Stronglight 93 Chainring Installation Notes
Fastening a triplizer ring or 37-tooth chainring to the crank spider: In most cases, a Red Clover Components double chainring can be bolted to a Model 93 crank spider with the chainring bolts that were used to secure the original rings. But there is one dimensional difference to keep in mind: RCC chainrings are machined from 3 mm stock, while the originals are 3.5 mm thick.
That change has no adverse effect on strength or durability, thanks to the use of modern 7075 aluminum alloy in place of the duralumin(equivalent to modern 2024 aluminum) used in the original Stronglight rings. Shifting performance is also unaffected. But because the original chainring bolts were most likely sized for the slightly thicker ring, they may be a fraction of a millimeter too long when used with one of our Stronglight-pattern rings. If that's the case, the bolt head will tighten against the sleeve portion of the nut, rather than tightening against the counterbore in the chainring itself. This will be evident if the nut and bolt assembly turns in its hole even after being fully tightened.
There are two ways to deal with this situation. The quick-and-dirty solution is to file or grind a something like .5 mm of metal from the inner end of each tubular nut to provide sufficient clearance between nut and chainring. This is invisible once the nuts are installed. It's a good idea to grease the filed or ground ends of the nuts to prevent rust.
A simpler and neater solutionto buy a new set of chainring bolts of the proper length. This isn’t always easy to determine, since the nominal lengths of chainring nuts and bolts don’t necessarily correspond to their actual lengths. For proper tightening, the tubular portion of the chainring nuts—not including the heads—should be 7 to 7.5 mm in length. Current production Sugino #203 chainring bolts or Problem Solvers CR1471 bolts--both of which measure an even 7 mm in length--have been found to work well.
Fastening a 74 BCD inner ring to a triplizer: A 3.8 mm aluminum spacer should be placed over each chainring bolt to provide proper clearance between the triplizer and the 74 BCD inner ring. Wheels Manufacturing CS3.8 spacers are a convenient choice for this.
Conventional double chainring nuts will protrude beyond the spacer and prevent proper tightening of the bolts, so the usual fastener configuration is to combine a nominal 8 mm-long inner chainring bolt with a nominal 4-mm chainring nut, of the type used with single-ring cranksets. The 4 mm nuts will extend about 2.5 mm beyond the inner side of the triplizer mounting tabs, and provide a good “seat” for the spacers. (To order the appropriate nuts, bolts, and spacers in kit form, see the “Store” section of this site.)
Installation tip: Use strips of masking tape to temporarily secure the outer circle of chainring nuts to the triplizer ring while the inner chainring and spacers are bolted to the triplizer. Once the inner ring/triplizer assembly is complete and has been bolted to the crank spider with the outer ring, the temporary strips of tape can be removed.
Spindle or cartridge bottom bracket selection for double cranksets: If you’re down-gearing a double crankset by replacing the second ring with our 37-tooth conventional ring, your existing chainline will be unchanged. There’s no need to change your spindle or bottom-bracket cartridge unless you were dissatisfied with the original chainline.
If you’re building up a frame for the first time and don’t know what length spindle to start with, the simplest solution is to install a modern square-taper cartridge bottom bracket. A 110 or 113 mm will generally give a good chainline with a Model 93 double.
Spindle or cartridge bottom bracket selection for triplizers: As with any double-to-triple conversion, adding a triplizer and third chainring calls for a longer cartridge or spindle. In most cases, adding 6 or 7 mm to the original drive-side length will give a good chainline. (It’s impossible to be precise here, because the lateral position of older cranksets will vary slightly depending on how much they’ve been “stretched” by repeated installation and removal.) For British-threaded bottom brackets, the 127.5 mm Shimano UN55 (or equivalent from another manufacturer) generally works well. Another option that offers a little more wiggle room is to opt for a 122.5 mm cartridge, and add a 1.5 or 2 mm spacer under the drive-side cup to fine-tune the chainline, if necessary. For frames with French bottom bracket threading, the 122 mm Grand Cru cartridge BB from Velo Orange generally fits fine, sometimes with the addition of a 1- or 2 mm spacer.
If you're lucky enough to have the original Stronglight cup-and-cone bottom bracket, you can swap out the original 118 mm spindle for a 123 or 125 mm Stronglight spindle and keep the original cups (a TA #377 spindle is also said to be a good fit, though I have never seen one myself). Unfortunately, these Stronglight triple spindles aren't easy to come by, although they do occasionally turn up on Ebay.
But as often as not, setting up a cup-and-cone bottom bracket for a Stronglight triple will involve mixing and matching parts from different manufacturers. Be prepared to do some test-fitting. Purists may scoff at using non-French parts on a French bike, but experience has shown that a Japanese-made JIS spindle works fine with Stronglight cranks, which were designed for the ever-so-slightly-different ISO spindle. (A well-illustrated discussion of mixing ISO and JIS cranks and spindles is available at http://www.sheldonbrown.com/bbtaper.html.)
When a JIS spindle is used with thick-walled cups, a 3S spindle usually gives a good chainline. New Chinese-made JIS spindles are available from online retailers such as Niagara Cycle. The quality of the machining, unfortunately, is often not very good, making precise bearing adjustment difficult or impossible. A better option may be to find a quality older spindle on an online auction site or at a bike coop or retailer who has a stock of old parts.
Chain: Use with 5-6-7-8-speed chain only.
144 BCD Triplizer Installation Notes
Fastening a triplizer (middle) ring to the crank spider: Most standard double chainring bolt sets will work fine. For best results with most Campagnolo cranksets, the nut section of the fastener should measure 8 mm long, not counting the head.
Fastening a 74 BCD inner ring to a triplizer: A 3.8 mm aluminum spacer should be placed over each chainring bolt to provide proper clearance between the triplizer and the 74 BCD inner ring. Wheels Manufacturing CS3.8 spacers are a convenient choice for this.
Conventional double chainring nuts will protrude beyond the spacer and prevent proper tightening of the bolts, so the usual fastener configuration is to combine a nominal 8 mm-long inner chainring bolt with a nominal 4-mm chainring nut, of the type used with single-ring cranksets. The 4 mm nuts will extend about 2.5 mm beyond the inner side of the triplizer mounting tabs, and provide a good “seat” for the spacers. (To order the appropriate nuts, bolts, and spacers in kit form, see the “Store” section of this site.)
If you'll be using an inner ring of 30 teeth or fewer, the inner ring and spacers can be bolted to the triplizer before the resulting two-ring assembly is bolted to the crank spider and outer ring. But if you're using an inner ring with 32 teeth or more, the teeth on the inner ring will extend past the outer 144 BCD ring of bolt holes, interfering with insertion of the outer chainring nuts. The solution is simple: just insert the outer ring of chainring nuts in the triplizer ring before bolting on the inner ring. Five short strips of masking tape over the bolt heads will keep them in place temporarily. Once the completed assembly has been bolted to the crank spider, the tape can be removed.
Spindle or cartridge bottom bracket selection: As with any double-to-triple conversion, adding a triplizer and third chainring calls for a longer cartridge or spindle. In most cases, adding 6 or 7 mm to the original drive-side length will give a good chainline. (It’s impossible to be precise here, because the lateral position of older cranksets will vary slightly depending on how much they’ve been “stretched” by repeated installation and removal.) For British-threaded bottom brackets, a 115 mm Shimano UN54/55 is usually a good choice. For bottom brackets with French threading, the 116 mm Grand Cru cartridge BB from Velo Orange should work.
Both of those cartridges use JIS square taper spindles, which are compatible with 144 BCD Campagnolo cranks and Japanese-manufactured Campagnolo clones from Sugino and others. At one time, Campagnolo made a standard cup-and-cone bottom bracket for their 144 BCD triple, and if you have one it should also work well with a triplized double crank. For cup-and-cone bottom brackets with thick Japanese-manufactured cups, a 3K spindle is a good starting point. Mixing and matching cups and spindles from different manufactures will sometimes work, but can get complicated at times. Before going down that road, it's worth doing some outside reading first. One useful summary on the differences between ISO and JIS cranks and spindles is available at http://sheldonbrown.com/bbtaper.html. )
Chain: Use with 5-6-7-8-speed chain only.
Please email me with any questions, comments, or corrections:
jon@redclovercomponents.com
Fastening a triplizer ring or 37-tooth chainring to the crank spider: In most cases, a Red Clover Components double chainring can be bolted to a Model 93 crank spider with the chainring bolts that were used to secure the original rings. But there is one dimensional difference to keep in mind: RCC chainrings are machined from 3 mm stock, while the originals are 3.5 mm thick.
That change has no adverse effect on strength or durability, thanks to the use of modern 7075 aluminum alloy in place of the duralumin(equivalent to modern 2024 aluminum) used in the original Stronglight rings. Shifting performance is also unaffected. But because the original chainring bolts were most likely sized for the slightly thicker ring, they may be a fraction of a millimeter too long when used with one of our Stronglight-pattern rings. If that's the case, the bolt head will tighten against the sleeve portion of the nut, rather than tightening against the counterbore in the chainring itself. This will be evident if the nut and bolt assembly turns in its hole even after being fully tightened.
There are two ways to deal with this situation. The quick-and-dirty solution is to file or grind a something like .5 mm of metal from the inner end of each tubular nut to provide sufficient clearance between nut and chainring. This is invisible once the nuts are installed. It's a good idea to grease the filed or ground ends of the nuts to prevent rust.
A simpler and neater solutionto buy a new set of chainring bolts of the proper length. This isn’t always easy to determine, since the nominal lengths of chainring nuts and bolts don’t necessarily correspond to their actual lengths. For proper tightening, the tubular portion of the chainring nuts—not including the heads—should be 7 to 7.5 mm in length. Current production Sugino #203 chainring bolts or Problem Solvers CR1471 bolts--both of which measure an even 7 mm in length--have been found to work well.
Fastening a 74 BCD inner ring to a triplizer: A 3.8 mm aluminum spacer should be placed over each chainring bolt to provide proper clearance between the triplizer and the 74 BCD inner ring. Wheels Manufacturing CS3.8 spacers are a convenient choice for this.
Conventional double chainring nuts will protrude beyond the spacer and prevent proper tightening of the bolts, so the usual fastener configuration is to combine a nominal 8 mm-long inner chainring bolt with a nominal 4-mm chainring nut, of the type used with single-ring cranksets. The 4 mm nuts will extend about 2.5 mm beyond the inner side of the triplizer mounting tabs, and provide a good “seat” for the spacers. (To order the appropriate nuts, bolts, and spacers in kit form, see the “Store” section of this site.)
Installation tip: Use strips of masking tape to temporarily secure the outer circle of chainring nuts to the triplizer ring while the inner chainring and spacers are bolted to the triplizer. Once the inner ring/triplizer assembly is complete and has been bolted to the crank spider with the outer ring, the temporary strips of tape can be removed.
Spindle or cartridge bottom bracket selection for double cranksets: If you’re down-gearing a double crankset by replacing the second ring with our 37-tooth conventional ring, your existing chainline will be unchanged. There’s no need to change your spindle or bottom-bracket cartridge unless you were dissatisfied with the original chainline.
If you’re building up a frame for the first time and don’t know what length spindle to start with, the simplest solution is to install a modern square-taper cartridge bottom bracket. A 110 or 113 mm will generally give a good chainline with a Model 93 double.
Spindle or cartridge bottom bracket selection for triplizers: As with any double-to-triple conversion, adding a triplizer and third chainring calls for a longer cartridge or spindle. In most cases, adding 6 or 7 mm to the original drive-side length will give a good chainline. (It’s impossible to be precise here, because the lateral position of older cranksets will vary slightly depending on how much they’ve been “stretched” by repeated installation and removal.) For British-threaded bottom brackets, the 127.5 mm Shimano UN55 (or equivalent from another manufacturer) generally works well. Another option that offers a little more wiggle room is to opt for a 122.5 mm cartridge, and add a 1.5 or 2 mm spacer under the drive-side cup to fine-tune the chainline, if necessary. For frames with French bottom bracket threading, the 122 mm Grand Cru cartridge BB from Velo Orange generally fits fine, sometimes with the addition of a 1- or 2 mm spacer.
If you're lucky enough to have the original Stronglight cup-and-cone bottom bracket, you can swap out the original 118 mm spindle for a 123 or 125 mm Stronglight spindle and keep the original cups (a TA #377 spindle is also said to be a good fit, though I have never seen one myself). Unfortunately, these Stronglight triple spindles aren't easy to come by, although they do occasionally turn up on Ebay.
But as often as not, setting up a cup-and-cone bottom bracket for a Stronglight triple will involve mixing and matching parts from different manufacturers. Be prepared to do some test-fitting. Purists may scoff at using non-French parts on a French bike, but experience has shown that a Japanese-made JIS spindle works fine with Stronglight cranks, which were designed for the ever-so-slightly-different ISO spindle. (A well-illustrated discussion of mixing ISO and JIS cranks and spindles is available at http://www.sheldonbrown.com/bbtaper.html.)
When a JIS spindle is used with thick-walled cups, a 3S spindle usually gives a good chainline. New Chinese-made JIS spindles are available from online retailers such as Niagara Cycle. The quality of the machining, unfortunately, is often not very good, making precise bearing adjustment difficult or impossible. A better option may be to find a quality older spindle on an online auction site or at a bike coop or retailer who has a stock of old parts.
Chain: Use with 5-6-7-8-speed chain only.
144 BCD Triplizer Installation Notes
Fastening a triplizer (middle) ring to the crank spider: Most standard double chainring bolt sets will work fine. For best results with most Campagnolo cranksets, the nut section of the fastener should measure 8 mm long, not counting the head.
Fastening a 74 BCD inner ring to a triplizer: A 3.8 mm aluminum spacer should be placed over each chainring bolt to provide proper clearance between the triplizer and the 74 BCD inner ring. Wheels Manufacturing CS3.8 spacers are a convenient choice for this.
Conventional double chainring nuts will protrude beyond the spacer and prevent proper tightening of the bolts, so the usual fastener configuration is to combine a nominal 8 mm-long inner chainring bolt with a nominal 4-mm chainring nut, of the type used with single-ring cranksets. The 4 mm nuts will extend about 2.5 mm beyond the inner side of the triplizer mounting tabs, and provide a good “seat” for the spacers. (To order the appropriate nuts, bolts, and spacers in kit form, see the “Store” section of this site.)
If you'll be using an inner ring of 30 teeth or fewer, the inner ring and spacers can be bolted to the triplizer before the resulting two-ring assembly is bolted to the crank spider and outer ring. But if you're using an inner ring with 32 teeth or more, the teeth on the inner ring will extend past the outer 144 BCD ring of bolt holes, interfering with insertion of the outer chainring nuts. The solution is simple: just insert the outer ring of chainring nuts in the triplizer ring before bolting on the inner ring. Five short strips of masking tape over the bolt heads will keep them in place temporarily. Once the completed assembly has been bolted to the crank spider, the tape can be removed.
Spindle or cartridge bottom bracket selection: As with any double-to-triple conversion, adding a triplizer and third chainring calls for a longer cartridge or spindle. In most cases, adding 6 or 7 mm to the original drive-side length will give a good chainline. (It’s impossible to be precise here, because the lateral position of older cranksets will vary slightly depending on how much they’ve been “stretched” by repeated installation and removal.) For British-threaded bottom brackets, a 115 mm Shimano UN54/55 is usually a good choice. For bottom brackets with French threading, the 116 mm Grand Cru cartridge BB from Velo Orange should work.
Both of those cartridges use JIS square taper spindles, which are compatible with 144 BCD Campagnolo cranks and Japanese-manufactured Campagnolo clones from Sugino and others. At one time, Campagnolo made a standard cup-and-cone bottom bracket for their 144 BCD triple, and if you have one it should also work well with a triplized double crank. For cup-and-cone bottom brackets with thick Japanese-manufactured cups, a 3K spindle is a good starting point. Mixing and matching cups and spindles from different manufactures will sometimes work, but can get complicated at times. Before going down that road, it's worth doing some outside reading first. One useful summary on the differences between ISO and JIS cranks and spindles is available at http://sheldonbrown.com/bbtaper.html. )
Chain: Use with 5-6-7-8-speed chain only.
Please email me with any questions, comments, or corrections:
jon@redclovercomponents.com