MikeSSS
1 kW
Bike is a Jamis Hudson, it has a single chainring on the front, I'd like to install one of my triples on it. This bike needs a new bottom bracket, should I use the present size or use a wider BB?
Thanks.
Thanks.
Change from single to triple on front, BB width?
- Thread starter MikeSSS
- Start date
markz
100 TW
Old E-Type front derailleurs will work as they clamp on the bottom bracket. I've been pondering the same with a 1x7 fatty.
Be a little bit of trial and error because a wider bb, would bring the whole triple crank further out.
You have the stock bb for the 1x already, so throw on the 3x crank and see how it fits, any issues, do the 3x gear teeth line up for a decent chain line. If everything is good, then give it a try, if not spend more money on a little bit wider bb.
Be a little bit of trial and error because a wider bb, would bring the whole triple crank further out.
You have the stock bb for the 1x already, so throw on the 3x crank and see how it fits, any issues, do the 3x gear teeth line up for a decent chain line. If everything is good, then give it a try, if not spend more money on a little bit wider bb.
are your hips or knees wider than comfortably pedal on it now?
is spreading your hips/knees out wider while pedalling uncomfortable for you, for the length of time youd be pedalling for a ride?
if the former is true, then wider might be a good idea.
if the latter is true, then wider might be a bad idea. (and long term may damage your ankle/knee/leg/hip depending on the severity)
secondarily, if the triple you want to put on there will hit teh chainstay if the bb is the same, then you need a longer bb on that side to fix the problem. doing that will push your right leg out farther than your left, so that may be uncomfortable, too. (and long term may damage your ankle/knee/leg/hip) you can even that out by using a bb shaft that is longer on both ends so the pedals are at the same point on each side.
if the triple will fit without hitting, you don't need to change the bb length.
remember also that you would only be changing the width of the shaft and possibly cranks/pedals, you don't want to get a bb that itself is longer between it's bearings/mounts, or it won't fit into the bb shell on the bike. meaning, if it's a 68mm bb shell, you still have to get a 68mm bb, even if you get one with a longer bb shaft.
is spreading your hips/knees out wider while pedalling uncomfortable for you, for the length of time youd be pedalling for a ride?
if the former is true, then wider might be a good idea.
if the latter is true, then wider might be a bad idea. (and long term may damage your ankle/knee/leg/hip depending on the severity)
secondarily, if the triple you want to put on there will hit teh chainstay if the bb is the same, then you need a longer bb on that side to fix the problem. doing that will push your right leg out farther than your left, so that may be uncomfortable, too. (and long term may damage your ankle/knee/leg/hip) you can even that out by using a bb shaft that is longer on both ends so the pedals are at the same point on each side.
if the triple will fit without hitting, you don't need to change the bb length.
remember also that you would only be changing the width of the shaft and possibly cranks/pedals, you don't want to get a bb that itself is longer between it's bearings/mounts, or it won't fit into the bb shell on the bike. meaning, if it's a 68mm bb shell, you still have to get a 68mm bb, even if you get one with a longer bb shaft.
markz
100 TW
I threw on a 3x crank on my 1x7 crank on the costco fatty. The gears on the cranks dont touch the chain stays and have plenty of room on the stock bb. The chain line: eyeballing from a few feet back of the rear wheel, to the crank, seems to work. Maybe an issue would be too much flex with the e-type front derailleur mounted to the bb. I am waiting on a few parts to get it going, the parts on on the slow boat from Mao-land.
dogman dan
1 PW
Try it on the old bb for fit. It should work, while going wider would require a special front derailleur. But I'd be open to the idea of riding it with no derailleur, since shifting the front ring happens so seldom for me. Stop and hand shift the chain to the little ring when you really need it.
A wider BB might though, allow use of a road crank, giving you the easier ability to put a huge ring up front.
A wider BB might though, allow use of a road crank, giving you the easier ability to put a huge ring up front.
