[Bobbie Martin]

I just recently did this on a MK 3. I used a Campagnolo Veloce crank. As I recall the BB was 115mm. I would do some checking on the crank tapers. The Mirage should be Campy taper, the Croce d’Aune is probably JIS taper, but not sure, you would need to check. You can find info on the taper here: http://tinyurl.com/pp6g3ey If you are keeping the original spacing on the rear hub, a 115 BB should work fine for the Mirage crank, I can’t really help on the older crank. Phil has some info on chainline spacing on their website, it may be worth having a look. I needed a dished cog to clear the rear triangle on the MK3, depending on which 5s hub you are using, it may require one as well. You can see the MK3 I did here: http://tinyurl.com/opver2f

[Malcolm J Greer]

Hi Bobbie, I was hoping to get a reply from you 😉 Your Orange MK3 is beautiful. You’ve got me thinking now about the tapers. I’ll try the Croce d’Anue on the Mirage BB I’ve got just to see if it works. I assumed (silly thing to do!) that a Campag taper would be the way to go. I thought that I’d need a longer BB than 115mm. I’d read the article on the Bike Hub http://bicyclehub.co.uk/index.php?option=com_content&view=article&id=57&Itemid=117 which advocates an axle of 125mm so now I’m really confused to be honest with you, could you have a check on size for me please? Thanks for the heads up on the SA 5 speed hub. It’s the current one in the catalogue I was planning on using. I’m trying to get matching 28 hole large flange front SA hub to match but can’t get one in Europe so I’ve got a friend trying to track one down in Thailand for me. I was going to get SJS to build me a pair of wheels using 16 inch Sun rims. Thanks for your help so far. Mal

[Bobbie Martin]

I did use a 115mm bottom bracket. I should have mentioned I narrowed the BB to the pivot eyes. I did another bike at the same time as the orange MK3 with a Sturmey SRF5(w) rear hub. Not sure they are all that way, but it was set up for two rear cogs, so only using one gives you a bit of chainline adjustment. On both bikes I used the inner chainring location so I could put a chainguard on the outer location. For the CdA taper question I think they were made around the JIS/ISO changeover. You might try looking around at http://www.campyonly.com/ Do yours have the self extractors?

[Malcolm J Greer]

Ah hah, that would make a difference in sizing wouldn’t it! I’m figuring that a 120mm might be the way to go with a BB shell that hasn’t been adapted. The Phil Wood BB cups would allow me to tinker with the chain line and would give me a few more mm clearance around the pivot bolt although I guess if it is a tight fit I can always shave the bolt a little. I can also use some shims on the chain ring bolts if necessary. My main concern is avoiding the chain ring arms fouling the pivot bolt. My C d’A does have the self extractors and from what I’ve seen on the Web it appears that a Campag taper wouldn’t be the way to go. I’ll do a little test over the weekend just to check. Thank you so very much for the pointers, I’m very grateful to you. have a great weekend, Mal

[Gary Knight]

I’m having trouble getting a good chain line. I reduced my MK3 shell to 73mm symetrical (not sure that the other F frames have symmetrical shells?) With a 107 JIS bb the axle is further out than on a conventional 68mm shell. It sits 2.5mm further out. The chain set is a 1st generation Dura Ace double. The chain hits the seat stay. I think I’m going to have to use a 103 Jis and take the lip off the cup so that I can get the chain set in as close as possible. I may also have to use a dished SA sprocket and a 6 speed chain. I’m not sure how longer axles work on these bikes as the requirement is to get the chain set in as close as possible to achieve a straight chain line. I’ve tried a Duomatic wheel and an FW wheel the sprockets are both in the same position and the chain hits the stay. For me a longer axle would not work.

[Malcolm J Greer]

I’ve given a lot of thought to this and have decided to go for a Phil Wood 68 by 125mm BB with a +5mm right hand side offset. I’ll get to it in the Spring time and in the meantime will have some fun riding it with the original chain set. I don’t intend to change the frame in any way other than to have a cable stop brazed on to the right hand chain stay which should look nicer than a bolt on SA one. Happy riding all, Mal

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