Classic & Vintage - Gran Spor/Stronglight question...

I picked up a ‘76 Raleigh Gran Sport today. The curious part about it is the Stronglight crank. The crank has a chain guard that bolts on like a chainwheel. In other words, the guard is like a third outside ring... just without teeth. Two questions: did Stronglight build this as a triple? And, if so, has anyone done the conversion? I’m not sure where you can find 122bcd rings, but I’m going to take a closer look at it tomorrow.

1. don't know
2. I'm sure you could do it up as a triple.

Harris, of course, has 122 bcd rings. But it doesn't seem like it would be practicle to do it as a triple, lowest ring only goes down to 38t. I think it's more likely they designed it especially to have the guard. Doesn't mean you couldn't lose the guard and move the rings over like a normal double, after getting the appropriate spindle, of course.

Not gonna ask what you picked the bike up for, cost wise. I just bought a crank like that on ebay a few weeks ago, wasn't cheap. Or exactly what I was looking for.

My Super Sport has this. I believe it's just what it is: a chainguard (of sorts). Dunno if a triple could work or not (spacing-wise), but with friction shifting, a lot of things are possible.

...it doesn't seem like it would be practicle to do it as a triple, lowest ring only goes down to 38t

I agree... I'd want to go to at least a 32t small ring. Although, it might be worth call to Harris, they do mention special orders.

I believe that the chainguard just unbolts with 5 small chainring bolts. I am quite sure that this crank was not offered as a triple and that 38 would be the smallest chainring that you could install. However, check the inside of the right hand crank arm to see, if by chance, there exist 5 drillings to which you could bolt a smaller (a la 28T) chainring.