Advanced Double Crankset Conversion - Historique des versions

Louison le 13 octobre 2024 à 21:01

2024-10-13T21:01:37Z

← Version précédente		Version du 13 octobre 2024 à 21:01
Ligne 31 :		Ligne 31 :
	If in theory the concept is pretty simple, the best way to prove that it is a viable way of doing things is an example provided by a credible source : a double chainring crankset being used a single chainring crankset that use both aforementioned chainlines. To build upon this proof of concept, we also need it to give us all bottom bracket dimensions mentioned.		If in theory the concept is pretty simple, the best way to prove that it is a viable way of doing things is an example provided by a credible source : a double chainring crankset being used a single chainring crankset that use both aforementioned chainlines. To build upon this proof of concept, we also need it to give us all bottom bracket dimensions mentioned.

	This proof of concept is given to us by the Stronglight 107 crankset, according to the 1984 Stronglight No. 27 catalogue<ref>https://labibleduvelocataloguesstronlight.blogspot.com/p/stronlight-1984.html, Stronglight No. 27 catalogue (1984)</ref>. The catalogue tells us that this crankset can be used as a track crankset or as a road double crankset. It also gives us all the dimensions of the bottom brackets used :		This proof of concept is given to us by the Stronglight 107 crankset, according to the 1984 Stronglight No. 27 catalogue<ref>''[https://labibleduvelocataloguesstronlight.blogspot.com/p/stronlight-1984.html Stronglight No. 27 catalogue (1984)]'', labibeduvélo.blogspot.com, last accessed : 13/10/2024</ref>. The catalogue tells us that this crankset can be used as a track crankset or as a road double crankset. It also gives us all the dimensions of the bottom brackets used :

	{\| class="wikitable centre" style="margin-left: auto; margin-right: auto; border: none;text-align:center;"		{\| class="wikitable centre" style="margin-left: auto; margin-right: auto; border: none;text-align:center;"
Ligne 96 :		Ligne 96 :
	! Measured chainline of the conversion		! Measured chainline of the conversion
	\|-		\|-
	\| Shimano FC-A551<ref name=a551>https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf, Service Instructions for the FC-A551, FC-A415 and FC-1056, https://web.archive.org/web/20240428115034/https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf</ref>		\| Shimano FC-A551<ref name=a551>''[https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf Service Instructions for the FC-A551, FC-A415 and FC-1056]'', shimano.com, [https://web.archive.org/web/20240428115034/https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf Archive], last accessed : 13/10/2024</ref>
	\| BB-UN52		\| BB-UN52
	\| 107 (?)		\| 107 (?)
	\| 102,5		\| 102,5
	\| 103mm Neco B910/B920/B940CT<ref name="neco23-24">https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>		\| 103mm Neco B910/B920/B940CT<ref name="neco23-24">''[https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en Neco 2023-2024 Catalogue]'', necoparts.com, last accessed : 13/10/2024</ref>
	(28mm)		(28mm)
	\|		\|
	\|-		\|-
	\| Shimano FC-A550<ref name=a550>https://si.shimano.com/en/pdfs/si/T-29/SI-T-29-000-00-ENG.pdf, Service Instructions for the FC-A550 and FC-1055, https://web.archive.org/web/20240428115310/https://si.shimano.com/en/pdfs/si/T-29/SI-T-29-000-00-ENG.pdf</ref>		\| Shimano FC-A550<ref name=a550>''[https://si.shimano.com/en/pdfs/si/T-29/SI-T-29-000-00-ENG.pdf, Service Instructions for the FC-A550 and FC-1055]'', shimano.com, [https://web.archive.org/web/20240428115310/https://si.shimano.com/en/pdfs/si/T-29/SI-T-29-000-00-ENG.pdf Archive], last accessed : 13/10/2024</ref>
	\| BB-A550		\| BB-A550
	\| 113 (31)		\| 113 (31)
Ligne 119 :		Ligne 119 :
	\|		\|
	\|-		\|-
	\| Shimano FC-1050<ref name=fc1050>~~{{cite web \|url=~~ https://si.shimano.com/en/pdfs/si/P-27A/SI-P-27A-000-00-ENG.pdf ~~\|title=~~ Service Instructions for the FC-1050 and FC-1051 ~~\|archive-date= \|archive-url=~~ https://web.archive.org/web/20240428115536/https://si.shimano.com/en/pdfs/si/P-27A/SI-P-27A-000-00-ENG.pdf }}</ref>		\| Shimano FC-1050<ref name=fc1050>''[https://si.shimano.com/en/pdfs/si/P-27A/SI-P-27A-000-00-ENG.pdf Service Instructions for the FC-1050 and FC-1051]'', shimano.com, [https://web.archive.org/web/20240428115536/https://si.shimano.com/en/pdfs/si/P-27A/SI-P-27A-000-00-ENG.pdf Archive] last accessed : 13/10/2024</ref>
	\| BB-1050		\| BB-1050
	\| 113 (30.5)		\| 113 (30.5)
Ligne 150 :		Ligne 150 :
	\|		\|
	\|-		\|-
	\| Shimano FC-4400<ref>https://si.shimano.com/en/pdfs/si/1DM0A/SI-1DM0A-000-00-ENG.pdf, Service Instructions for the FC-4400, https://web.archive.org/web/20240428115803/https://si.shimano.com/en/pdfs/si/1DM0A/SI-1DM0A-000-00-ENG.pdf</ref>		\| Shimano FC-4400<ref>''[https://si.shimano.com/en/pdfs/si/1DM0A/SI-1DM0A-000-00-ENG.pdf Service Instructions for the FC-4400]'', shimano.com, [https://web.archive.org/web/20240428115803/https://si.shimano.com/en/pdfs/si/1DM0A/SI-1DM0A-000-00-ENG.pdf Archive], last accessed 13/10/2024</ref>
	\| BB-UN52		\| BB-UN52
	\| 110 (?)		\| 110 (?)
Ligne 158 :		Ligne 158 :
	\|		\|
	\|-		\|-
	\| Shimano FC-7400<ref>https://si.shimano.com/en/pdfs/si/N-69/SI-N-69-000-00-ENG.pdf, Service Instructions for the FC-7400, https://web.archive.org/web/20240428120056/https://si.shimano.com/en/pdfs/si/N-69/SI-N-69-000-00-ENG.pdf</ref>		\| Shimano FC-7400<ref>''[https://si.shimano.com/en/pdfs/si/N-69/SI-N-69-000-00-ENG.pdf Service Instructions for the FC-7400]'', shimano.com, [https://web.archive.org/web/20240428120056/https://si.shimano.com/en/pdfs/si/N-69/SI-N-69-000-00-ENG.pdf Archive], last accessed 13/10/2024</ref>
	\| BB-7400		\| BB-7400
	\| 112 (32.5)		\| 112 (32.5)
Ligne 166 :		Ligne 166 :
	\|		\|
	\|-		\|-
	\| Shimano FC-7402<ref>https://si.shimano.com/en/pdfs/si/R-89/SI-R-89-000-00-ENG_GER_FRA.pdf, Service Instructions for the FC-7402, https://web.archive.org/web/20240428120212/https://si.shimano.com/en/pdfs/si/R-89/SI-R-89-000-00-ENG_GER_FRA.pdf</ref>		\| Shimano FC-7402<ref>''[https://si.shimano.com/en/pdfs/si/R-89/SI-R-89-000-00-ENG_GER_FRA.pdf Service Instructions for the FC-7402]'', shimano.com, [https://web.archive.org/web/20240428120212/https://si.shimano.com/en/pdfs/si/R-89/SI-R-89-000-00-ENG_GER_FRA.pdf Archive], last accessed 13/10/2024</ref>
	\| BB-7400		\| BB-7400
	\| 112 (32.5)		\| 112 (32.5)
Ligne 174 :		Ligne 174 :
	\|		\|
	\|-		\|-
	\| Shimano FC-7402-SG<ref>https://si.shimano.com/en/pdfs/si/T-28A/SI-T-28A-000-00-ENG.pdf, Service Instructions for the FC-7402-~~SGhttps~~://web.archive.org/web/20240428120333/https://si.shimano.com/en/pdfs/si/T-28A/SI-T-28A-000-00-ENG.pdf</ref>		\| Shimano FC-7402-SG<ref>''[https://si.shimano.com/en/pdfs/si/T-28A/SI-T-28A-000-00-ENG.pdf Service Instructions for the FC-7402-SG]'', shimano.com, [https://web.archive.org/web/20240428120333/https://si.shimano.com/en/pdfs/si/T-28A/SI-T-28A-000-00-ENG.pdf Archive], last accessed 13/10/2024</ref>
	\| BB-7400		\| BB-7400
	\| 112 (32.5)		\| 112 (32.5)
Ligne 233 :		Ligne 233 :
	= Practice =		= Practice =

	In reality this practice is a LOT more common than we can imagine. We saw it with the Stronglight 107 but Cheap "fixie" bikes also very often use double-chainring cranksets with the sole chainring being on the outer placement. Good exemples stem from Bianchi's offering of fixie bikes<ref>https://https://www.bianchi.com/wp-content/uploads/2019/12/tech-book-international-2015.pdf, 2015 Bianchi Tech Book (pages 128 & 130)</ref>. The Bianchi "Pista Steel" uses a "FSA Tempo CK-200S" crankset (and the following year, this becomes a "FSA Tempo Track"<ref>https://www.bianchi.com/wp-content/uploads/2019/12/Bianchi-Catalogue-INTERNATIONAL-2016.pdf, 2016 Bianchi International Catalog (pages 67 & 123)</ref>) and the "Pista Sei Giorni Alu" uses a "Truvatic TOURO Track 1.1" crankset. Both crankset are in every possible sense not designed to be used as either a single chainring crankset (despite the Track name used sometimes) or as a crankset with a 42,5mm chainline. Yet, I am sure that neither bike have a bent 42,5mm chainline. If anything both bikes are Proof of Concept that it works.		In reality this practice is a LOT more common than we can imagine. We saw it with the Stronglight 107 but Cheap "fixie" bikes also very often use double-chainring cranksets with the sole chainring being on the outer placement. Good exemples stem from Bianchi's offering of fixie bikes<ref>''[https://https://www.bianchi.com/wp-content/uploads/2019/12/tech-book-international-2015.pdf 2015 Bianchi Tech Book (pages 128 & 130)]'', bianchi.com, last accessed : 13/10/2024</ref>. The Bianchi "Pista Steel" uses a "FSA Tempo CK-200S" crankset (and the following year, this becomes a "FSA Tempo Track"<ref>''[https://www.bianchi.com/wp-content/uploads/2019/12/Bianchi-Catalogue-INTERNATIONAL-2016.pdf 2016 Bianchi International Catalog (pages 67 & 123)], bianchi.com, last accessed : 13/10/2024</ref>) and the "Pista Sei Giorni Alu" uses a "Truvatic TOURO Track 1.1" crankset. Both crankset are in every possible sense not designed to be used as either a single chainring crankset (despite the Track name used sometimes) or as a crankset with a 42,5mm chainline. Yet, I am sure that neither bike have a bent 42,5mm chainline. If anything both bikes are Proof of Concept that it works.

	= References =		= References =
	~~{{reflist}}~~

Louison le 12 septembre 2024 à 18:36

2024-09-12T18:36:53Z

← Version précédente		Version du 12 septembre 2024 à 18:36
Ligne 119 :		Ligne 119 :
	\|		\|
	\|-		\|-
	\| Shimano FC-1050<ref name=~~1050~~>{{cite web \|url= https://si.shimano.com/en/pdfs/si/P-27A/SI-P-27A-000-00-ENG.pdf \|title= Service Instructions for the FC-1050 and FC-1051 \|archive-date= \|archive-url= https://web.archive.org/web/20240428115536/https://si.shimano.com/en/pdfs/si/P-27A/SI-P-27A-000-00-ENG.pdf }}</ref>		\| Shimano FC-1050<ref name=fc1050>{{cite web \|url= https://si.shimano.com/en/pdfs/si/P-27A/SI-P-27A-000-00-ENG.pdf \|title= Service Instructions for the FC-1050 and FC-1051 \|archive-date= \|archive-url= https://web.archive.org/web/20240428115536/https://si.shimano.com/en/pdfs/si/P-27A/SI-P-27A-000-00-ENG.pdf }}</ref>
	\| BB-1050		\| BB-1050
	\| 113 (30.5)		\| 113 (30.5)
Ligne 127 :		Ligne 127 :
	\|		\|
	\|-		\|-
	\| Shimano FC-1051<ref name=~~1050~~></ref>		\| Shimano FC-1051<ref name=fc1050></ref>
	\| BB-1050		\| BB-1050
	\| 113 (30.5)		\| 113 (30.5)

Louison le 11 septembre 2024 à 20:30

2024-09-11T20:30:36Z

← Version précédente		Version du 11 septembre 2024 à 20:30
Ligne 96 :		Ligne 96 :
	! Measured chainline of the conversion		! Measured chainline of the conversion
	\|-		\|-
	\| Shimano FC-A551<ref name=a551>https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf, Service Instructions for the FC-A551, FC-A415 and FC-1056, ~~archive-url=~~ https://web.archive.org/web/20240428115034/https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf</ref>		\| Shimano FC-A551<ref name=a551>https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf, Service Instructions for the FC-A551, FC-A415 and FC-1056, https://web.archive.org/web/20240428115034/https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf</ref>
	\| BB-UN52		\| BB-UN52
	\| 107 (?)		\| 107 (?)

Louison le 11 septembre 2024 à 20:29

2024-09-11T20:29:46Z

← Version précédente		Version du 11 septembre 2024 à 20:29
Ligne 31 :		Ligne 31 :
	If in theory the concept is pretty simple, the best way to prove that it is a viable way of doing things is an example provided by a credible source : a double chainring crankset being used a single chainring crankset that use both aforementioned chainlines. To build upon this proof of concept, we also need it to give us all bottom bracket dimensions mentioned.		If in theory the concept is pretty simple, the best way to prove that it is a viable way of doing things is an example provided by a credible source : a double chainring crankset being used a single chainring crankset that use both aforementioned chainlines. To build upon this proof of concept, we also need it to give us all bottom bracket dimensions mentioned.

	This proof of concept is given to us by the Stronglight 107 crankset, according to the 1984 Stronglight No. 27 catalogue<ref>~~{{cite web \|url=~~ https://labibleduvelocataloguesstronlight.blogspot.com/p/stronlight-1984.html ~~\|title=~~ Stronglight No. 27 catalogue (1984) ~~\|archive-date= \|archive-url= }}~~</ref>. The catalogue tells us that this crankset can be used as a track crankset or as a road double crankset. It also gives us all the dimensions of the bottom brackets used :		This proof of concept is given to us by the Stronglight 107 crankset, according to the 1984 Stronglight No. 27 catalogue<ref>https://labibleduvelocataloguesstronlight.blogspot.com/p/stronlight-1984.html, Stronglight No. 27 catalogue (1984)</ref>. The catalogue tells us that this crankset can be used as a track crankset or as a road double crankset. It also gives us all the dimensions of the bottom brackets used :

	{\| class="wikitable centre" style="margin-left: auto; margin-right: auto; border: none;text-align:center;"		{\| class="wikitable centre" style="margin-left: auto; margin-right: auto; border: none;text-align:center;"

Louison le 11 septembre 2024 à 20:29

2024-09-11T20:29:00Z

Voir les modifications

Louison le 11 septembre 2024 à 20:19

2024-09-11T20:19:38Z

← Version précédente		Version du 11 septembre 2024 à 20:19
Ligne 96 :		Ligne 96 :
	! Measured chainline of the conversion		! Measured chainline of the conversion
	\|-		\|-
	\| Shimano FC-A551<ref>~~{{cite web \|url=~~ https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf ~~\|title=~~ Service Instructions for the FC-A551, FC-A415 and FC-1056 ~~\|archive-date= \|~~archive-url= https://web.archive.org/web/20240428115034/https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf }}</ref>		\| Shimano FC-A551<ref>https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf, Service Instructions for the FC-A551, FC-A415 and FC-1056, archive-url= https://web.archive.org/web/20240428115034/https://si.shimano.com/en/pdfs/si/14S0E/SI-14S0E-000-00-ENG.pdf</ref>
	\| BB-UN52		\| BB-UN52
	\| 107 (?)		\| 107 (?)
	\| 102,5		\| 102,5
	\| 103mm Neco B910/B920/B940CT<ref>~~{{cite web \|url=~~ https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en ~~\|title=~~ Neco 2023-2024 Catalogue }}</ref>		\| 103mm Neco B910/B920/B940CT<ref>https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>
	(28mm)		(28mm)
	\|		\|
Ligne 108 :		Ligne 108 :
	\| 113 (31)		\| 113 (31)
	\| 105.5 (26.25)		\| 105.5 (26.25)
	\| 103 mm Neco B910/B920/B940<ref>~~{{cite web \|url=~~ https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en ~~\|title=~~ Neco 2023-2024 Catalogue }}</ref>		\| 103 mm Neco B910/B920/B940<ref>https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>
	(28mm)		(28mm)
	\|		\|
Ligne 123 :		Ligne 123 :
	\| 113 (30.5)		\| 113 (30.5)
	\| 105.5 (26.75)		\| 105.5 (26.75)
	\| 103mm Neco B910/B920/B940<ref>~~{{cite web \|url=~~ https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en ~~\|title=~~ Neco 2023-2024 Catalogue }}</ref>		\| 103mm Neco B910/B920/B940<ref>https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>
	(28mm)		(28mm)
	\|		\|
Ligne 131 :		Ligne 131 :
	\| 113 (30.5)		\| 113 (30.5)
	\| 105.5 (26.75)		\| 105.5 (26.75)
	\| 103mm Neco B910/B920/B940<ref>~~{{cite web \|url=~~ https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en ~~\|title=~~ Neco 2023-2024 Catalogue }}</ref>		\| 103mm Neco B910/B920/B940<ref>https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>
	(28mm)		(28mm)
	\|		\|
Ligne 139 :		Ligne 139 :
	\| 113 (31)		\| 113 (31)
	\| 105.5 (26.25)		\| 105.5 (26.25)
	\| 103mm Neco B910/B920/B940<ref>~~{{cite web \|url=~~ https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en ~~\|title=~~ Neco 2023-2024 Catalogue }}</ref>		\| 103mm Neco B910/B920/B940<ref>https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>
	(28mm)		(28mm)
	\|		\|
Ligne 154 :		Ligne 154 :
	\| 110 (?)		\| 110 (?)
	\| 103.5		\| 103.5
	\| 103mm Neco B910/B920/B940CT<ref>~~{{cite web \|url=~~ https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en ~~\|title=~~ Neco 2023-2024 Catalogue }}</ref>		\| 103mm Neco B910/B920/B940CT<ref>https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>
	(28mm)		(28mm)
	\|		\|
Ligne 162 :		Ligne 162 :
	\| 112 (32.5)		\| 112 (32.5)
	\| 104.5 (28.75)		\| 104.5 (28.75)
	\| 108mm Neco B910/B920/B940<ref>~~{{cite web \|url=~~ https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en ~~\|title=~~ Neco 2023-2024 Catalogue }}</ref>		\| 108mm Neco B910/B920/B940<ref>https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>
	(29mm)		(29mm)
	\|		\|
Ligne 170 :		Ligne 170 :
	\| 112 (32.5)		\| 112 (32.5)
	\| 104.5 (28.75)		\| 104.5 (28.75)
	\| 108mm Neco B910/B920/B940<ref>~~{{cite web \|url=~~ https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en ~~\|title=~~ Neco 2023-2024 Catalogue }}</ref>		\| 108mm Neco B910/B920/B940<ref>https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>
	(29mm)		(29mm)
	\|		\|
Ligne 178 :		Ligne 178 :
	\| 112 (32.5)		\| 112 (32.5)
	\| 104.5 (28.75)		\| 104.5 (28.75)
	\| 108mm Neco B910/B920/B940<ref>~~{{cite web \|url=~~ https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en ~~\|title=~~ Neco 2023-2024 Catalogue }}</ref>		\| 108mm Neco B910/B920/B940<ref>https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en, Neco 2023-2024 Catalogue</ref>
	(29mm)		(29mm)
	\|		\|

Louison le 28 avril 2024 à 18:49

2024-04-28T18:49:35Z

← Version précédente		Version du 28 avril 2024 à 18:49
Ligne 81 :		Ligne 81 :
	Issues arise from the dimensions given by the manufacturers and the different types of bottom brackets nowadays. The days of adjustable bottom bracket like the ones the 107 used are long gone, and while dimensions shouldn't suffer from it, as the bottom bracket box dimensions are still the same and the chainline remains the same, the cups and bearings have changed. It's hard to find schematics of a brand new bottom bracket that are as simple and precise as the ones from the Stronglight catalog. So, much of what will follow is strictly theory and there will be trial and error if you seek the perfect chainline.		Issues arise from the dimensions given by the manufacturers and the different types of bottom brackets nowadays. The days of adjustable bottom bracket like the ones the 107 used are long gone, and while dimensions shouldn't suffer from it, as the bottom bracket box dimensions are still the same and the chainline remains the same, the cups and bearings have changed. It's hard to find schematics of a brand new bottom bracket that are as simple and precise as the ones from the Stronglight catalog. So, much of what will follow is strictly theory and there will be trial and error if you seek the perfect chainline.

	As Shimano cranks are universally common and cheap and as Shimano have a lot of documentation on them even from decades ago, making educated guesses about converting Shimano cranks is a lot easier than almost anything else. Campagnolo on the other hand makes it extremely difficult as they very rarely provide any information, let alone specifications of something like a bottom bracket axle.		As Shimano cranks are universally common and cheap and as Shimano have a lot of documentation on them even from decades ago, making educated guesses about converting Shimano cranks is a lot easier than almost anything else. Campagnolo on the other hand makes it extremely difficult as they very rarely provide any information past 1990, let alone specifications of something like a bottom bracket axle.

	== Database ==		== Database ==

Louison le 28 avril 2024 à 18:48

2024-04-28T18:48:23Z

← Version précédente		Version du 28 avril 2024 à 18:48
Ligne 80 :		Ligne 80 :

	Issues arise from the dimensions given by the manufacturers and the different types of bottom brackets nowadays. The days of adjustable bottom bracket like the ones the 107 used are long gone, and while dimensions shouldn't suffer from it, as the bottom bracket box dimensions are still the same and the chainline remains the same, the cups and bearings have changed. It's hard to find schematics of a brand new bottom bracket that are as simple and precise as the ones from the Stronglight catalog. So, much of what will follow is strictly theory and there will be trial and error if you seek the perfect chainline.		Issues arise from the dimensions given by the manufacturers and the different types of bottom brackets nowadays. The days of adjustable bottom bracket like the ones the 107 used are long gone, and while dimensions shouldn't suffer from it, as the bottom bracket box dimensions are still the same and the chainline remains the same, the cups and bearings have changed. It's hard to find schematics of a brand new bottom bracket that are as simple and precise as the ones from the Stronglight catalog. So, much of what will follow is strictly theory and there will be trial and error if you seek the perfect chainline.

			As Shimano cranks are universally common and cheap and as Shimano have a lot of documentation on them even from decades ago, making educated guesses about converting Shimano cranks is a lot easier than almost anything else. Campagnolo on the other hand makes it extremely difficult as they very rarely provide any information, let alone specifications of something like a bottom bracket axle.

	== Database ==		== Database ==

	Here is a list of a few cranksets, the associated bottom bracket and its length, the length of the drive side of the axle, the recommended length for a conversion with an exemple of available bottom brackets and what the measured chainline is. This will serve as a database for the fixed gear cyclist on a budget that has a totally functionning double-chainring crankset and wants to use it for his fixed-gear bike conversion.		Here is a list of a few cranksets, the associated bottom bracket and its length, the length of the drive side of the axle, the recommended length for a conversion with an exemple of available bottom brackets and what the measured chainline is. This will serve as a database for the fixed gear cyclist on a budget that has a totally functionning double-chainring crankset and wants to use it for his fixed-gear bike conversion.

	{\| class="wikitable centre" style="margin-left: auto; margin-right: auto; border: none;text-align:center;"		{\| class="wikitable centre" style="margin-left: auto; margin-right: auto; border: none;text-align:center;"

Louison le 28 avril 2024 à 12:04

2024-04-28T12:04:09Z

Voir les modifications

Louison : /* Hypotheses */

2024-04-28T10:05:30Z

Hypotheses

← Version précédente		Version du 28 avril 2024 à 10:05
Ligne 104 :		Ligne 104 :
	\| 107 (?)		\| 107 (?)
	\| 102,5		\| 102,5
	\|		\| 103mm Neco B910/B920/B940CT<ref>{{cite web \|url= https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en \|title= Neco 2023-2024 Catalogue }}</ref>
			(28mm)
	\|		\|
	\|-		\|-
Ligne 111 :		Ligne 112 :
	\| 113 (31)		\| 113 (31)
	\| 105.5 (26.25)		\| 105.5 (26.25)
	\|		\| 103 mm Neco B910/B920/B940<ref>{{cite web \|url= https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en \|title= Neco 2023-2024 Catalogue }}</ref>
			(28mm)
	\|		\|
	\|-		\|-
Ligne 125 :		Ligne 127 :
	\| 113 (30.5)		\| 113 (30.5)
	\| 105.5 (26.75)		\| 105.5 (26.75)
	\|		\| 103mm Neco B910/B920/B940<ref>{{cite web \|url= https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en \|title= Neco 2023-2024 Catalogue }}</ref>
			(28mm)
	\|		\|
	\|-		\|-
Ligne 132 :		Ligne 135 :
	\| 113 (30.5)		\| 113 (30.5)
	\| 105.5 (26.75)		\| 105.5 (26.75)
	\|		\| 103mm Neco B910/B920/B940<ref>{{cite web \|url= https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en \|title= Neco 2023-2024 Catalogue }}</ref>
			(28mm)
	\|		\|
	\|-		\|-
Ligne 139 :		Ligne 143 :
	\| 113 (31)		\| 113 (31)
	\| 105.5 (26.25)		\| 105.5 (26.25)
	\|		\| 103mm Neco B910/B920/B940<ref>{{cite web \|url= https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en \|title= Neco 2023-2024 Catalogue }}</ref>
			(28mm)
	\|		\|
	\|-		\|-
Ligne 153 :		Ligne 158 :
	\| 110 (?)		\| 110 (?)
	\| 103.5		\| 103.5
	\|		\| 103mm Neco B910/B920/B940CT<ref>{{cite web \|url= https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en \|title= Neco 2023-2024 Catalogue }}</ref>
			(28mm)
	\|		\|
	\|-		\|-
Ligne 160 :		Ligne 166 :
	\| 112 (32.5)		\| 112 (32.5)
	\| 104.5 (28.75)		\| 104.5 (28.75)
	\|		\| 108mm Neco B910/B920/B940<ref>{{cite web \|url= https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en \|title= Neco 2023-2024 Catalogue }}</ref>
			(29mm)
	\|		\|
	\|-		\|-
Ligne 167 :		Ligne 174 :
	\| 112 (32.5)		\| 112 (32.5)
	\| 104.5 (28.75)		\| 104.5 (28.75)
	\|		\| 108mm Neco B910/B920/B940<ref>{{cite web \|url= https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en \|title= Neco 2023-2024 Catalogue }}</ref>
			(29mm)
	\|		\|
	\|-		\|-
Ligne 174 :		Ligne 182 :
	\| 112 (32.5)		\| 112 (32.5)
	\| 104.5 (28.75)		\| 104.5 (28.75)
	\|		\| 108mm Neco B910/B920/B940<ref>{{cite web \|url= https://web.archive.org/web/20240426151909/https://www.necoparts.com/Templates/att/2023-2024%20Catalogue%20Updated.pdf?lng=en \|title= Neco 2023-2024 Catalogue }}</ref>
			(29mm)
	\|		\|
	\|}		\|}
Ligne 181 :		Ligne 190 :

	Most of the recommended bottom brackets come from Neco. They offer a lot of different dimensions, and some of them are weird to say the least : if you look at the B920HAL, the first two Bottom Bracket dimensions are 107.5mm and 110.5mm. Yet both drive side axle length are 20.5mm, the box being the same 68mm, the difference comes from the length of the non-drive side : 19mm vs 22.5mm. In general, it is better to go with a matching (or closer) drive-side axle length than a matching (or closer) total axle length and then go with the non-drive side as close to the drive side as possible, to get closer to a symmetric bottom bracket.		Most of the recommended bottom brackets come from Neco. They offer a lot of different dimensions, and some of them are weird to say the least : if you look at the B920HAL, the first two Bottom Bracket dimensions are 107.5mm and 110.5mm. Yet both drive side axle length are 20.5mm, the box being the same 68mm, the difference comes from the length of the non-drive side : 19mm vs 22.5mm. In general, it is better to go with a matching (or closer) drive-side axle length than a matching (or closer) total axle length and then go with the non-drive side as close to the drive side as possible, to get closer to a symmetric bottom bracket.

			== Conversion table between 68mm and 50mm B-dimension bottom bracket dimensions ==

			{\| class="wikitable centre" style="margin-left: auto; margin-right: auto; border: none;text-align:center;"
			\|-
			! total length
			! A
			! B
			! C
			\|-
			\| 103 (50)
			\| 25
			\| 50
			\| 28
			\|-
			\| 103 (68)
			\| 16,5
			\| 68
			\| 18,5
			\|-
			\| 107,5 (50)
			\| 27,5
			\| 50
			\| 30
			\|-
			\| 107,5 (68)
			\| 19
			\| 68
			\| 20,5
			\|-
			\| 108 (50)
			\| 29
			\| 50
			\| 29
			\|-
			\| 108 (68)
			\| 20,5
			\| 68
			\| 19,5
			\|}

	= Practice =		= Practice =

Advanced Double Crankset Conversion - Historique des versions

Louison le 13 octobre 2024 à 21:01

Louison le 12 septembre 2024 à 18:36

Louison le 11 septembre 2024 à 20:30

Louison le 11 septembre 2024 à 20:29

Louison le 11 septembre 2024 à 20:29

Louison le 11 septembre 2024 à 20:19

Louison le 28 avril 2024 à 18:49

Louison le 28 avril 2024 à 18:48

Louison le 28 avril 2024 à 12:04

Louison : /* Hypotheses */

Louison : /* Hypotheses */