Symox

After disassembling and cleaning my new* Bitex RAR12 rear hub I noticed some shiny wear spots on the pawls and the idea hit me... use some metal polish (carefully) on the pawls and other mating surfaces on the freehub using a Dremel tool and a felt tip. I removed the pawls and springs and got to work. I was very careful not to get any metal polish in/on the bearings. The pawls are now have an almost mirror finish. I applied the same treatment to the track that the C ring and seal rides in using twine soaked in the metal polish. I cleaned everything off thoroughly with a rag and rubbing alcoholI and applied a *light* coat (I've made that mistake before if you know what I mean) of Park's poly lube grease.


The hub free rides better than ever. The hub is so smooth that I even tried removing half the pawls (there are six) after a recommendation by someone on the forum and didn't notice a difference in the resistance when freeriding. In other words, the resistance is dominated by something else (likely the four cartridge bearings and/or grease drag). I put all six of the pawls back in went for a ride and had to report back.


So, if your pawls are dirty or rough, give 'em a nice polish and be amazed at the difference.


(btw, i'm quite proud of that eye catching and immature title )


*yes, I'm that much of a geek that I have to disassemble new gear to see how it works

Iride01 

I knew a guy when I was a kid that was a machinist. He took a big deep sea fishing reel he just bought and put valve lapping compound on the gears and ran it for a good long bit. It was probably the smoothest running action on a fishing reel I've ever experienced.

Don't know how many more fish were caught because of that. Nor do I know how much better your cycling will be. Pawls are only needed when you are coasting. Don't coast so much!

masi61

By polishing the pawls does this diminish the strength of engagement when in drive mode?

Just curious.

Symox

I doubt it. Plus I avoided that contact point

rjones28 

tmi

Psimet2001 

You will without a doubt have a quicker failure of the freehub. The pawls aren't tarnished - they have a coating on them to help with long term wear and you have removed it making them softer. That freehub has 6 pawls that are timed in 2 groups by removing 3 you've doubled the engagement time and considering how quickly those pawls wear anyway you have most likely effectively cut the lifetime of that freehub in half.

Just an FYI.

WhyFi

^^^ Well, sure, but other than that, sweet job!

phrantic09

Debbie DOwner

Kimmo 

Hub drag is pretty trivial; lots of folks way overestimate its effect.

I think it's either directly proportional or proportional to the square of speed, while air drag starts off much bigger and rises with the cube of speed. But even leaving that aside, the way some peeps talk about hub drag, it's like they haven't even considered the leverage the tyre has over it.

The only reason I'd be mucking around like this is trying to make the ratchet quieter.

SoSmellyAir

The OP did reinstall them and so is back to six pawls.

SoSmellyAir

I thought the whole point is to make the ratcheting louder in lieu of using a bell or calling out to people?

Symox

I didn’t remove metal. I polished them

You seem to know a lot about the coating, care to share its thickness?

Kimmo 

A quiet ratchet is a minor one of the many reasons I consider Shimano freehubs far superior to the rest.

Symox

Shimano does make excellent hubs, I have several. However, not having to tweak the cone tightness is a real benefit to me of the cartridge style bearing hubs. If it’s well made there is really little maintenance.


one benefit I see to the Shimano design is that the bearings carrying the weight are at the extremes of the hub - much like an external bottom bracket.

if I’m not mistaken, the four cartridge bearing style that Bitex uses has the weight bearing bearing close to the freehub to hub interface. (There are two bearings in the hub body and two in the freehub body. ). Someone please correct me if wrong

asgelle

Sure that isn't speed to the fifth power?

Symox

Just an FYI, but you might not want to brush your teeth as you will without a doubt remove the enamel and ruin your teeth.

Camilo

That's exactly why I don't use abrasive whitening toothpastes and don't have the hygienist polish my teeth after a cleaning. It serves no purpose other than customer satisfaction (the teeth feel so smooooth), and does take a tiny amount of enamel off. So, like the advice given about the pawls, it's a good idea not to needlessly remove the protective enamel from your teeth.

As for:
I have no idea what the finish is or how thick that he referred to, but I do know that some anodizing and other treatments on metal are very, very thin and, if removed, can leave the metal much more susceptible to wear, oxidation and other things that they were designed to protect against. I for one appreciate his comment, lest I would be tempted, on a slow, winter, pandemic day to take on such a project.

Racing Dan

This is true. Many modern hubs even have the right hand bearing behind the spokes. Its worse than an old school screw on cassette style hub, and needs a VERY strong axle for it to not bend. Im betting this issue is partially the reason for the new through axle standards. - the TA also supports the hollow hub axle besides holding the wheel in place. I would think twice before getting a weight weenie TA.

Imo a QR shimano hub with the bearings in the ends is far better.

Racing Dan

Im certain the pawls are hardened all the way through. I wouldnt worry about it. I wouldnt remove half the pawls tho.

Kimmo 

IMO, losing the means of preload adjustment is too high a price to pay for not having to do preload adjustment.

Cartridge bearing hubs with preload adjustment (and decent sealing) are rarer than rocking-horse poo.

Racing Dan

This isnt strictly true. Its the power to overcome "air drag" that rises with the cube of the speed. The drag itself rises by the square of the speed.

Kimmo 

Totally happy for my dribble shot from the hip to be corrected

waters60

Glad to see others have the same idea! My Campy Bora One wheels can wake the dead but coasting up behind people they hear it quite well!

SoSmellyAir

Two weeks ago I passed another cyclist going the other direction on a local bike path, and his freehub sounded like a miniature minigun; it was the loudest freehub that I have ever heard. Judging by the frequency of the ratcheting -- I am referring to the period between each ratchet rather than the pitch here -- it also sounded like it may have a relatively high number of pawls, hence the minigun reference. He passed me before I could ask about his wheels. Maybe he has the same wheels as you do? For reference, I have two sets of Mavic wheels (Aksium, Kysrium Elite) so that is the freehub volume that I am used to. I have heard that Shimano freehubs are quieter.

Symox

The Bitex hubs aren’t obnoxiously loud. I think it quieted a bit after I polished. I do
like using them to make recent COVID walkers in the middle of the neighborhood streets know I’m coming (or scare them when I pass)