|Tiagra-105 crank upgrade||Alr|
Dec 6, 2001 1:00 PM
|Is it worth it to upgrade cranks from tiagra to 105. Is there much perfomance benefit from the hollow tech system on a road bike? Also, on a two chainring system can you get a bigger cassette than a 12 - 25 eg. 27 or 28 teeth low sprocket.|
|re: Tiagra-105 crank upgrade||Chen2|
Dec 6, 2001 2:09 PM
|I assume you could run an HG 6500 (Ultegra) 12-27 cassette with the 105 crank, as long as the chain and rear derailleur and rear shifter are 9 speed.
|re: Tiagra-105 crank upgrade||allervite|
Dec 6, 2001 4:30 PM
|Definately an upgrade. 105 Hollow tech is much lighter, but make sure you get the hollow version. A 27 will work, anything more and you are probably going to have to get a long cage rear derailleur.|
|re: Tiagra-105 crank upgrade||cyclaholic|
Dec 6, 2001 9:42 PM
|I am in agreement that an upgrade is definitely appropriate. But I would advise that if it is at all possible, you should go ahead and make the jump up to Ultegra.
I do have a compatibility question for you, though. The Tiagra cranks that I've changed out have all had square taper spindles. (I had a real fight getting one of them off once!)Unless my mind is playing tricks on me, the Shimano 105's are now octalink, which means they must go on a splined bottom bracket.
Whatever the compatibility issues, moving to an Ultegra crank combined with an Ultegra BB will make a significant difference in both weight and performance and it won't cost much more. Now I understand how $5 here and $12 dollars there adds up. But you can probably find a ULT crank for $90 or so and a Ultegra BB for around $30. Very reasonable.
All that said, the 105's have a good reputation. Either way, you'll be happier. Just make sure that you have the right crank for the BB - and vice-versa.
|re: Just the Facts||allervite|
Dec 7, 2001 3:31 PM
|105 cranks--$99.,643 grams; Ultegra cranks--$129.00, 663 grams.
However, with Ultegra Cranks you could buy a Dura ace bottom bracket--$48.95, 173 grams. The 105 BB--$27.,250 grams.
A gram is about the weight of one raisin. Raisin weights get expensive don't they.
|re: Just the Facts||cyclaholic|
Dec 7, 2001 8:44 PM
|I must quibble with these figures you've presented.
I know that weights for the components tend to waver from vendor to vendor, but I don't think there is any disputing that Ultegra cranks are lighter than Shimano 105 cranks. For instance, I am using a catalog from one vendor and it gives these weights:
Ultegra Double crankset: 632 grams
Shimano 105 Double crankset: 680 grams.
If there is are questions concerning this, one may consult the Shimano website where, if memory serves, weights are listed.
And these must be retail prices you are listing. I have bought a couple of Ultegra cranksets from an internet vendor at $90. You can certainly find 105 cranksets cheaper than the $99. A careful search of the internet vendors will find prices much lower than those you've listed.
Yes, you can easily find Dura-Ace bottom brackets in the mid $40 range. But I bought my last couple of Ultegra BB's for $29, just a little more than the best price you can find for a 105 BB.
Now as to whether or not it is worth it to spend $29 on an Ultegra BB or $48 for a DA BB, I will withhold my judgment. But since this is roadbikereview.com, I think it would be wise for the interested upgrader to read those reviews and evaluate their worth before making such a decision.
And you are correct about those grams. On many components, it ends up costing you a dollar or so for each gram saved. Kinda backwards, isn't it?