Bicycle Mechanics - Going from Triple back to Double

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA

View Full Version : Going from Triple back to Double

P. B. Walker
03-10-03, 04:18 PM
Hi all,

I have a 105 Triple Crankset on my road bike. I've been debating if I should go back to a double. I have a 12-27 cassette on the back, and I looked at the ratios... basically I don't gain too much for the hills... just 2 lower gears. So I was wondering, what all do I need to replace to go back to a double? I would like to go to either a Ultegra or 105 double (39x53). I assume I'll definitely need a new crankset, plus the front deralliuer. Will I also have to replace the rear derailluer?

Thanks,

PBW

SamDaBikinMan
03-10-03, 04:24 PM
Rear deraileur should be fine and you may just be able to adjust the front bottom travel limit on the front deraileur and keep the one you have. I did it on my mountain bike when I switched to a double.
BikerRyan
03-10-03, 09:51 PM
I would recommend changing the front derailler along with the crank and bottom bracket. Your current triple setup has a 118mm spindle in the bottom bracket and a shimano double takes a 109.5mm spindle. The rear derailleur having a long cage will work just fine and will leave you more options for cassette ratios. Your shifter should also be fine assuming it is of the recently produced shimano STI type as they are both double and triple compatible (exception: Dura Ace).

-Ryan

cycletourist
03-11-03, 08:07 AM
I've been using a triple (48/38/26) but I would be willing to use a double if the gears were right- maybe a 48/34.
RainmanP
03-11-03, 11:55 AM
Tecnically what others have said is true. You would need the new crank and a new bb with shorter spindle.
HOWEVER, unless you are just DYING to buy a new crank why not just pull the small chainring off and adjust your front der lower limit? Obviously this won't be the same as a true double crankset, but think about it. Everything is working now right? You don't use your big ring with the big cog or second cog, right? So what's the difference? With the triple front shifter and front der you actually wind up with more trim options. No, your chainline won't be optimal, and, yes, Pokey will consider this a cheesy suggestion, but again, everything is working fine now, right?
1oldRoadie
03-11-03, 02:36 PM
What the RainmanP says......
......OR......
Just don't shift to the little ring!!!!