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XT/XTR or PW+Middleburn?

2K views 18 replies 9 participants last post by  Wildeyes 
#1 ·
Being an older dinosaur, I have yet to make the jump to external BB-type cranks. After sifting through this subforum there seems to be a pronounced discussion with maintenance and life expectancy of the external BB bearings. No doubt that is were the current trend is heading but there is still the old square taper BB and cranks available.

So the scenario is with a new ride in the works what would you folks suggest between a current production XT or XTR crankset compared to a Phil Wood BB and Middleburn crankset?

Weight difference(s), stiffness, Q-factor etc.

Bling be damn, performance is paramount.

Suggestions/ideas are most appreciated!

TIA!
 
#2 ·
If you really wanna crank that is GUARANTEED go for Middleburn.

Skip the Phil Wood Square Taper non-sense, and use an SKF ISIS BB.

If you're a weight-weenie, XTR, though I suggest you save the weight on your wheels not your cranks. Of course, when seeking thoughts or advice, the type of riding you do would be a helpful piece of information: singlespeeding, geared, free riding, crosscountry, short track, 24 hour racing, et all.
 
#4 ·
verrocchio100 said:
Being an older dinosaur, I have yet to make the jump to external BB-type cranks. After sifting through this subforum there seems to be a pronounced discussion with maintenance and life expectancy of the external BB bearings. No doubt that is were the current trend is heading but there is still the old square taper BB and cranks available.

So the scenario is with a new ride in the works what would you folks suggest between a current production XT or XTR crankset compared to a Phil Wood BB and Middleburn crankset?

Weight difference(s), stiffness, Q-factor etc.

Bling be damn, performance is paramount.

Suggestions/ideas are most appreciated!

TIA!
I would use the Middleburn and PW with a 5-bolt spider.

Weight, stiffness and Q differences? I really do not care much but I do care about reliability and durability.
 
#5 ·
Thanks folks for the replies!

And you're right Nat, I left out that pertinent information.

Frame is gonna be a 4" variety built trail-friendly. Not weight wennie light, but well proportioned ;) Don't get me wrong I like light, but light parts will be employed on the right pieces of equipment.

As for riding, pretty much everything singletrack/fireroads/x-country/all day epic adventures, just no DH/Freeride/hucking/etc with this particular rig.

Geared, yes. Been thinking of using a 2x9 setup just to simplify things. I find myself not using the big ring as much with the riding I am doing now and days so the Middleburn Duo set up is quite intriguing. Though I don't know how well I can push a 29/42 set up with my current level of fitness. So that leans me back to a triple set up.

The ISIS-style BB is intriguing and I had no knowledge of the SKF BB until you mentioned it Nat. The Phil Wood boys are just down the street from me, and their products are on some of my bikes so there's gotta be a noticeable advantage to go with the SKF ISIS system.

You're right though Shiggy, reliability/durability are crucial considerations. But I still consider the Q-factor as and important factor for ME. As for my riding style and pedal stroke, I have found that the older M900 XTR cranks with the UN91 BB the ideal width for me.

Keep the info coming!
 
#6 ·
verrocchio100 said:
...You're right though Shiggy, reliability/durability are crucial considerations. But I still consider the Q-factor as and important factor for ME. As for my riding style and pedal stroke, I have found that the older M900 XTR cranks with the UN91 BB the ideal width for me.

Keep the info coming!
I think you will find the Middleburn to be narrower than the outboard bearing cranksets.

The PW BB will give you some options and slight adjustment but the real limiting factor will be the swing arm of the frame. The crank arms can only be so close together before they hit.
 
#7 ·
Good point Shiggy! Another issue to contend with; rear suspension flex/activeness, damn.

As I ponder this delimma of mine, how can one quantify flex in the crankset? I mean, how does one even "feel" it? I weigh 165lbs geared up and run the M900 cranks with UN91 and RF Turbine LP with PW BB and honestly, I can't tell the difference.

But there must be SOME validity to this argument.

Hey Nat, not to steer this thread off too far but why are you a proponent of the Ultegra 11-27 cassette versus a 11-32 or 11-34 setup with a 29/42 Duo setup? It would seem to me that the 29/27 combo wouldn't yield a very low gear?

Teach me...
 
#8 ·
verrocchio100 said:
why are you a proponent of the Ultegra 11-27 cassette versus a 11-32 or 11-34 setup with a 29/42 Duo setup? It would seem to me that the 29/27 combo wouldn't yield a very low gear?
You're right, it is not a very low gearing, and by no means am I a masher, however, at times on the lowest gear with a Ultegra 12-27 and 29/42 setup I'll have to stand out of the saddle which gets me up and over most serious inclines. Shifting is also much smoother using a road cassette. I'm also not doing major climbs lasting more than an hour, preferring short track cross-country riding.

As for my comments about Phil Wood, they do make quality, that I'm not disputing. Their square taper bottom brackets are the best out there. It's the technology behind having a crank forced upon a tapered square versus that of a strait splined interface. For shear longevity of crank removal, cleaning and what-not, there are simply no worries with an ISIS interface. The past problems of ISIS were the bottom brackets, poorly designed, and they'd be shot to hell in less than one season. Now, square taper cranks, that's different, by design they are more prone to falling out of compliance, even if their bottom brackets will last forever. Oh, and the potential for creaks ... well, it's about risk management isn't it?
 
#9 ·
Ah, I see what you mean Nat.

Well there are some wicked climbs where I am at and where I can go so a lower gear would be most welcome. So I guess a 29/42 with a 12-32 8spd combo would yield lower gearing for those longer/steeper climbs. Ideally though, something like a 26/36 would seem better on paper?

I do agree about the press fitting of the crank onto a square taper, that the technology is somewhat dated and the potential for creaking, yup. But the options for well designed ISIS BB seem limited. The new Crank Bros BB have yet to prove themselves and the SKF looks to have distribution/availability issues.

As Shiggy had mentioned the outboard bearing BB/cranksets will be wider compared to an ISIS/square BB/crankset so that is a factor I need to consider.

Granted there is no perfect design or combination, I'm just considering a nice compromise.

Keep the info comin, it's helping a bunch!
 
#10 ·
verrocchio100 said:
Ah, I see what you mean Nat.

Well there are some wicked climbs where I am at and where I can go so a lower gear would be most welcome. So I guess a 29/42 with a 12-32 8spd combo would yield lower gearing for those longer/steeper climbs. Ideally though, something like a 26/36 would seem better on paper?

I do agree about the press fitting of the crank onto a square taper, that the technology is somewhat dated and the potential for creaking, yup. But the options for well designed ISIS BB seem limited. The new Crank Bros BB have yet to prove themselves and the SKF looks to have distribution/availability issues.

As Shiggy had mentioned the outboard bearing BB/cranksets will be wider compared to an ISIS/square BB/crankset so that is a factor I need to consider.

Granted there is no perfect design or combination, I'm just considering a nice compromise.

Keep the info comin, it's helping a bunch!
I run a 36/24x11-28 (8-sp). Works well. There are a few times where a 11-32 would be nice and would still shift well (I am using a Tiagra short cage rear derailleur). I see no advantage to a 11-27 9-sp as the closer ratios just mean I would be shifting more and shifting 2 cogs at a time for most shifts. Also use a 34/24x11-34 (9-sp) on a 29er with the same RD.

I have never had any real issues with square taper cranks and have no desire to have an ISIS version. I do use BMX 48-spline cranks but mainly because I can get them in 185mm and I like the adjustable chainline.

If I could get a reasonably priced square taper in 185 I would be using PW BBs, which also allow several mm of chainline adjustment in addition to a wide range of spindle lengths.

I have heard plenty of creaking ISIS/splined BBs on my riding buddies' bikes (and my own BMX BB) but rarely from those with square taper.

I just say NO to ISIS, 4-bolt spider and/or outboard bearing cranksets.
 
#11 ·
Thanks Shiggy!

Well, now that you mention it, is there any particular "formula" in making a double crankset? The reason I ask is the same reasoning I meantioned above to Nat. I don't think the 29/42 crankset from Middleburn would yield a low enough gearing for the stuff I will be climbing.

Is it just a matter of slapping on a set of rings in the appropriate bolt pattern and tooth set up of rider choice and calling it good? Or are there shims/hardware needed?

Been looking at the Middleburn RS8 crank arms with either the 4 arm or 5 arm spider and appropriate rings.

As for the rings, will I need to consider ring clearance to chainstay when using either a square taper or ISIS BB?

Thanks!
 
#12 ·
verrocchio100 said:
Thanks Shiggy!

Well, now that you mention it, is there any particular "formula" in making a double crankset? The reason I ask is the same reasoning I meantioned above to Nat. I don't think the 29/42 crankset from Middleburn would yield a low enough gearing for the stuff I will be climbing.

Is it just a matter of slapping on a set of rings in the appropriate bolt pattern and tooth set up of rider choice and calling it good? Or are there shims/hardware needed?

Been looking at the Middleburn RS8 crank arms with either the 4 arm or 5 arm spider and appropriate rings.

As for the rings, will I need to consider ring clearance to chainstay when using either a square taper or ISIS BB?

Thanks!
For my 2x setups I have basically just removed the outer ring. You can use a 94/58 (compact) or 110/74 ("standard") 5-arm spiders. Plenty of ring size choices for each and you do not need a ramped/pinned ring for it to shift.

For the "ideal" chainline you would move the crank out 2-3mm compared to a triple but it is not necessary. Square taper BBs, and especially the PW, have more spindle length options.
 
#13 ·
Thanks Shiggy!

Why would the crank need to be moved outward to compensate for the missing ring? Or is it a function of alignment?

So are you suggesting when using a PW to obtain the model with adjustable offset versus symetrical version for compensation as above?

I'm a little fuzzy on this....?
 
#15 ·
shiggy said:
I would use the Middleburn and PW with a 5-bolt spider.

Weight, stiffness and Q differences? I really do not care much but I do care about reliability and durability.
Shiggy I guess you are saying you would use the 5 bolt spider over the duo spider.

Why??

I have the duo and have alot of deflection when the rings spin. Would the 5-arm spider help this?

Thanks
 
#16 ·
I run Phil Wood Titanium with Middleburn Triples on both my racing bikes for 2 years. I have also run the X Type XT crank in between, and aftr two months of racing on the XT, I had no problem throwing it in the garbage can and going back to my Phil Wood and Middleburn Square Taper setup.

You can look too much into the whole square taper vs. ISIS vs. X Type if you really have nothing better to do. From experience alone, the external type BB's don't work for me and I think the design is one of the worst I have seen forced upon the industry in a long while. As for the difference bewtween ISIS and Square Taper, I am not that anal about such things. The Square Taper works on my systems flawlessly, with no noise, and rarely have I have to trouble shoot any noises from the PW+Middleburn setup.

My external BB cranks were in need of constant cleaning maintenance due to unwanted noise and lots of sand and dirt getting into the bearing area. The XT's were the worst crank I have ever used on a race bike, and I wouldn't go there again.

PW + Middleburn is a great choice. When picking your spider for the cranks, you do have a few more options on chainring sizes depending if you buy the CD spider of the 4 arm spider. The CD Spider seems to be more friendly to people who go the 2x9 route at a later point (you can get certain chainrings in CD you can't get in 4 arm).

Go Middleburn and enjoy the hassle free riding you will have.
 
#17 ·
verrocchio100 said:
As I ponder this delimma of mine, how can one quantify flex in the crankset? I mean, how does one even "feel" it? I weigh 165lbs geared up and run the M900 cranks with UN91 and RF Turbine LP with PW BB and honestly, I can't tell the difference.
I never was able to get my Middleburns to flex and I weigh 250#. I ran an FSA mega ISIS bb with no issues, so Phil or SKF square would do the trick. Order it with the 5 arm compact spider (not the duo) and you can run a 20/30.

The q factor on My Middleburns was only 5mm less than my XT's if memory serves.
 
#19 ·
I agree about Shimano cranks of old. I still have my Square Taper XT cranks from early 90's that still are very good cranks and I use them as spares sometimes.

The newer stuff is such a far cry from the quality that company used to use when making their older products.

You do get more ring options if you choose the CD spider route with Middleburn. I love mine and won't ever run anything else.

PS- those self extracting bolts for Middleburn are pretty bad. They are a big reason you will have creaking from the cranks if you don't set them up right and glue them in. I would go with the old fashioned bolts if you get the Middleburn cranks.
 
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