mrblue

I got a new bike a few months back, BC (before COVID), and I've been having some minor rear derailleur shifting issues ever since. No matter how I adjusted the the rear derailleur the shifting just wasn't very crisp or smooth. So today, I decided to check the rear derailleur hanger alignment using the Park DAG-2.2. Apparently the hanger was out of alignment by a few millimeters. I adjusted the hanger accordingly and the rear derailleur seems to shift much better, now.

My question is: How common is it for new bikes and frames to have rear derailleur hangers out of alignment, even by a couple to a few millimeters?

Thanks.

Prowler 

Not common but not unheard of. Friday or Monday bikes. I've built many bikes out of the box and I've seen it. It has gotten so I eyeball every bike I work on to see if the hanger is bent - new, in service or old gold. VERY common on used bikes in for service.

What do you mean by "out of alignment by a few millimeters"? Where are you seeing the few mm?

What was your point of reference? Did you true the wheel/rim first, to within 0.5mm? If not you must use the same point on the rim(ex: the valve stem) for every check at the 4 points.

Kapusta

In my experience, it is not uncommon for new frames to need a tweaking on the hangar alignment. I think this is more of an issue as cog spacing has gotten tighter and cassettes wider with 11 speed.

it may also be a function of the more affordable steel frames I tend to buy (e.g., Soma, Surly, Salsa).

ARider2

Derailleur hangers that are out of alignment on new bikes does happen on occassion. I have not seen many on new bikes but it is very common on used bikes. All it takes is for a bike to fall over and land on the derailleur to push it out of alignment.

HillRider

Maybe I've been lucky but I've had three Surly frames, a Cross Check, a Pacer and currently a Midnight Special, all built up with 10-speed triple drivetrains. All three frames came with properly faced bottom brackets (Hollowtech II cranks installed with no alignment problems at all) and perfectly aligned rear derailleur hangers that always gave great shifting.

cxwrench

I put the tool on every new bike I build. At least half need some adjustment. I find it amazing that the OP would try to adjust for "a few months" and not check the hanger. The very first thing I do when someone brings in a bike that isn't shifting correctly is to put in the stand and then look at it from behind. I won't try to shift it or anything before looking at the hanger.

mrblue

• Checked alignment at the following points on the wheel using the Park DAG-2.2
  • 12 o'clock
  • 3 o'clock
  • 6 o'clock
  • 9 o'clock
• Used the valve as the reference point
• The 3 & 9 o'clock positions were perfectly aligned
• The variation was between the 12 o'clock & 6 o'clock positions
  • When the gauge was against the rim at the 12 position it was, conversely, away from the rim by ~4mm when checked at the 6 position (again, using the valve as the point of reference). Therefore the hanger was out of alignment by ~2mm's.
• After adjusting the 6 position, checked all other positions again.
  • All was good.
• Should be noted this is on a Canyon Ultimate CF SLX purchased earlier this year with no history of knocks, falls or any trauma to the RD or hanger.

Kapusta

Huh. I have two Surly frames. Karate Monkey came as a frame, Wednesday as a complete bike.

Niether had a faced bottom bracket shell, Can’t tell if the Wed had chased threads, but the KM did not. A non issue, though as that is almost never necessary these days.

Wednesday hangar was a little off, and the Fog Cutter hangar was quite a bit off.

woodcraft

The 2mm that you describe I would consider good enough, & would be surprised if a change from that to 0mm made a difference in shifting.

HillRider

As above, all three of my Surlys were purchased as bare frames from Jenson USA so they were never unpacked or handled by an LBS. I didn't mean the bottom bracket shells were "faced" meaning they were clear of paint and had obviously had facing/chasing tools used. What I meant was that the HTII bb cups threaded in perfectly and the crank spindles fit through the bearings in a perfectly straight line with no wiggling or bending needed.

mrblue

You are probably right since, I believe, in the instructions for the DAG-2.2 Park says within 3mm is acceptable. It's hard to say since I haven't actually ridden the bike since making the adjustment. That being said, in the stand it seems to be a much better. But how well something works in the stand compared to on the road can sometimes be very contrasting stories.

Kapusta

Same experience here.

But I believe we have drifted off-topic, as the question is regarding derailleur hangars.

veganbikes

Anything could happen to a bike at any point along the journey. Never a bad thing to check it with a tool (personally would go HAG over DAG but either will work). The way bikes are shipped and the abuse they can take sometimes is pretty great and while probably most bikes are pretty good some don't always handle the trip well or get handled for the trip well. That is why I tell mechanics riding the bike after it is built before it goes to another mechanic for check-over if they are going to be smart enough to do that, they should ride it themselves. If they aren't comfortable riding it after they built it (unless significant size issues) then it shouldn't go to a customer.

rydabent

When a good LBS builds up a bike out of the box, I would think they would check the hanger alignment.