Cassettes, chainsets, derailiers and shifters.



Fixinabike

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Mar 27, 2012
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I think this could be the first of many posts. I decided to build my own bike, despite not really knowing much about bikes. But I do want to learn.

My question to get me going is this:

The frame I have bought has mounts for downtube shifters. Does this mean I have to use them, or can I get away with the bar end shifters I have also got? And how does this affect the rest of the gear I get? I have a Shimano 600 chainset, but nothing else so far...

Also, Is this a massive can of worms?

If you fancy having a laugh at total amateur trying to build a bike, read this:

http://fixinabike.wordpress.com/2010/09/24/so-far/

Thanks!
 
Fixinabike said:
I think this could be the first of many posts. I decided to build my own bike, despite not really knowing much about bikes. But I do want to learn. My question to get me going is this: The frame I have bought has mounts for downtube shifters. Does this mean I have to use them, or can I get away with the bar end shifters I have also got? And how does this affect the rest of the gear I get? I have a Shimano 600 chainset, but nothing else so far... Also, Is this a massive can of worms?
You do not have to use the downtube shifter mounts. You can use bar ends if it you so desire, and you can even use a modern group with integrated shift/brake levers. Heck, if you were of the mind you could even use an electronic group. I believe Shimano makes pieces that replace the downtube shifter with a cable stop.
 
Yes they do - shown in step 4 of the pdf link below:

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Dura-Ace/SI_6RP0A_001/SI_6RP0A-001_En_v1_m56577569830651784.pdf

I can't remember if they're included with the bar end kit or not... but regardless, they're an easy bolt on and have a handy cable adjuster.

Shimano still make old style downtube shift levers that index 10 speed - in addition to the STI (brake/shifter combo), bar end shifters and electronic shifting.

Depending on the age of the frame you might have 126mm spacing between the rear dropouts. Wordpress and the companies internet filter don't get on too well, so I'm not looking at that link right now but for an older bike the only issues you might encounter are spacing for the rear wheel (126mm rather than 130mm) and replacement forks if it doesn't have an "aheadset" style system.
 
Aah, that's very useful, thank you. I was having reluctant visions of trying to drill holes through the downtube mounts to route the cable up to the handlebars! Thankfully Shimano have a much better solution.

I do already have the bar end shifters, I'm not sure how many speeds they index, I guess that could dictate which cassette I need to get, along with the spacing on the rear dropouts. The seller on ebay from whom I got my frame wasn't even sure what brand it is, he suggested Claude Butler or Carrera which I think stands to reason as it has an oval shape downtube. I don't have a headset yet, all I know is that it seems like the stem will fit ok in the top of the forks. I can feel a lot more research coming on!

Than you both for your help- very useful, and good foundations for my learning curve.
 
I definitely will post pictures, though I think it may be a fairly slow moving project! Part of the reason I started the blog was for an excuse to take lots of photos, so you can follow my progress there in the meantime. Link in my original post.
 
Ok, so the rear dropouts are spaced at 130mm, so I guess this means I can fit a 10 speed cassette on, although my shifters only index 8 speeds. I wonder what happens if I remove a couple of gears from a 10 speed cassette, or If I have to fit one whole but just have two of the gears redundant...hmmm!
 
Fixinabike said:
Ok, so the rear dropouts are spaced at 130mm, so I guess this means I can fit a 10 speed cassette on, although my shifters only index 8 speeds. I wonder what happens if I remove a couple of gears from a 10 speed cassette, or If I have to fit one whole but just have two of the gears redundant...hmmm!
You can still buy 8 spd cassettes. Besides, the spacing on a 10 spd cassette is different:
  • Shimano 8 spd spacing = 4.8mm; Shimano 10 spd spacing = 3.95mm
  • Campy 8 spd spacing = 5mm; Campy 10 spd spacing = 4.12mm
  • SRAM 8 spd and 10 spd spacing works with Shimano's.
 
Originally Posted by alienator .


You can still buy 8 spd cassettes. Besides, the spacing on a 10 spd cassette is different:
  • Shimano 8 spd spacing = 4.8mm; Shimano 10 spd spacing = 3.95mm
  • Campy 8 spd spacing = 5mm; Campy 10 spd spacing = 4.12mm
  • SRAM 8 spd and 10 spd spacing works with Shimano's.
Wow, you know your stuff! So this must be where the correct size chain is important. I can't work out if I should be more or less concerned than I am that everything I buy is compatible.

Thanks alienator, I have just won an ebay auction for an 8 speed cassette with 11-28 cogs which seems comparatively wide range. I feel my learning curve is accelerating at great speed thanks to your knowledge!