Basic Bike Problem Help!

[Progressive]

Hi all,

A little bit out of touch with general bicycle maintenance these days, it's been years since my days of fettling with my BMX in Dad's garage!

I've got a cheap-ish single speed road bike that I use to get around town and do the odd 25km weekend ride on. It's relatively new, I've done about 250km on it.

As of yesterday, it has developed a problem whereby when I pedal, it feels as though somebody has got hold of the saddle and are pulling me back. The resistance tends to get worse the harder I'm pedaling. It doesn't seem to happen when coasting. The brakes have loads of clearance so pretty sure it's not that.

There is a bit of a rumble and a squeak coming from the bottom bracket area (or the chain) when pedaling or back-pedaling slowly. The freewheel has knocked like heck since I got it and seems to be getting a bit louder of late. Could it be that? Easy fix?

Cheers.

[tigger1]

Bought new or used?

Either way, I'd be concerned about the rear hub / freewheel - especially as it's noisy!

Equally though, could be a lack of grease in the bottom bracket.

<Shrug> Difficult to say with any level of certainty.

[Progressive]

Had a bit of a tinker tonight and observed the following:

- Cranks and bottom bracket spin smoothly and freely when the chain isn't on.

- Rear wheel spins smoothly when the chain isn't on.

- When the chain is on and it's 'coasting' the chain bumps around and the freewheel seems to have quite a bit of play and rumble (up and down, and back and forth).


So it would seem it's the freewheel. Still not sure how this could manifest in the 'brakes on when pedaling' feeling.

Any more suggestions before I replace the wrong part!?

[BliarOut]

How free does the chain feel when it's off and how far can you pull it off the chainwheel?

You could test the freewheel by (carefully) holding it when you spin the back wheel. You should be able to feel any bearing problems with your fingers when you do that. (Assuming you don't detach them!)

[upsidedownmark]

Progressive said:

Had a bit of a tinker tonight and observed the following:

- Cranks and bottom bracket spin smoothly and freely when the chain isn't on.

- Rear wheel spins smoothly when the chain isn't on.

- When the chain is on and it's 'coasting' the chain bumps around and the freewheel seems to have quite a bit of play and rumble (up and down, and back and forth).


So it would seem it's the freewheel. Still not sure how this could manifest in the 'brakes on when pedaling' feeling.

Any more suggestions before I replace the wrong part!?

Back wheel is properly bolted in and not moving around / rubbing the frame under load? (It's a bit of a fetch, but..)

Also, try to spin the various parts with some load - cranks particularly can feel smooth when you spin them on an upturned bike, but actually be rough/draggy when they're trying to spin with 50kg of load on them..

[spikeyhead]

I'll guess that the back wheel either isn't bolted in securely or that there's a crack in the frame causing it to twist as you pedal.

[crisisjez]

If the spokes are loose it could cause wheel flex which would cause the symptoms you describe.