I recently installed a Shimano Deore RD-M5100-11 rear derailleur, and it was giving me nothing but problems. I adjusted it myself (I admittedly am not very good at adjusting RDs) and couldn't get it dialed in so I took it to my LBS where it sat for 4 days and I paid $25.00 to have them adjust it. Bottomline is they couldn't get it dialed in either. I had 2 options, great high gear shifting and shitty low gear shifting or great low gear shifting and shitty high gear shifting. I tried it with the clutch on and with the clutch off, my derailleur hanger was not bent, it was fine. I decided to give a 12-speed SLX RD a try, thinking maybe since it's a higher tier then M5100 Deore, that maybe it would fix everything….and it did. I just got done installing and adjusting the 12-speed SLX RD, indexed it for 11-speed and it shifts great. So, is Deore really just that shitty compared to SLX? Also for anyone who also sucks at adjusting RDs I can't recommend enough this video on YT https://youtu.be/BxsV_uXTeJg?si=MCJ9jSr9xBDG0DS1 adjusting a RD the way he does it in the video is the only way I've ever been able to do it correctly.
On another note I bought both derailleurs on eBay. The Deore derailluer was from a Chinese seller who had a warehouse in the US and the SLX derailleur was from a bike shop in California. So, did i possibly get a counterfeit Deore RD? It arrived in a padded envelope wrapped in bubble wrap with no original packaging or documentation. I know counterfeit Shimano derailleurs aren't really a thing, I've never heard of it, but maybe?
by Legitimate_Pea_143
19 Comments
My 9sp Deore group (shifters, crank, FD, RD) outlasted my commuter bike when the frame broke at like 70 000 to 80 000 km. Only ever had two issues and that was when the B pivot got sticky and I had to overhaul it twice. I commuted on that bike including rain rides. I did weekend mild MTB rides – probably what some would call gravel ride but gravel bikes did not exist back then. I did stuff like mixed terrain 100km rides with 2000m of climbing.
That was the highest spec hybrid I could find other than a few with geared hubs, though I also would not have bought anything above Deore. I initially did not know I was gonna be eventually riding that bike off-road when I bought it.
RD arriving in an envelope could have been bend or damage in the mail.
Something’s wrong here. You can’t just slap a 12 speed derailleur on 11 speed parts and expect it to work because the cable pull ratios are different.
And no Deore isn’t that bad.
It sounds to me like you’ve got some mishmash of parts that’s not working out so great.
Maybe you got a counterfeit derailleur
I have deore 11 speed on my MTB and it shits incredibly well. I’m inclined to thing something is wrong elsewhere. Derailleur hanger is a likely culprit but if it’s bent just changing to an SLX derailleur wouldn’t fit that
Deore is a great group set, if a little heavy and sometimes klunky in shifting
However 11 and 12 speed Shimano are not compatible. So something else is wrong/weird with you’re drivetrain.
What do you mean that you “indexed it for 11 speed”? You don’t “index” a derailleur, you lock out the high and low and set the shifing from the small cogÂ
Deore has been bomber for me, no issues
I just put together a special order bike with 11 speed Deore for a customer yesterday. Works just fine, as have all Deore derailleurs I’ve used from every generation. As others have said, 11 and 12 speed Shimano are not compatible. You likely have a counterfeit Deore or another problem.
It could possibly have been a refurbished derailleur, instead of a counterfeit. It wouldn’t surprise me if some shady Chinese seller tried to fix a defective part and wasn’t able to get it right.
My 5100 derailleur worked flawlessly from day one, until it got pulled into the back wheel and was destroyed. Its replacement has been perfect too
I put a 5120 RD (10s) & 4100 cassette on a 90’s MTB rebuild with a (hopefully) Shimano shifter from Ali Express. Shifting is spot on. I keep waiting for it to mess up.
I use a Deore Derailleur on my longer travel bike and it works fine for me. Easy to get dialed in quickly and takes a decent beating (unless I catch it on a stump or rock which happens way too often, and is also why I buy em cause they’re cheap).
Could have been damaged/used in some way which is why they couldn’t get it right.
Maybe you had your pulley wheels backwards, a bent cage or put the cable through the derailleur the other way around (common mistake, where the cable is pressed down with a bolt it should go straight down, otherwise it shifts like shit).
Deore, SLX and XT have all felt quite similar aside from the shifters in my experience.
are those road wheels?
I think you got a garbage/knockoff derailleur. The 5120-SGS I have is awesome. As is the SLX m7000-11-gs. They’re essentially identical and both work great.
The only issue I’ve had with both of them is it would get stuck in the lowest gear and sometimes don’t want to shift to the highest gear. After all sorts of shenanigans, I decided to just drip some lube on the derailleur pivot points for the parallelogram and it fixed that issue. So I’m back to loving them again.
I’ve had good success running that RD. I was actually very surprised by how reliable it was considering it only cost about $35 at the time. It is heavy for sure but it should pair fine with any 11 shifter. It’s specc’d quite a bit on lower end 1x systems now.
There’s something else going on, unfortunately. You could have a legit grey market RD or not…it’s so hard to say with Chinese sellers. Some are legit, some are not. The general rule is to just avoid going down that path (although I’ve done it myself).
That video maker is great. He has some really good ones for setting up GRX too.
That’s a really good question. IMO yes slx and xt are better. The problem is that they only go up to 46T for max cog size. I’m running 11-52t. So I buy deore M5100. The ironic thing is that although xt shifts better, you have to get the barrel just right or it won’t shift into all 11 cogs. So I just do deore to solve that problem but yes I agree that xt shifts better, at least for the cogs it goes into. For the rd only; did not notice a difference in the actual shifters between slx xt and deore.
Deore is solid so I’m leaning towards either a counterfeit or damaged goods. Might have been a legit Shimano derailleur but one that didn’t pass quality assurance and was sold gray market instead of being destroyed. It’s hard to say.
I have 10 speed Deore on my cargo bike and it’s the smoothest drivetrain I’ve experienced.
You really had the nerve to take a part you bought on line from a Chinese company to your LBS??? They should have charged you $75 to try to fix it. Probably why it sat 4 days.
I converted an old bike to 1x using the 11 speed deore groupset. It’s a less than ideal install with alignment issues, both chain line and derailleur.
Other than the expected adjustment for cable stretch I’ve had no problems and can’t fault it.