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11 votes

Help choosing right chainset / crankset - commuter looking for a faster top speed

There is quite alot to unpack here. Single chainring (The cog at the front), (Often called 1x, meaning "1 times" rear cogs vs 2x or 3x) has been around for a long time in the MTB world and ...
mattnz's user avatar
  • 51.3k
9 votes

How can I measure whether pedals and bottom bracket are properly aligned to each other and parallel?

The big issue with the test you're doing is that misalignment of this type, resulting in the warbly pedal feeling, can be either in the pedal spindle, the crank, or the BB spindle, and if all you're ...
Nathan Knutson's user avatar
8 votes

What is the role of the "safety plate" on a Shimano Hollowtech II crank?

It tries to prevent incorrect assembly. The axle has an indent to accommodate the pin of the safety plate. If you do not push the crank arm all the way onto the axle, the safety plate will not sit ...
g.kertesz's user avatar
  • 287
8 votes

Is an Ultegra Shimano left side FC-R8000 crank arm compatible with newer Shimano Ultegra R8100?

The left cranks of Hollowtech II cranksets are independent from the rest. You can even combine different levels like 105 and Ultegra or even cheap Sora. Be sure to get the right length. However, as ...
Vladimir F Героям слава's user avatar
7 votes
Accepted

Saddle fore-aft compensation in relation to crank length change

There is no rule of thumb for this that I've ever seen. Saddle fore-aft adjustment is used by different types of cyclist in different ways. Performance-oriented cyclists and people that fit bikes for ...
Nathan Knutson's user avatar
7 votes

Left side crank arm stuck to spindle due to stripped threads, how to remove bottom bracket

As @ChrisH points out, destructive removal methods can be effective if you don't care about the parts in question. An alternative is to use jacobs wedges to pry off the crank arm. Choose a set that ...
Ken Carlson's user avatar
6 votes
Accepted

XTR 9100 left power meter on XT 8100 crankset

MaplePanda is correct, M8100 is incompatible with M9100. From the Stages website (emphasis added): SHIMANO HOLLOWTECH II MOUNTAIN BIKE For Shimano Hollowtech II mountain bike cranks, compatibility is ...
Ted Hohl's user avatar
  • 6,437
6 votes
Accepted

Crank bolt missing, unsure about mounting

First and foremost, stop riding immediately. The crank arm could fly off entirely and you will crash if and when it does. Additionally, the bottom bracket bearings could lose preload and wear ...
oscu0's user avatar
  • 805
6 votes

What is the role of the "safety plate" on a Shimano Hollowtech II crank?

The Park Tool site on step 3a for "Crank Removal and Installation: Two-Piece Compression Slotted" says: For Shimano® Hollowtech® II, inspect for a “stop plate” inside the left arm slot. Use ...
David D's user avatar
  • 22k
6 votes
Accepted

What is the role of the "safety plate" on a Shimano Hollowtech II crank?

Based on my observations from many Hollowtech II installs, I think it serves to retain the left crankarm (and thereby the whole crankset assembly) together if the two left crankarm bolts loosen (but ...
Ted Hohl's user avatar
  • 6,437
6 votes

How can I measure whether pedals and bottom bracket are properly aligned to each other and parallel?

The situation in the center diagram can arise if the pedal spindle is bent. This can occur as a result of crashing. Or (a riding partner experienced this) damage inflicted by airline baggage handlers. ...
Andy Hutcheon's user avatar
5 votes

XTR 9100 left power meter on XT 8100 crankset

Since Ted covered the main points, I shall provide some supporting information and visual aids, as promised. The XTR FC-M9100 and -9120 cranks feature a single-bolt attachment for the left crank arm. ...
MaplePanda's user avatar
  • 15.8k
5 votes
Accepted

How to remove deep scratches from Shimano Dura-Ace crank?

One problem is that the crankset is anodized black. Strictly speaking, anodization is when we use electric current to change the thickness of the oxide layer at the surface of a metal like aluminum. ...
Weiwen Ng's user avatar
  • 32.9k
5 votes
Accepted

How can I know if I need spacers for my bottom bracket / crank?

With modern cranksets, you will know you need spacers if the manual says you do, and if spacers came with your bottom bracket. Shimano and Campagnolo cranks don't use spacers, which is why the dealer'...
Weiwen Ng's user avatar
  • 32.9k
5 votes

Upgrading my chainring

Your frame is the limiting factor on your chainring size. Check if the manufacturer has a suggested maximum chainring size, via their website or in your manual. Otherwise, print out the Wolf Tooth ...
Criggie's user avatar
  • 127k
5 votes
Accepted

crank arm with 15mm diamond holes

It may be possible to get cranks to fit, but it won't be easy or cheap. Instead it's possible to get the pedal thread restored in the cranks you have. The process is called fitting a helicoil. ...
Chris H's user avatar
  • 60.3k
4 votes

Upgrading my chainring

The largest chainring you can fit on the bike is determined by the clearance of the chainrings teeth in relation to the chainstay (that is the lower tube coming from the bottom bracket shell back to ...
Jeff's user avatar
  • 10.8k
4 votes

How to remove a crank arm with stripped threads?

I just had a crank seized so badly that none of the usual methods worked, and I thought it would be worth adding this to show what the last resort options are. This was a fairly new bike that the ...
John Rennie's user avatar
  • 1,039
4 votes

Saddle fore-aft compensation in relation to crank length change

In theory, trigonometry could help you do this. You can measure the distance from the center of the BB to the top of the saddle, which is the hypotenuse of the triangle. You know the bike's seat tube ...
Weiwen Ng's user avatar
  • 32.9k
4 votes

Crank bolt missing, unsure about mounting

You must not ride it with the crank bolt missing. The crank is held on to the spindle with a press fit. The crank bolt is what initially presses it on and also acts as security against the crank ...
Nathan Knutson's user avatar
4 votes

Crank bolt missing, unsure about mounting

The crank arm could have been put back on after the bolt was removed. That's most likely with a self-extracting crank, though removal of the whole crank bolt assembly is possible. Then it was ...
Chris H's user avatar
  • 60.3k
4 votes
Accepted

how to avoid 14mm hex tool getting stuck in the fastening bolt when installing crank?

If the hex bit is simply stuck in hex-shaped recess in the bolt after tightening, then I'd simply lightly tap it on the side back and forth with a hammer to loosen it and then pull it out, whilst ...
Megavole's user avatar
4 votes

Old chain and crankset, I can't replace the crankset yet, should I replace just the chain?

It is hard to judge from outside because we can't assess the overall age and wear of your drivetrain and the costs involved. I think, eventually, you will come to the point where cassette/chainrings ...
DoNuT's user avatar
  • 4,496
4 votes

Left side crank arm stuck to spindle due to stripped threads, how to remove bottom bracket

I've removed a couple of crank arms with stripped threads. It's a bit tedious but doable on aluminium. I just drilled repeatedly and hacksawed/filed away material until I had a slot into which I could ...
Chris H's user avatar
  • 60.3k
4 votes

Left side crank arm stuck to spindle due to stripped threads, how to remove bottom bracket

I ended up using a Unior square taper crank puller - 1662/4, to bite into the stripped threads and pull out the crank.
hyankov's user avatar
  • 233
4 votes
Accepted

Replacing the crankset on Cannondale CAADX 105 from 2017 (BB30)

There are several options available to allow a BB30 bottom bracket shell to accept most any standard of crankset. For any bike having any given bottom bracket standard, the key to knowing what bottom ...
Jeff's user avatar
  • 10.8k
3 votes
Accepted

Can't remove crankset! bad tool?

Remove the bolt from the bottom bracket. On the crank remover, unwind the center bolt until it is all the way out - this is super important. Screw the crank puller onto the crank until it stops, ...
mattnz's user avatar
  • 51.3k
3 votes

Can I replace Shimano 105 FC-5501 crankset with Ultegra FC-R8000

The two cranksets use different bottom brackets, so you will need a replacement BB. Something like the SM-BBR-60 has an MSRP of only $32. It does need different tools to install than the old Octalink ...
Weiwen Ng's user avatar
  • 32.9k
3 votes

How do i remove a stripped crank?

Unior (and I think a couple others) makes a tapered crank remover for trashed crank threads. https://uniortools.com/eng/product/1662-4-tapered-crank-puller#88225
Nik Kharlamov's user avatar
3 votes
Accepted

How do i remove a stripped crank?

Option 1 - try and back out the drive side cup while working around the crank. Since you've removed the NDS crank and cup, the whole mess should be able to come out the drive side and into the ...
Criggie's user avatar
  • 127k

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