I got this Dahon Mariner from craigslist. The guy I got it from kept it in his attic for years and its cherry. I just needed to oil it up and it rides smooth. I think its a great bike but quite heavy, the thing is like all steel.

The only real problem is the plastic parts of the bike seem to be deteriorateing. The plastic disk behind the cogs crack to the touch. The front fender broke off when I took a tumble, I'm still learning how to ride. The plastic shield around the chain is a gone too. Who says plastic lasts forever.

I'm thinking about getting new brake paddles. The stock paddles dont have the reach adjuster, I have to reach pretty far to grasp the paddles.

Welcome noob_island, to the wonderful and money-annihilating world of folding bikes!

Plastic disc behind the cogs: you should just do away with this, instead of risking it catching the chain.
Brake levers ("paddles") you could try using just two fingers. It would be a long reach for all four fingers.

Other things to check:
- Check & adjust frame hinge to eliminate any play/wobble. I see you have two.
- Ditto the handlepost hinge

It is sort of addicting, I've only had it a month and I'm already thinking of stuff to mod it. I think the upgrades will cost more than the bike!!!

The dreaded folderitis claims another victi... erhm... happy customer.

--sam

You're not folding it correctly.

1. Fold the handlepost down. Don't rotate the steering axis.
2. Push seatpost down.
3. Fold frame. handlepost ends up between the wheels.

If the handlepost interferes with something, pull the handlebars further out of the handlepost so that they end up below the wheel axles - there is lost of room there for the handlebars. You should be able to get the axles to touch each other when successfully folded.

Actually if I dont rotate the front wheel the handle bars stick into the pedal gear and prevents me from closing the bike. The handle bar goes down at that odd 5 o'clock angle.

The odd angle after folding suggests the handlepost itself is not fitted correctly. The hinge should be at 45deg so that after folding the handlepost down, the handlebars are parallel to the front wheel.

You also have to find the most optimum place for the pedal crank arms to be. For the smaller Classic Dahon, that position was with left crank at 12 o'clock.

That does make sense. I looked around the pivot point but i can't see a way to correct it. The lock mechanism that connects the handle post to the fork forces me to put it out at that angle. You can sort of see it on the picture.

I think my Mariner must be pre-internet because I cant seem to find a picture of it folded even on the Dahon website.

I did find this picture of the bike unfolded and the hinge position is the same. But there is no picture of it folded so I have no way to confirm if the handle bar is at an angle when folded.

Unfortunately it is not easy to correct it. The 2 locking nuts inside the hinge have to be tapped with hammer and drift to loosen them a bit which frees the handlepost to rotate to the correct orientation.

I took a tumble the other day. The bike flew out from under me but I managed to keep standing by holding on to the handle bar. I thought I heard a cracking sound but I checked out the bike and everything was fine. I got back on and the bike didn't feel right. I got off and looked down and the handle bar was misaligned. I pulled the handle bar out of the handle bar post and the plastic guide shim was broken.


Here is a close up of the broken shim.

The right piece has the guide for the handle bar post.

I put tape where the crack is but the handle bar still wobbles. I have to eyeball the handle bar every time I unfold the bike. Anyone know where I can get a replacement?

Seatpost adapter shims are available from most bike parts dealers. Try Universal or Performance Bike. They run around $8 or $9, and they don't have the stud in the side, but the right size will give you a smooth sliding surface, and enough clamping pressure should keep the stem from rotating.

^ agree with 2wheeldeal. Don't ride it if you can't clamp it properly.

I think Im going to try that out. I'm looking at the shim closer and I found a smaller crack.

I don't have the tools to fix the handle post and I didn't want to spend the cash at my LBS for them to do it. I just recently found this Zoom 20 inch MTB Suspension Fork at NYCBikes.com. Now I would spend some cash for front suspension and have them fix the handlepost at the same time. I was just wondering if anyone knows if something like this will fit on my bike?

https://www.nycbikes.com/item.php?item_id=484

I don't think so. Dahon headset designs were radically different from the beginning.

I just got this exact same model of Dahon Mariner, and I can't figure out how to fold the frame!!!!?!?!?!? I see the latch, but, I don't even see how it is theoretically supposed to move, and pushing it and pulling it in various directions has not made it move yet?!!? I don't want to break my new/old bike which has made it this far and is still in good working order, but it's not much good as a folding bike if I cant fold it! Thanks in advance to anyone who can help! (Note: no manuals or videos available anywhere online :-( )