Arthur Peabody

The wheels of my 3.5 year old (about 10K miles) SRAM X3 rear derailleur are floppy: their bearings have worn out. The rest seems to be as good as new. I can replace it for $27 - why would I replace only the wheels instead? I remember ads for Bullseye wheels about 50 years ago, how much effort they saved over a 100 miles (equivalent to 100 feet of altitude was it?) - didn't make the sale to me. What's the nomenclature? Is one the pulley wheel, the other the jockey wheel? I think Bullseye called theirs pulley wheels.

Andrew R Stewart 

Various reasons to only replace your rear der's pulleys. You like the rest of the der and the pulleys are worn out. You want the specific color the new ones are offered in. You have drunken the kool aid that brand X pulleys will let you climb an extra 20' over your next ride. I'm sure others have their reasons.

The X3 der is pretty entry level and one would think that their rate of wear might be quicker then the expensive stuff. So do check the der's overall condition. Are it's pivots still tight and not sloppy? Has rust frozen the limit screws yet?

BTW worn out chains will wear out pulleys faster then if the chain is kept in good condition. Andy

Bill Kapaun

Guide & Tension pulleys.

cobba

SRAM mightn't want you to replace the wheels.....

https://www.bikeforums.net/bicycle-m...ey-wheels.html

Arthur Peabody

Colors? Really?

Do you remember Bullseye pulleys? I think I saw them on a card in a bike shop as well as small display ads somewhere.

They're the cheapest SRAM, nearly the cheapest overall, but they always work for me. I've bought only cheap SRAM, Shimano, and a few other brands. Other than lasting longer and being less frictive (probably too little for me to notice) what do you get in an expensive derailleur? How much longer could I expect it to last? I have a 34-tooth cog on the cassette and a 24-tooth chainring in the front, which limits my choices.

Pivot's okay, limit screws still move.

Thanks.

Thanks for the link. I hadn't looked. Had I found rivets I wouldn't even think about it. I've replaced rivets with screws on my pickup, but a new part would have cost a lot. Notice he calls them jockey wheels. Thought I had heard that term somewhere.

Bill Kapaun

You'll hear it frequently by people that don't know the correct term.

Geepig

hear from? spoken by? - in spending half my working life as an editor of different brands of English I have discovered there is nothing so unreliable as 'correct' or 'proper'

I use 'jockey wheels' when speaking about them as sets or just in plural generally. It is like with a manual transmission in a car when you know that one 'gear' may be nothing more than two shafts dog-clutched together.

Amt0571

You get more cogs, less weight, and better materials which are more durable. How durable? I don't know... I never managed to wear a derailleur. My old mountain bike went through 5 or 6 jockey wheels and the RD was still working like new. That doesn't mean that a cheap RD can't work well though.

In any case, If I have to go cheap, I think Shimano is better engineered. Cheap SRAM derailleurs are generally crap IMHO with this and the SRAM SX being prime examples.

In any case, you already have it, and if it was mine i'd try to cut the rivet and replace it with a bolt before throwing it away. I don't like throwing things than can be repaired.

Marcus_Ti

Hehe,

Shimano uses Tension/Guide terminology...Some aftermarket 'upgrade' pulley makers use the Idler/Jockey nomenclature. I think SRAM just calls them 'pulleys'. Ceramic Speed uses 'upper' and 'lower'.

Bill Kapaun

Don't care-
Ignore list

HillRider

So does Campy.

BTW, the OP wore out his SRAM in 10K miles and asked; "..... what do you get in an expensive derailleur? How much longer could I expect it to last?" I have Shimano mid-level (105 and Ultegra) rear derailleurs with well over 40K miles and still working perfectly and a Campy Chorus with 33K that I retired for other reasons and am selling in "nearly new" condition. So, yes, more expensive rear derailleurs, within reason, do last a lot longer.

Russ Roth

A better der will just work better overall and to a point can make a noticeable difference. Sealed bearing pulleys are faster, then bushing and iin a side to side comparison you can just notice the difference. After a few thousand miles of basic maintenance you will really notice the difference. As to life span, a good der should easily live 2-3x longer.

Arthur Peabody

I've never worn anything out but the wheels.
You answer my question: thanks. Many bicycle parts are a little lighter, which makes no difference to me; some are a tiny bit less frictive, which also doesn't matter to me, though both matter to performance cyclists.

I've been keeping records for the last 16 years, have gone through a few rear derailleurs, usually because they break. Once a plastic shopping flew into the mechanism, bending it into the spokes of the rear wheel; once someone t-boned me; once somebody bent it while it was parked... A good derailleur worth replacing the wheels/pulleys on may have lasted longer over that 100K miles. Then again it's that much more costly to replace in mishap.

Amt0571

Well, decent derailleurs don't start at such a hefty price. An M6100 derailleur is 45€ and it may be basic but its definitely built to last.

Meanwhile, on the road side of things, a 105 derailleur is even cheaper, around 38€, and well maintained it's more likely to die from external damage than from wear.

Russ Roth

I've wrecked a der or two by putting a stick through them, always hate that one but the pleasure of a der that works smoothly and consistently with no worries in between is preferable to me. My son's 20" flat bar cross bike came with a cheap rear der that had the pulleys freeze in only a couple of months of riding through mud and wet and being riveted I had to toss the der. My daughter's bike had decent pulleys that were bushings but had a tendency to rust at the pivots, having to lube the pivots every time I lubed the chain to keep the bike running smoothly was just a nuisance. Both kids could feel a difference when swapped out. I've also had ders last long enough to wear out the pivots and joints over many years and miles of use. I'd rather spend a little more at 50-70.00 and have something that feels better, lasts longer, and is more precise then deal with cheap ones that need more maintenance and slow me down. Or for my nicest bikes something that costs a couple hundred and just seems to work silently and flawlessly.

Redbullet

Strange. Since the rest of derailleur looks as new, I'm sure there is no sign of rust from long riding in rain.

The forces in derailleur are so small compared with the forces that steel bearings can face, that I can't imagine how those bearings can be worn. After 25000 km with a SRAM road deraileur, heavily shifting (in average at intervals of 3-6 minutes for preserving optimal cadence) and never greasing the bearings, I observed only minor signs of wearing at the level of plastic wheels, but nothing at the bearings. I had to change the derailleur to accommodate bigger cogs, but I think that the plastic wheels could easily resist at least 25000 km more.
As about derailleur steel bearings, if one greases them at each 20000 - 30000 km and avoids high proportion of rides in torrential rain, I think they can't be worn.