dr_cantalope

I live a few miles down the road from my LBS. They guys there are really nice and we are all on a first name basis (probably due to the massive amount of money I spend there as opposed to my award winning personality). It's very convenient to just swing by on my way home after a ride for a quick adjustment etc.

Wednesday I told them to order up a new crankset & bottom bracket for the bike. It was supposed to come in on Thursday, which it did, but could not be put on because they didn't realize that the bottom bracket wasn't included with the cranks. So today, the bottom bracket came in, and I dropped my bike off to have it all installed. Originally I was told that they would order the 10 speed Ultegra set, and that using a 10 speed chain with my 9 speed cassette would be fine. But today, I was told that they were waiting for a call back from someone to verify that this would work.

Long story short, it turns out that the 10 speed crankset/chain will grind and prematurely wear out when used in combination with my 9 speed cassette. It's now that I realize the mechanics seem to know more about mountain bikes than road bikes. I'm really tempted to take my business to another shop, but the nearest one is about 30 minutes away as opposed to 5. Also, I've been looking online and found some great deals on components. What's the ettiquete on bringing parts into a shop to have them installed? On one hand I don't want to get screwed over, but on the other hand it's sooooo convenient to have a shop close by that knows me and won't charge me for service everytime they put the bike on the stand to adjust my derailleur or something.

What to do???

Ray Dockrey

I don't know why what you have know wouldn't work? Maybe somebody can give more info here but I would think you would just run a nine speed chain with the new cranks. I know the spacing is a little different between the chainrings so shifting may be a little slow but it should work just fine. The only difference between a nine speed chain and a ten speed chain is the outer width. The innner width is the same.

uga8589

Have you been happy up until this point? Everybody makes a few mistakes and a wrench at your LBS will make a few too. I would do my research before I go in there. As far as stuff you buy elsewhere, you have to always pay them for work that they do and honesty is the best policy for dealing with them. If you try to buy it from them and they are significantly more expensive, ask them how much they would charge to install. You may find that they will ultimately be less expensive if you buy it from them and have reduced to little labor costs. Good Luck

twahl

Give them a little credit. At least they are confirming the information rather than just slapping it together for you. Sounds like they want to be able to take good care of you and are willing to find information they don't have. A little delay while they do this is better than tearing stuff up, and finding a mechanic that would rather admit they don't know than pretend that they do is a rare and valuable thing.

dr_cantalope

Definitely a good point, and I do give them tremendous credit for wanting to do it right. As much as I have the "want it, need it, gotta have it right now" mentality, I am willing to wait in order to do it right. My concern stems from the fact that they seem to really know mountain bikes, and know road bike ok. I feel that knowing the compatibility issues of 9 speed/10 speed would be something that should come up more often and thus they would know the answer without going to an outside source (in this case I think it was their distributor). I have no problem paying extra for the parts, because I'm indirectly paying for knowledge, but when that knowledge isn't there... that's when I start to reconsidder things.

Kenal0

9 speed and 10 speed chain are the same dimensions except the side plates on the links are thinner on a 10 speed chain to accomodate the necessary clearance difference on the casstte between cogs.
I use a 10 speed chain on my 8 speed cassette without any problems at all. I do this because I upgraded my front derailleur to an Ultegra which is narrower than the original Sora.
I have hundreds of miles on this setup without any problem.
Kenal0

helmets save

+1 for doing research before hand. In addition, a fix to your "'want it, need it, gotta have it right now' mentality" is do to your own wrenching. It seriously is not that hard.

dr_cantalope

That's what I thought. I was under the impression that Shimano says that the cranks are 10 speed only because of marketing. But I want to make sure I get this right.

Hundreds of miles on your setup I'm not really worried about, I'm sure it will perform fine and there won't be any excessive wear. I'm looking to get thousands of miles out of it. I do about 200+ miles per week.

Kenal0

This still does not make any sense, the tooth spacing on a the 53 and 39 (if it is a double) 130 chainring is the same on 9 speed or 10 speed so I would definitely think a second opinion is in order. I think you need to feel comfortable that what you are getting will work and you will get the longevity but I am not sold on what they told you.
Kenal0

slide13

Don't worry, that is just what Shimano says to cover their ass and to increase sales of 10spd stuff. Your shop either doesn't know better or is just erring on the safe side by not recomending usage outside of Shimano's recomendations. Sounds like you have a good shop for the most part, I wouldn't worry about it too much.

dr_cantalope

The tooth spacing was not the issue (incidentally I am going for the 53 39). The issue in question is the spacing between the rings. Supposedly on the 10 speed the rings are closer together. Personally I think this is not an issue. I looked at some of the specs of the FSA cranksets and they openly say on their web site that the spacing between the rings is an average of the spacing between Shimano and Campy 9 and 10 speed systems and that the tolerances are so small there is virtually no difference.

Basically the more I go over this the more I convince myself that a 10 speed crank will work on a 9 speed cassette.

msheron

I was thinking the same thought.