boneshaker78

I guess this crankset is intended to be used with a 122.5mm bottom bracket, but I can’t find what the chainline was with this combo. Is anyone familiar with the crankset and the chainline that exists with this bottom bracket? I’m guessing 50mm, but I need to be certain. Thanks 🙏🏽

KCT1986

Here we go again (?). At least this is higher quality, and some specs are available.

Per the attached, the stock BB gives a CL of 47-47.5 (nominally).

The # in red is approximately what the spindle would convert to in a 68mm cartridge style BB. So, using a 118mm BB should result in a CL of about 46mm +/- (1.55 or so less than with the stock spindle). With a used crank, the taper in the alum. may have wallowed out some and fit closer to the frame.

boneshaker78

Thanks… yes, still working on this project. The rear derailleur will not shift out far enough for a 47.5 chainline and the chain barely has enough clearance between the cassette and the frame. I’m trying to get ahead of things if the 113 bottom bracket creates problems with the A10 crankset. If I can get closer to a 46mm chainline I will make it work with the A10. This bike refuses to work with any other chainline than 45mm or very close to it. The crank selection for a 110/74 bcd triple with a 45 chainline is very limited. This is a much more challenging issue than I first thought and it’s trying my patience.

KCT1986

Don't understand why the RD is having problems, in the pics on your other posts the H limit screw is not totally loose.

Another thing to check is the placement of the wheel in the dropout, shoving the wheel to the bottom of the slot is not proper for SIS. See the attached for Shimano's placement of the axle in a horizontal dropout. Pay attention to the angles in the diagram, (not vertical to the ground line)

boneshaker78

You’re right the H screw isn’t out all the way, I’ll have to take another look. I seriously have brain damage and mix things up all the time. I was looking at the L screw. Maybe I can get away with 47.5 after all. I typically push the rear axle towards the end of the dropouts when horizontal, I just don’t like how close the chain is getting to everything. Got a 113 BB in the mail… have to wait and see where that gets me. Thanks for your help. Think I’ll end up getting the Deore DX used and hope I can use the 113 BB with it, add a spacer or two and get it as close as I can.

KCT1986

With proper setting of the H limit it should shift to the outermost sprocket. Shimano RD from that era usually have a lot of usable range. As long as the hanger is aligned and not excessively thick, you shouldn't have a problem. Most freehub/cassette combos place the small sprocket quite close to the dropout and the RD works properly.

Adjust the B screw to clear the cassette's largest sprocket, then confirm that the other end remains adequate 'close'.

boneshaker78

Your words give me hope that I can make the components I have work. Very much appreciate the help, thank you for sharing your knowledge.

ShannonM

I'm running mine on a 118 Shimano cartridge BB. I had the opposite problem... the road double front derailleur I had to use for a 45/42/30 half-step triple couldn't swing out far enough to get the big ring with the 122.5 that Shimano liked to spec for its triples.

It works just fine, and gives a bit narrower Q to boot.

I'd be worried that a 113 might hit the chainstay, but that's frame-dependent.

--Shannon

boneshaker78

It won’t hit my frame, I can tell you that. I could mount the crank arms flush with the ends of the bottom bracket shell and still have plenty of room.

frdfandc

If you get the crank flush with the bottom bracket, more than likely you over torqued the crank bolt and wallowed out the taper in the crank. Hollow spindle cranks usually sit flush or close to flush with the bottom bracket when the correct spacers are used. Get the correct length bottom bracket and torque the crank bolts to the manufactures recommended specs. That will give you the best outcome. With integrated bottom brackets, spindle length is the key to get the correct chain line. Get that correct and your chain line will be in spec for the bike. With press fit and external cup BB's, it's really hard to mess up the chain line.

boneshaker78

I agree. I’m just mentioning that I have plenty of clearance for the crank and arms. It’s typically not appropriate to have them that close, although sometimes certain setups that are properly setup will look close to being flush.

'02 nrs

is the hanger straight within specs?

A misaligned derailleur hanger can cause skipping, missed shifts, and wreak general havoc on your bicycle's drivetrain. The DAG-2.2 is an indispensable shop tool that can be used to both measure and straighten misaligned derailleur hangers, diagnosing and solving many shifting problems. Compatible with virtually all derailleur-equipped bicycles, and adjusts to work with wheels from 16" to 29"+.

boneshaker78

It appears very straight, but no way to tell without this tool. It is on my wish list of bike tools, but for the time being I think I’m going to be okay. Awaiting the arrival of a bottom bracket tomorrow so I can take my project further. Thanks for the help