Why can't I ride my city type (folding) bike uphill? I'm a newbie when it comes to biking. I don't plan on taking it as a very serious hobby; I'm really more of just a leisure rider who enjoys touring around town, but I'd also like to be able to drive efficiently.

I bought a Doppelganger Spiegel 214 a few days ago, and I really like it. However, I'm currently finding difficulty driving it uphill. I can't tell the slope angle exactly but I think it's somewhere above 30 or 40 of a decent stretch of road (maybe around 10-15 meters) that I'm finding a hard time driving on.

I'm not sure if it's because I don't know how to shift gears and that I'm using the wrong one, or my legs aren't strong enough (yet?) or my bike just isn't up for it. Can anyone enlighten me on this?
Folding bikes have a very limited gear range because they usually have only a rear derailleur. From the manufacturer's website, your bike has:


20" wheels with 20x1.5 tires
52T chainwheel
14 - 28T rear cassette


Running this through a gear-inch calculator shows that your highest gearing for going fast is 66 gear inches and lowest gearing for going up hill is 33".  Your total range is 33-66" or 2x.

Link: What are gear-inches?



In comparison, a bog-standard 700c hybrid bike at the bike shop with 3x9 speeds is going to have around 24" on the low end and 116" on the high end -- a range of over 4.8x. It's going to be both much easier going uphill on the hybrid (24" versus your 33") as well as much faster downhill and in the straightaways (116" vs. your 66"). Standard (big) bikes also have full length cranks - sometimes our folding bikes come with kid-size cranks which also reduces leverage uphills.

You can do some things to improve the overall spread and to reduce the gearing to make it easier to go uphill. You could replace the 14-28T 7-speed cassette with a 11-32T which has a larger spread so it would help a bit going downhill as well as uphill. In addition, you could reduce the size of your chainwheel from 52T to something like 48T to again help with the hills.  I'd recommend against an 11T sprocket on a 20" wheel as there will be a lot of wear on the teeth and so you'll chew up your chain and sprocket really quickly.  

With a more reasonable 13-34T cassette and 48T chainwheel, for example you'd get 27.5" - 85" gear inches which should be enough for many purposes.

You're limited in modding by the capacity of your rear derailleur -- and if you swap it out with a long cage, it may drag on the ground on corners. The standard Shimano Tourney 7-speed on your bike seems to be ok - most models in that series are specced for 11-34T capacity. I should also note though that some sprocket/chainwheel/chain lengths may no longer allow the bike to fold smoothly or result in the chain derailing when you fold, so you'll need to fiddle a bit. 

If it were my bike, I'd look at the terrain and make the decision. For my Brompton, for example, I got a smaller chainwheel as I live in a hilly neighborhood and needed the reduction in gear inches and don't mind my top-speed being limited. I had to take a few links out of the chain but it still folds ok.

Finally, I should note that even at the same gearing it's harder to go uphill with a small-wheel folding bicycle than it is a full-size bicycle. Our tires are smaller so they have less stability (less gyroscopic effect/leverage); our cranks are shorter so we have less leverage; and our steering is squirrelly so it's harder to go in a straight line.