Posts
36
Joined
11/4/2012
Location
Pleasant Hill, CA
US
Why do most fork manufacturers have a max axle-to-crown restriction? Is it due to a risk of the stanchions failing or a risk of the head tube snapping? Long story short is my DH bike rides better with the increased front-center and stack height that my boxxer pushed past that limit is giving me.
Leverage. Testing. Liability.
The farther the axle is away from the headtube there is more leverage the fork will have. Many reasons to stay in the recommended ball park.
Another way to adjust what you are trying to achieve without messing up all the geo or going beyond the recommended A2C.
-Reach adjust headset (Will extend front center and reach)
-Longer offset clamps (will extend front center and reach)
-Risers under stem (Raise stack but reduce reach)
-Taller bar (raise bar height(stack feel) but not reduce reach)
The stanchion tubes are butted internally in certain places to allow for them to be clamped properly and to resist the leverage of a DH fork. Sliding them too far down can make it more likely to bend or crack. Also if there is more stanchion below the crown there will be less spacing between the upper and lower crown as well. Those specs are there for a reason, I wouldn't push too far outside of them. The kinds of issues it can create might not seem directly related - stuff like your headset might come loose more often or start creaking
Yeah, I've experimented with most of those, but increased axle-to-crown is what gets me "there". I'm already running a -.5 offset bushing and a -1 headset.
Thanks, that's what I suspected. From what I can tell Ohlins doesn't have a max axle-to-crown spec, so I may switch to a DH38,
What frame and fork are you using?
Post a reply to: Reason for max axle-to-crown restriction on dual crown forks?