I'm tired of getting grease & grime on my right pant leg even with trouser straps, and I don't much want to wear full gaiters. My bike has a standard 3x9 Shimano mountain drivetrain. Can anyone recommend a chaincase that would protect my pants from brushing against the side of the chainrings and chain? I understand that it's much easier to design a chaincase for a drivetrain without derailleurs (especially for coverage above the chain), but doesn't anyone make one that works on a bike with front (and rear) derailleurs?

Rivendell used to offer one, but I can't find it on their website. I know one did exist at some point in time, but that's all.

SKS Chainboard

https://www.sks-germany.com/?l=en&a=p...2a412c21ad9ed1

From what I gather, people tend to use the 199mm one and that it may require modification (with a dremel).

Good luck

Velo orange , maybe.. cant cover the whole thing m but the front portion ,at least..

maybe you can fake it with a kids BMX one . comes in box with bike.
they get tossed at LBS since they get stripped off 1st thing anyhow.

Euro city bikes come with a plastic chainguard or chaincase designed for derailleur systems. I have never seen these on sale, only as OEM items, bought by the 100.

Most city riders in the UK use "trouser clips" and have no problems with oily "pants".
Check your lube and switch to a cleaner one.
Check your pants, switch to a less flappy one.
Use an effective trouser clip.

Available in 2 sizes...don't know how well they work

https://www.bikeman.com/CR3200.html

little reflective band snaps around the pant leg and you'll never even get close to the chain again, unless you put your right foot down and roll your bike forward into your leg all the time.
Do you constantly get the "fredly chainring tattoo" on your right calf?

After much research into the different alternatives, I decided that the best and most cost-effective solution was to buy a new bike. The n+1 rule is a good answer to most cycling problems.

I have this on my commuter:
"BANJO STYLE CYCLE FULL CHAINGUARD FOR GEARED BIKES WITH TRIPLE/DOUBLE CHAINRINGS" from eBay seller bankrupt_bike_parts.
https://www.ebay.co.uk/itm/BANJO-STYL...-/400347677076

My son's last bike had one of these it worked great:

https://store.somafab.com/ogkchainguards.html

Chainthong.com. It doesn't cover the whole chain ring but it seems like a cool idea for eliminating chainring tattoos.

Plastic chainring protectors don't last long for me. Around 5000km - 4 months riding at best less if its summer.

I use this shimano tourney crankset, And I've had no problems with my trousers, lots of use in my diary commute. https://articulo.mercadolibre.com.mx/...no-tourney-_JM

It's on ebay too https://www.ebay.com/itm/Shimano-Tour...item48417e952f

Sram dual drive 3x9 hub eliminates the FD *, then a chain case over the front works better..
*[3 speed IGH + a cassette driver.. ]

I've just used the "long socks -- tuck in the pants" method of chainring pants protection.

Thanks, everybody. One thing that's rather disappointing is that the illustration for my Deore (M591?) crankset on Amazon showed an integrated chain guard like what Gnosis and Rapidoyfurioso describe, but I got the crankset without the chain guard -- and haven't had luck finding online sellers of just that part. Maybe it's time to call the LBS and see if they can get me parts w/ numbers from the techdocs EV diagrams? Or try that Soma/OGK set...

-Peter

+1 on the SKS Chainboard. I have three bikes fitted with SKS Chainboards, two IGH and one 3X9. The Chainboard doesn't need any special modifications for front derailleur clearance as there is a square removable tab on the top forward portion of the guard that easily removes (breaks free) without any specialized tools creating a notch for your derailleur to move back and forth within.

Now, my IGH Dahon Cadenza w/eccentric bottom bracket, that did require some ugly and somewhat hamfisted modifications. :shrug:

Thanks for the advice. The tab wasn't in the right spot for me, but it was a pretty easy Dremel job. I've had it on for a couple weeks now, no problems. I'm posting a pic of the final results for anyone who stumbles on this thread later. FWIW, the crank is a Shimano FC-M591. The chainboard bracket replaced one of the BB's spacers. BB shell here is 68mm.