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Newbie needs help on basic 105 configuration....(11 posts)

Newbie needs help on basic 105 configuration....kkwiatek
Oct 7, 2001 1:05 PM

I am thinking of buying an 2000 Giant OCR 1 for $700 with 500 miles (is this a good deal?). It has full 105 components. It has 21 speeds, which I find odd since I thought 27 was standard on this year, but in-any-case, I am thinking that I want to make it a 24 or 27 speed. BUT I am not sure if this is technical possible, and HOW would I do this? Is it just a matter of swapping out the rear cassette?

re: Newbie needs help on basic 105 configuration....Jofa
Oct 7, 2001 2:20 PM
Firstly: the actual number of gears isn't very important.

Secondly, it's probable that this bike is an 18 speed: it has 9 cogs attached to the back wheel, and two chainrings attached to the pedals (9*2=18). 27 speeds occur when you choose three cogs at the front (near the pedals) rather than two (9*3=27).

It's only in recent years that the third chainring has become an ordinary option, and its primary function has been to increase the range of the gears, rather than to 'fill in the gaps'. The popularity of the mountainbike, which was designed to be ridden up slopes far steeper then ever would be allowed for public roads, originated this design: the subsequent resurgence of road cycling went with it.

It's a widely-held belief amongst new or novice cyclists that very many gears are always beneficial: this is a reasonable conclusion, given the prevailing theory, but it generally encourages too great an emphasis on what is a relatively unimportant element of the cycling experience. The 'third' (smallest- often known as the 'granny ring) chainring usually allows for much lower gears than the others, which are intended for use whilst climbing long grades: whether you feel you need this gears is a matter of personal preference, but remember that the hills haven't got any steeper since your recent ancestors were happily riding up them on what might seem to your eyes to be astonishingly high gears: maybe, after all, you'll get by with just the two rings.

I'm approaching a position which might be judged to be snobbery... the cycling fraternity is a sensitive group, maybe I should back away. My point is: you can make your gear range and number more or less whatever you want, according to your demands: as you suggested, new cassettes are cheap, and though a conversion from double to triple at the front is more complex, it's something you probably won't want to do, once you've ridden a little and understood the way the gears work. You assuredly haven't been cheated: but by all means, choose gears which favour your climbing.... you can always freewheel downhill.

Enjoy, Jofa
re: Newbie needs help on basic 105 configuration....kkwiatek
Oct 7, 2001 3:15 PM

Thanks for your input. I heard there were people like you out there... that had such purest views. But I do not want to debate such things. I just want to know if I can take my current 105 components with a triple crank and 7 gear cassette, can I throw in a 8 or 9 gear cassette, or would that require changes to the durailer (or however you spell it)???

re: Newbie needs help on basic 105 configuration....Jofa
Oct 7, 2001 4:40 PM
I didn't mean to paint myself as an apologist for high and difficult gears.... though that's a fair response. My intented point was that it doesn't really matter. As the other respondent said, if this is genuinely a 2000 bike, then it will have 9 cogs at the back. If it only has seven, then you have been sold a much older bike, as it took some time for the ordinary number of gears to move up to 8 let alone 9; the only potential problem here is that you night have been cheated. I think this is unlikely however.... count the cogs at the back... I bet you find 9.

If you do have only 7, for whatever reason, then it's usually not practicable to try to change up to 8, 9 or 10, as this would require a sea-change in the entire gear- system of your bike. If you wanted lower gears, then it's usually possible to install triple chainring system from an existing double- but complex and expensive; otherwise, get a cassette which includes a big 28 tooth cog, or something. My original point still stands: it's not the number of grears, but the range which they cover, which matters.

re: Newbie needs help on basic 105 configuration....Birddog
Oct 7, 2001 4:18 PM
If this bike truly only has a 7 speed cassette, then someone has altered it or it isn't a 2,000 model. 7 speed cassettes as new equip were phased out back in the early 90's. Measure the space between the rear dropouts, if it is 135mm or about 5and1/2 inches then it should accept an 8 or 9 speed cassette. Does it have STI shifters on the brake levers? How many clicks does it have when you shift it? You will probably have to remove the chain from the cassette to give it full range.
re: Newbie needs help on basic 105 configuration....kkwiatek
Oct 7, 2001 6:10 PM

Thanks for the info... What do you mean by "STI Shifters" ? It has the little paddles behind the brake levers, if that is what you mean... What do you mean "how many clicks does it have"?

re: Newbie needs help on basic 105 configuration....Birddog
Oct 7, 2001 9:21 PM
OK, now we know that you at least have an 8 speed set up. That would give either 16 or 24 when you multiply by chainrings up front. Assuming that you are correct and you have only 7 gears on your cassette (rear cluster at wheel), you can elevate the rear wheel of the bike (put it in a trainer or on a workstand) and by hand turn the pedal crank. While turning, click the right hand brake/shift lever by pushing in toward the center of the handlebar until the chain has climbed up to the largest gear on the back. Push one or two additional times to make sure it is as far to the inside as it will go. Now while turning the crank, push the smaller paddle behind the brake lever until it won't click any more. As you do this count how many times it clicks. If it clicks 8 distinctive times then you have a 9 speed setup. If it clicks only 7 times then you have an 8 speed. You may have to remove the chain from the chainring in front and hang the rear part of the chain on the hook just above the cassette, and do this without turning the pedal crank. Just count the clicks from the small paddle as above. Again, if there are truly only 7 gears on the cassette, then somebody has replaced this for some unknown reason.
re: Newbie needs help on basic 105 configuration....Chen2
Oct 10, 2001 5:53 AM
Shimano did have a 7 speed STI in 1995, had one.
re: Newbie needs help on basic 105 configuration....Birddog
Oct 10, 2001 8:51 PM
I learn something new every day!
re: Dropout spacing...& speeds.Rusty Coggs
Oct 8, 2001 5:55 AM
8,9,10 speed rear dropout spacing on road bikes is 130mm.Sora was and may currently still be available as 7 speed.
Good deal??? YES.jtolleson
Oct 8, 2001 1:12 PM
The other part of your inquiry... is it a good deal? Yes. Especially if you think that the 500 mile figure is an honest one. Look for wear on the cogs on the front and rear cassettes. A full 105 bike from a reputable manufacturer for $700 is a fine deal. You didn't say what pedals will be included.

I'd relax over the gearing. You've got a wide range already with a triple in front, and the addition of other gears will make not one bit of difference, IMHO (my current ride is a 9 spd ultegra triple... hey I'm in Colorado ... and older bike is a 7 spd. RSX triple, and as far as number of gears and range there is no perceptible difference).