Bicycle Mechanics - Double to triple crank conversion, Shimano 105

I am about to change my Shimano 105 double crank to a triple. I am looking at a triple crank on e-bay that says it comes with a BB5500 bottom bracket that measures 68 x 118.5 mm. I want to be sure it will fit what I have, what do the measurments mean?

I am also buying a left side 105 shifter for a triple ..do I need a new FD as well?

Thanks!

68 refers to the width of your bike's bottom bracket shell in millimeters. That's the common width for an English threaded road bike.

118.5 refers to the width of the BB spindle. That's the right length for an Octalink triple crank.

Assuming your bike has 9 rear cogs I'd double check the need for a front shifter. I could be wrong but I'm thinking Shimano 9-speed shifters were double/triple compatable. I know for sure that Ultegra's are.

If you want your bike to look and function like a factory set up you'll also need new front and rear derailleurs. The triple front derailleur has a wider inside blade to pick up the chain from the granny gear so it'll shift quite a bit better. The long arm rear derailleur takes up the additional chain slack that a triple generates.

I agree with Retro Grouch, check your 105 to see if you have enough clicks to handle the triple. I know for a fact that the ones with black/dark gray top caps are double/triple compatible. The earlier light gray models I'm not sure about. That can save you some $$ that can pay for the triple front derailleur. I remember a little while ago JensonUSA had the DuraAce 9spd triple FD's for like $35 or something.

Assuming your bike has 9 rear cogs I'd double check the need for a front shifter. I could be wrong but I'm thinking Shimano 9-speed shifters were double/triple compatable. I know for sure that Ultegra's are.



+1. I took 105 shifters that came with stock my Cannondale double and swapped them onto my Jamis triple. They worked fine with the triple. The Ultegra's I now have on Cannondale also will work with triple. Quick way to check is to disconnect the cable so shifter isn't affected by the derailleur limit settings and see how many times the shifter clicks.

Here's a good price on a new ultegra med cage rear.

http://www.cambriabike.com/shopexd.asp?id=68265&page=SHIMANO+ULTEGRA+RD-6500+REAR+DERAILLEUR

Man..you guys rock! I will check my left side shifter for the extra click and get a new triple compatable FD. I recently converted this bike (95 Paramount) from down tube shifters to brifters and it went slick as s*** mainly because of help I picked up here.

Thank you, thank you!

Mike

All 9-speed 105 shifters are double/triple compatible. Only recently has Shimano offered a double only 105 left shifter, that shifter is marked "DOUBLE".
Shimano triple shifters have 4 main positions for the 3 chainrings, plus a trim position for the smallest chainring. This allows for trimming on all 3 chainrings.

Al

All 9-speed 105 shifters are double/triple compatible. Only recently has Shimano offered a double only 105 left shifter, that shifter is marked "DOUBLE".
Shimano triple shifters have 4 main positions for the 3 chainrings, plus a trim position for the smallest chainring. This allows for trimming on all 3 chainrings.

Al


My shifters are Shimano 7 speed and they look like this:

Afraid I don't know about those. Start with all of the cable out and count the click stops as you reel the cable all the way back in. You may need to release the cable from the derailleur to get an accurate count.
For a triple crankset you will need a triple front derailleur. The wider cage will reduce chain rub.

Al

And it makes shifting up off the granny a lot easier.

bykemike, let us know how it goes.

Afraid I don't know about those. Start with all of the cable out and count the click stops as you reel the cable all the way back in. You may need to release the cable from the derailleur to get an accurate count.
For a triple crankset you will need a triple front derailleur. The wider cage will reduce chain rub.

Al

7 speed? Sti? Shimano sora. They came in both double and triple configurations.

I looked at the Shimano Tech Docs site and could only find the 8spd Sora datasheet. The 8spd are separate double and triple parts. My guess is that your 7spd Sora's are the same and thus, you won't be able to use the shifter for your triple upgrade.

Tested the Sora and it is a double so now to hunt down a triple...

Mike

So here I am hunting down a Sora triple shifter and I realize I can buy a set of shifters for a 9 or 10 speed rear with a triple front for low dollars..especially if I am looking at units that may be dinged or scratched.

Now I am buying a triple crank, FD, RD and a set of shifters I am thinking why not dump the seven speed cassette and go to a 9 or 10 speed cassette? (hell, why not a new bike?:>))

Can I make my bike a 9 or 10 speed at this point? It is a 95 Paramount steel frame.

Mike

So here I am hunting down a Sora triple shifter and I realize I can buy a set of shifters for a 9 or 10 speed rear with a triple front for low dollars..especially if I am looking at units that may be dinged or scratched.

Now I am buying a triple crank, FD, RD and a set of shifters I am thinking why not dump the seven speed cassette and go to a 9 or 10 speed cassette? (hell, why not a new bike?:>))

Can I make my bike a 9 or 10 speed at this point? It is a 95 Paramount steel frame.

Mike

You can if your bike is already 8/9/10. If your 7cassette has a .~4.5mm spacer on the backside then you can use 8/9/10, assuming it's a shimano hub. If not you'll need a new rear hub.

To the OP: Any chance that Double is has a 130 BCD, and if it does would you like to get rid of it?

Shimano triple shifters have 4 main positions for the 3 chainrings, plus a trim position for the smallest chainring. This allows for trimming on all 3 chainrings.

Per a (possibly new) tech doc that I found on Shimano's website, it's not quite that simple. Different levels and series of shifters have different trim options. For instance, Ultegra 6500 shifters have 3 main positions plus a trim for the inner and middle ring. Ultegra 6600 shifters have 3 main positions plus a trim position for all three chainrings. I found the tech doc after getting really annoyed that I could not find the same big ring trim position on my 6500 shifters like I had with my 6600 shifters.

Link: http://bike.shimano.com/publish/content/global_cycle/en/us/index/tech_support/tech_tips.download.-Par50lparsys-0030-downloadFile.html/06%29%20Trim%20Function.pdf

Note that this document unfortunately does not cover all Shimano shifters, just select models.

I did a 105 double to triple, just changed the front der. Shifters and BB were OK but I was sure to shop online for a triple that would accept the BB on there already.

"bykemike, let us know how it goes. "


It went way better than expected! Today I found a 2009 Cannondale Synapse 56cm triple on Craigslist for $500! including pedals, shoes, helmet, front/rear lights and a wired computor. I left work right away and was at the guys house 20 minutes after he listed it.
It needs a chain (rusted) and a look over but this was way better than trying to convert my '95 Paramount. The deals are out there my friends.

Mike