to get rid of it because it's getting old , it's not worth rebuilding anymore(at least to me) and it has the creaking issue.

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#7 ·
asyluminc said:
I currently have 120 millimeter Fox f29. I want to get rid of it because it's getting old , it's not worth rebuilding anymore(at least to me) and it has the creaking issue.
Click to expand...
Makes sense. But for what bike? If built for it, then 140 would be fine. If not, then what eb1888 said makes a lot of sense. Maybe a newer fork will just be sweet riding compared to the F29...
 
#8 ·
I have a 80mm Manitou Tower Pro on a hardtail I keep for freinds. I did some custom shim tuning for the compression stack. It rides better than any 100mm fork I've ever been on for my rocky/rooty trails. I'd look at a Boost Ohlins 29 fork if I didn't care about money because of the high speed compression damping adjustment range.
Ohlins RXF 36 29"/27.5"+ Fork > Components > Forks & Suspension > Suspension Forks | Jenson USA
Comes 120 and 140 but not adjustable.
You'd need a new wheel but that gets you into wide rim and tire options to play with.
 
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asyluminc
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