Changing 9 speed triple to a double



southwind

New Member
Sep 27, 2004
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Ok, here's the deal...my Giant road bike came stock with a Shimano triple 9 speed and I am thinking about changing it to a double crankset instead. The Trek Store I went to said with the Shimano 9 speed I can change my crankset to a double without having to replace my shifters or my cassette. Cost installed will be about $280.00. My question is, will this change improve performance very much. I never use the small ring on my triple. The triple crankset I currently have is TruVativ so I guess the Shimano will be an upgrade.
 
southwind said:
Ok, here's the deal...my Giant road bike came stock with a Shimano triple 9 speed and I am thinking about changing it to a double crankset instead. The Trek Store I went to said with the Shimano 9 speed I can change my crankset to a double without having to replace my shifters or my cassette. Cost installed will be about $280.00. My question is, will this change improve performance very much. I never use the small ring on my triple. The triple crankset I currently have is TruVativ so I guess the Shimano will be an upgrade.
There are a number of ways to make a double crankset bicycle from one that originally had a triple. $280.00 sounds to me like the price of doing a "factory look" conversion including both derailleurs.

As for improving your performance, my bet is it will make no change at all. Possible arguments include better shifting (what percent of your total riding time do you spend front shifting? That's the maximum it can save you) and chainline issues (How often do you use the big ring with the biggest rear cogs?) Oh yeah - whenever somebody does something to their bike that they can't justify otherwise, they always say that it weighs less. (I can't argue that one.)
 
Wow! Almost thought we'd have a week go by without this question asked, but no luck. Search the forum, it should be a "sticky" by now. Depends on how much dough ya wanna blow. Rip off the granny ring and "PRESTO" ... you have a double.
 
capwater said:
Wow! Almost thought we'd have a week go by without this question asked, but no luck. Search the forum, it should be a "sticky" by now. Depends on how much dough ya wanna blow. Rip off the granny ring and "PRESTO" ... you have a double.
Sorry to bother you. I don't spend much time on here and didn't search the previous posts to see if this has been brought up. Thank you for taking the time to comment.
 
benkoostra said:
I would go to a different shop. That's too much money for a simple procedure.

Also you can get a double pretty cheap from here:

http://www.nashbar.com/results.cfm?category=81&subcategory=1034&storetype=&estoreid=&init=y&pagename=Category%3A%20Cranks
They quoted $20.00 for labor, the rest being the cost for the crankset and cups for the BB. I had thought about looking online for the parts at a cheaper price and then just paying the $20.00 for install. If I buy them myself, I just want to make sure I get the right parts that are compatible with my 9 speed shifters.
 
southwind said:
They quoted $20.00 for labor, the rest being the cost for the crankset and cups for the BB. I had thought about looking online for the parts at a cheaper price and then just paying the $20.00 for install. If I buy them myself, I just want to make sure I get the right parts that are compatible with my 9 speed shifters.
I wouldn't worry that much about the crank. The spacing is almost exactly the same between a 9 and 10 speed crank.

Get that cheap Dura Ace! It's a bargain and will have the bling factor that you know you crave.:D
 
southwind said:
They quoted $20.00 for labor, the rest being the cost for the crankset and cups for the BB. I had thought about looking online for the parts at a cheaper price and then just paying the $20.00 for install. If I buy them myself, I just want to make sure I get the right parts that are compatible with my 9 speed shifters.

Virtually any crankset will work with your 9s set-up--those labelled 8s, 9s, or 10s will all work.

As suggested, if you don't need the inner ring, just remove it--or just don't use it. You can lock out the shifting to the inner ring with your front derailleur stop.

I guarantee you that you will ride no faster on your bike with a double than with a triple. You will also notice very little (if any) performance difference with the shimano vs. truvativ.
 
John M said:
Virtually any crankset will work with your 9s set-up--those labelled 8s, 9s, or 10s will all work.

As suggested, if you don't need the inner ring, just remove it--or just don't use it. You can lock out the shifting to the inner ring with your front derailleur stop.

I guarantee you that you will ride no faster on your bike with a double than with a triple. You will also notice very little (if any) performance difference with the shimano vs. truvativ.
Thanks for the info. Sounds like there is a consenus on here that it would be a waste of money to buy a double crankset. I'll look into the stop on the front derailleur you mentioned. Hadn't heard of that before. My largest ring is a 52 and I wondered if a 53 would make much of a difference or not.
 
southwind said:
Thanks for the info. Sounds like there is a consenus on here that it would be a waste of money to buy a double crankset. I'll look into the stop on the front derailleur you mentioned. Hadn't heard of that before. My largest ring is a 52 and I wondered if a 53 would make much of a difference or not.
Your middle ring is probably a 42. Buy a 39 and switch it out. YOou won't notice the difference between 52 and 53, but you will between 42 and 39.
 
benkoostra said:
Your middle ring is probably a 42. Buy a 39 and switch it out. YOou won't notice the difference between 52 and 53, but you will between 42 and 39.
Good call. Looks like you guys are saving me about 300 bucks. The LBS won't be too happy though...
 
The only other consideration is that my position on the bike was recently measured and it was recommended that my cranks should be 172.5mm rather than the 170mm that I am currently using. I've ridden this set up since 2004 and haven't had any problems, but am not sure if this would make a difference in performance either.
 
Just go with the cheap plan. Crank arm length is really not that big a factor. a 172.5 creates a circle that is 5mm bigger in diameter than a 170.
 
southwind said:
My question is, will this change improve performance very much.
None at all.

Until one day you go somewhere with a mountain and spend the entire ride wishing you'd not downgraded from the triple.
 
Interesting, in the 3 years I've had a triple on my bike most have been acting as though triples are nice for beginners but something you move away from as you get stronger. But now that I'm changing to a double, everyone on this forum is saying it is better to keep the triple. I'm guessing most of us spend money on our bikes somehow, some even upgrade to an entirely new bike just to get a carbon frame even though they don't compete. I bought the components this weekend on coloradocyclist.com for a decent price and don't feel bad about making the change from Truvativ to Ultegra. I plan on keeping the bike a long time and if this makes me happy enough to keep from buying an entirely new bike then I think the price is worth it. Thanks for all the comments though. I'd say the consensus was don't change to a double.
 
southwind said:
The only other consideration is that my position on the bike was recently measured and it was recommended that my cranks should be 172.5mm rather than the 170mm that I am currently using. I've ridden this set up since 2004 and haven't had any problems, but am not sure if this would make a difference in performance either.
Look, if you think you'll have better performance with a double and have the money to burn....then by all means do it. The perceived (in your mind) difference will make you go faster ...at least for the first few weeks.

Also, there's no point in getting up every Saturday morning for the group ride and having second thoughts about your bike.

If you've got the money and makes you happy, then change the cranks.
 
LeDomestique said:
Look, if you think you'll have better performance with a double and have the money to burn....then by all means do it. The perceived (in your mind) difference will make you go faster ...at least for the first few weeks.

Also, there's no point in getting up every Saturday morning for the group ride and having second thoughts about your bike.

If you've got the money and makes you happy, then change the cranks.
Probably the main motivation at this point is feeling good enough about my bike so I don't go out and spend a lot on a carbon frame. I'm one of the few devoted cyclists in my area still riding an aluminum frame, so I guess for me this a much cheaper way to upgrade my bike to satisfaction. Although I was curious about a possible boost in performance, it looks like the answer to that is no.