Options for a square taper BB renovation

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audaxer
Posts: 25
Joined: 13 Jan 2009, 3:34pm

Options for a square taper BB renovation

Post by audaxer »

I've just had a Flying Scot renovated and it has a BB-UN55 bottom bracket but I see all the 105/Tiagra stuff is Hollowtech II. Would anyone have any recommendations for a good square taper crankset? Not sure if I can fit a Hollowtech II BB to the Scot (1968).

Ideally I'd like to equip it with a 105 groupset but with the modern double chainring that gets you the same range as the 'older' triples (e.g. like the one on a Genesis Croix de Fer).

thanks,

Alistair
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Options for a square taper BB renovation

Post by Brucey »

you should be able to fit an H-II BB if your BB shell is ~68mm wide, so you can fit an H-II compact double if that is what you really want to do.

However Spa's ST triples or a ST double may well serve you as well or better; it is easier to get a wider range of gears with a triple of this sort and a ST BB unit is less likely to need new bearings after a year.

If you want retro-but-functional then it is worth looking at Velo Orange chainsets; you can build a nice alpine double using those.

I must say that both aesthetically and functionally, modern components increasingly leave me cold; they are only 'the latest thing' for a year or two and after that they are just another 'obsolete design'. Where I can, I quite like to be able to buy parts that are not going to be a flash in the pan.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
audaxer
Posts: 25
Joined: 13 Jan 2009, 3:34pm

Re: Options for a square taper BB renovation

Post by audaxer »

thanks Brucey, will take a look at the Orange stuff. Yes it's a 68/118mm BB in it just now so that's good to know I can use Hollowtech II if needed. Agree on the aesthetics. It had ancient campag gear on it but too rusty to put back on.

Alistair
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Options for a square taper BB renovation

Post by Brucey »

I prefer the look of rusty old campag gear to some of the new stuff.

Does that make me weird? :wink:

One of these looks and works well I reckon;

Image

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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recordacefromnew
Posts: 334
Joined: 21 Dec 2012, 3:17pm

Re: Options for a square taper BB renovation

Post by recordacefromnew »

Brucey wrote:I prefer the look of rusty old campag gear to some of the new stuff.

Does that make me weird? :wink:

One of these looks and works well I reckon;

cheers


Well in that case I am weird too...

But I am unsure if it is possible to stick within the OP's remit.

Like the OP, I also happen to be toying with getting a compact, rather than a triple, for a build. I agree with you re vintage Campag and I want to stick with it for groupset marque consistency, but identifying a suitable vintage Campag double chainset that will let me run say 46/34 rings to replace the current 144mm bcd one has so far been fruitless in a casual search. To me using two rings on a triple crank is a kludge that I would like to avoid - what to do with the outer ring? Neither leaving it out, leaving it on nor replacing it with a bash guard is ideal is it? I would like to avoid using a triple because of unnecessary weight, and it will certainly breach the wrap range of an early 80's SR rear mech, which given it is one of the finest ever made, I hope to stick with.

I would be glad to be proven wrong regarding chainset availability.

If they are yours, those chainrings don't owe you anything do they? :wink:
Brucey
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Re: Options for a square taper BB renovation

Post by Brucey »

no, those chainrings are not mine. I will own up to having ridden worse though!

Campag did make three bolt and later five bolt 'touring' chainsets in times past but IIRC the five bolt went to a 36T smallest, with two or three rings on the same 116mm BCD. Would that work for you? The genuine NR triple is a rare beast; conversions such as the one pictured above are far more commonplace.

Image

campag GS 'touring' chainset. They carried the same ring BCD over into the victory and triomphe gruppos. Rings are hard to find these days.

cheers
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recordacefromnew
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Re: Options for a square taper BB renovation

Post by recordacefromnew »

Brucey wrote:IIRC the five bolt went to a 36T smallest, with two or three rings on the same 116mm BCD. Would that work for you?


Great! That would do me just fine. I am in no hurry to get it done, so will definitely keep an eye out for suitable arms and rings. Thankyou.
Brucey
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Re: Options for a square taper BB renovation

Post by Brucey »

the one in the previous picture is a 1980's one I think; the chainrings (with the angled struts) are identical to those seen on Victory/Triomphe cranks. There is also a slightly older 1970s version of the GS crankset with the same cranks but chainrings with curved cutouts that echo the design of the 'Nuovo Record' chainrings like this;

Image

I reckon that would look just nice on the right bike with 46-36 on it as you intend.

[edit; hang on, those are not campag cranks; are they Zeus or galli or something....?... but anyway I am pretty sure I've seen the same kind of thing in campag GS...]

cheers
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AM7
Posts: 362
Joined: 18 Jul 2014, 10:24pm
Location: North West Essex

Re: Options for a square taper BB renovation

Post by AM7 »

The 116bcd Campag Victory/Triomphe/GS chainsets take a 35t smallest chainring. Unfortunately, Campag rings in anything other than 53, 52 or 42 sizes are as rare as hens teeth. I've got a 50/36 set and a 46/36 set which took me years to find. In fact I've never seen another 50 or 46 Campag 116bcd ring!

Having said that, Miche now make 36/46 116bcd rings for their Young junior chainsets - they're readily available on Ebay. They're not the same angular shape as the Campag rings unfortunately but you can't have everything I suppose :)
audaxer
Posts: 25
Joined: 13 Jan 2009, 3:34pm

Re: Options for a square taper BB renovation

Post by audaxer »

I've got a rather old Campag 54/48 chainring that came off the Scot, with a nice old Campag rear mech. They could do with some buffing up but they do look nice. Problem is, the rings are practically the same size! Not sure what the point of that is. I'd rather have a compact as everything round here is at the top of a very steep hill.

Was looking at a new Campag groupset but not sure whether the power torque BB would be compatible with a 1968 frame? Plus the BB doesn't half stick out.
andrewjoseph
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Re: Options for a square taper BB renovation

Post by andrewjoseph »

I've put a compact double on my stronglight triple crank. Took off the 24t inner, still using 34t middle and 48t outer. Set up with sram apex shifters and mechs.
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Classtimesailer
Posts: 9
Joined: 24 Feb 2014, 2:33am

Re: Options for a square taper BB renovation

Post by Classtimesailer »

I just put a Sugino Mighty tour (new) with a 34/48 on my 10 speed Shimano bike. Very vintage looking. Used a phil wood BB. I wish Sugino made JIS spindles so I could go back to loose ball BBs.
AM7
Posts: 362
Joined: 18 Jul 2014, 10:24pm
Location: North West Essex

Re: Options for a square taper BB renovation

Post by AM7 »

audaxer wrote:I've got a rather old Campag 54/48 chainring that came off the Scot, with a nice old Campag rear mech. They could do with some buffing up but they do look nice. Problem is, the rings are practically the same size! Not sure what the point of that is. I'd rather have a compact as everything round here is at the top of a very steep hill.

Was looking at a new Campag groupset but not sure whether the power torque BB would be compatible with a 1968 frame? Plus the BB doesn't half stick out.


I've got an ancient Rudge with 47/49 chainrings up front and a 14-22 five speed block at the back! Riders were obviously a tougher breed back then :D Seriously though, that was probably the limits of the technology at the time.

With regard to fitting a power torque BB, there should be no problem with that as you've got a standard 68mm BB shell on your bike.
fastpedaller
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Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Options for a square taper BB renovation

Post by fastpedaller »

Planet X are selling a rather nice 'On One Touring' chainset in the campag style. 48/34 rings. Might suit as a compact - not sure it's really touring. For what it's worth I'd go for a spa triple at £35, based on the sugino forged XDR-2 cranks - various lengths (including shorter) ones avalable.
JohnW
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Re: Options for a square taper BB renovation

Post by JohnW »

Brucey wrote:............Spa's ST triples or a ST double may well serve you as well or better.................


For what it's worth, Spa would be my first port of call in your situation. If you look on their website, you'll see that they have choices. Been there - done that - no T-shirt though...............
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