Cycling UK Forum

Posted: **3 Mar 2023, 5:00pm**

My son's fairly elderly Dawes Galaxy has a problem with the drive train. When turning the cranks the everything is fine until randomly while pedalling the rear cogs freewheel so that you spin out, like you selected neutral.
What should we be looking for here? Any thoughts welcome - it's a Shimano set-up. Cheers, Garry

Posted: **3 Mar 2023, 5:15pm**

7 speed, which I guess dates it a bit!

Posted: **3 Mar 2023, 5:16pm**

Sounds like broken or sticking pawls (sprung teeth in the ratchet). It could simply be a need for lubrication. Photos of the hub might tell the more informed here what you need to do.

Posted: **3 Mar 2023, 5:32pm**

If it is just a matter of lubrication, rather than broken pawls, it is possible to introduce gear oil into the freehub without disassembly, but sticky pawls would suggest dried grease/oil which needs to be removed before adding lubricant. R J The Bike Guy's videos are good for this:

If you need to check the pawls, amongst his other videos is one showing how to completely disassemble the freehub.

Posted: **3 Mar 2023, 5:40pm**

Another vote here for adding oil, preferably light oil, into the ‘freewheel’ part of the hub.

Posted: **3 Mar 2023, 6:18pm**

Does the hub have a freewheel (screw on) or a cassette ?

Posted: **3 Mar 2023, 6:39pm**

If it's a freewheel, it's basically the same as for a freehub, i.e. remove to degrease and lubricate.

Posted: **3 Mar 2023, 7:10pm**

If it's a freewheel it's easier to dismantle on the wheel but only as a last resort. The centre cone unscrews clockwise.. Do this with the wheel resting in a bowl to catch the ball bearings as you lift the sprockets off.
If you discover a broken pawl or pawl spring then it's unlikely you will find spares so it's trash. Reassembly means winding cotton around the pawls to hold them closed whilst you replace the sprockets, having put the balls back in place. If you get that far then gently pull the cotton out to release the pawls. Try removing a shim before tightening the cone to reduce the play in the freewheel. Good luck and patience is a virtue.

Posted: **3 Mar 2023, 10:28pm**

I just had a look through the few 1990's catalogues and it looks like the Galaxys went onto Shimano freehubs for 7 speed, the last freewheel hub was listed as a 6 speed Atom in 1990. Seven speed Shimano freehubs variously from earliest in 1991 : Exage 400LX, Deore LX and STX .If you look on the hub shell you may still be able to see the hub type with the part number,
e.g for STX it is FH-MC32, if it is an STX there are some new old stock freehub bodies (3AP9802) for sale on ebay at the moment e.g.
Hopefully a bit of lube will free it up though, good luck.

https://www.ebay.co.uk/itm/255868896867 ... R76P7JjVYQ
https://www.ebay.co.uk/itm/255670597908 ... R76P7JjVYQ

Posted: **4 Mar 2023, 7:46am**

rjb wrote: ↑3 Mar 2023, 7:10pm If it's a freewheel it's easier to dismantle on the wheel but only as a last resort. The centre cone unscrews clockwise.. Do this with the wheel resting in a bowl to catch the ball bearings as you lift the sprockets off.
If you discover a broken pawl or pawl spring then it's unlikely you will find spares so it's trash. Reassembly means winding cotton around the pawls to hold them closed whilst you replace the sprockets, having put the balls back in place. If you get that far then gently pull the cotton out to release the pawls. Try removing a shim before tightening the cone to reduce the play in the freewheel. Good luck and patience is a virtue.

I remember doing this as a teenager 55years ago !!.I couldn,t/wouldn,t attempt it now! However,I would remove the freewheel,immerse it in white spirit ,spin it with an electric drill(jam an old rag in and put a wood boring bit in the drill)Heat it up (outside or garage)to drive the solvent out,relube with a thin oil.If it,s a broken pawl spring,this,of course,won,t cure it.Replace asap!! I recall a failed freehub ,having to cobble it into a fixed with wire,just remember to keep pedalling !!

Posted: **4 Mar 2023, 7:58am**

One obstacle, if you haven't done it before, is working out how to get the freewheel (if the cogs are an integral part of it) or freehub (if the barrel in the centre is a unit on its own) off the hub shell. Freehubs come off much easier, using a massively oversized allen key. Exact size varies. For the older style freewheel a special tool is required, and access to a bench vice saves a lot of cursing.

Posted: **4 Mar 2023, 8:44am**

A 10mm allen key has fitted all the freehubs I've dismantled from that 7 speed era.
Edit; potentially confusing sentence altered for clarity, see the original below !

Posted: **4 Mar 2023, 10:15am**

colin54 wrote: ↑4 Mar 2023, 8:44am A 10mm allen key has fitted all the freehubs I've had apart from that era.

Yes. I have a couple of allen keys that fit Shimano freehubs from different eras, but I can't be specific about 7 speed.

And as we both know, the axle and bearings have to come out to allow access. Which makes this the opportunity to give the bearings a good clean and re-grease.

Posted: **4 Mar 2023, 6:55pm**

Great feedback! Thanks everyone for taking the time to give this advice - I really appreciate it. It's time like this when you know it's worth subscribing to CTC. G

Posted: **23 May 2023, 10:43am**

rjb wrote: ↑3 Mar 2023, 7:10pm If it's a freewheel it's easier to dismantle on the wheel but only as a last resort. The centre cone unscrews clockwise..

Thanks RJB - I'd thought I'd re-shim a freewheel this morning. Completely forgot which way the centre undid. Luckily a quick search on this forum provided the answer

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