Zippa Lite BSA Chain Guide

The BSA guide clamps between your drive-side bottom bracket cup and the frame, so it needs a threaded BB shell — the kind where the cups screw in. Look at the drive side: threaded cups have splines or flats for a BB tool, press-fit cups are smooth and were tapped in. A press-fit frame cannot take this guide at all; it needs ISCG05 tabs and the ISCG05 version instead.

26T to 38T, single ring — the widest range in the Zippa Lite family. Oval rings work, but count them as two teeth larger than their stated size when you check the range, so a 36T oval behaves like a 38T and sits right at the top end. The guide has to sit close to the teeth to do its job, which is why the range matters: below 26T the chain has room to escape underneath it.

Yes — the backplate sits between the drive-side BB cup and the frame, so that cup has to come out and go back in. It is a short job if you have the right BB tool, and it is the only time you need to touch the bottom bracket. Once the plate is clamped in place, the guide itself adjusts on the bike without disturbing anything else.

No — take the ISCG05 version every time. It bolts straight to the tabs without disturbing your bottom bracket, it is 5g lighter at 30g, and it is the one the Zippa Lite Bash Guard bolts alongside. The BSA version exists for frames that have no tabs at all — that is the only reason to choose it.

Not to this one. The Zippa Lite Bash Guard mounts to ISCG05 tabs, and a frame that needs the BSA guide does not have them by definition. So if rock strikes on the chainring are the worry, chain retention is all you can add here — a bash needs a frame with tabs.