Topic: Check my chain length math, please

[Scott S]

 I converted to a 520 chain, since I'm using a 2000 Katana engine in a 1980 GS550 frame. I have 15/45 sprockets. The conversion kit came with a 116 link chain, which would have been fine on a stock Katana. I'm a few links short.

 I used this chart: https://store.schnitzracing.com/motorcycle-chain-length-calculator/

 I have 28" from center of output shaft to the center of the axle, if the axle was in the middle of its adjustment range. The chart tells me 122 links, and subtract 2 links for the 15T sprocket (vs. the 17T the chart is based on).
 So....120 links.
 

 I can find 120 chains, but if I'm even one link short, I'm screwed. To get the tensile strength I need, I have to go up to 130 or 150 links and the price goes up noticeably. You think the 120 will work? Or should I just get the 130 to be on the safe side?

[jgger]

Do you have any other bikes with 520  chain to compare it to? Or maybe try the chain....IDK.

[BenelliSEI]

Scott..... i’m Not checking the math, but reducingthe Drive sprocket by two teeth won’t shorten the chain by the same amount. The chain only contacts 1/2 the sprocket, so maybe 1 link less (at most).

[Scott S]

 I'll just get the 130 link. With my luck, I'd be short one link with the 120.

[Kevin D]

Scott, best I can tell A 1980 gs550 uses 110Links 15T front 50T rear:

https://www.suzukipartshouse.com/oemparts/l/suz/50d3f5a5f8700230d8b4c718/1980-gs550-parts

Do you have some old 530 chain for a test fit?
Is the front sprocket location so much different between a Katana and a GS?
Or exactly the same?

A Katana uses 118L 15T 47T but your frame (and swing arm?) is gs550?

https://www.suzukipartshouse.com/oemparts/l/suz/50d3fbcff8700230d8b4d63d/2000-katana-gsx600f-parts

I'm screwed

Such is the nature of online shopping and picking your own parts.🙄

[Scott S]

 This isn't a stock GS550. It's a 550 frame with a 2000 Katana/GSX750F engine and suspension,  including the swing arm.

 I switched to 520 chain and sprockets for frame clearance. I'm pretty sure I'll need around 120-122 links. Better get the 130 just to make sure I'll have enough.

[seanbarney41]

don't forget that 520 and 530 chain links are the same length, only the width is different

[Bodi]

Put the chain on, with both ends on the rear sprocket. Count the missing links between the ends.