|   Front deraileur doesn't seem to be compatible... | Sheedy
Jan 10, 2004 3:00 AM | | I've just gone from tapered cranks to LX splined.The Shimano's came with an extra wide(121mm)BB.I can't seem to get the front deraileur to shift the chain on to the largest front ring.Do I need to buy a new front deraileur or is there some way I can get my very usable but down-market Alivo to do the job?Thanks in advance and all the best for the New Year. |
| sounds like the spindle is too long | club
Jan 10, 2004 8:16 AM | | assuming you unscrewed the hi limit screw all the way and the cage still won't move outboard far enough for the big ring, you need a shorter spindle.
eyeball from the middle chainring back to the cogs. with a 9 sp. or 7 sp. cluster, the middle ring should line up with the middle. With and 8 sp. cluster, the middle ring should line up between the 4th and 5th cogs (although if you spend most of your time climbing in the middle and granny rings, there's an argument for moving the chainrings a little further inboard so the chain is straighter in the high tension gears, but we needn't get into that for your purposes).
I though most splined cranks want a 113 or 118mm spindle? Could be wrong though, all my bikes use tapered spindles... |
| Any chance you installed a 68mm BB in a 73mm shell??? | f'nætik (aka næstep)
Jan 10, 2004 10:14 AM | | The 121mm ES51 is the shortest spindle you should use with the LX 572 cranks, and along the lines of what club was saying, that should get your middle ring almost exactly aligned with the center of the cassette.
You can also measure with a ruler, from the center of the middle ring to the center of your downtube. You should be looking at a number in the 47 to 48mm neighborhood, or just shy of 2".
So my first inclination is that you installed a 68mm bottom bracket in to a 73mm bottom bracket shell. What frame are you working with? |
| Any chance you installed a 68mm BB in a 73mm shell??? | Sheedy
Jan 10, 2004 2:49 PM | | Thanks for the input.Before I bought my new drive train I e-mailed Trek,I'm working on a Trek 4900 frame,about what size BB to get.Like you said they told me to go with a 121mm spindle and to get a 73mm version.So I think the sizes are fine,leading me to believe that it must be the lack of range of my front deraileur.Even when I released its cable and manually pushed it as far as it would go the outer cage barely reached the front big ring.I was wondering if newer or higher grade deraileurs have more reach.Thanks for your time. |
| Shouldn't matter... | f'nætik (aka næstep)
Jan 10, 2004 3:08 PM | | ...at least in theory. I'm 95% sure even the older 7 speed stuff worked with the same chainline range of 47 to 50mm.
What you can try is reconnecting the cable, ensuring the "High" limit screw is dialed all the way out, and manually tug the exposed cable away from your frame to force a shift. If you can get it to go into gear using that method, you've got a simple setup issue to resolve.
Then again, front derailleurs are relatively cheap. Why not use this as an excuse to go grab an LX or XT unit to erase any doubts.
Did you measure the chainline spacing to the middle ring? |
| Shouldn't matter... | Sheedy
Jan 10, 2004 3:42 PM | | I'm going to measure it soon,I've just got up and it's freezing outside!BTW,what front deraileur do you recommend,I've used mine for a few years so I guess it is time for an up-grade. |
| LX or XT are fine. Both work well, both get beat to crap over time (nm) | f'nætik (aka næstep)
Jan 10, 2004 3:46 PM | | |
| LX or XT are fine. Both work well, both get beat to crap over time (nm) | Sheedy
Jan 11, 2004 7:00 PM | | Thanks alot.I'followed your advice and managed to get everything up and runnning. |
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