RoadBikeReview.com's Forum Archives - Components
DOG, Tell me how your XTR rear Der.works.......(18 posts)
|DOG, Tell me how your XTR rear Der.works.......||Len J|
Nov 7, 2001 4:45 AM
|on your climbing bike.
I think I remember reading that you had put an XTR rear Der on your climbing bike in order to give you the capability to put larger toothed rings on your rear cassette. Couple of questions:
1.)How does it shift? Same, worse, or better then D/A.
2.)Do you ever use it with a "regular" road cassette (i.e. 12X25, 12X23)? How does it shift?
In thinking about it, it seemed like this combination would give me the most flexibility (for the dollars), short of changing to a triple. Since most of my riding is on the flats, I'd use a 12X23 (or my custom 15X23) most of the time changing to a 13X34 or 13X32 when I ventured into the hills for a century or charity ride. This flatlander needs flexibility when he ventures into the mountains. I really am interested in the downsides, if any, of this setup.
Thanks in advance for any info.
Nov 7, 2001 6:44 AM
|Excuse me for breaking in, but there's a less expensive alternative if you can live with a 13x30. I bought a 'century special' cassette from Sheldon Brown a couple of months ago to use on one particularly steep climb at the Six Gap Century in Dahlonega, Ga. It appears to be a 12x27 Ultegra cassette modified by dropping the 12t and adding a 30t. The gears are, 13-14-15-17-19-21-24-27-30. I installed it, adjusted the b-screw in until the upper pulley cleared the 30t cog and it worked fine with my Dura-Ace r.der.|
|re: XTR rear Der.works||Chen2|
Nov 7, 2001 7:15 AM
|Excuse me also, but we replaced the rear derailleur on my wife's Ultegra equiped road bike and the shifting performance is as good as with the original der and cassette. The down side is the "wide ratio" gaps between the 12, 14, 16, etc. My wife is not mechanically inclined and I was surprised that she immediately started complaining about not being able to find the right gears to match speeds with me or others drafting on a flat ride. I like 12x23's idea of a closer ratio cassette, but was surprised he was able to engage the 30T with a D/A rear der. I've always heard it was limited to 28T, Shimano says 27T max. Always like to hear about someone beating the system.
I may try a custom cassette on the wife's bike. She sure doesn't need a 12T.
|engaging the 30||12x23|
Nov 7, 2001 7:26 AM
|I called Harris Cyclery and asked this same question. They advised a little more chain might be required, and that I might have to fiddle (b-screw/cable tension) with it a little bit. That's all that was required. I bought a Sram PC89R chain to use with this gearing and think it is one, maybe two, links longer than what I use with my 12x23 cassettes.|
|Do you.......||Len J|
Nov 7, 2001 7:34 AM
|switch back & forth between the Cassette with the 30 & a regular 12X23 & if so does the extra links cause any performance problems when using the 12X23 cassette?
Nov 7, 2001 9:28 AM
|I've only used this cassette once. I have a chain, PC89R, dedicated to use with this combination. It is no more difficult to switch, thanks to the Sram powerlink, than having to adjust cable tension when swapping different brands of wheels. The b-screw adjustment is pretty easy, also.
I only intend to use this combination when riding hilly centuries with very steep climbs, such as Six Gap.
|Thanks. nm||Len J|
Nov 7, 2001 12:37 PM
|Any problems........||Len J|
Nov 7, 2001 7:33 AM
|switching back and forth between 12X32 & 12 X23 (in terms of performance/ I can't tell from your post if you do this?|
|re: XTR rear Der.works||Chen2|
Nov 7, 2001 10:07 AM
|Actually I think the XTR der and cassette are perfect for a mountain dedicated road bike, the down-side that I mentioned in my earlier post is with respect to flatter rides when you're looking for a sweet spot rpm/speed combination, especially on windy days, that's when the close ration cog sets really pay off.
|Are you saying that you don't change cassettes........||Len J|
Nov 7, 2001 10:50 AM
|on the XTR equipped bike?
If I haven't been clear, let me try again. I am thinking of equipping my bike with an XTR rear Der. and using it for both Daily flat riding & mountainous riding. For the majority of my riding,(Flats) I would use a 12X23 (or 15X23 corn cob) cassette. When I ride in the mountains I would change the cassette to a 13X32 or 13X34. I am trying to determine how much of a degradation in shifting should I expect when using the 12X23 with the XTR.
|Are you saying||Chen2|
Nov 7, 2001 11:42 AM
|Sorry, didn't fully understand your post ('cause I didn't read it closely). We haven't tried running a road cassette on the XTR derailleur. I believe that will work, but should have stayed out of this and let Doug answer your question.
|No Problem.......||Len J|
Nov 7, 2001 12:20 PM
|I appreciate your perspective. I just couldn't tell if you had run a road cassette. If you do put a road cassette on your wifes bike, let me know how it works.
Thanks for your attention.
Nov 7, 2001 12:44 PM
|It works perfectly fine. Since it has the range for 11-34, it works with anything in between, too. Works with the DA Sti shifter. No issues. Works just as well as DA or Record. Don't think I had even one missed shift in the 508.
You will need a longer chain, though. DA again.
What's nice about this setup vs. a triple is that you can easily change it to a narrower range; just change the cassette or a wheel with another cassette.
Nov 7, 2001 12:58 PM
|that's what I expected, but I didn't want to assume.
As always, Appreciate it.
|One other thing.......||Len J|
Nov 7, 2001 12:59 PM
|Wonder why more people don't try this?
Seems like the best of both worlds.
|it looks a little dorky||Dog|
Nov 7, 2001 8:24 PM
|That 34 is really big. If there was an 11-30 XTR (titanium), that would be better. But, I did use that 34 on the 508. Nothing like spinning away up a long steep hill when you are dehydrated, nauseated, bonked, and sore.
|One other thing.......||breck|
Nov 7, 2001 8:32 PM
|Saved the remarks for late as my set up is older, etc ... |
Triples allow a closer ratio cassette and more ops to get the straight chain line, etc. Old guys like me have to run the triple in the steep mountains here about with grade between two and twenty five percent(!).
My seven year old mountain road set up is 1995/7 mix-n-match Dura-Ace dt shifters, cassette, chain; 105 triple 175mm 30-42-52 crank/chain rings, front dX; XTR rear dX ...on the '96 OCLV & shifts perfectly regardless cassette used and have all the D-A 1997 8-speed fixed yoke cassettes and earlier pinned cassettes too for EZ custom build. But run mostly 12-25 fixed cassette rear for mountain w/ the triple.
You may want to adjust your chain length for max cassette tooth to avoid accidental rear dX damage just in case you forget switiching cassettes. Extra wheel sets with specific cassette already installed are fine too but you may/will have to make minor rear dX adjustment as you change wheels. No biggie.
Hay, everyone has a slightly diff take due to all factors, etc. Experience is the key and fun besides to try the combos. If you build your own kit gives you lot of leeway for experimenting except Shimano likes to throw the spanner into the mix from the older 7-speed compatibility to the current 9-speed. Have no intention of changing from the 8 :)
IMHO, the ~1995 eXTRa expensive ($85 at the time) mid-cage model M900 was one of the most beautiful rear mountain derailleurs made, unlike the gray or black ones to follow. Bought three as run this on the MTB full XTR Klein too; should have bought five!
|follow on ...||breck|
Nov 8, 2001 11:07 AM
|Slightly off thread but nun the less & apologies to those "in the know" :) |
Some may want to run a 'short chain' for their max cog tooth cassette so as to have less slack when using the less toothed cassettes regards more mountain type cass's such as the 12/32 whilst also wanting to use the 12/28 or 12/23 , etc. with the least amt. of chain slack.
The idea here is that you never expect to be in the 53/32 tooth and guard against it. However in the heat-of-the-climb, esp. during the group "fun" ride, translate "race" you may find your self too far upon the cassette in the big ring and jam the derailleur. It can happen :)
If you cannot get the rear wheel out of the drop outs to un-jam the rear dX, simply use the chain tool (you always carry one, right?) and un-pin the chain. Hopefully the Dx is OK.
And speaking of true bull-dog-low mountain gearing for the MTB (as opposed to road) on steep narrow-twisty-hard-turn rocky rutted single track, we locals used to use a White Limbo Spider adapter to replace the small ring MTB 24t granny with an 18t. The Limbo replaced the small ring and had a clip to use Sun Tour type A freewheels as the low-gear chain-ring giving u options from 16t to 22t to use. This was 7-speed and before compact gearing. Severe chain suck ruled in them dayz :) But hay, the one thing the 18/32t(34t! for sum) combo at less than 15 inches of gearing surely taught was balance. The ability to not dab was prized more than any other skill esp on the feared Oriflamme Gold Mining grade "trail" path near the old (est.1870) Julian, Ca. mining town that took me thirty or more tries to master.