I just received my new DT swiss wheels. I had the shop (mail order) install a new Shimano Ultegra 11-28 cassette, my oem wheels has a shimano 105 cassette 12-25.
My problem is when I put the NEW wheel on the bike it doesn't make it on the largest gear on the (11-28) cassette and is shifts like crap on all the others.
Is this normal ??? Do I have to have the derailleur adjusted ??? I wanted to be able to go from one wheel to the other , if I have to adjust the rear derailleur to work for the 11-28 I'm screwed if I want to go back to the 12-25..
I called Colorado cyclist (the place where I bought them ) and they said I had to adjust the derailleur and that makes no cents to me , both cassettes are 10 speed shimano ( 105 group and Ultegra ). I even measured the width and they are the same, the chain seems to be plenty long enough.. I'm Confused big time HELP !! I really want to be able to go from one wheel to the other...

Very likely, your new wheel is missing a spacer outside the largest cog. Remove your cassette and look. If in doubt, take the cassette off of your old wheel and see if the spacers are consistent between the two wheels.

I wouldn't say it's "normal", but what you describe isn't surprising, especially since you are going from a 25t to a 28t (which is usually the upper end of what a short cage rear derailleur can handle). Assuming you aren't missing the 1mm 10-speed cassette spacer, then chain length/tension could be the culprit.

I don't have the tools , that's why I had them install the cassette. It looks like I have to bring this wheel to a local dealer and bring in wheels and parts I didn't buy from him. Not fun..

And now you know why dealing with the local bike shop (LBS) is sometimes a necessity. There are several reason it might not work, but only someone with some experience can look at it and tell you why.

Mark

Well, if your cassette is on the freehub without any play, then it's not likely due to a missing 1mm spacer at the end of the cassette.

It happens. Probably won't be the last time.

could just be that your "B" screw needs to be screwed in some so the derailler pulley will clear the bigger 28t cog. if so, your old cassette will still work. probably a spacing issue tho. recommend you buy a cheap tool kit that comes with a cassette tool and a chain whip. will save you $ and time.

I called them again and they said there are no spacers behind the cassette....they don't seem to have a clue , they said they would look into it and call me back . I'm not holding my breath..

The folks at Colorado Cyclist have a clue.

time will tell

How many miles do you have on your chain? Used chain + new cassette = bad news.

It seems to me (from memory), that the RD from the prior iteration of 105 (5600 series) has a stated maximum cog size of 27 teeth. I have 5600-series 105 on my bike, and when I got it I had the 12-25 cassette changed out to a 12-27. At that time, there was an 11-28 Ultegra cassette available, but not for 105. I seem to think that this was a limitation in the 105 RD. The new 105 (5700) will support an 11-28, in any case....

That said, even if the above is correct, you may still be able to make things work with some adjustments, since the size difference between 27 and 28 is pretty small. Barring that, perhaps a new RD will solve the issue (either Ultegra or the new 5700 105), if you really want a 28-tooth cog.

Less than 500 miles and well cared for.

...chuckling...not at your problem. But at your dilemma.

I own a 2010 cannondale Synapse , not sure if it's a 105 rd or 5700 ??? as I look at the specs it list the rear cogs as a Shinano 105 , 12-25 (c) , 12-27 (t). Mine being the 12-25

no cents?

Wheels dished the same? I have Mavic Elite and Zipp Team Issue wheels, both with Dura Ace 11-21's and have to adjust the derailleur when I switch due to the wheel.

Even if you have to adjust when swapping wheels you aren't necessarily screwed. Once you get it right on one wheel swap to the other and then see how many times you need to turn the barrel adjuster to get the shifting correct, it could be as simple as that. If the limit screw needs changed for each wheel then yeah, you're kinda screwed.

Also, if I'm not mistaking some hubs don't need the spacer.

Take it to the shop and have them look at it. It's going to be hard to diagnose over the web

^^^ what he said! its likely do to the wheel and you will need to adjust the RD when you swap wheels. so what that takes like 5-10 min max. i suggest you learn how to adjust your RD as it sounds like you dont. its not as hard as you think and the only tools you need are your fingers and a philips head screwdriver (maybe an allen wrench if you need to take off or tighten cable but unlikely for what you are doing). good luck

with a ten speed cassette you should need a spacer. that doesnt mean it wont work without one but it wont be spaced normally from the outer cone lock nut to the first cog. take it to a shop, add the correct spacer and try again.

You mean the wheels, and parts your friend with more money than sense, or your boss, who knows you love cycling, gave you ...

A shimano 10 spd normally needs a 1 mm spacer at the beginning of the cassette next to the biggest sprocket. It could be the dish of the wheel is slightly different and this would be a case of adjusting the derailluer. I just built a new set of wheels and did the same a new cassette. It required a very small addjustement to the derailluer since the wheel I built was perfectly dished. My factory wheel was dish ok but off by maybe 1 mm, just enough to make the rear derailluer need a touch up. Your problem is probably 3 fold in that they might have missed 1mm spacer, 28 cog cassette, and wheel dish. I am betting as long as the derailluer will handle at 28 tooth this is an easy fix. I could fix it in less than 15 minutes.

First i'm going to find out if my bike (RD) is suited for a 28 cog if so, I ordered a parks AK-37 tool set, once in i'll take off the cassette check for a spacer, if none I try finding one and installing it. If this doesn't work I'll have to adjust the RD. MY HOPES was to be able to switch from one wheel to the other without adjusting the RD. I did find https://bicycletutor.com/basic-tools/ to be very helpful. I own 4 motorcycles and have done all the maintenance from valve adjustmens, to wheel bearings, fork oil change, swingarm removel, I haven't had to bring any one of them to a shop in ten years and now for some reason a bicycle is got me messed up. my bad..
Thank You all for taking the time to help !!!!!!!!!!!!!!!

A couple things:

The dish of the wheel does not matter (some have mentioned it). Dish only affects the relative position of the rim to the hub, not the gears/cassette on the hub. IF the dish on the wheel is different, it might require an adjustment of the brakes, but not the derailer.

105 (assuming it's 5600), officially supports up to 27 teeth, but seems to work fine with 28 (I run it fine on my bike and I've never heard of anyone having issues). IF you did have an issue, it would likely be a clearance problem with the derailer, not what you describe. Regardless, it's doubtful this is your problem.

I'd agree with others that the most likely culprit is the missing spacer behind the cassette.

It's also possible that 2 different hubs could position the cassette with slightly different alingment, but I assume there is a standard spacing all manufacturers follow. I have 3 rear wheels that I can switch around without issue, maybe I'm just lucky.