Speedo drive

swesty

swesty

Junior member
I'm trying to remove the speedo drive gear from the front wheel to reuse on my spoke conversion.  I'm applying what appears to be a huge amount of heat and a liberal dose of mechanical sympathy but cannot seem to get it to move.  So, more heat?  bigger hammer?  Some other trick?

Thanks
 
Ah, been there, done that a few times.
Some just fall off with light persuasion and others won't budge.
Lots of force could snap the gear ring.
Heat is not a good idea and alloy expands faster than steel so any heat applied will make it tighter.
Ideally some sort of 3-legged puller would work.
 
Yes, grant is right. Aluminium expands more than steel. So heating it up will make it tighter unless you can get some heat into the ring very quickly before the aluminium has a chance to heat up.
Cooling the wheel down should make the ring gear looser - well, if not loose, then less tight.

If you have a big enough freezer, chuck the wheel in there for a while. If not, go and have a chat to your nearest place with a freezer room (eg. frozen food seller) and ask if you can leave the wheel in their freezer room overnight. Bulk frozen food storage warehouses are about -40 deg, so a lot colder than your home freezer. Take your tools with you when you go to pick it up and give it a try while it's still very cold. If it's still stubborn, give the ring gear a quick run-around with a gas torch. You may be able to get some heat into the ring while the hub is still at freezer temp.
 
There are coolant sprays, that are available at
technical or electronic DIY shops, e.g.
http://www.ebay.co.uk/itm/MG-Chemicals-SUPER-COLD-134-Electronic-Component-Freezer-Spray-403A-400G-/321930749070?hash=item4af491648e:g:DXoAAOSwfcVT~Y~-
Usually they go down to -50?C, might work for your
problem.

Ernesto
 
No problem with the factory tool... :D

2- or 3-legged puller might damage the edge of the teeth.  They may then require a bit of fettling before refitting.

piet
 
Difficult to describe Simon.

Basically an internally stepped cylinder, cut in half to grip the gear and provide a purchase for a puller.  A 2nd cylinder is slipped over the first once the 2 pieces are placed around the gear and the puller that supports itself against the hub centrally to the gear.  Tighten up the spindle and the gear just pops off! :D

I can take a pic tomorrow if you like.

piet
 
Maybe this might help: it's shown in the middle of the ILOC tool page:
http://www.iloc.co.uk/gallery/albums/userpics/10001/tool_library.pdf (Copyright by ILOC)

Ernesto
 
Ernesto said:
Maybe this might help: it's shown in the middle of the page:
http://www.iloc.co.uk/gallery/albums/userpics/10001/tool_library.pdf

Ernesto
Click to expand...

well bugger, have had one of those speedo gear removal tools for years and never knew what it was for


 
Photo's would be great Piet, could I press you for some dimensions too and I'll have a go at making one.  BTW, dry ice (circa -80 c didn't work).

Thanks
 
or buy another speedo drive gear..

I have the opposite problem...fitting a gear to the wheel...My plan is leave the wheel outside at night on a cold night in Jan, heat the gear in the morning and work very fast..

joe
 
This is the tool.

I have not been able to successfully pull the gear from the disc brake/wire wheel hub, only from Laverda drum brakes where there is room behind the gear to place the puller.

Marnix
 

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I have removed 4 or 5 of these without the special tool.
Not easy, but quite variable in resistance.
Some popped off with little fight and one just plain refused to come off so I cut the wheel off it!
(yes, the wheel was scrap anyway)
 
From memory I managed to make a bearing separator work - IMO a bit of heat helps if there is oxidised 'bonding' between alloy and steel.

I cut of the alloy sleeve once I had the gear off anyway  :eek: I had to lose it to fit my hub wideneing disc carriers for the 320mm Brembos and USD Kayabas with R1 monobloc calipers. I'm goin' digital anyway!
 
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