Electronic groupset installation help and suggestions/recommendations
07-17-20, 09:01 AM
#26
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Join Date: Dec 2010
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We thought long and hard about taking that approach with our new tandem last year. In the end we didn't do it because the XTR front derailleur is limited to a 46 tooth big ring. We love our fast group rides too much for that. We went with Di2 double, 50-34 up front and then 11-34 for our road wheels and 11-42 for our gravel wheels. We find that that's plenty low gearing.
Wire length is not an issue, everything we needed was available from Shimano.
Wire length is not an issue, everything we needed was available from Shimano.
07-17-20, 09:27 AM
#27
Senior Member
I was wrong. The max chainring is 40 teeth.
https://www.bike-components.de/en/Sh...illeur-p44318/
There are ways to get around this. At least one tandem builder makes a modified derailleur hanger that tilts the derailleur so it works with a bigger chainring. You can also build a tapered shim. I explored this but decided I would rather go with the double.
https://www.bike-components.de/en/Sh...illeur-p44318/
There are ways to get around this. At least one tandem builder makes a modified derailleur hanger that tilts the derailleur so it works with a bigger chainring. You can also build a tapered shim. I explored this but decided I would rather go with the double.
07-17-20, 04:05 PM
#28
Clipless in Coeur d'Alene
Contrary to the posts above, here is proof of a XTR Di2 triple setup using 48/36/26 rings...
upgrade to triple XTR Di2 and Lightning cranks
We have had zero issues with this setup. My only install issue was that we use a special narrow q-factor crankset which also moved the chainrings inboard and so I needed to create a special FD mount to move the FD inboard as well. Otherwise, no other adapters, shims or whatever.
Our middle 36 chainring will move us along at up to 25mph before needing the big ring and that will get us up to >35mph at which point we tuck and coast. Unless you race, "needing" a gear bigger than 48x11 is somewhat subjective. That said, my single/race bike is geared bigger, but the tandem is a different beast. Our tandem wins the top speed award at > 60mph. Anyone that has ridden with us knows we don't need a bigger gear
upgrade to triple XTR Di2 and Lightning cranks
We have had zero issues with this setup. My only install issue was that we use a special narrow q-factor crankset which also moved the chainrings inboard and so I needed to create a special FD mount to move the FD inboard as well. Otherwise, no other adapters, shims or whatever.
Our middle 36 chainring will move us along at up to 25mph before needing the big ring and that will get us up to >35mph at which point we tuck and coast. Unless you race, "needing" a gear bigger than 48x11 is somewhat subjective. That said, my single/race bike is geared bigger, but the tandem is a different beast. Our tandem wins the top speed award at > 60mph. Anyone that has ridden with us knows we don't need a bigger gear
Last edited by twocicle; 07-17-20 at 04:11 PM.
07-17-20, 05:41 PM
#29
Senior Member
Contrary to the posts above, here is proof of a XTR Di2 triple setup using 48/36/26 rings...
upgrade to triple XTR Di2 and Lightning cranks
We have had zero issues with this setup. My only install issue was that we use a special narrow q-factor crankset which also moved the chainrings inboard and so I needed to create a special FD mount to move the FD inboard as well. Otherwise, no other adapters, shims or whatever.
Our middle 36 chainring will move us along at up to 25mph before needing the big ring and that will get us up to >35mph at which point we tuck and coast. Unless you race, "needing" a gear bigger than 48x11 is somewhat subjective. That said, my single/race bike is geared bigger, but the tandem is a different beast. Our tandem wins the top speed award at > 60mph. Anyone that has ridden with us knows we don't need a bigger gear
upgrade to triple XTR Di2 and Lightning cranks
We have had zero issues with this setup. My only install issue was that we use a special narrow q-factor crankset which also moved the chainrings inboard and so I needed to create a special FD mount to move the FD inboard as well. Otherwise, no other adapters, shims or whatever.
Our middle 36 chainring will move us along at up to 25mph before needing the big ring and that will get us up to >35mph at which point we tuck and coast. Unless you race, "needing" a gear bigger than 48x11 is somewhat subjective. That said, my single/race bike is geared bigger, but the tandem is a different beast. Our tandem wins the top speed award at > 60mph. Anyone that has ridden with us knows we don't need a bigger gear
