Will a 7-speed freewheel work with a single speed chain and crank?

[ibie1983]

Hello guys

I have a folding bike with 7 speed freewheel in the back. My front crank needs changing. I have seen one but it will only run a single speed 1/8" chain. My question is can I run a single speed crank & chain with a 7-speed freewheel?

Thank you in advance for any help.

[DaveM]

Not with a 1/8" inch chain. If the crank would take 3/32" it would be fine. But you'll probably have trouble running the wider chain on the freewheel. BTW, it shouldn't be hard to find a single crank that will take a 3/32.

[nfmisso]

Assuming that your folder has smallish wheels, I'd get this:
http://www.amazon.com/Sunlite-Alloy-Double-Crankset-Square/dp/B003CO2RTS/
and remove the inner ring, move the big ring to the inner position and put a chain guard on the outer position, like this one: http://www.ebay.com/itm/mr-ride-Driveline-chain-guard-53T-BCD-130mm-100g-Gray-/261481708008?pt=US_Chainrings_BMX_Sprockets&hash=item3ce18639e8

[ibie1983]

Thanks for your help guys. I suspected a 1/8" chain wouldn't work on a 7-speed freewheel. I tried one on the freewheel and it looked very tight. Don't think it will shift down the cogs well.

[nfmisso]

(05-20-2014, 12:48 PM)ibie1983 Wrote:  Thanks for your help guys. I suspected a 1/8" chain wouldn't work on a 7-speed freewheel. I tried one on the freewheel and it looked very tight. Don't think it will shift down the cogs well.

It also may not go through the rear derailleur (RD). I have a Shimano 2200 8 speed RD on one of my bikes, and a 7 speed chain will not go thru it smoothly.

[DaveM]

(05-20-2014, 12:48 PM)ibie1983 Wrote:  Don't think it will shift down the cogs well.

Note that even in 3/32" inch chains, there are chains made for single speed and ones made for multi-speed bikes. Single speed chains don't flex side to side enough to shift well. If you have 7 speeds in the back, make sure to get a "7 speed" chain. Not a single speed and not an 8+ speed chain.

[nfmisso]

(05-20-2014, 02:54 PM)DaveM Wrote:  ....... If you have 7 speeds in the back, make sure to get a "7 speed" chain. Not a single speed and not an 8+ speed chain.

Actually you need a chain that matches the RD as well as not being too far off the cog spacing. My 2x7 SR requires an 8 speed chain because the Shimano 2200 8 speed RD rubs on 7 speed chains.