rog2e

I've been trying to troubleshoot myself so before I throw in the towel and take it to a shop I thought maybe I could see if there is anything else to look at. I My bike is new and it was just received on May 30th. It's a Guerilla Gravity Smash with a 1 x 12 setup. I don't know if I just never realized it before, but while cleaning I noticed that it does not shift to the (2) highest gear (smallest cogs). I don't use these gears that much on the trail ...I first played around with the barrel adjuster by turning it all the way clockwise to give it slack, but that didn't work. If anything it would no longer go to first gear (largest cog) so I adjusted it back until it could go to first gear again.

I then thought it was maybe the high limit screw or the cable was too tight but before I started playing with those settings I did observe the following:

If I lightly push the derailleur out with my hand, it will line up with the smallest cog so I assume that tells me that the limit screw is ok? I can then crank the pedal and it moves to the smallest cog no problem. When I shift down 1 click it will go to the next smallest cog, but then if I try to shift back up it will not go back to the 12th cog. It's almost as if the derailleur does not want to come out to the farthest point unless I gently give it an extra push. I tried putting some WD40 on the spring and wherever there was movement but no luck.

When none of that worked tried the high limit screw and even tried to redo the tension on the cable (even made it extra loose just to see if it would go to the smallest gear) but that thing will not go to the smallest gear unless I give it the extra nudge with my hand.

As I mentioned this is a new bike and I have taken it on the trail maube between 10-15 times. I probably also never noticed it not switching to the 2 highest gears (it is 12 speed) because I don't need those that much for trail riding.

Any tips before I throw in the towel and take it to the shop?

dedhed

Sounds like a cable friction issue. The RD is moved to the small cogs by the RD spring tension, so the only thing holding it back is the cable.

Kapusta

Are you saying that even when the cable is completely Slack in the highest gear that the derailer will not shift to the smallest cog unless you push it?

BCRider

That's a good call. To separate the possible causes I'd unclamp the cable and see if the derailleur will push itself out to the smallest cog on it's own. If not then I'd say it's warranty time.

And just to eliminate all the possibilities check that the hanger is as straight as your eye can detect. From there if your shifter cable is not a full coverage cable then check that each section of housing is easy moving. With the cable disconnected you can even draw out the section at the shifter a little and check that section too. If there's anything but easy movement in all sections then either fix it yourself or take it in for them to fix.

Iride01 

If you bought the bike locally, then take it back to them. It's great that you want to DIY your bike, but for new bikes you need to deal with the seller just in case there is a warranty issue that arises or just for the sake of the shop finding out that their person building bikes screwed up.

If you bought it online and it was shipped to you, then call the people you bought it from. Make certain what you can and can't do to the bike with them before messing up any chance you have to return it.

Though if you detatch the cable from the pinch bolt of the rear DR and it still won't go to the smallest cog, then you probably have a bent hangar. Unless perhaps someone got the high limit adjustment way out of whack.

If your DR and other parts are Shimano, you can find the installation and adjustment info at their tech doc site. If there is a DM for any of the stuff on your bike that is what you want to read. The exact model and version number of your rear DR will be on the backside of the parallelogram if it's Shimano. Use that to look it up. The fancy name and numbers on the front are much like fake tire size emblazoned on the side of tires. Useless.

https://si.shimano.com/#/

rog2e

Yes this the case at the moment. By fully slack I mean that the barrel adjuster on the lever is screwed all the way in. There is no barrel adjuster on the RD.

rog2e

Thanks for the responses all.. Yes that was going to be my next step to just remove the cable and see if the RD returns all the way out and is in line with the smallest cog. Maybe I'll post some videos too if I have time.

The cable is full housing.

If it turns out to be some type of cable friction, I assume the fix would be just to lube up the cable. Will post back tomorrow with my findings.

Iride01 

I wouldn't think so for a new bike. If it does turn out to be a cable issue then probably a installation or routing error. Perhaps the housing weren't checked after cutting them and the ends need to be rounded back up.

Might be the cable wasn't installed correctly in the shifter and something got buggered up, but that I'd tend to think will be issues for going the other way. Though a frayed cable strand in the shifter will cause what you are experiencing. But frayed cable would not be expected for a new bike.

You won't be able to post pics yet but you can upload them to the gallery here on BF or some other site like imgur.com and just let us know they are there. For imgur or other site you'll need to obfuscate the URL when you write it in your post.