I have been looking for a 700c clincher rimmed rear wheel to use on one of my 10-speed bikes (5-speed rear cogs) to replace the tubulars. I picked up a nice Shimano 105wheelset with 3-crossed 32s fronts and 36s rears and ($35 for both), with 700c Mavic rims. My rear dropout spacing is 120mm. The rear axle fits, but the problem is that my RD (Simplex SX-410) won't cover the six gears. I'm sure that if I could remove one of the cogs (i.e. make it a 5-speed) the RD would work fine. My question is, can I remove a cog and make it a 5-speed? I know that the Uniglide uses the smallest cog as a "lockring" and you remove it using two chain whips. Can I just remove the 2nd smallest gog and leave it at that, or do I need special spacers?