I received my new bike about a month ago and from the beginning I have been having a problem with ****ting the rear gears. It seems whenever I try to shift up from 4 to 5 and all the way to 8th gear, the shifting take some time and makes a grinding sound in the process. Often, when the chain take too long to move, slowing down peddling or stopping peddling for a very quick instance moves the chain up quickly. I took the bike to the store and they did some adjustments and raised the back of the bike with a rope and had me pedal by hand while they shifted the gears and the problem seem to have gone away. Once I took it back and started riding the bike it went back to the same problem. The store keeps telling me it could be my timing, but I really doubt that. Any advice on what is problem and how to fix this it?

My rear derailleur and cassette are Shimano Ultegra and this is a link to the bike:

https://www.trekbikes.com/int/en/bike...ne_4_5_compact

I am sorry you are having this problem. Please just let me say your lingo makes it a little hard to understand the problem. Nobody with much cycling experience talks about the gears by numbers. It is better to describe which front ring you are on (small ring, big ring or in the case of triples granny ring, middle ring, big ring) and which rear cog (third smallest, etc.). You have to say whether you are shifting to larger or smaller cogs as there is no real numbering convention. One possibility is your cable tension isn't quite tight enough, a common problem on a new bike. Take the bike back to the shop again, and instead of pedaling it for them, watch what they are doing. That is much more important. For most adjustments, they don't need anyone sitting on the bike, and you are more likely to get it right when you are back at home if you know what to do, than they are at the shop. Get them to show you how to use the adjustment screw(s) to loosen/tighten the cable and also how to loosen the cable fixing bolt and pull it tighter. Most importantly a modern Ultegra rear derailleur and shifters should work wonderfully well. You shouldn't be having this problem.

Good luck.

Probably already covered this. But for me I would think, if you have Ultrega/Shimano chain, it's put on wrong. The Shimano label has to be facing outward and it has to be threaded in the right direction. The other is, your deraileur hanger is bent?

Search the net on setting up the deraillers.
Also make sure the cable is clamped in the derailler clamps groove.
I recently swapped my cable and there was a small bend in the cable by the rear derailler clamp that kept it from shifting through all the gears properly.
Once I put in a new cable and it was clamped perfectly my shifting was back to normal.

It's a new bike. Take it back to the store and a)have them do a proper adjustment and b)work with you to get comfortable on shifting. I'm a bit suspicious of a bike store that is having to raise the bike up with a rope. What gives with that? Once they think they have it adjusted properly they should put the bike on a trainer and give you a chance to practice shifting in the store.

+1 it sounds like a cable tension adjustment needs to happen.

If the basic tuning items like adjusting the cable tension don't work have them check the derailleur hanger and B screw tension after they check the hanger. .

Thanks for replying. The shifting problem I am having is with the rear cog. To simplify things I will use number of teeth on each gear. For example, on my 11-28 cassette if I shift from 15 to 14 or 13 to 12 I will have this problem. I think this is called shifting up, right? On the other hand if I shift from 14 to 15 things usually go smoothly. It doesn't matter which front ring I am using, this problem is always present.

I prefer to learn this on my own, I am just not happy with the dealer I ordered my bike from. If you have any good links kindly share it with me.

Thanks, it sounds from your description that the chain is facing the right direction, but I am not sure what the thread in the right direction means? Here are some pictures:

Thanks, I am researching as we speak to learn how to adjust the derailleur. If you have a good guide kindly share.

This bike store fit me wrong, they ordered for me 62 instead of 60 and they can't even understand that my stretched arms (source of my discomfort) are in unnatural position. I really have no fate in them fixing this problem and try to keep dealing with them to a minimum.

I like the Park Tool Repair Help pages for learning repairs. Sometimes, a youtube video helps on complicated repairs.

The rear derailleur adjustment page starts from the beginning, setting the high and low limit screws, then adjusting the shifting. Do the whole thing so you know it's correct. Then you'll understand how to adjust it quickly in the future. It's easy after you do it the first time.

If the low limit screw is set too far, it'll allow the chain to go past the large cog, into the spokes. Then the derailleur catches on the spokes, and rips it off the bike. It'll need spokes, derailleur, and often the frame is damaged too. An expensive problem.

That's messed up. Even amidst all of your anticipation in taking delivery of your new bike you most definitely should have refused or at very least have them fit you properly to the larger frame (shorter stem for your arm issue?).

As for DIY'ing your rear derailleur, search for Park Tools rear derailleur guide and then get on youtube for a good visual. Lucky for you this is pretty easy to do on your own. Honestly, I never even follow the guides unless things are screwed up extremely badly. I just tinker with the limit screws back and forth a bit until I'm shifting smoothly again, more of a guess and check technique I guess..

Had a local shop pull this crap on me earlier this year, be very careful! I had to replace my wheels and rear derailleur, luckily my my frame pulled through or I might have accidentally been forced to drive my car through their front door (was pretty damn mad though this shop has always been beyond great otherwise, first road bike too!). Small adjustment, big damage..

Where are you located Abdul10000 ? I have a real bad feel about that bike shop. Is there a better shop around?

There are great videos on youtube for rear derailleur. First step is to set the limits. Bottom make sure it gears properly on smallest cog. Then on largest cog, make sure when you pull the cable hard, it doesn't drop off the cog. There are labels on the deraileur, H and L. L would be the largest cog. You don't adjust the shifting with those screws, those are just the limits. For example that large plastic you have behind your largest cog? It's not needed if you have the limits set properly. You adjust the deraileur with the micro-adjuster, turning thing you see to the left of the deraileur. You can put the gearing into the middle cog and adjust it in the middle from there. Then you just shift up and down until it's smooth, adjust a quarter turn at a time.

If you can get it to shift fine on the one half of the cogs but not the other half, that is indication that your hanger may be bent. Cost me $20 to have my hanger adjusted at a LBS. It was worth it. Even a slight bend can affect your shifting.

For me at least. If you can get it to shift one way fine, but the other way it hangs a bit or causes issues, that indicates to me the chain is in the wrong direction. Shimano chains are directional.

Thanks that looks like the best guide I have seen yet. Just to make sure I understand the part in bold, the largest cog is the first one counting from the wheel side or in my case the gear with the 28 teeth, correct?

Yes it is, but since this is my first road bike I wasn't sure how to fit on it. After riding it for 15+ min several times and feeling uncomfortable I realized there was something wrong. Doing research and seeking professional advice proved my suspension. Since then I ordered a shorter stem and I am waiting for it to arrive.

I live in Jeddah, Saudi Arabia. It's the best shop, period.... and the only one in town, lol

Thanks for this detailed advice, I will put it to use as I start making adjustments.

Correct.

Discomfort after 15min on your first couple rides on your first road bike? Sounds pretty normal to me. My bike came with a 120mm stem and for the first few months it felt like waay too much for me and I always felt overstretched. Now, about a year later I'm feeling like I could use a bit more stretch.. Give yourself a few months to get used to it on longer 2+ hour rides is my best advice.

Thanks for your feedback. Look at the picture below to see how stretched my arms look. I dont think that is normal position and it's been almost 1 month since I got the bike and it still feels uncomfortable. In fact, I think this position can be dangerous over time because it over stretches the shoulder and arms muscles.

Au contraire, mon frère! The bike looks to be not too large at all, if anything maybe a little short in the top tube. Your arms would be more relaxed if you bent more at the hips. If you want to ride that upright, you may have the wrong type of bike. Try bending more at the elbows and see where that takes your bend at the waist/hips. There is nothing at all dangerous about your position.

this is is one of the best resources out there on adjusting your rear derailleur. Your description really sounds like a derailleur adjustment problem - if you find that you can switch gears very quickly going up but it's very hesitant going down the gears then chances are that it's your rear derailleur cable tension. The little barrel adjuster that sticks out of the derailleur can be turned clockwise or counter-clockwise and makes small adjustments in where the chain is positioned relative to the cogs.

the only other piece of advice about switching gears while riding is to change gears earlier than you need to - if you're trying to change from a harder to an easier gear while pedaling very slowly with a lot of force, you will not make a smooth shift. Shifting gears while pedaling more quickly is the way to go.

good luck!

Well I hope you are right and that it is my correct size.

I will try your suggestion but I got the Domane for this particular reason, it offers a more relaxed position over the Madone. One thing I did to try and solve this problem was to order a 90mm 17degree stem to replace the 110 7 degree stem. If this bike is the correct size I think the new stem should help relax my arms.

Yes, this is exactly where I started and I am seeing an improvement after turning the barrel adjuster tighter. The chain is not dragging between shifts as much as before now. It's better now but a bit snappy I guess I have to keep trying different settings and keep re-reading the guide until I get perfect shifting. Although I have little experience, I am pretty sure when ultegra gears are tuned correctly they shift so smoothly it's hard to notice when they do.

That's really useful to know. The rep at the Trek dealer kept telling me the shifting problem I was having was the result of poor timing on my part but could not explain what he meant by timing. This clarifies things.