Quantcast

2019 Stumjumper chain guide compatibility issues

csermonet

Monkey
Mar 5, 2010
942
127
Anybody run into this yet? If you don't buy a upper spec they don't come with a guide, and there appears to some pretty shitty compatibility, particularly with the OneUp.
 

Jm_

sled dog's bollocks
Jan 14, 2002
18,851
9,556
AK
Uh, chain retention?
Your chain is falling off in 2018 on a stumpjumper? I launch the hell out of my bike downhill and the chain sticks like glue. Are you running a 2004 LX derailleur?
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,005
Seattle
Your chain is falling off in 2018 on a stumpjumper? I launch the hell out of my bike downhill and the chain sticks like glue. Are you running a 2004 LX derailleur?
I don't have a Stumpy, but do have modern, high end clutch derailleurs and narrow wide rings on all my bikes. Every experiment with not running a top guide has resulted in at least occasional chain droppage.
 

canadmos

Cake Tease
May 29, 2011
20,190
19,156
Canaderp
Yeah the narrow wide rings and clutch are definitely not perfect. I had my chain slip off a brand new chain ring half way up Laurel Mountain in January; when that one happened I though the chain broke. Almost started crying before I realized what happened, that would have sucked so damn much. :rofl:

The most frequent issue I have is a stick getting sucked up in the chain ring and essentially derailing the chain. That's happened a bunch of times and is pretty annoying.
 

Jm_

sled dog's bollocks
Jan 14, 2002
18,851
9,556
AK
I don’t know, it just doesn’t happen for me anymore. The two times I can remember since about 2012 a large stick jammed in between the chain and ring and the other my derailleur was about to fall off (loose). This includes many park days, DH races, etc. Its truly something that is right with the industry(tm).
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,005
Seattle
I've gone on one ride in recent memory without at least a top guide, after I broke it, and had one chain drop in a rough section. A new guide went on the next day.
 

'size

Turbo Monkey
May 30, 2007
2,000
338
AZ
I've gone on one ride in recent memory without at least a top guide, after I broke it, and had one chain drop in a rough section. A new guide went on the next day.
right? there's no reason to not run one if you've dropped a chain even once when you didn't want to. they're cheap, install in a minute and weigh almost nothing.
 

toodles

ridiculously corgi proportioned
Aug 24, 2004
5,479
4,719
Australia
OneUp guide is like $50 and 30g and will save your teeth if your chain comes off while sprinting. The real question is why you wouldn't run one.
 

Jm_

sled dog's bollocks
Jan 14, 2002
18,851
9,556
AK
right? there's no reason to not run one if you've dropped a chain even once when you didn't want to. they're cheap, install in a minute and weigh almost nothing.
If you feel you need it, go for it. This is one of the areas where I feel progress really has been made, where in the past I would occasionally drop chains or have to run a guide, these days no need for me.
 

csermonet

Monkey
Mar 5, 2010
942
127
jeeze this is a shit show. It's a 2019, i purposely left out the issue to keep it relevant with people actually building it. Its ISCG05, and depending on the layout of your guide (this bike is intended to only run an upper guide, as it doesnt have the lower mounting tab), and depending on what the orientation of the backplate is, it will not clear the pivot. As far as i can tell, you have to run either a Spesh guide, I've seen people make an MRP work, I think i can get my Wolf Tooth to work as well although haven't attempted yet. If you look where the adjustable part of the backplate is (for different chain ring sizes), the OneUp is to the left of the upper mounting tab, and on WT, MRP, and Spesh guides that adjustable section is either right above that upper tab, or above it and to the right. When the adjustable portion is on the left like the OneUp, it makes the backplate extend too far towards the rear of the bike and it will not clear the pivot. Anyways I was peeved because I already bought the OneUp guide, i also think it looks the cleanest and I really like what they are doing in general, but I guess I can shop it around to friends and sell it.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,005
Seattle
I've got an MRP ISCG05 top guide that I'm not using if you want it. Used but still plenty functional.
 

csermonet

Monkey
Mar 5, 2010
942
127
I've got an MRP ISCG05 top guide that I'm not using if you want it. Used but still plenty functional.
I really appreciate the offer thats actually really nice of you. i think i can manage though. The Wolftooth works when I bring the guide out with their nifty little chainline adjustment thing they have. We'll see if that plays nice with the actual chainline though, still waiting on my Renthal cockpit and chainring.

and possibly get enough for it to cover the $30 specialized guide.
This is true, I might end up keeping it for a future build. Specialized makes it hard to buy that guide, they should have included it in every spec, it probably has a sub $2 manufacturing cost. They won't let you buy direct because its a "service part" and no one has it online, so you have to go to a shop. They do sell a guide on their site but it's a different part number, i'm pretty sure the one they include with the top spec bikes is a custom part specifically designed with the new SJ in mind.