Sabi

I'm trying to avoid buying an inexpensive folding bike that seems to lack the proper gears. I have a bike with 7 gears which are usually enough for me. However, when I'm on a flat surface and want to really pedal effectively, my current bike seems to lack the "next gear." Is this a function of how many teeth are on the chainring? If so, how many teeth should I look for? If it's not the chainring, what is it a function of?

Thank you,

Sabi

Joe Remi

You seem to already know the answer based on the title of this thread. A lot of folders come with a 7-speed freewheel and single front chainring, with the chainring sized as a compromise between flat speed and hill-climbing ability. If you think you can live without your lowest current gear ratio then a larger chainring is the ticket. How you get there depends on the bike: If you have a crank with a removable chainring then you're good to..a 4-tooth bump probably won't even require a longer chain. But a lot of those 7-speed folders have one-piece cranks, so you'll need a whole new crankset in that case.

fietsbob

Count teeth, do the math ? it's a Ratio..

you can also put on a cheap double chainring and just change gears with your fingers..

when stopped.. Aka, greasy finger shifting..

Bonzo Banana

If your happy with your current bike except speed why not upgrade it, maybe it isn't a folding bike and that is what you want if so you are in the right area with a 52T chainring and perhaps an 8 or 9 speed bike with a cassette with a 11 tooth high gear. Even with 20" wheels that will be pretty fast. Where do you live?

Sabi

Thank you for all the helpful responses. I'm going to take the little bike to my local bike shop and get them to upgrade it with a bigger chainring.

Sabi



PS I loved the "greasy finger" shifting.

Bonzo Banana

Just remember your lowest gear will become faster too making hills harder to climb. If you don't want that you'll have to change your rear freewheel/cassette to something with more teeth on the largest cog. I think there is a 14-34 Shimano freewheel. It really depends on what is fitted there already and what your derailleur will work with. I'm sure your bike shop will advise. If there is a single labour charge in play and they are reasonable for freewheels then that might be an option. Also if your chainring and freewheel have already had a lot of use you are probably best advised to change chainring, freewheel and chain all at the same time. Might be expensive though.

Sangetsu

52 teeth would be better if you live in a flat area. I run a 53/11 top gear combination with 20" wheels, and I often find myself wanting an extra gear, or even two.

Doc_Wui

Our folders are 46T and 52T respectively, and both have a 34-11T DNP in back. I would rather have them both at 52T. The difference in teeth is about the same as the difference between 16 mph and 18 mph, which are the upper speeds I get on both bikes with a comfortable pedal speed.

The gear is about $50 on ebay. Maybe $100 to buy one and have it installed at a bike shop?

Edit: One more comment. I hope you like to shift. My wife doesn't and she was complaining about falling down trying to start off on a hill with that 52T. Me, I love clicking the gears up and down on both cars and bikes.