06-03-2013, 06:13 PM
Hi guys,
I have a fairly long-in-the-tooth Dawes Giro bike, bought around 2000 or so. Over the years I've just replaced all the bits on it, so I've kind of become attached to it. It was, and still is, a 7-speed bike.
Back in around 2005, I got new wheels for it, and decided to replace most of the drive train but keeping it 7-speed (since the shifters are so damn expensive). I measured it and found 130mm clearance at the back so ordered the wheels with the then-current 8/9-speed 105 hubs. In order to keep the 7-speed cassette working correctly, a spacer has to be added on the freehub ahead of the cassette. Installed a SRAM PC95 chain, seems to work fine.
The bike was a bit worse for wear recently so I decided to spend a couple of quid and replace the cassette, chainrings, chain and derailleur. The derailleur is a new 105 jobbie, it's the long cage model (it was a real pain finding a new 7-speed cassette, I can tell you that much!).
The spacer arrangement with the cassette is as before but I just can't get the index adjustment to work right, despite hours of fiddling. On one hand, the all the sprockets shift fine, except I can't change out of the largest sprocket. If I slacken the cable slightly, just enough to allow it to shift, the cable is then too slack to pull the chain off the smallest sprocket when shifting up. The limit screws are correctly adjusted as far as I can tell.
Googling around, it appears that I may be hitting some sort of a compatibility issue. Back in the old days (groan) this sort of thing didn't happen, 7, 8 and 9 speed derailleurs from the same manufacturer just worked.
I guess my question is .. should I now solve this by going out and buying a set of 9-speed 105 shifters and installing a 9 speed cassette on the wheel ? (I know I can't do ten speed with this hub - but 9 should work). At this point I'm wondering if it's still worth keeping the bike going. A lot of love has gone into it so it's really painful to be in a position where I have to think about putting it on the scrapheap.
I have a fairly long-in-the-tooth Dawes Giro bike, bought around 2000 or so. Over the years I've just replaced all the bits on it, so I've kind of become attached to it. It was, and still is, a 7-speed bike.
Back in around 2005, I got new wheels for it, and decided to replace most of the drive train but keeping it 7-speed (since the shifters are so damn expensive). I measured it and found 130mm clearance at the back so ordered the wheels with the then-current 8/9-speed 105 hubs. In order to keep the 7-speed cassette working correctly, a spacer has to be added on the freehub ahead of the cassette. Installed a SRAM PC95 chain, seems to work fine.
The bike was a bit worse for wear recently so I decided to spend a couple of quid and replace the cassette, chainrings, chain and derailleur. The derailleur is a new 105 jobbie, it's the long cage model (it was a real pain finding a new 7-speed cassette, I can tell you that much!).
The spacer arrangement with the cassette is as before but I just can't get the index adjustment to work right, despite hours of fiddling. On one hand, the all the sprockets shift fine, except I can't change out of the largest sprocket. If I slacken the cable slightly, just enough to allow it to shift, the cable is then too slack to pull the chain off the smallest sprocket when shifting up. The limit screws are correctly adjusted as far as I can tell.
Googling around, it appears that I may be hitting some sort of a compatibility issue. Back in the old days (groan) this sort of thing didn't happen, 7, 8 and 9 speed derailleurs from the same manufacturer just worked.
I guess my question is .. should I now solve this by going out and buying a set of 9-speed 105 shifters and installing a 9 speed cassette on the wheel ? (I know I can't do ten speed with this hub - but 9 should work). At this point I'm wondering if it's still worth keeping the bike going. A lot of love has gone into it so it's really painful to be in a position where I have to think about putting it on the scrapheap.