Chain Guides and Bash Guards
Used chain guides and bash guards for mountain bikes from UK sellers, in ISCG05 and direct mount fitments. MRP, e*thirteen, OneUp, Wolf Tooth, Hope, Funn and Race Face all turn up secondhand — they keep your chain on and protect your chainring from rock strikes.
Do you still need a chain guide?
Chain guides keep the chain on the chainring over rough terrain and bash guards protect the chainring from rock strikes, with some devices doing both. Now that narrow-wide chainrings are standard, full chain retention devices are less critical than they used to be, but for DH, enduro and rocky riding a guide is cheap insurance against dropping a chain mid-run — and one of the cheaper MTB components to fit.
Top guide or full guide?
A top guide (upper slider only) stops the chain bouncing off the top of the chainring. That is all most trail riders need: it weighs 20-40g and works with narrow-wide rings to provide near-total chain retention, with the OneUp Top Guide, Wolf Tooth Gnarwolf and MRP 1x V3 among the popular options. A full guide adds a lower roller or bash guard to catch the chain if it drops off the bottom of the ring and to protect against rock strikes. Full guides are heavier at 80-150g but essential for DH racing, where chain security is non-negotiable.
Which mount does your frame have?
ISCG05 is the standard chain device mount — three threaded holes on the frame near the bottom bracket, in a triangular pattern. Most mid-range to high-end MTB frames have ISCG05 tabs. Direct mount guides from OneUp and Wolf Tooth bolt to those tabs or, on some frames, to the derailleur mount or bottom bracket, and some guides clamp around the seat tube as a universal mount — less elegant but it works on frames without ISCG05. Check your frame for tabs before buying, because a chain device is frame-specific in a way that handlebars and pedals aren't.
What does a bash guard add?
Bash guards are plates, usually polycarbonate or alloy, that sit behind the chainring to protect it from rock strikes, and they also shield the chainstay from chain slap to some extent. e*thirteen, MRP and OneUp all make integrated guide and bashguard combos. If you ride rocky terrain and burn through chainrings, a bash guard pays for itself after one saved ring, while standalone bashguards from Race Face and Funn are cheaper alternatives if you don't need chain guidance.