Tell me about freewheels...

[DCBassman]

Have noticed that if I spin the cranks on my Trek 800, on the service stand, the pedals rotate also. Presume this means the freehub needs attention?
This would be my first time with freehubs...
Happy to dive in, just not wanting to do something egregious to it...

 

[cm2mackem]

Have noticed that if I soon the cranks on my Trek 800, on the service stand, the pedals rotate also. Presume this means the freehub needs attention?
This would be my first time with freehubs...
Happy to dive in, just not wanting to do something egregious to it...

I presume you meant turn backwards, if so yep probably freehub/pawls

 

[si_c]

Sorry, slightly confused about what you're doing, turning the cranks would imply turning the pedals no?

If you mean you turn the cranks in reverse as per @cm2mackem, and the wheel turns, that's different.

 

[Racing roadkill]

The pawls May just be stuck, give the freehub a clean and lube, and see if it sorts it

 

[gbb]

Being a Trek 800 i assume it's pretty old and IIRC it had 26 inch wheels and maybe 7 or 8 speed in which case it could well be a freewheel not a freehub.
Sticky pawls in feewheels can often be salvaged by laying the bike on its side, squirting WD40 or thin oil into the upturned freewheel lockring (NOT into the hub/axle bearings), it'll make its way down and hopefully free the sticky pawls. Insert some oil later in the same way if you've used WD might help it last longer.

 

[DCBassman]

Spin up the rear wheel, let go of pedal. Rear wheel spinning freely turns the cranks. If you then stop the cranks, the wheel comes to stop more quickly than it should. 2001 purchase, 2002 spec, Shimano Altus 7-speed. Will try @gbb suggedition and see what happens.

 

[Ajax Bay]

Spec may be:
Hubs: Joy Tech alloy cassette hubset, Q/R
Rims: Weinmann 4019, 36-hole

 

[DCBassman]

Spec is: Matrix 550 rims, unspecified alloy hubs. QR - yes. Cassette: Sunrace 13-30 7-speed.

 

[si_c]

Sounds like the freehub, chances are you won't be able to replace it, so a new hub and wheel rebuild or new wheel is the best bet. I'd get the wheel rebuilt around a new hub, but best getting a price on that.

Reason I'd do that is to be able to replace the freehub body later.

 

[DCBassman]

Thanks for the replies, will try @gbb's suggestion first. If it is a freewheel, is it more difficult to remove the cassette?

Edit: apologies for apparently dim questions, but the bike and I are not currently co-located, as the saying goes...

 

[Ajax Bay]

Cassette: Sunrace 13-30 7-speed.

If it is a freewheel, is it more difficult to remove the cassette?

If it's a freewheel it's impossible to 'remove the cassette'. Removing freewheels is always harder than removing cassettes.
https://www.sheldonbrown.com/free-k7.html

 

[DCBassman]

If Sheldon is right, this is a freehub anyhow, 2001 bike. So hopefully a fairly easy fix. Or a new wheel...

 

[Ajax Bay]

If Sheldon is righ

Catholic identity and Pope come to mind.

 

[gbb]

I'd gladly be corrected but i still suspect its a freewheel.
My son had a Trek 800, late 1990s i guess and there was nothing special about it and 7 speed freewheels were as common as anything.

This may help to confirm one way or the other, specifically the hub design,....a bulge on the drive side indicates a freehub....symmetrical hubs are usually freewheels...
https://www.sheldonbrown.com/free-k7.html

 

[Ajax Bay]

If Sheldon is right, this is a freehub anyhow, 2001 bike.

i still suspect its a freewheel

OP says: "Cassette" is Sunrace 13-30 7-speed. OP means: there are sprockets on the back 13-30.
A freewheel like this one: SUNRACE-7-Speed-Freewheel
https://www.spacycles.co.uk/m2b0s112p342/SUNRACE-7-Speed-Freewheel
Spot on @gbb
OP: read this Sheldon article on Freewheels which covers servicing (scroll 4/5ths down), and maybe amend the thread title -
Tell me about freewheels...