Bicycle Mechanics - any problems running only one chainring at the front with a 8sp cassette

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highplainsdrift
10-01-06, 01:35 AM
Hi,
I'm in the process of building up a commuter out of an old avanti blackthunder. At the monent it's got 7speed acera hub on the rear, older ST EF20 3/7sp brake/shifters which I kind of like the look of but they are rusty and only 7sp. I've got a shimano deore lx 8sp wheel to put on. I've also got a deore lx derailleur for the rear and some V brakes and am looking for a shifter and levers at the moment. I'm going to replace the cranks and I'm thinking of ditching the front derailleur and only running it as a 8 speed.

Am I going to run into any problems with only the one chainring on the front. Especially with weird angles on the chain in the large cogs on the rear. Or would it be best to replace the current front derailleur(acera) with a higher grade one. I'm mainly considering this for simplicity and I also rarely use the smaller 2 rings on ther front and figure I'd just get stronger legs from using the big one on the front when going up hills.
cheers
http://static.flickr.com/75/192461440_3ab9e96857_m.jpg

bykerouac
10-01-06, 06:59 AM
If you use the big chainring as your solo front, you might have some rear derailleur issues when you shift to the larger cogs at the rear. I see no problem though if you use the middle chainring as your solo.
MichaelW
10-01-06, 07:07 AM
You could put your big ring in the middle position for better chainline. You may need some form of chainkeeper either a bash-guard style or a front mech (no cable needed)

Retro Grouch
10-01-06, 07:36 AM
It's a beater - right? Why not try it and see how it goes? My bet is that it'll work fine for sure in the middle of the cassette. If you have a problem it'll probably be derailling the chain from the front chainring when you're in the innermost or outermost cassette cog. If that happens you can always reinstall the front derailleur without a shift cable and dial the limit screws into the middle to serve as a chain guide.

If it was my bike I'd also probably install the big ring in the middle ring position to sweeten the chainline.