i have a beautiful 1975 Nishiki Custom Sport which was given to me by its original owner and am in the process of replacing some of the components. i am tempted to go with shimano 600 for everything, keep the japanese theme alive. i would like to forgo a front derailleur and only use the larger chainring, i usually only use this when riding. i feel that this would clean up the look a bit. would this create any problems if i kept a 5-speed freewheel on the back?

Since nobody else has chimed in, I'll ask which generation of 600? If you're talking old parts (like the arabesque group or 6207) I'd probably find a shorter bottom bracket spindle to move the big ring closer to the center of the freewheel (3rd gear chainline). Normally, with the big ring you can get away with the smallest three gears (more or less) in the back before things start getting too cross-chained but if you line it up with the center of the freewheel you should be okay for all five. Of course, if you're going to go with new parts you're better of talking to yourself than to me - I'm not even sure it can be done now that they're building glorified ashtabula cranks .

Hmm. Others have had success with this but I didn't. I was hoping for a 6 speed, vintage time trial set up. I got my single ring right down the middle after a lot of work with the BB, and then found that when I shifted to the smallest cog, the chain rubbed the crank arm. When I shifted to the granny cog the chainline looked way off to me. I went through so much time and $ with the crank/BB set up the bike is now going to be a singlespeed. Anyhow if you are sticking with the same crank and chainring anyway, you can definitely give it a shot and see if it shifts okay. Others have had issues with the chain jumping off the chainring with this set-up, so just be careful on your test ride. Good luck.

You can check in the cyclocross forum for more info...Some of them to run 1X8 or even 1X9 gearings.

Front chainring is redundant like front windshield.

You should have no problems, especially with a nice narrow 5-sp rear.

However, if you go over lots of bumps, you may lose your chain once in a while up front. The FD helps in that regard.

Otherwise, I just ran a TT and 3 or 4 of the bikes were running 1 ring up front.

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