redclay

Hey, new here. If anyone can give advice to a folding bike neophyte I'd appreciate it. I just bought a used Dahon P-8 in good condition. I find it well put-together, but in riding it there is a loud clanging each time I hit an irregularity in the pavement. I've determined so far that the noise comes from the chain, specifically the top run of the chain from cassette to chainwheel. The chain seems to be under greater tension there than on a standard bike, therefore sounding loud when it slaps against the sprockets. That's what I'm guessing anyway. The rear tire is a pretty narrow one, so it doesn't dampen much of the shock that causes the noise.

Is this just a drawback to folders in general, or can I quiet this bike down? It drives me a little nuts. Thanks if you can help.

tds101 

Welcome aboard!

As for the noise, the P8 rear derailleur isn't the greatest, and I do find it a bit noisy rolling over potholes and such. I'd recommend going to a bike shop and getting a tune-up. This way, if there's anything wrong, it can be corrected. Better safe than sorry I say.

jur

Probably chain slapping against the chain stay, ie the lower tube between the back and the crank, rh side. Wrap something soft around it to see if the clanging improves. If so, then you can get a chain stay protector.

It is weird that it happens so easily though if it is that.

linberl

Obvious advice, but did you go through and check every single bolt on the bike once you got it for tightness? Big ones and little ones, cranks and pivot bolts, make sure the cassette is snugged down properly, etc. Sound is weird and sometimes the cause is not where it makes you think it is.

redclay

Thanks for everyone's suggestions. I do believe I've got everything tightened down back there and everywhere. I even suspected the rear magnet was clanking around, but that wasn't it. What I'm thinking is that the wee bike just makes a different sound when it hits the cracks (bumps don't seem to be a problem). It's kind of like the diff between a violin and cello. Also I've been riding it mainly on a bike trail that has frequent fissures, unlike roads are likely to have. So I may be just overly sensitive. I noted that the P-8 previously came with Big Apple tires, and I wonder whether one of these on the rear would cushion out some of the noise.

Now, while I have your attention, I'll ask whether any of you have experience with a stem extender for Dahon. I'm right at the upper height limit for the bike, and though the seat height is ok, the reach is too short. I've got the seat shoved back as far as it can go. I also tried handlebar ends to stretch out on, which help, but I'd like to be further out when I'm holding on to the hb.

HGR3inOK

I used an Aber Hallo on my last Speed P8 to raise the handlebar height. It worked well and, IMHO, it is a well-deigned, high-quality item. For other options see:
Handlebars, Extenders and Bar Ends


-HANK RYAN-
Norman, Oklahoma USA

redclay

Thank you, Hank, I appreciate this information. The stem and MKS folding pedals are the first upgrades to the bike I'll be making.

Interesting (I think) note about folding bikes. A friend is a wary bike rider, never gained confidence on full-sized wheels. I bought the Speed P-8 and suggested she try it. She immediately said she felt more comfortable on the mini--something to do with feeling less far from the ground. I think the feel of getting the small wheels rolling instantly probably also has something to do with her reaction. She now has the bike on a long-term loan!

linberl

I had the same reaction. I had been riding 700c bikes and when I got my folder, in no time I was so much more comfortable. I'm guessing your friend is not super tall? The physics folks can chime in on the reasons, but I just know that leaning, flipping the whole bike into rapid left/right turns, turning tight circles, etc., feel so much safer on a smaller bike. I definitely feel more like part of the bike, rather than just a rider perched on top. And knowing just how easy it is to put a foot down to stop makes it even more secure. You may never get that bike back

Tourist in MSN

I had an odd noise when I hit bumps that took forever to find. My cassette lock screw was a bit loose. I do not remember how I tightened it, but I did not use a cassette lock ring tool. Initially it was fine, it was tighter than hand tight, but after a while it became loose enough that the sprockets could rattle on the free hub when I hit bumps. On that particular bike my regular cassette tool did not fit, I had to buy a new tool that would fit on the Sram Dual Drive hub to get it tight enough.