moulton speed 1965 restoration

[Stephen Lounton]

Hello everyone , not sure if i,m in the right place to ask sorry if i,m not , as i have just discovered this forum . I am currently restoring a 1965 noulton speed , one of 4 moultons i have , it has a sturmey 4 speed hub,I am wanting to upgrade to new modern components , i have replaced the bottom bracket with cartidge type with square taper axles, and as per the original it is 120mm axle length, i have been looking on ebay for a new chainset, the original chainring has 52 teeth , on searching ebay some of the chainsets reccomend certain axle lengths , but am i right in thinking i have to keep the standard axle length of 120mm, also would it make much difference if i used 46 or 48 tooth chain ring , also what chain would anyone reccomend , , any help greatfully received ,, kind regards steve

 

[curzons246]

My little experience is with road bikes - I have changed by front rings to suit my ability and the area I cycle in - on a road bike 52 is a big front ring but I would have thought if thats what the manufacturer put on it will suit - did you try it and find it to big - good look Bill

 

[Stephen Lounton]

No it was on the bike already , but as I'm changing all the components , the new modern stuff seems to have smaller front chain rings , just wondered if say a 46 or 48 would be ok with the sturmey 4 speed hub and 16" wheels , and if the axel length of the original 120mm would be ok with newer chain sets , cheers bill

 

[stevevw]

I would have thought that you would be able to find a single speed/track chainset that takes a 52 ring or use a road double and take the inner ring off using shorter bolts from the likes of Velosolo.
130bcd 52t ring here http://www.spacycles.co.uk/products.php?plid=m2b34s172p1960

As for BB size you will probably have to suck it and see to get the front ring to line up with the hub. Chain will depend on sprocket size which on the SA should be 1/8" so somthing like a Sram PC1 1/8" Chain will work with either a 1/32" or 1/8" chainring.

Would it not be easier and more in keeping with the bike to restore the original chainset? Thats what I would do. Have you had a look round here? http://www.moultonbuzz.com/community/forums/

Good Luck Steve

 

[Stephen Lounton]

hi thanks , i prefer to upgrade with new components , i did it before bout 10 years ago but left all my info and the bikes at my ex wifes , who promptly chucked everything out ,,

 

[bobg]

I did the same mod with my 65 Speed. It's in a garage about 150 miles away at the moment but from memory I used the bigger ring from a Tiagra double,(52 teeth I think) a standard BB and a 16 then an 18 tooth sprocket on the 4 apeed SA hub. Apart from the usual SA 4 speed problem of the excessive pressure necessary to engage 1st using the old style lever shifter, it works fine for me. I believe a non indexed bar end shifter works too, and is handy on drops.

 

[spark303]

Hi, I updated my 1965 Moulton Deluxe with more modern (and lightweight!) components last year.

IMO a 120mm bottom bracket axle is way too long for a modern chainset with a single chainring. Cottered chainsets like the type originally fitted to the Moulton required much longer axles than cotterless chainsets. I was guess you would need a bottom bracket somewhere between 110 and 115mm, depending on the chainset you use. I used an old 1980's SR alloy chainset on mine and a 113mm bottom bracket was fine. Don't forget that you can also adjust the chainline on the Sturmey hub by altering the order of the sprocket and the two sprocket spacers - that gives you about +/- 3mm adjustment.

You should also be aware that the bottom bracket shell on F-frame Moultons is offset to the left, so you need to add about 3mm of spacers on drive side bottom bracket cups. Two sturmey sprocket spacers do the trick nicely.

It doesn't really matter what size chainring you use at the front (or sprocket at the back), but just be aware that if the front chainring is too small, the chain will hit the rear brake. When I first put the new chainset on my Deluxe, I used a 48t front, 14t rear and there were no problems. 46t might also be okay, but if you want to lower your gear range, it might be safer to keep a larger sprocket at the front and put a bigger sprocket on the back to ensure the chain clears the brake. I recently changed my rear hub from an FW to a 5 speed S5 and I changed the ring and sprocket to 50t front and 16t rear.

+1 to an SRAM PC1 chain - fit and forget.

Hope that helps

Gavin

 

[ChopperGav]

Hi, I updated my 1965 Moulton Deluxe with more modern (and lightweight!) components last year.

IMO a 120mm bottom bracket axle is way too long for a modern chainset with a single chainring. Cottered chainsets like the type originally fitted to the Moulton required much longer axles than cotterless chainsets. I was guess you would need a bottom bracket somewhere between 110 and 115mm, depending on the chainset you use. I used an old 1980's SR alloy chainset on mine and a 113mm bottom bracket was fine. Don't forget that you can also adjust the chainline on the Sturmey hub by altering the order of the sprocket and the two sprocket spacers - that gives you about +/- 3mm adjustment.

You should also be aware that the bottom bracket shell on F-frame Moultons is offset to the left, so you need to add about 3mm of spacers on drive side bottom bracket cups. Two sturmey sprocket spacers do the trick nicely.

It doesn't really matter what size chainring you use at the front (or sprocket at the back), but just be aware that if the front chainring is too small, the chain will hit the rear brake. When I first put the new chainset on my Deluxe, I used a 48t front, 14t rear and there were no problems. 46t might also be okay, but if you want to lower your gear range, it might be safer to keep a larger sprocket at the front and put a bigger sprocket on the back to ensure the chain clears the brake. I recently changed my rear hub from an FW to a 5 speed S5 and I changed the ring and sprocket to 50t front and 16t rear.

+1 to an SRAM PC1 chain - fit and forget.

Hope that helps

Gavin

Hello, could I ask what the S5 has been like in terms of reliability & rideability? I only ask as I am looking to install a nos S5 & second hand S5/2..
Thanks.

 

[St-Pedali]

Hello everyone, I hope somebody can help me with a question concerning the conversion from the original SA 4speed hub to a modern SA 5 speed. The hub I am looking at has a width of 130 mm, that is 15 mm more than the rear fork accomodates. What do I do? Squeeze the fork by 15 mm apart or find a different hub? Second choice seems to make more sense. So, what 5 speed SA hub fits into the second generation Moultion rear forks? Thanks for your help.