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4

I'll keep this answer short and simple. Cartridge bearings from reputable manufacturers such as NTN, NSK and FAG will outlast their loose ball bearing counterparts assuming no maintenance is done. 90% of the issue arises when people do not use cartridge bearings from reputable manufacturers. As such, the argument that cartridge bearings are "unreliable&...


3

Yes, if you're going to a 130 rear end, the chainline moves in about 2.5mm so generally you'll want to get a 5mm shorter spindle. Ideally you would measure the front chainline with the current spindle and do the math from there based on what rear chainline you want and whatever your clearance needs are. In some cases you would find you might want to go more ...


2

Here's a similar topic: Italian bottom brackets and modern cranksets - a compatibility guide? The documentation for the crankset will indicate what "chainline" it is designed for. The chainline is basically the side-to-side offset distance of the chain from the centerline of the bike/wheels. If you have a triple front crankset, it will probably ...


2

From semi-contemporary notes at the (seemingly inactive and archived) bikepro.com site: (circa 1996?) "In 1992, Shimano released their sealed bearing cartridge bottom brackets for use with their road and mountain bike parts groups, this is the "UN" series of bottom brackets. The three, and the added Dura-Ace 7410 model, have some variations in ...


-3

First, let's take a look at different types of cartridge bearings. There are angular contact bearings that require an axial preload and can handle both radial and axial loads, and deep groove radial bearings that are best at handling radial loads but can handle usually axial loads as well. Headsets use angular contact bearings, whereas hubs and bottom ...


0

What kind of bike do you have? Are you using clipless pedals? It is hard to answer without knowing more. Some things I have experienced to cause something similar are: Issues with cleat and pedal interface - Some wet lube helps fix this on the cleat Your left crank arm has play in it (never felt it first hand, but is possible) Something is going on with ...


2

It can be many kinds of stuff. The obvious to look for are the pedal bearings, the bottom bracket bearings or the interface between the crankarms and the bottom bracket (for 3-piece cranks) or the interface between the crank spindle and the left crank (2-piece crank), but many other things could do it. It is useful to test the pieces in isolation. Disconnect ...


0

Check the obvious things, which are that you have the cups in the right sides, and the expanding rubber collet parts are present and in place. It may be helpful to take the BB all the way out and then take before and after measurements with a caliper to confirm that it's actually expanding as much as it should. This problem could be caused by the frame bore ...


3

As others have pointed out, you can get an adapter bottom bracket and then use whatever crank you want. There are some bikes in the world this can make sense for, namely those with good production values that happen to use one-piece cranks, which are uncommon by numbers but do exist. In the more common situation of a department store bike that someone is ...


3

There are many levels of "upgrade". To be "better than the junk it came with" there are at least two options with many shades of quality level. 1. One piece crank upgrade There are different qualities of one piece cranks / bearings / cones / races. Murry, Huffy etc. come with the lowest quality. Back when Schwinn bicycles were made in the ...


-2

Is it a threaded bottom bracket? if so maybe apply more grease and torque it down to the manufacturer's recommended amount. if that doesn't solve your problem, maybe go to a bike repair shop and get it checked out.


2

You have a frame designed for what's called an 'Ashtabula' crank. Details can be found here https://www.sheldonbrown.com/opc.html. Apparently Ashtabula frame to English/ISO threaded bottom bracket cups are available. RJ the Bike Guy has a video on how to do the conversion:


2

Bottom bracket standards are numerous and confusing. Have a look at https://wheelsmfg.com/bb-standards. That's the best online resource I have found so far that explains them. PF30 bottom brackets are designed for a 30mm crank axle. Shimano cranks have a 24mm axle. What you need is a bottom bracket that adapts between the PF30 specification frame and the ...


2

As per the documentation provided on Merida's website, the bottom bracket standard is PF86. Source


1

One aspect of the question that @Argenti didn't cover is Boost. Boost increases the spacing at the front fork (from 100mm to 110mm) and at the rear dropouts (from 142mm to 148mm). This is a mountain bike design standard, which increases wheel strength and allows for bigger tires. It does also move the chainline outward (i.e. away from the bottom bracket). ...


1

No, DUB cranks are not compatible with any existing bottom bracket. DUB is the deign of the crank spindle and the bearings in the BB. A dub crank only fits in a dub bottom bracket. It’s possible to get DUB bottom brackets that fit in many different frame bottom bracket shell standards, that may be where the confusion originates. If you want different cranks ...


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