SBTurtle

My current setup is a Felt F5 2010 Road Bike but I made some modifications to deal with extremely long and steep hills where I live.

I converted to the following:

Shimano 105 Medium RD
Wolftooth Roadlink
Praxis 48/32 Crankset
Sunrace 11x42 Cassette

I spend over 90% of my time in the small chainring.

Something I’ve noticed:

If I cross-chain 42R and 48F, the chain angle looks really bad.
If I cross-chain 11R and 32F (besides FD rub), the chain angle looks fine.

This makes me wonder, could I just simply set the FD limit screws to the point where I’m using only the smaller 32 chainring with the entire 11x42 range?

Would that be possible? Would it cause any problems?

Thanks!

Eric F 

As long as nothing is rubbing weirdly, it should be fine. If I was going down that road, I would start by riding without shifting the front to see if the range works. If it proves itself on the road, it’s not hard to remove the front derailleur and cable.

I’m guessing you will find a 32T chainring to be too limiting for a road bike. I have a 38T 1x setup on my gravel bike. 38x11 gets me to 27+mph comfortably. Much faster than that, and I’m probably going downhill, and I can be just as fast or faster by coasting.

SBTurtle

That’s very good advice to test it out. I was mainly concerned on what I’ve been reading about cross-chaining. I found it odd the big-big is the bad angle and the small-small looks fine, which is the opposite of what some articles say.

Eric F 

With small-small you might run into issues where the chain is rubbing against the larger adjacent cog and/or chainring, and that is something you want to avoid. If that isn’t an issue, you’re probably okay.

SoSmellyAir

What front derailleur ("FD") do you have? Does it have a trim function?

Shimano 2x10 and 2x11 drivetrains are designed such that, generally, one can reasonably use (a) the big chain ring with all or almost all of the cogs in the cassette, and (b) the small chain ring with the bigger half of the cassette plus at most 2 more cogs. Shimano dealer manuals expressly warn about chain rub and noise (presumably from the FD cage) when riding on the small chain ring and the smallest 3 or 4 cogs.

Are your 48/32 chain rings on a Praxis crank? Just spit balling here, but when you "converted to" these chain rings, you may have inadvertently moved the front chain line outward, which would be consistent with the chain lines you observed above while cross-chaining.

Shimano 2x10 and 2x11 FD can take four positions (from outermost to innermost): Top, T-trim, Low, L-trim. The Low position is for small chain ring cross-chaining, and is affected by the cable tension. However, based on what I outlined above, I don't think it is possible to eliminate chain rubbing on FD cage when cross-chaining on or near the small-small combination.

I agree with Eric F that a single 32T chain ring would be too limiting on the "extremely long and steep hills where [you] live." It may work for climbing those hills, but you got to come down at some point, right?

PeteHski

On hills that steep you are almost certainly going to be coasting down. But I suppose shallow slopes could be a potential issue if you really want to max out on speed. I know I don’t pedal much on long alpine descents and certainly not on descents requiring a 32:42 on the way up!

SBTurtle

It does have a trim feature. It’s a Shimano 105 FD. Based on what you have EricF have said, I will skip this whole drop the FD idea and adjust it better. I’ve had to replace the FD because something broke so I purchased a replacement Shimano 105 5700 (still being delivered). I’m told the broken FD might have been a 5600. So maybe the new one will operate so smoother. The praxis is a crankset https://praxiscycles.com/product/zayante-carbon-s/ — 165. I think you’re right in how it probably modified the chainline.

With my bicycle I also put on butterfly bars and I’m using Microshift Thumb Shifters made for 2x10 road. I use the FD in friction mode, the RD in index mode.

SBTurtle

That was my original thinking. Here’s a common ride that I make (roundtrip): https://ibb.co/M6G399v

Eric F 

Your link doesn’t give me any ride info.

For a road bike, with an 11-42 cassette, I wouldn’t go smaller than a 42T chainring, unless you’re climbing 10+% grades for long distances.

SBTurtle

I realized this whole removing the FD is a bad idea, thanks to your and others’ comments. I appreciate the help figuring that out.

SoSmellyAir

I suggest double checking the installation of the bottom bracket, crank, and chain rings prior adjusting the FD.

Another thing to consider is whether you have installed the 10-speed 11-42 cassette onto an 11-speed freehub (e.g., Shimano HG11) without first installing the necessary 1.85 mm spacer behind the cassette. What wheels are on this bike?

SBTurtle

When I bought the bicycle, used, everything except for the seat was standard as if newly purchased. The original owner didn’t ride it much.

• Wheels:
• Rims MAVIC CXP-22S Aluminum Rim w/ Machined UB Control Braking Surface & Wear Indicator laced 3-Cross Rear, Radial 0-Cross Front
• Spokes DT Champion Stainless 2.0mm
• Front Hub Felt Sealed Forged Aluminum w/ Quick Release, 28H
• Rear Hub Felt Forged Aluminum Sealed Shimano 10, 9, or 8 speed Compatible Cassette w/ Quick Release, 32H
• Tires Vittoria Rubino, 700c x 23c

https://99spokes.com/bikes/felt/2010/f5

I did change the tires to: Continental Grand Prix 4-Season Bicycle Tire (700x23, Wire Beaded, Black)

SoSmellyAir

This freehub is for a Shimano 10-speed cassette, so you should be fine there. (IIRC 10-speed Shimano road and MTB cassettes have the same cog spacing.)

SBTurtle

Update:

So my other FD was going bad — it was difficult to shift, and the limit screws would barely do anything. At some point the cable clamping bolt broke off during a ride. So I ordered a 105 5700 replacement on eBay (new, open box) and wow! I rewatched a Park Tool how-to install and adjust a FD video for a refresher course. It took me about a half-hour to dial it all in. It shifts super fast and smoothly. A major lesson learned. Replace old stuff when it’s not working.

Thanks everyone for all the help!

SoSmellyAir

Happy to hear that you have replaced the FD and now have fully functional front shifting. Did that also fix the observed chain line anomalies when cross-chaining?

SBTurtle

Oddly enough it did! The cross-chaining now performs exactly as expected when not in the proper gearing - rubbing the FD, etc. The chainrings switch back and forth very quickly and smoothy like a new bike when not cross chaining. So the problem was probably the bad FD? I think the bad FD has something wrong with the spring or is super gunked up — the limit screws barely moved it, and it took a lot of effort to go from low to high. I read somewhere that the 105 5700 may tend to do that if it wears out. The replacement is slick.

I found two of them open box, new, on eBay for a decent price so I ordered them both from different sellers.