Hi everyone I really need so help here. I have a restored early 80's looptail pk ripper. I have a redline techmatic BB but need a lock ring or some form of substitute if possible as it came without. Also I have to use a few spacers (which look ugly and not right) to get my flight crank arms to miss the chain stays. Is this normal. Any advice would be so welcome.

Tony

if by "lockring" you mean the outside nut for the non-drive side like a 1 piece crank uses...a tecmatic doesn't use one. the arm just goes against the collar/cone with the necessary amount of spacers in between.

and yes, you often need spacers to get the arms to clear. PK loops are prime offenders for needing a lot of spacing. 401s sometimes won't really work on those frames, depending on how good the tolerances were when they bent the frame tubing.

Hi and thanks for the reply but i dont think that would work there is a threaded section which looks like a nut goes on and the arm would not be flush against the bearing anyway. washers would be quite large to buffer against the arm and go over the thread. I can supply a photo. Cheers

tones-

I had the same issue with a PK back in 85. I had to use a LOT of spacers and was concerned about enough of the crank being on the spline.

As for the bearing nut, I ended up putting on a regular bb outside nut mainly to cover the space and secure the given bearing nut/holder that goes into the bearing. Like Mr. CB said, normally the spacers ride on the given retainer and the tension keeps it from coming loose. Not only did the regular bb nut fill the remaining threads, it also reduced need spacers, but I still needed more than I wanted. It did look goofy, but it worked. Wouldn't be too pleasing on a show bike for sure.

I rode the PK with the flights for about a week and then my mind got to me and went back to one peice as I didn't want to take a chance on messing up the cranks.

It won't be era correct, but for aethetics, you could buy a newer style spindle and a Profile bb and Hop-up kit. Especially if you plan to ride it much.

Just a thought.

Paul

if there are enough threads you could add a nut.

in most cases, there are just a couple threads (if any) exposed that you'd cover with the spacers. it varies depending on the frame spec.

So true. I may have just used the bigger nut for a spacer as they are thick. I even tried putting a shim on the drive side of the bearing race before putting it on the dimpled spindle. It pushed the whole spindle out to the right and less shims were needed on the drive side, but it reduced the spline area on the left crank. It was fugly and I was just not comfortable with it at all for strength.