I bought a (new) Trek Crossrip recently, which has a Shimano Sora groupset, but with a SRAM 11-32 cassette.

I noticed that some of the gears (somewhere between 5th-7th gear) would sometimes be a bit "indecisive" when changing, and shift down, then up again, making me nudge the lever again to shift up.

I thought this was just cable stretch on a new bike and after a few weeks took the bike into the LBS for its post-sales service, mentioning the issue. They supposedly adjusted the gears, but it seems simply to have move the same behaviour to slightly higher gears (around 7th-8th). They may have just tweaked the limits, but not actually addressed the indexing. I'm not actually sure how how a continuous system operated with a cable can be set to jump precise amounts. Is it all just a question of cable tension?

Is this kind of thing normal? I know I have an entry-level groupset and not a Di-2 Dura Ace, but it's a bit disconcerting to have gears change by themselves.

As a comparison, I tried someone else's bike using an fairly old MTB groupset (XTR?). The gear changes felt smoother on this bike, but I sometimes found I had to click the lever twice to actually shift gear for some changes.

I know most gears are fundamentally mechanical and analog, so there is probably an element of "feel" to changing them. Is this something I just need to learn?

Thanks!

John

The two limit screws adjust the upper and lower limits to keep the chain from falling off of the cassette on either end (bad to let it fall into the spokes).

The indexing is fixed by the manufacturer, but you adjust it, affecting all gears, with the fine tune cable adjuster, normally where the cable enters the derailleur, but you may also have them at the first cable stop on the frame.

There are two types of cable housing. Typically brake cable housing has spiral wound steel,and gives the housing an effect of rings along it. Shifter cable housing usually has a cluster of lengthwise reinforcing wires, and should feel more smooth along the length of the cable housing. Using brake cable housing for shifters could cause inaccurate shifting.

None of the crossrips on trek's site come with a SRAM cassette. I'm assuming you bought the crossrip 1, as that one comes with sora shifters.

Take it back to the bike shop, ask why it has a different cassette on it, tell them it doesn't shift well and how it doesn't shift well. It's their responsibility to get it to work right, especially since it's still new, and double especially since it didn't come with parts that it should have come with.

But to answer you question, try turning the barrel adjuster on the derailleur a bit either way to see if it helps or hurts the shifting. My guess is that if you turn it 1/2 to 1 turn counterclockwise, your shifting will improve.

Its NEW? talk to the dealer , there is new bike settling in that gets taken care of in the first free tune up..

My Local has 6 months to sort it out.

First, it is never normal for a bike to "ghost shift" or jump cogs. Usually it is an adjustment or alignment issue, but sometimes it is simply chain, cassette, and chainring wear. Since this is a new bike, you shouldn't have any worn parts so its not wear.

As has been said, limit screws make sure the derailleur moves just far enough to shift to the smallest and largest cogs without overshifting. If you're having issues in the "middle gears" than the limit screws are not the problem.

Cable tension establishes indexing and whether the chain is correctly positioned over each cog in the middle of the cluster. This is an easy adjustment on most bikes as there are adjusters at the derailleur and possibly at either the shifters or downtube cable stops. Generally, you just eyeball that the top RD pulley is exactly under each gear as you shift through the cluster. Sometimes a little nudging of the tension is necessary to ensure a crisp shift up or down. It's possible that on a new bike you have a problem with the cable housing terminations which is putting a lot of slop in the system such that you can't get consistent tension, but this is unlikely.

A final adjustment is the b-screw which determines how close the top pulley is to the cogs, with typically the largest cog governs. You want the pulley to be fairly close, but not so close that the chain binds as it tracks from the cog to the pulley. But improper b-screw adjustment seldom causes skipping of cogs.

If the RD or RD hanger is bent, this can cause skipping. But it is unlikely to be bent on a new/uncrashed bike. Definitely something that should be checked if the problem can't be solved by normal adjustments.

The SRAM cassette is odd if Trek specs Shimano, but SRAM and Shimano cassettes are generally interchangeable for a given number of speeds. I doubt this is an issue, but it is curious why a change was made. Does the rear cassette look brand new?

For a new bike, the selling shop should sort this for you. Have them do the adjustment than immediately ride the bike to confirm the fix, returning as necessary. If adjustments can't solve the problem, then you probably have something defective or bent and they should start checking alignments and swapping parts.

By far the most likely cause is simply that the cable tension needs to be tweaked, but if the LBS didn't get this right when you first complained, then you're looking at gross incompetence on their part.

Good luck,

- Mark

That seems like you are not moving the lever(s) far enough. Index shifting should be deliberate with steady force and complete motion, without being forceful. Usually one will move the lever a little past the click. Maybe demonstrate your shifting technique to the LBS next visit.

Also, entry level Shimano groups shift well when setup properly.

Thanks for the suggestions. The bike is the 2016 model (2016 CrossRip Elite - Bike Archive - Trek Bicycle) , which has the SRAM PG950 cassette as standard.

I'll try to adjust the barrel adjuster on the derailleur as you suggest. It's a good idea for me learn som "DIY" bike maintenance skills in any case. If I still can't fix it or get it to work satisfactorily, I'll take it back to the LBS for another look.

So it sounds like this is not something that one has to just live with :-)

John

It's already been in for one check up (2 months after sale), which didn't fix the problem completely. I have a year of free check-ups with the sale, so I'll use them if necessary.

I know this is under warranty and LBS should fix it. But this is a great opportunity to learn how to adjust derailleurs and know your bike. After the first year (as things wear, get bent a bit) you may have to adjust every once a while and don't want to pay the LBS to do that.

I once rode my bike on my former commute. There was a bicycle event with free breakfast. Naturally I stopped there. some LBS had booths with free adjustment for anyone. Nothing was wrong with my shifting, but I thought "why the hell not have a professional adjust for free". Since then I never could get my front-derailleur right since that guy screwed it up. The only thing I got for free (besides the breakfast) was the lesson that I don't let someone else touch my bicycle and learn to do it myself. Even if I don't know what I'm doing, at least I care. On a former bike (bought new) I also had to bring it back multiple times to LBS for shifting issues. The problem was, they only adjusted it on the stand, never while riding. Well, with no load it probably worked. But in the real world I don't pedal while the bike is off the ground. The owner got all weird and told me after many times I shouldn't be so picky since he lost a lot of money on the bike since I got a good price blah, blah blah. It was a shimano Deore, so it was clearly able to shift well. After I gave up on the LBS I taught myself by looking at it (that was pre-internet) how to adjust it and it shifted flawlessly for many years.

If you want to have something done right, you have to do it yourself. Obviously under warranty give the LBS a chance and show them how you shift and have them re-produce the problem or reproduce it in front of them.

Edit: after some years the sifter cables stretch out and you need to replace them. Obviously this should not be the problem of your new bike.

limiters affect min and max motion range

cable tension (barrel adjuster) affects calibration of the indexing to the cogs

b-tension affects distance between pulleys and cogs which affects 'decisiveness'

and that last one, lots of people overlook
try backing the b-tension screw out

A bike repair stand even a cheap one that is not "perfect" is a really nice thing to have at home.

I bought a sub $100 one from Amazon, it's only flaw is that the clamp that holds the seatpost clamp will not allow one to rotate the bike in any direction.

It allows you to very easily spin the cranks while you shift gears and watch things, I agree the bike shop should make it work right for you, but eventually you will want to learn yourself, and the stand is handy for doing all kinds of other everyday stuff too, even cleaning the bike.

Sora level stuff can shift totally perfect in my experience.

Bill

[QUOTE=johngwheeler;19476759]Is this kind of thing normal? I know I have an entry-level groupset and not a Di-2 Dura Ace, but it's a bit disconcerting to have gears change by themselves.[QUOTE]

Normal isn't a word that I would use but it is common.

I think that a new bike should be "right" when it is delivered. It doesn't sound to me like your is. If you brought it to me, the first thing that I would do would be to check the derailleur hanger alignment. A hanger that's just a skosh out of alignment can make your shifting act the way that you are reporting. Cable tension adjustments only serve to move the problem around.

FWIW, resist the temptation to fiddle with the high and low limit screws. All that will do is introduce an additional problem.

No.

Usually one company's mechanical groups work the same. Spending less just means fewer cogs, more weight, and/or inferior aesthetics.

Where that's not the case (Camapgnolo has two mechanically different shift mechanisms) the less expensive groups still work great because they need to compete with two other vendors and warranty returns are expensive.

Something is wrong.

You could be using it wrong - some shifters allow a little overshift (Campagnolo mechanical) moving to larger cogs and you want to hold the lever until the shift completes.

It could be mis-adjusted. That could be from lower tension to work around excess cable friction (bends tighter than they need to be, bad housing, housing lining not opened up after cutting, frayed cable strands, cables rubbing crossing under the down tube) which makes shifts to smaller cogs slower.

You could have a bent hanger that makes it impossible to achieve correct adjustment across the entire cassette.

That's also a problem.

I tried this today, and *bingo*! A quarter turn made things much better :-)

So simple, but I wonder why the LBS couldn't do this? My guess is that they clicked through the gears with the bike on a stand, saw that it worked, and say "job done". Actually riding the bike with some power through the chain is a different story.

At least this was an easy fix - thanks!

John

I never return a bike to a customer without a test ride - unless it's a really small kids bike.
There are number of things that show when a bike is loaded and some force applied on the pedals.

However, to be fair to the LBS people, what you are describing could still be cables and housing bedding in. Often takes at least one tweak from brand new, to completely bedded in. Some groupsets are more sensitive to cable/housing play - especially the 10 speed Shimano road shifters (except the Tiagra 4700 series). Even temperature change can affect shifting and require some fine tuning at the RD barrel.

Also, the quality of factory cables and, more important, housing also plays a part. I've seen some cheaper models use brake housing instead of shifter housing for shifters!

Finally, could be just your preferred shifting pattern. Some people prefer to have quicker upshifts, some quicker downshifts, having to move lever a bit further and hold it a bit longer for the upshift.

No.. shifting mis adjustment and chain wear will do it,

the teeth are cut down short and cogs ramped on their sides to be eager to shift.




...

I know you don't want to hear this .......... But, I've had RD's that just would not shift properly and, no amount of adjustment would correct it. Most RD's are mass produced items that have several parts that are stamped & pressed together and, sometimes they're out of tolerance. Consider upgrading you RD to a higher model level. None of Shimano's RD's are any good until you get to the 105, Deore, or maybe Sora level stuff.

Trek Cross Rip is built up with a decent parts pick.. Sora, it's not the bottom of the line stuff...

My bike has a Sora groupset, but with SRAM cassette. It's "OK", but I can certainly imagine smoother shifting.

I also ride a bike with SRAM Rival 1x11. This has very positive gear changes - they make a big "clunk" when shifted - but I wouldn't call it a smooth change (the 1x11 gearing also has large ratio jumps compared to a 2 x11).

I'll ride the bike for another 6-12 months (it's my commuter / general-purpose bike) and decide whether it's worth upgrading to Shimano 105 / Ultegra level. But I'll learn how it adjust everything first!

John

If we're ignoring wal-mart level stuff, Sora is only one step above "bottom of the line" in shimano's road hierarchy.


I have a Sora equipped bikes direct bike. I have it adjusted to the best that it can be (I've adjusted hundreds and hundreds of RDs), but it still shifts bit clunky, especially when compared to my older DA equipped bike. Both are 8 speeds, and the sora bike is actually a triple, so you'd expect is has a smaller range on the cassette than the DA bike. The sora bike has brand new nice shift housing and cable, and nothing is rubbing anywhere and there is lube in the appropriate places along the cable route. (And it's clean.)

However, I think it's less the derailleur and more the brifter. The sora brifter has play. A good bit of play. I can move the lever a full inch+ (at the tip) to the side before it even starts to shift. The DA brifter, on the other hand, has little play. Maybe less than a quarter inch-1/2 inch at the tip. (Before it starts to shift.)

Derailleurs are relatively simple. They're just a lever attached to a swinging parallelogram. Brifters are complicated. They're worth investing in for better shifting.

You CAN get acceptable shifting with sora parts, but any money spent on better shifters will probably make the shifting experience a bit nicer. They work perfectly well, they're just not "refined."