Originally Posted by
FBinNY
Both brakes have identical threads. 6x1 has been standard for decades. Odds are there's a burr or some minor out of tolerance problem with the front bolt, and the long one is loose enough to accommodate it up to a point and the short ones aren't.
Take an eyeball down the nut, and see how far the thread goes. Or go to any hardware store and buy a 6mm bolt and nut. Use the nut to "dress" the front brake bolt's threads, and the bolt to dress the threads on the nuts. Use plenty of oil and work by degrees, 3 steps forward, one step back. Feel for heat, and if it warms more than hot tap water stop and rest it. Remember, do not force anything, gust go a bit farther each time.
BTW- you can use the same method with the parts you have, but using a commercial bolt and nut eliminates the risk of the bad part damaging the good one.
Success! I thank you sir, you are a cyclist and a gentleman. It was precisely as you said, some issue on the bolt that the longer nut was more 'tolerant' of. Threading on a bolt was enough to dress it, it did take a liiiittle force but not much. Woohoo, I'm so happy. It looks like you CAN technically replace that center bolt but it does not look like fun- it's pinned in there so it won't ever move. Now I move on to internally routing my brake and shift cables,lol, I'll be back! I don't want to make it weird on the forum, but I LOVE YOU GUYS
