Author Topic: G31 sprockets  (Read 469 times)

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Offline hoejmark

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G31 sprockets
« on: 13 Aug 2021 at 09:26 »
From a great motorcycle museum here in Denmark I have been asked about the correct sprocket sizees for a G31 they are going to restore.

Frame No. Ed 180 (I believe should be FD 180) and Engine No. EU 139.

They ask for the sprocket size on the rear wheel and on the gear box (present is 59T)

From the Machine Register I can see that this bike must be very rare, and we used to have another one here in denmark (Frame FD178, Eng. EV113 (should be EU113?)), that I don't know where is now.

Can someone help with information.

Regards
Hoejmark



Offline Daren W Australia

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Re: G31 sprockets
« Reply #1 on: 13 Aug 2021 at 09:58 »
Hi Hoejmark

Try www.buyoldengineering.com scroll down to Douglas they might be able to help

Ta Daren
too many dougli not enough time!

Offline hoejmark

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Re: G31 sprockets
« Reply #2 on: 13 Aug 2021 at 16:05 »
Thanks Daren

I will have a look at the site.

hoejmark

Offline hoejmark

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Re: G31 sprockets
« Reply #3 on: 27 Aug 2021 at 11:51 »
Hi again

The BuyOld Engineering doesn't have sprockets or know sprockets data for the G31/32.

Is there a helpful guy out there who can have a look into the Spare Parts List or similar booklet dealing with G31/32 to find these data as I have no booklets myself dealing with OHV models.

Hoejmark

Offline Doug

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Re: G31 sprockets
« Reply #4 on: 28 Aug 2021 at 05:24 »
I have never seen or heard tell of a spares list or manual for the 1931-32 or the 1934-34 ohv models. If there was one, I would certainly like to see it too! So I think you will need to look at the few surviving examples and try to count sprocket teeth. I do have some F/G31 pics, but I am on the road at the moment and do not have access to them. It is not a common model and info on them is quite scarce.

-Doug

Offline eddie

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Re: G31 sprockets
« Reply #5 on: 28 Aug 2021 at 07:56 »
The publicity sheets for the F/G31 didn't give any details of the gear ratios, but the later sheets for the OW1 (with a 4 speed 'box) gave the ratios as 4.4, 5.8, 7.56, 12.7. If you aimed for a 4.4 ratio in top gear, you shouldn't be very far out.

  Regards,
               Eddie.

Offline hoejmark

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Re: G31 sprockets
« Reply #6 on: 29 Aug 2021 at 17:19 »
To Dave and Eddie
Thanks for your replies and I understand, that the G31 is a rare model making it difficult to find informations.

However I managed to find a photo in a therad from alex912, where i am able count 18T on the rear chains gear box sprocket.
Thats a beginning,  together  with aiming for a ratio of 4.4 in top gear.

Regards
Hoejmark