Seven Cycles fork questions

[chris7ed]

I got a used Seven Elium with the stock Seven fork (not the 5E). The fork seems flexible. Seven claims that the 5E is a stiffer fork but how much? Also, I'd consider other fork suppliers. Anybody have experience with the stock Seven fork?

The next question. I've looked at different forks and the axle to crown lengths vary. At the long end maybe 8mm. How much effect would that have on the handling everything else being equal? Anybody have experience with that?

[SignatureJustin]

Is it a Wound Up fork or the stock Seven fork? Most likely a Wound Up.

[chris7ed]

It's not the Wound Up. Looks like the "stock fork" they sell today. All carbon (carbon crown and head tube) with straight blades.

[fa63]

What makes you think the fork is flexible?

As far as axle-to-crown height goes, most forks are in the 370±5 mm range (367 mm being very common). I don't think you would notice a significant difference, other than a slightly higher / lower handlebar depending on which way you go.

[SignatureJustin]

What makes you think the fork is flexible?

As far as axle-to-crown height goes, most forks are in the 370±5 mm range (367 mm being very common). I don't think you would notice a significant difference, other than a slightly higher / lower handlebar depending on which way you go.

Changing a-t-c changes the geometry of the bike all around.

I have ridden a 5E for a couple years and they are great forks. They fit nice wide tires up to a 30C with a standard reach brake. The stock fork that Seven use has the same A-T-C as there 5E. The 5E would be a great upgrade to the current fork without any compromise to the current geometry of the bike.

Good luck.

[fa63]

Changing a-t-c changes the geometry of the bike all around.

Theoretically yes, but a minor change (±5) will be barely noticeable. I certainly couldn't tell a difference going from a 367 mm ATC fork to a 372 mm ATC fork. Now if you put a cross fork on a road bike, that is a different story, but that is not what we are talking about here.

[chris7ed]

[QUOTE=fa63;466946]What makes you think the fork is flexible?

Two other road bikes seem more stable. One is all steel. The other is a ti frame and a carbon fork. Nothing over built on either bike. The Seven front seems more unstable. Hard really to say why. Just a feeling.

[shiggy]

I got a used Seven Elium with the stock Seven fork (not the 5E). The fork seems flexible. Seven claims that the 5E is a stiffer fork but how much? Also, I'd consider other fork suppliers. Anybody have experience with the stock Seven fork?

The next question. I've looked at different forks and the axle to crown lengths vary. At the long end maybe 8mm. How much effect would that have on the handling everything else being equal? Anybody have experience with that?

A 8mm change in A-C changes the frame angles (HTA & STA) by ~0.5 degree. That in itself may or may not be noticeable to you. But fork offset also affects handling, and forks can a have different offsets as well as different A-Cs.

[Peter Polack]

Since you describe the fork of the Seven as feeling "unstable" it sounds more like a fork rake issue rather than a stiffness issue.

Sometimes the fork has a stamp or sticker on the fork steerer listing the fork rake. Pull the fork and look for a number between 40 and 50. If you don't want to pull the fork then you can try my method of measuring the rake without removing the fork:

Remove the front brake, front wheel, and loosen the stem clamp. Measure from a convenient point on the crank such as the crank arm bolt, straight to the front dropout to where the center of the axle would be. Rotate the fork so it's facing backwards. Measure again. Subtract the smaller number from the larger and divide by two. That's your fork rake. I realize there's a little angle error built in to the method but the results are close enough.

A fork with less rake than what you have will make the bike feel more stabile. A 3mm difference is probably not worth changing the fork over. I can personally say a 5mm difference is noticeable.

Is it possible you can sway in a fork from your other bikes just for testing purposes?

[fa63]

Two other road bikes seem more stable. One is all steel. The other is a ti frame and a carbon fork. Nothing over built on either bike. The Seven front seems more unstable. Hard really to say why. Just a feeling.

The feeling of front end instability is usually caused by factors other than a "flexible" fork in my experience. Could be that the headset is a bit loose, or one bike has more/less trail than another and gives a different feeling, or one bike has a big stack of spacers under the stem, etc... If you haven't already done so, I would check the headset on the Seven first. After that, I would compare the front-end geometries (fork rake/head tube angle and the resulting trail) to see if there is a common denominator for the two other bikes you find to be more solid.

Edit: Looks like Peter just beat me to the bunch :)

[chris7ed]

73.5 ht and 45 rake on the Seven. Surely this is a step set up and I have considered changing to a 43 or 40. Hard to say if this is a solution for the wiggly flexible feel. So say it is. Any opinions on what rake? I'm a bike rider not a bike racer.

[fa63]

With a 73.5-deg HTA and 45 mm rake (and assuming a typical 367 mm ATC) you should have a trail of 53 mm on the Seven, which is a bit on the quick side and might be contributing to the feeling of instability. I personally prefer a trail of 56-58 mm on my bikes.

[roseyscot]

How old is the frame? Early eliums were too lightweight and handled poorly.

[chris7ed]

2012 model.