Problems changing Stronglight chainrings.

NeilMac

New Member
I am trying to service my bike but am having a bit of a problem, and would appreciate any help you can give.

I run a 1970/80s frame with a Stronglight double front chainring. The teeth on this are badly worn but I managed to pick up a set of replacement old stock rings.

I managed to remove the outer ring with no problem, as this just needed a 5mm alen key to remove the bolts. The inner ring however seems to be held by a different method, the 'bolt' for this is hollow (it is what the front ring bolts screw into from the other side) and the only releif on it is two small slots at opposite sides - so looks like a drilled out screw - but this is wider than any screwdriver I have, and there is not much metal to get any leverage on even if I had one.

Does anyone know how these should be removed? Is there a good technique for doing it, or is there a special tool that I can buy?

I am hoping to get these rings changed over soon, as my chain is now looking very poor, and although I have a replacement ready I really did not want to put a new chain on with old rings.

Neil
 

Rohloff_Brompton_Rider

Formerly just_fixed
you need a special 2 pronged tool.costs about £5. lbs might crack em for free.
 

Landslide

Rare Migrant
NeilMac said:
...the 'bolt' for this is hollow (it is what the front ring bolts screw into from the other side)
If you've removed the bolts with your allen key, there shouldn't be anything holding the other parts on (unless these are some strange breed of chainring bolt that I've never met before...). It may be that there's a bit of corrosion holding the crank/chainring/inner parts of the bolts together.
 

Will1985

Über Member
Location
South Norfolk
Landslide is correct - either bang out the nuts or knock the chainring inwards (hitting next to the bolt holes).
The chainring spanner isn't really necessary unless you can't tighten them up properly later.
 

RecordAceFromNew

Swinging Member
Location
West London
Landslide said:
If you've removed the bolts with your allen key, there shouldn't be anything holding the other parts on (unless these are some strange breed of chainring bolt that I've never met before...).
I have to disagree with Landslide. What the OP talks about are these. If you don't have the chainring spanner holding on to the hollow "nut" then IME the allen key may just spin both the "nut" and the hollow "screw" around forever.
 

raindog

er.....
Location
France
Yes, but the OP has already removed the allen bolts along with the outer ring, so the slotted "nuts" should tap out. As someone already mentioned, they've probably been in a long time and are a bit seized.
 

Will1985

Über Member
Location
South Norfolk
I don't see how Landslide is wrong...he just called the nuts (inner ring side) "other parts".

Stick your finger on the nut if it spins.
 

e-rider

crappy member
Location
South West
Landslide said:
If you've removed the bolts with your allen key, there shouldn't be anything holding the other parts on (unless these are some strange breed of chainring bolt that I've never met before...). It may be that there's a bit of corrosion holding the crank/chainring/inner parts of the bolts together.
+1

just give it a push!
 
OP
N

NeilMac

New Member
Many thanks for all your help.

I have just been out to the shed armed with a big hammer. The parts were as in the photo linked above. I had previously got the inner nuts out without the outer ones moving at all so has been assuming they should not have been free. A light tap on each and I managed to remove the inner chain ring. The inner nuts are still stuck in the inner chainring, but I think I should be able to get those out.

Whether or not I will be able to reassmle things without the spanner remains to be seen, but at least now I can see clearly what I am working with so hopefully I will be OK.

Heres to the next 10,000 miles. Again, thank you very much for all your detailed and very prompt assistance.

Neil.
 
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