[ChrisRobin]

(When I say chain guide, I'm referring to the ones with the lower pulley that add tension to the chain...mainly for DH bikes)

With clutch derailleurs, what's the point nowadays with chain guides having that lower pulley? When chain guides were designed, we didn't have derailleurs with a clutch mechanism. But now with clutches there's a lot less derailleur cage movement, so I'm wondering what's the point of adding extra tension to an already tensioned chain? Unless you're running a chain guide with lower pulley to take up any little slack there may be left in the drivetrain?

 

[Jm_]

So, depending on your chain wrap/extension (where it kind of sends shock-waves backwards from the chain before the clutch can catch) and age of your chain ring, you may be able to get away without one, even for top-shelf DH action. Then it becomes a matter of if you want to take the chance during enduro and DH racing. If the chain comes off, that essentially wipes your chances of placing where you wanted to, but again, these are so damn reliable most of the time that it's not worth it for me. The worn chainring is a chance I take, if it drops a chain, it's usually time to replace. Bash guards on the other hand seem to serve more purpose of course, but are fairly rare. So running one can be a little extra insurance...but like most insurance, not needed most of the time.

 

[ChrisRobin]

Oh I'm talking about the full chain guides: upper guide, bash guard, lower pulley.

The upper guide and bash guard are a must (for me anyway) on both bikes, but I'm mainly questioning the need for the lower pulley on DH bikes with clutch derailleurs.

 

[canadmos]

Lower guide will basically make it near impossible for the chain to come off the ring.

Compared to without one, if the chainring is worn, the chain will start to come off from the bottom up (counter clockwise) like @Jm_ said.

 

[Pneuma]

I had great success using an MRP SXg on my DH bike.

Its the best of both worlds, no roller on the lower chain, but it is still retained.

 

[jonKranked]

not this shit again

 

[Milleratio]

not this shit again

Would you be so kind and reveal me the end result that this discussion will have after the next 24 pages? I am eager to know more on this subject as I'm trying hard to learn new things on mountainbiking on this very nice professional forum.

 

[MikeD]

Belt

and

suspenders

(Although technically, those are braces...)

 

[kidwoo]

Belt

and

suspenders

View attachment 203270

(Although technically, those are braces...)

Your Daniel looks very secure and not likely to be dropped in rough terrain