Crank forward hack on Dahon

If I had to guess, I would say that at least 50% of those riding bikes are either not on a bike that is the right size or the handlebars and/or seat are not in the optimal position.  I'm no bike fitting expert, but I have a lot of conversations with people that complain about their butt, wrists, knees, or neck after doing a decent amount of riding.  The best way to make sure you do not experience discomfort might be to buy a bike from a shop that knows how to fit you, or you can experiment on your own with different positions and/or hacks.  And if you run into a person who rides a recumbent, you will likely get an earful of how great a riding experience a recumbent offers.  I myself will just have to take recumbent rider's word for it =)

Reader J experienced some discomfort when riding his Dahon and he came up with ideas to help increase his pleasure and reduce his pain.  Take it away J . . . .

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I stopped riding the Dahon folder for close a year now due to neck/wrist pain and groin numbness.  Nothing wrong with the bike, it's just age.  I moved to a recumbent which cured everything. But I miss the portability of the folder.  I rode a Townie crank forward bike and it seemed to be a good compromise between a recumbent and a regular bike.
 
The Experiment
 
Starting with an existing folder,  we decided to test the crank forward position by doing a double bend on the seatpost. It moved the crank about 4 inches forward. To raise the handlebar for a straighter back position, we used a wide cruiser bar.  The result is an upright comfortable position without the associated pains of a regular bike for an aging rider.

 A word of caution!  The double bend may weaken the seatpost, especially for a heavy rider.  I'm only 160lbs and have not noticed any catastrophic bending. The center of gravity does shift backward as well.  On the flats,  there is NO noticeable twitchiness.  Stability seems to be same as an unmodified folder.  On uphills,  there is some wheel lift.  Overall it feels like a folder with loaded panniers in the back.

 
Doing It Right
 
The correct way of doing a crank forward hack is to weld a new bottom bracket in front of the existing one.  You can go about 5" forward before there is pedal and wheel overlap.  Then use a regular straight seatpost.  There will be some extra weight to the front wheel which will only add stability.  One thing I like about the crank forward design is the ability to put your feet down when stopping without getting off the seat.
 
Another project for the fall.

Comments

[timebobmtimmy]

I have an old folding bike that was a bit uncomfortable as the seat was pretty far forward. I rotated the saddle clamp and pushed it as far forward as possible in the seat which has helped. Although I have gotten used to the configuration, I am still considering a lay back post, but what I have found locally are all short. Doing something like this is an idea, though a little out of my skill/tool set.

Can someone clarify the 'Doing It Right' section? It doesn't seem to make sense to me to put a new bottom bracket forward of the existing one to achieve what was done here.