Harley/Indian drive chain

[exeric]

In this modern age, I assume Big Twin H-Ds and Indians use #530 drive chain. But, wasn't there a narrow width drive chain used in earlier days? If so; is there a modern equivalent available, and from whom? I have a persistant chain rub on this '41 Sport Scout that I can remedy but I wonder if Indian specified a narrow chain width (nothing mentioned in the parts book). Everything on the dang bike is line-on-line tight, and close quarters. . . Sh!t design and apparently why Indian didn't build the SS after WW2. . . Sorry, bad day fighting stuff that shouldn't be an issue.

[Peter Cooke]

Won't the thickness of the sprockets determine the narrowest chain you can use Eric?

[pisten-bully]

Peter's on it, and I never knew how chain sizes were de-coded. So what do people do nowadays when they don't know the answer?....They Google it (and now I know something that I didn't know before Eric asked, so thanks Eric!)

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[exeric]

The width of the chain applied to the width of the sprockets makes perfect sense, but I recall someone on this forum asking about narrow width, 5/8" pitch chain. That person said it was common in the earlier motorcycle days but hard to find these days. I didn't pay much attention to that post but somehow that got stuck in my noodle. I'll measure my sprockets tomorrow, but I'll pursue a better solution. I wouldn't trust industrial chain for a motorcycle. I appreciate the replies.

[aumick10]

While it is necessary to match up the chain to the sprocket, the outside width of any chain will depend on its construction. A std 530 non o ring chain will be 19mm wide at rivets. A heavy duty chain will be 24.5mm at rivets (side plates are thicker). An O ring chain will be 22mm at rivets. These dimensions may vary slightly between manufactures

[duffeycycles]

Short track race bikes from that era often used narrow sprockets & chains for part of the weight reduction

[chuckthebeatertruck]

I am not familiar with Indians - so take what I'm about to type with a grain of salt.

A small, but mighty group of people turn down the thickness of sprockets so they can run lighter (and narrower) 520 chains. Some bikes just don't allow for heavier chains and the small but mighty group favors oring/xring chains. To make them fit - they go with 520 versions.

You may want to consider the same.

[duffeycycles]

Eric, is the chain hitting the frame ? I was asked to solve this problem on a couple of Chiefs [with aftermarket frames] When I checked the alignment of the sprockets the rear was in .170" further than the trans sprocket. I had an offset rear sprocket made for them & that gave enough clearance.

[exeric]

Thanks, Steve, and Roger; good information. The detachable rear section of the frame assembly was damaged on the right side (drive chain side). I went to great pains to make sure it was straight, and properly repaired so that it would be in-line with the center-line of the main frame. The chain clears the frame by a generous margin, but rubs on the rear fender reinforcing plate that accepts the chain guard. My rear fender is a reproduction Iron Horse fender that was very well made, but I have to wonder if there were Springfield Indian factory adjustments that got missed by Iron Horse because there has never been much of a demand for '41-'42 Indian SS parts. And, as Steve said, there are applications for a narrower chain and perhaps Indian dug that hole on the late model SS. Again, I appreciate the observation you all have given, which gives me more option to pursue. This Scout is suppose to be a rider so I want it to be free of petty B.S. problems like this.

[duffeycycles]

They were converting '41-'42 SS into race bikes when new. Smitty the Rock Island dealer told me he special ordered a new '41SS & did it up as an all chrome racer. Post war, '41-'42SS little base racers got more mods. 741 front & rear forks, chief aluminum oil pump & chief mag with a timer hole mount. I've seen far more as bobbers & racers than stock. As far as the straight from factory rear fork, my brothers didn't square up to the frame quite right. The 741 rear fork top bolt to frame would go thru one direction but was funky misaligned if you tried from the other direction. Smitty had a NOS '41-'42 frame & NOS 741 rear fork. We checked it & it was also bit wonky the exact same as my brother's was ! Smitty said their WW11 production was a bit rushed & not always good parts. pic of me when I was building it & one from it's 1st show at Delmar 2003

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