10sp usable gears

[alienator]

Campy anyone? FD trim lets you cross-chain to your heart's content with no rub.

Get right in there.

I'm curious...why all the funky chain ring sizes? What is wrong with the 53/39 or 50/36 that come standard on most cranks? Smaller rings give wider gear ratios? IMO, the only place a 52 chainring belongs is on a junior's bike.

Campy Record, here (10 spd). Generally trimming the FD doesn't prevent chain rub in all cases. I can shift gears, even on both chainrings. It's easy, and requires about as much energy as relaxing to fart. It can't be all bad, anyway. I mean, heck, thems pro riders and stuff....you don't see them staying in one chainring to save the time and complications of shifting to the other. It's almost like they know that shifting is easy.

 

[Dietmar]

Campy Record, here (10 spd). Generally trimming the FD doesn't prevent chain rub in all cases. I can shift gears, even on both chainrings. It's easy, and requires about as much energy as relaxing to fart. It can't be all bad, anyway. I mean, heck, thems pro riders and stuff....you don't see them staying in one chainring to save the time and complications of shifting to the other. It's almost like they know that shifting is easy.

As an aside, on my Campy SR, I can fully cross-chain without any issues, of any kind, and without FD trim. The way I have set things up, I only need to trim when I'm in my largest cog. Just the other day, I was climbing in my small ring while chatting with a buddy. When the terrain became flat again, I continued shifting my rear derailleur, and it was only when I couldn't shift to a higher gear anymore that I realized that I was still on the small ring and had reached my smallest cog. My drivetrain was just as silent as always.

 

[The S is Silent]

As an aside, on my Campy SR, I can fully cross-chain without any issues, of any kind, and without FD trim. The way I have set things up, I only need to trim when I'm in my largest cog. Just the other day, I was climbing in my small ring while chatting with a buddy. When the terrain became flat again, I continued shifting my rear derailleur, and it was only when I couldn't shift to a higher gear anymore that I realized that I was still on the small ring and had reached my smallest cog. My drivetrain was just as silent as always.

And that's when I attack and make you pay for not paying attention to what gear you need to be in! While you're spinning at 150 rpm to keep up while in your small ring...I'm walking away from you. Mwa ha ha!

 

[Dietmar]

And that's when I attack and make you pay for not paying attention to what gear you need to be in! While you're spinning at 150 rpm to keep up while in your small ring...I'm walking away from you. Mwa ha ha!

Yep, destroyed on a Sunday afternoon no-drop group ride...

 

[dhk2]

Guess we all have different definitions of "the cat's meow", but still having trouble seeing why the ability to cross-chain is so important to you. Assume your FD shifting is working properly, really can't grasp the adversion to using your LH shift lever. You paid a lot for the lever so it can be more than a front brake, right? Sounds like your ultimate bike would have a single chainring, maybe 42 or 46 teeth, with an 11-34 cassette.....but you've probably already thought of that.

Consider the losses involved with running the chain at an angle: geometry loss of running the chain not-perpendicular to the axle, as well as friction loss from making the chain flex sideways over the cog, along with the added losses from making the chain turn tightly on a small number of teeth, particularly the 11. How about the added wear on the chain and small cogs, the added rolling resistance from twisting the rear axle counter-clockwise under heavy loads, along with the additional fatigue loads on the rear dropouts and frame? Pretty scary stuff, huh?

 

[crankitfast]

Guess we all have different definitions of "the cat's meow", but still having trouble seeing why the ability to cross-chain is so important to you. Assume your FD shifting is working properly, really can't grasp the adversion to using your LH shift lever. You paid a lot for the lever so it can be more than a front brake, right? Sounds like your ultimate bike would have a single chainring, maybe 42 or 46 teeth, with an 11-34 cassette.....but you've probably already thought of that.

Consider the losses involved with running the chain at an angle: geometry loss of running the chain not-perpendicular to the axle, as well as friction loss from making the chain flex sideways over the cog, along with the added losses from making the chain turn tightly on a small number of teeth, particularly the 11. How about the added wear on the chain and small cogs, the added rolling resistance from twisting the rear axle counter-clockwise under heavy loads, along with the additional fatigue loads on the rear dropouts and frame? Pretty scary stuff, huh?

From my riding style and liking what I've enjoyed as far as shifting goes for quite some time, maybe I've been spoiled when I look at a number of new bikes out there and what gearing they may offer. However, I have in the past read other thoughts about certain gearing and they say similar ideas, in that it encourages cross chaining and dbl shifting, which also to this person was not "desirable".

That is precisely the case. I totally realize that having lots of diff gears is nice, but in total reality I find that I primarily use 5 unless I go down a hill: 45x14/15/17/19/21. That is IT! I "can" use more on the low end and on the really high end as well, but the 45x spread stated is NOT available on what I see on the market.

And yes, you are likely correct in your assumption on my "ultimate" gearing, but actually a 38x13 availability would be cool & work ok for me if I could get a bike w/ that on it.

Point is: Shifting is there when needed, but WHY!!!???? do it more than necessary? Design around it, NOT do it "because it is there".

I understand more wear is likely, but my spinning in those gears would really not cause issues whatsoever. There is far, far more going on rocking the bike up a hill than spinning on level in a 38x small cog.

I guess if I went w/ one of these bikes I'd have to shift more or find a stock setup w/ a 42x52 or something like that to increase gear ratio on small chainring. Or, plan on swapping cranks in the future.

I "guess" I could get used to the newer gearing setups, but would I "like" it? Probably not. "Non value added" activities are what I avoid...no matter how simple or easy it may seem ---just a bother and unnecessary.

 

[alfeng]

Yes, I am talking about primarily chainring rub, which in the end affects gearing. If I knew that chainring rub could be "mostly" eliminated, I'd look at it differently. This bike had a 38/52 x 12/23 and the chain rubbed the 52 ring when using the 38x12/13/14 gears. I realize the 38x12 concerns, but the other are what puzzle/bother me in this setup and not sure if I could live w/ that. Interestingly, the 52x23 runs perfect!

Those 38x13/14 are what I would use to spin approaching any hill and then merely dwnshift as needed. However, in this particular case I'd have to use similar gearing w/ the 52 ring and double shift on the hills which is really where one doesn't want to have to fuss w/ shifting lots!

Suggestions?

Well ONE question SEEMS obvious to me which could clarify a LOT -- Does your bike's frame have 135mm rear spacing?

Based on what I have gleaned from this thread, if you want to limit the chainrub so that you can shift less that I would suggest to you (crankitfast) that you change your outer chainring to a 48t.

The average person whose bike has a 12t cog really doesn't need anything larger than a 48t in most normal riding conditions (i.e., NON-mountain roads) -- heck, 30+ years ago, a 52t chainring with a 14t smallest cog was more common than not.

IF your bike's frame does have 135mm rear spacing, as I suspect, then the other option is to move the 4mm spacer from the non-drive side of the hub to the drive side AND redish the wheel, accordingly ... THAT suggestion is just in case you want to continue to maintain your 52t chainring.

 

[crankitfast]

Well ONE question SEEMS obvious to me which could clarify a LOT -- Does your bike's frame have 135mm rear spacing?

Based on what I have gleaned from this thread, if you want to limit the chainrub so that you can shift less that I would suggest to you (crankitfast) that you change your outer chainring to a 48t.

The average person whose bike has a 12t cog really doesn't need anything larger than a 48t in most normal riding conditions (i.e., NON-mountain roads) -- heck, 30+ years ago, a 52t chainring with a 14t smallest cog was more common than not.

IF your bike's frame does have 135mm rear spacing, as I suspect, then the other option is to move the 4mm spacer from the non-drive side of the hub to the drive side AND redish the wheel, accordingly ... THAT suggestion is just in case you want to continue to maintain your 52t chainring.

This would be another good idea if I were to get the bike. The 48t would probably solve the "problem", AND the 48x12 is plenty big enough for my purposes. Maybe even a 50t would be enough change to yield good results.

 

[crankitfast]

I never eluded nor suggested that I don't understand bikes. I fully understand bikes and what cross chaining is and certain no-no's. 10spd cassettes are not that different in concept and that is why my original post. Re-read it and MAYBE you'll step back and see the legitimacy of my question.

Sorry, you're still one of the few with the problem.

That is exactly what you said wouldn't change a thing!!!!

Nope. You read poorly. You said dishing, and I didn't assume that you were respacing the hub. That's a different matter.

FYI: I run a 45/50 x 13/21 6spd freewheel and I ONLY have to use the fd when going down a hill. Think about that and you'll maybe just see why it is so NICE to only shift one der(mainly)..if not, then enjoy the unnecessary(under most conditions). It's there when needed, but the fd is not an enticing main entree. No matter how quick shifting is, less is better.

Unnecessary from your point view. You've shown nothing that proves that's the case. Less is better? Prove it. Not by waving your hands and insisting. Prove it objectively. I wager you can't.

BTW, gearing can change only just so fast, and there is absolutely NO comparison between double shifting and merely dwnshiftng the rd a gear or two. Absolutely two diff animals NEVER to be stated similar.

Golly, you mean gears cannot shift in an infinitely small interval? Who knew! Double shifting? What problem is that? I can do both at the same time Even if I needed to the shifts separately, it'd still take less than a second. Even if it took a second. It'd have no impact on a climb. If you're worried about shifting and "losing speed", then you're shifting too late. Sorry bub. You've brought nothing to the table but your own assumptions.

Nice try, though.


Yup

Whatever....

I posted a legitimate question which was of interest to me and my riding style. IF you believe that extra shifting is of no concern or bother, let it be so. My direction to you then is to remove any index shifting and go back to downtube shifting because, after all, it only takes a second, right???

If you like shifting the way you do now, then that just adds flavor to your unhelpful and stupid replies because your shifting IS faster than it used to be and if you like faster then you actually like less shifting (even while you mock it). Hmmm....faster shifting or less shifting.....YOU really shouldn't be shifting w/ those index units because YOU don't care about shifting speed, correct????!!!!Gosh, my preference is faster yet! Minimize fd shifting!!! HA!

BTW, genious, I am NOT in my own world. I did addn'l checking on this and it is a mfgr issue. Someone who races at a shop did some checking for me and the mfgr got back w/ him on it, who, by the way, agrees w/ me and says all but the smallest cog should ALWAYS be able to be used, even if it is not for long term.

Have your way, genious, but you are more STUCK on yourself than willing to objectively accept riding preferences and helping out. All you did was cause "issues" on what could have been an informative posting.

Go enjoy YOUR little world, loser.

 

[frenchyge]

I did addn'l checking on this and it is a mfgr issue. Someone who races at a shop did some checking for me and the mfgr got back w/ him on it, who, by the way, agrees w/ me and says all but the smallest cog should ALWAYS be able to be used, even if it is not for long term.

...which is ultimately what we said here, based upon derailleur setup -- chain rub on the big ring should not happen. Who is the mfgr?

 

[oldbobcat]

I appreciate your answers, but, as I stated above, it is NOT front der rub....it's chainring rub I am investigating.

I hear you, crank. And I've seen the problem, mostly on triples with short chainstays. And I imagine you don't want to buy a new frame with longer chainstays.

If you have outboard BB bearings, try a thin shim between the drive-side bearing (or cup if you have inboard bearings) and the BB shell. This will screw up the chainline a little in favor of your small cassette cogs, but it should push the rings out enough to stop the rubbing. 10-speed chains are flexible enough that a little chainline fudging isn't going to break anything.

See your local shop about bottom bracket shims. And remember to re-adjust your front derailleur cable tension and limit screws.