Dahon Eco 3 higher gears?
 

I ride a Speed D7. The gears go from 34" - 92", and I think this is pretty good for most purposes. I bought my daughter an Eco 3, and while it also has seven speeds, it goes from 41" - 77". Everybody who rides this bike says that it is nice but it pedals too easy and it isn't fast. Does anyone know if it is possible to put a Speed D7 sprocket cassette on an Eco 3? The D7 has a Neo derailleur while the Eco 3 has a Shimano.

Thanks,

John

At 41" the lowest gear it isn't going to go up too many steep hills either.

Ask Thor (owner of Thor USA and a participant in this Forum) about the interchangeability of the cassettes you mentioned.

According to the Dahon website, the Eco 3 uses a freewheel hub and a 14-28t freewheel.

This is different from the Speed D7, which uses a freehub.

Here is a rundown, if you need one:

http://sheldonbrown.com/k7.html

Essentially, no, you can't. You would need to replace the rear wheel with one that uses the freehub system in order to access modern sprockets.

You may be able to locate a freewheel with a gear range that is more impressive. This is difficult, as major manufacturers such as Shimano have discontinued freewheels with wider gearing.

I know of sources for 11-28t freewheels, but not for ones that have a better low end than what you have right now. Not in 7 speed, at least. That doesn't mean that it isn't out there, though!

You may be able to find an old Shimano megarange freewheel as NOS, which would give you what you want.

he is right ... its probaly easier to buy a rear wheel with a cassette and than you are more flexible ..however larger screw on freewheels do exist .. just need a little more time looking
Shimano megarange will most likely only work with a megarange rear derrailleur ( they have this funky red large wheel at the bottom to have more chainwrap )

thor

Your thread title asks for "higher gears". Abneycat and brakemeister have it exactly backwards: a Shimano Megarange 14-34 freewheel will lower the gearing on the Eco 3.

I'm seeing Google hits for Shimano 7-speed 11-28 and 12-28 freewheels. Those will deliver the higher gearing you asked for.

HTH,
tcs

Very interesting. That's a great link, Abneycat. It is odd that Dahon would use such completely different technology on similar bikes.

At first I was confused by the gearing in inches, and the sprockets, which I guess are measured by the number of teeth. The lowest tooth count is the highest gear, right?

For me, the Speed D7 gearing is just about ideal for what I do, which is mostly recreational biking on bike paths. I spend most of my time in 5th gear. Whoever is riding the Eco 3 is usually in 7th gear and struggling to keep up, so tcs is right, we are looking for some higher gears. This is all good info.

Thanks,

John

I have nothing backwards, although I may have regarded the OP's desires as wanting the gear range of the Speed D7, rather than just the top end. To that end, I already mentioned the top end, but specified that there weren't common freewheels that gave low end as well.

However, I looked around at some tech docs last night - if you were wanting a lower end as well, it would become trickier. The RD-FT30 equipped on the Eco 3 has a max sprocket of 28t.

However, I now see that it seems like you are primarily concerned with high end gearing, so this is fine. It'll take an 11-28 without issue.

On a side note, Shimano used to have megarange freewheels with an 11-34 ratio, although long discontinued now.

11-28 freewheels are relatively common, I know that the shop across the hall from mine has them, and has an online website as well.

http://us.itselectric.ca/Bike_Parts_s/57.htm

Its an electric bike store. Actually, such stores commonly carry strange freewheels (as electric hub motors use freewheels), so you could look around.

That said, buying a Dahon rear wheel is only $45 from Thor's store. It would save you piddling around with outdated, inferior components like freewheels.

Couldn't the OP also swap out the front chain ring for a larger one? If this is possible, I suspect it would be easier and cheaper.

On the cheaper Dahons, the chainring is a part of the crankset, much as on other cheaper bicycles. It would certainly be possible to shop for a new crankset and then put a new chainring on it, but to equal the same gains one would get with changing from a 14t rear high sprocket to an 11t rear sprocket, an extremely large chainring would be needed.

Chainrings much larger than 55t are not typically catalogue items, and may be difficult / expensive to buy. And if the crankset called for a spindle length too different from what the Eco 3 currently has, you're looking at another expense there.

This also adds weight from considerably larger rings and additional chain.

In short, no, unfortunately not. Even on a lot of folding bicycles which do have common interchangeable chainrings, huge rings can be hard to come by. I know that Bike Friday carries some 60t chainrings, but those would not quite catch the ratio needed.

I bought an 11-28 freewheel gear set from ItsElectric for my Citizen Tokyo - they gave good service, and it works great. Their shipping and handling charges are a little high though, IMHO. You'll need a freewheel removal tool and a bench vise to get the original gears off - about $8. You may have to do a little adjusting on your derailleur, but other than that it ought to be a straight swap.

Here is the link to the 7 speed freewheel that might serve the purpose.

http://us.itselectric.ca/Freewheel_7...l-7-spds-n.htm

That 11 tooth cog will definitely give your daughter's bike a top end comparable to your D7.

DT Nova owners, take note as your bikes also come with a 14-28 freewheel, and this could be a good alternative if you happen to seek higher gearing while retaining the same low end ratio for climbing.

Edward Wong III
Qile Duo 5 Speed 20" Folder