drrobwave

OK I'm about out of questions and ready to put my Soma Saga on the road Thursday with the great weather we are about to receive in eastern NC. I do have one situation that I would like some wisdom on - Background: I am fairly new to road bike riding and have only used STI brifters, my experiences on the Blue Ridge Parkway and Skyline Drive have led me to see the usefulness of bar ends. Right now I have a low rise XT derailleur on the bike - it is backwards from the normal XT - it is loaded to start at the largest cog on the cassette . Never have used bar ends so I don't know the difference in shifting. I like the idea of the derailleur defaulting to the biggest cog especially if something goes wrong I would still be able to use my lowest gear. The bike seems to shift well on the rack.

Does anybody see an issue with using the low rise derailleur?

nubcake

They actually do make a lot of sense as far as helping prevent damage if you try to shift under load. The reason they never caught on is everyone was already use to the way things were and did not want to make the change. No problems at all if you chose to run it.

Clem von Jones

You did the right thing. I'm doing the same thing on my next build

paxtonm

That's the way I went when I built up my tourer, and I did it for two reasons. First, it "defaults" to the big end of the cassette, as you said. But second, like you, it was my first foray into bar-end shifters, and I anticipated (correctly) that with a new style of shifter, I wouldn't be vexed by "reversed" shifting. I wasn't, and in fact I encountered another unexpected benefit. With bar ends, to shift down to a lower gear, either the front or rear shifter is moved down (downshifting, get it?) and to go up, you pull either one up. It's so completely intuitive, that I quickly began shifting without even giving it a thought.

cyccommute 

There is a reason that RapidRise is often referred as RapidFail. The problem with them is that they tend not to shift under load, just as a front derailer might not shift to a lower gear under load. Considering that you usually need to downshift under load, having a derailer that is balking about shifting doesn't do the rider much good. "High normal" (or regular) rear derailers pull the derailer up to the larger cogs and make the shift when you need them to.

Back in the 90s Suntour made a front derailer that was high normal, in other words the cable dragged the derailer to lower gears. It was brilliant.

Tourist in MSN

Your components last longer if you do not push hard when you shift. So, try to anticipate your shifts and shift early.

I found a local store that had some new old stock Suntours like that when I was building up my LHT about 8 years ago. I have put them on my two touring bikes and I also bought several additional spares.



For highest gear, both shift levers (bar end shifters) are pushed all the way forward. The Suntour is great for this setup.

You don't have to stay in your highest gear if a cable fails, you can adjust your limit screws to have a better gear. I learned that the hard way during a century ride several years ago.

nubcake

That is the very reason it is better for your drivetrain, you NEVER want to shift under load, that is a quick way to either break a chain or bend a cog. If you need to go to an easier gear while pedaling uphill you can just quickly accelerate to build some momentum and as soon as you let off shift. No load on the drive train and you were able to shift while going uphill.

cyccommute 

Either of you ever mountain biked? Sure, you aren't supposed to shift under load but in the real world it happens all the time. Sometimes you have two choices, make the shift under load or walk. Accelerating isn't always possible. That's what all the fancy carving on modern cassettes is all about...being able to shift under load when you have to. In addition, shifting from a higher gear to a lower gear is the definition of shifting under load. You are going from a low torque situation to a higher torque situation every time you downshift, especially when you do it while going uphill.

All that fancy carving makes shifting a whole lot easier than it was in the past but it's still better to use cable pressure to drag the chain from low torque to higher torque than to try and let the spring push it. The spring, even in a Rapidrise derailer, is weaker than the pressure you can put on the cable.

nubcake

I have been mountain biking for almost 10 years now and never felt shifting under heavy load was needed even when I was racing regularly, I was always able to accelerate just enough to be able to let off and make the shift under very light load. Those ramps are there to help shifts go quicker, they are not about letting you shift under load. Shifting under load side loads chains and the pins in chains just are not meant to take side loads, not to mention the possibility of bending cogs.

djb

the key word here is anticipation, with just a little bit of anticipating, you shouldnt have to shift under load. Sure, in mtn biking it can happen more, but if you are in control and are thinking ahead a bit, you can avoid it.
Lets face it, some people are just not mechanically sympathetic (and no Cycco, this is not aimed at you) and are just plain ham-fisted with shifting and a poor sense of timing. If you develop a finesse for shifting, your drivetrain lasts a lot longer and the risks of messups with chains are that much less. Its like shifting a motorcycle without the clutch, its all about timing and developing a feel for when to do the various actions and how much pressure and when.

Even road biking and climbing, one can upshift while standing in a way that with combining timing, and taking weight off your foot slightly at the right time and position, you can non-abusively upshift under a very slight load. You just have to get the timing right and figure out how to reduce the load for that fraction of a second.

I follow motorsport, and one event I've always been fascinated with is the LeMans 24 hour race. In the past, before electronic rev limiters, and sequential gear shifter controlled by computers, the guys who won were those who were both fast AND had a proper seat of the pants feel for being mechanically sympathetic, shifting, braking, and a general finesse with all aspects of their driving.

ps, re: mtn biking derailleurs etc, its probably because of mtn biking that there has been so much advances and improvements to drivetrains being easier to shift, robust etc--which in the end has been a great benefit to all riders as the cog ramping etc and overall robust derailleur designs mean that drivetrains are pretty reliable, under all kinds of rider abuse.

Tourist in MSN

Actually no, but I was commenting on a touring forum, not a mountain biking forum.

I have had chain suck occur a couple times when I shifted under load and have bent my front derailleur from that. It is not just the rear that you need to be careful with.

Burton

Several high end derailleurs are available in high-normal or low-normal configurations. The choice is normally according to the driving style and preference of the individual rider. There was some resistance to Shimano low-normal derailleurs when they were introduced, but it was largely because the visual displays on the shifters would read backwards, not because of shifting issues. Currently with numbers removed from the visual displays and some models where the display can be removed completely, there isn't an issue.

I currently have XT Shadow low-normal rear derailleurs installed on two bikes. That was a deliberate choice and a personal preference. Since I can stand on the pedals while going uphill and shift through all gears while doing so on either bike, I suspect that anyone thats having an issue either doesn't have them set up correctly, or needs riding lessons.

Low normal actually makes more sense for mtb bikes, touring bikes and road bikes where climbing is involved. It facilitates shifting to a lower gear when climbing and allows multile cog-shifts in one sweep when decending.

cyccommute 

Those ramps make shifting quicker and easier...under load. Because, like I said above, shifting down goes from a low torque to a higher torque. If you've only been mountain biking for 10 years, you've spent your entire mountain biking experience in the Golden age. Try finding an old freewheel without the ramps and sculpting. You'll quickly find out how much those ramps help even a ham-fisted shifter.

cyccommute 

It would make sense if shifting up were ever a problem. Even with old friction shifters and weak springs, shifting up has never been difficult because of the torque differential. Shifting down has always been an issue on either front or rear.

nubcake

My point is their intended purpose is not to make ham-fisted shifting easier, why would one encourage poor technique? I have ridden plenty of bikes without shift ramps.

Burton

So lets be blunt. It isn't a problem that shows up on MY bike, so if the same equipment gives YOU a problem on YOUR bike - then I tend to believe the problem is YOU and not the equipment.

AdamDZ

OK people, shift happens. Under load or not. I personally prefer the traditional RDs too and I never had any issues with shifting that would make me consider changing. Whatever works for you.

cyccommute 

Let's be even blunter. If low normal shifting offered any serious advantage, it would appear on all Shimano derailers...whether road or mountain. Obviously, it doesn't. Shimano must not think that well of it.

cyccommute 

Shift ramp are intended to make shifting faster and easier...under all conditions. Their very existence encourage a shift technique that would be very poor indeed without shift ramps. If you click on the shifter with shift ramps, sooner or later the derailer is going to make the shift. The shift is just a little quicker...when you might need it...if the cable drags the derailer to a lower gear than if the spring on the derailer pushes the derailer there. There are times when you need to shift now and can't accelerate to let off on the pedal pressure.

drrobwave

Didn't mean start an argument. I did get a chance take a short ride - unloaded except for the winter load on the seatpost. Worked fine, no problems. I can see some advantages and still have questions that only experience will answer. Thanks for all the input.

Burton

I have absolutely no idea why you think you have a clue how or what the guys at Shimano think - its obviousky very different from your views of things: https://nsmb.com/gear/shimanocamp_11_04.php

And the pros and cons of both systems for road, mtb and touring are spelt out in the Wikipedia:
"High normal or top normal rear derailleurs return the chain to the smallest sprocket on the cassette when no cable tension is applied.[9] This is the regular pattern used on most Shimano mountain, all Shimano road, and all SRAM and Campagnolo derailleurs. In this condition, spring pressure takes care of the easier change to smaller sprockets. In road racing the swiftest gear changes are required on the sprints to the finish line, hence high-normaltypes, which allow a quick change to a higher gear, remain the preference.

Low normal or rapid rise rear derailleurs return the chain to the largest sprocket on the cassette when no cable tension is applied. While this was once a common design for rear derailleurs, it is relatively uncommon today. In mountain biking and off-road cycling, the most critical gear changes occur on uphill sections, where riders must cope with obstacles and difficult turns while pedaling under heavy load. This derailleur type provides an advantage over high normal derailleurs because gear changes to lower gears occur in the direction of the loaded spring, making these shifts easier during high load pedaling."

In 2010 I prepped some titanium framed prototypes for tested by some of the top riders at the UCI Mountain Bike & Trials World Championships in Mount Ste Annes. They were ALL equipped with Shimano XTR low normal derailleurs and the riders, without exception, absolutely loved them. And then there's your opinion...

Of course the bikes at that competition needed to be power-washed (power-washing booth courtesy of Pedro's USA) and as per some of your previous posts - even your chains never get dirty. So maybe the big difference is these people are actually riders.

I'm also aware that the best selling bicycles in the world are department store bikes with a Tourney rear derailleur. Just because most people buy something doesn't make it technologicaly superior. And just because something was taken off the market doesn't mean the technology was inferior. The Avro Arrow CF-105 is proof enough of that. Shimano is running a business and will continue to develop advanced technology, but can only be expected to produce what sells.

djb

Burton (you must have added in the Arrow line, I didnt see that last night, and I would have noticed, being a Canadian and knowing the story....bloody Diefenbaker...)

but I digress-neat article there about the mtn guys trying out the low normal, rapid rise...I can see how it must be neat, as the writer describes, to be able to shift with abandon. I can also see how it must be pretty darn weird, and I think that I am a good example of a lot of people who because we arent hardcore mtn bikers (disregarding the crucial point he brings up about really hard, steep, technical trails) getting ones head around a diff way of shifting would be more bother than its worth.

That said, going from what the writer described as how he tried his darndest to do a hack of shifting, but it just worked, I can see the advantages, and very "real world friendly" for lots of people if they have no background with traditional. One aspect I can see (other than the forementioned steep trails situation) is that for riding in touring situations (and I dont mean out in Tibet, but just far away from a town) I wouldnt want a busted derailleur cable to mean I was in the lowest gear, would prefer to be in a 11 or 12 tooth and go from granny to middle chainring to get around.
I realize this hardly ever happens, so I guess for me, it really comes down to having the instincts of a lifetime of riding, plus your other bikes being the same too, so for me while I find it fascinating, cant really see it being a realistic option.

tks though for putting up that article, made it a lot easier to see how it works in real life. Plus it was good as the fellow wasnt only praising it, but had a good unbiased view on the pluses and minuses.

also, before this thread came up, I had no idea that some derailleurs were set up the opposite way. Je vais dormir moins naiseux ce soir.