I bought this and a K-edge guard so I could run a single ring setup on my Speedvagen cross bike, it works perfectly, even better than the Paul's chainkeeper it replaced. Just cheap, simple and works great.

This thing does the job on my 1 x 9 conversion. I use a bash on the other side and have yet to drop the chain.

Service and delivery comments:

Easy and fast delivery. I've ordered from jenson a couple of times without dissapointment. Easy, great prices, fast shipping.

I run a 3 ring crank and I've always wanted to tune the FD to allow a snappier downshift from the mid-ring to the granny but It would mean adjusting the FD too far inboard allowing the chain to drop straight to BB when downshifting during rough riding.

The Jumpstop cured all that. I could tune the FD as far inboard as I want without having to worry about the chain dropping to the BB anymore. The Jumpstop would "catch" the chain if it went too far and guide it back on the granny. I simply can't see any reason to buy the other products that cost up to 5 times more.

Installation was a breeze. The included instruction manual was well written and came with enough pictures as to remove any doubt as to how to correctly install the product.

The band that goes around the seat tube is flexible and doesnt mind a little bending around welds if you have them in the way. Though I'd rather grind the welds flat if they seem a bit too large and stretch the band too much. The band is narrow enough to fit under my low-band FD but I wish it could be slightly narower to allow installation in frames that have too much going on in that area(suspension linkages and bent seat-tube designs come to mind).

I'm going to have one in all my bikes that allow installation from now on.

works great, and very easy to put on. Before installing the jump stop, I would drop my chain at least two to three times a ride. Haven't dropped it once since putting it on. I highly recommend this to any body having a problem dropping their chain.

Outstanding results. Before using this I had to be very careful with my front gear shifts. Once I put this on, I literally didn't have to even worry about it. Flawless shifts with this.

After converting my bike to 1x9, I couldn't keep the chain on the front ring. I installed one of these and haven't had a problem since.

Flawless design for my application. I used to have to have a front derailleur to keep my chain on, and I still dropped it twice per ride, at the least. I've never dropped the chain since I've installed it. I love the simplicity of it's design.

The Jump Stop works incredibly well!! I wish I would have discovered this much sooner! It has worked just as advertised!

Where I ride the trails loop through rolling terrain and up and down steep ravines. A loss in momentum would mean either stopping or "throwing the chain" if I attempted to downshift (unless, of course, I adjusted the derailleur as Shimano recommends, in which case the derailleur doesn't have enough travel to shift onto the 'granny gear'). With the 'Jump Stop', I can set the adjustment all the way out and never have to worry about the chain falling off the inside... it has nowhere else to go but onto the inner chain ring! It works, and it works everytime!