Head set replacement question
05-17-24, 04:32 PM
#1
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Thread Starter
Head set replacement question
I have a 1979 Trek 736.
The bike came with different parts : Shimano 600, Dura-ace and Campagnolo, and I try to replace the non-original parts with the Shimano 600 Arabesque.
The actual headset is Campagnolo.
When I tried to replace the fork crown race, the Shimano has the interior diameter (26.8mm), and is bigger than that Campagnolo (26.3mm).
I tried other crown races (Tange and no name), and these are bigger too.
What's the solution/ problem here?
The bike came with different parts : Shimano 600, Dura-ace and Campagnolo, and I try to replace the non-original parts with the Shimano 600 Arabesque.
The actual headset is Campagnolo.
When I tried to replace the fork crown race, the Shimano has the interior diameter (26.8mm), and is bigger than that Campagnolo (26.3mm).
I tried other crown races (Tange and no name), and these are bigger too.
What's the solution/ problem here?
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1992 Torelli Nitro Express; 1972 Claud Butler.
1992 Torelli Nitro Express; 1972 Claud Butler.
Last edited by marius.suiram; 05-17-24 at 08:04 PM.
05-18-24, 02:27 AM
#2
https://www.sheldonbrown.com/cribsheet-headsets.html
Best you measure the cup and seat diameters as well.
Best you measure the cup and seat diameters as well.
05-18-24, 03:13 AM
#3
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Thread Starter
https://www.sheldonbrown.com/cribsheet-headsets.html
Best you measure the cup and seat diameters as well.
Best you measure the cup and seat diameters as well.
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1992 Torelli Nitro Express; 1972 Claud Butler.
1992 Torelli Nitro Express; 1972 Claud Butler.
05-18-24, 05:00 AM
#4
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Did you remove the current Campy fork crown race and take an accurate measurement of the fork crown seat? Is it ~26.4mm? Did you test the Shimano fork crown race? Just curious.
05-18-24, 06:53 AM
#5
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Thread Starter
I measured the Shimano crown fork, 26.8mm.
The Campi was pressed on the fork, the Shimano is moving free.
I will measure the fork seat, but will be probably around 26.4mm
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1992 Torelli Nitro Express; 1972 Claud Butler.
1992 Torelli Nitro Express; 1972 Claud Butler.
05-18-24, 06:59 AM
#6
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After you measure the fork seat I would slip the Shimano crown race on there just to check. It may work, maybe just would not need to be tapped down as much. Or it could be that your Shimano headset is the one for a 30.0 crown seat. Do you have a metric caliper accurate down to 0.1mm? This might come in handy here.
05-18-24, 07:42 AM
#7
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the only other option would be have a frame builder add some materiel to the seat and the remill to the larger size.
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk
05-18-24, 10:21 AM
#8
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The Campagnolo dimensions are what became the ISO specification, so any ISO-spec headset of the same or shorter stack height should work. The Shimano headset is likely JIS-spec. Most Tange headsets can be had in either ISO or JIS spec.
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05-18-24, 07:10 PM
#9
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Thread Starter
The fork seat is 26.4 mm
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1992 Torelli Nitro Express; 1972 Claud Butler.
1992 Torelli Nitro Express; 1972 Claud Butler.
05-22-24, 03:25 PM
#10
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I found a replacement: Stronglight
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1992 Torelli Nitro Express; 1972 Claud Butler.
1992 Torelli Nitro Express; 1972 Claud Butler.
05-22-24, 04:10 PM
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Well done on succeeding despite our best efforts to confuse. There are plenty of options with 26.4 crown race. I had a Shimano 600 at one time with a 26.4 but more commonly found in 27
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05-22-24, 04:18 PM
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