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PostPosted: Sat May 18, 2013 4:36 pm 
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All good info so far - think i've understood the principles.

However, stack height?!?! measured the steerer and it's exactly 16cm. measured the headtube at 12.5cm. does that mean a stack height of 3.5cm give or take a few mm as the bottom cup won't be right on top of the fork blades?

If that is the stack height is that 'normal' i.e. pretty much most headsets will be of that height or is it low stack?

any input would be welcomed as the headset i'm after dont seem to appear that frequently and the last thing I need is to buy one that isn't the right height!

cheers...


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PostPosted: Sat May 18, 2013 4:36 pm 
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Location: Completely in the dark, thanks to me good mate Terry....
Midlife wrote:
Looked at a modern Tange Falcon and they now have "Falcon" on them. Levin or Passage might be better?


Also in the modern-but-doesn't-look-it category if the used/NOS routes are pricey or fruitless, the Stronglight A9 is worth a look too. But go for the silver alloy one, not the black version which is steel and not so well engineered.

Having said that, I like Tange-Seiki kit too and the budget Tange BB on my touring bike was money well spent. If only I could find a UK outlet for their much flashier LN-9100 titanium BB unit to use on my race bikes....

David


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PostPosted: Sat May 18, 2013 4:56 pm 
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One way to explain stack-height is: a)measure the total length of the head-tube. b)measure the total length of the steerer-tube from the bottom of the crown-race seat to the top of the thread. c)subtract 'a' from 'b'.

Another way of putting it: It is the total height of all the bits that make up both the top and the bottom parts of the headset, (not including the parts of the top-race and bottom-cup that fit into the head-tube)

There is a small discrepancy between these two ways of measuring, because of the very top of the locknut, where it covers the end of the steerer-tube. If you measure the head-tube and steerer-tube, instead of the headset, That extra mm. or so would be missing.

so...which of these is the proper stack-height? No idea! :?

Hope this makes sense.
(edit; 35mm is fairly low stack, Campag. pista was about that. Alloy strada was about 40mm?)


Last edited by torqueless on Sat May 18, 2013 5:03 pm, edited 1 time in total.

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PostPosted: Sat May 18, 2013 5:03 pm 
retrobike rider
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Handy headset cribsheet here at Sutherland's Manuals.

The stack height is the height combined height of the lower and upper sections of the headset. Don't include the parts that press-fit into the headtube, and subtract a couple of millimetres for a little bit of clearance at the top of the thread.

Image
All the best,


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PostPosted: Sat May 18, 2013 5:19 pm 
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The tange range of modern but retro do look nice, and the Stronglight appeals as it looks nicely made and it says 1970's - 1980's on velobase so that could be option B - think if I went that route I'd still be looking around at Campag as i'm only a seatpost away from having all the Campag bits I can get for this bike. Stem / bars / freewheel / chain / saddle still to source but they arent campag. oh and pedals but that's a whole different headache as I can't ride in straps so that's a bridge to cross at a later date.

Now to stack height - cheers for the info / diagrams - it does make sense reading it, not quite so when I take measurements. As stated the difference of the steerer vs headtube is 3.5cm.

If I stack the various bits of the headset that come on the frame (excluding the top & bottom cups that sit in the headtube) i'm looking at 3cm so 5mm difference - seems rather a lot?

Headset i've got really is a piece of crap - it has a moulded rubber case so there's no way of really knowing what the stem looked like as it entered the headset as this poxy case covers it up - I wish i'd of asked this earlier as i'd of cut the rubber case to have a look. as it is the bike is totally in bits and covered in nitromors as I write this!

So a low stack height needed & given I'm after nuovo / record / super or indeed period pista, then chances are i'll be ok?


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PostPosted: Sat May 18, 2013 6:31 pm 
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I've just done some measuring for you; Using danson67's 'A' and 'B' in the diagram.. (but for 'A', measuring to the top of the locknut)

Super Record Pista: 'A'- a shade over 25mm. 'B'- about 10.5mm. 35.5mm. stack?
Super Record Strada: 'A'- about 29.5mm. 'B'- a shade under 15mm. 44.5mm. stack?

Quite a difference! The stack-heights over at Velobase are slightly less.. maybe they didn't measure to the top of the locknut as I did? The Pista is well worn- and polished. The Strada is hardly used. No small part of the difference between the two is down to the Strada spacer-itself over 4mm high, and the very much beefier crown-race. IIRC the balls are smaller on the Pista too.


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PostPosted: Sat May 18, 2013 6:51 pm 
retrobike rider
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Nice new old style alloy Tange Falcon on eBay UK £23.19 posted. 35.3mm stack. Not mine.
http://www.ebay.co.uk/itm/Tange-Falcon- ... 0842094228

Also, Hilary Stone has a few Campag Sport ones from £24 to £59. 32mm stack. (cut a little bit off your steerer length).

All the best,


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PostPosted: Sat May 18, 2013 7:25 pm 
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Sterling work Danson, it's a bit of bloody minefield this headset lark! Are you selling the Pista headset?

Have been thinking as you do, frame is 70's, but had certainly been back to a shop in the 80's for a new look. The frame / forks and the strada cranks & BB are all that remain of the original. everything else was 80's. Im wondering if during this revamp the owner wanted a lower front end and so cut the steerer down and was left with little option but to put a rather nasty headset in - even the rest of the 80's gear that was on the bike was decent, cinelli stem / criteririum bars, ofmega mech, gipiemme seatpost etc etc so to have a crappy headset doesnt stack up (sorry - as TGR says I'll get my coat :facepalm: ).


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PostPosted: Sat May 18, 2013 8:37 pm 
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I believe there may be more than a few '70s road frames about with this sort of stack-height- Judging from my '75 frame, It may often go with 65mm bracket-shell and 120mm rear-end? I would like to know more about this myself... Perhaps it was a late '60s/ early '70s standard, from before Campag. Record and 6-speed blocks monopolised the peloton?

Regarding the 70s frame/80s components thing- it really could take that long to get a decent bike together back then, from a standing start in a somewhat unhelpful environment.. :cry: :x :facepalm: .. :)

Thinking about my measured stack-heights again, I guess both Strada and Pista require upwards of 2.5mm 'allowance' to prevent the shoulder at the top of the locknut from bottoming out onto the end of the steerer, while still using the maximum amount of thread. Subtracting 2.5mm from my measurements, they are pretty much the same as the ones at Velobase.

Quote:
Cut a bit off your steerer length
.. or use a fatter spacer.


Last edited by torqueless on Sat May 18, 2013 8:46 pm, edited 1 time in total.

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PostPosted: Sat May 18, 2013 8:46 pm 
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Dan................now that's what a Tange Falcon should look like :D

Now not sure if my EDCO had room for a spacer and the locknut is against the race at the top?

Shaun


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