mismatched octalink crankset : V2 for V1 swap

[bishopdante]

Hey everybody, been building up a nice old orange 1" steerer tube frame, 1995, which I've been fitting with various parts from the cupboard. Simple & nice singlespeed cromoly thing for general daily runabout. All done, but one small problem...

I appear to have mildly screwed up with the cranks. I bought some XT octalink cranks, unfortunately they are the V2 long-spline spec, and my bottom bracket is a NOS octalink V1 XTR needle bearing jobbie, it's been hiding in a box, and I'm extremely keen to use it. Lovely and smooth.

I have a fairly extensive list of hard-to-find parts which I'd be willing to swap for a pair of V1 octalink cranks I could use on the build, but the ideal would be somebody who needs the cranks I already have (M751).

I would also hand over money for the right parts, obviously.

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Some of the things that are sitting in storage (which I should probably photograph and list as parts for sale in a separate thread):

Hope Big'un 20mm through-axle wheelset
Stratos XC pro shock (minty & never used)
White Bros UD150 forks
Hope C2 brakes of various sorts, including a Nº2 caliper & set of Hope Sport Wheels w/shortened axle & trunnion mount
Viking spring shock (ultra-heavy)
Marin Mt Vision Mk1 Frame
Shimano Deore M525 disk wheelset w/rigida rims
XT M760 9spd cassette
XTR 9spd right hand shifter
XTR M971 mech minus cage (back wheel ate that, been meaning to make a Carbon Fiber DIY one)
L&M square taper cranks
Bunch of oldschool CNC stems, Ballistic, Amoeba etc, all 1&1/8

So perhaps if these are parts you seek, and you have some XTR octalink cranks you don't want / haven't got the BB for, we could organise a trade.

Anyhow, do post or PM, most appreciated, keep the pedals spinning!

 

[bishopdante]

Photographic evidence of the hitch:

The general bike

The misfit:

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Also, I'm curious about whether the brake bosses are set up correctly on these Pace RC35 forks. I think they're supposed to be on the other side, no? This is how I received them:

Am sufficiently confident the bosses are on the wrong side that I haven't turned the brake blocks on the V brake round. At the moment it's all being offered up & checked for size etc, rather than ridden.

 

[ishaw]

I've got a set of xtr cranks not doing anything at the moment:

viewtopic.php?f=39&t=344546&hilit=Xtr

As for the forks, they are wrong only in terms of pace forks, but can be used either way. I prefer the look of them on the rear and it makes sense too in terms of pushing the braking force against the fork rather than the bolt as it would be as in the picture.

Of you decide to swap them round, be careful when opening them up to fit over the drop outs, as they can snap due to the drilled out holes.

 

[bishopdante]

Re:

Those Cranks look pretty minty, lovely. Got any movement on the price / parts you're seeking in trade?

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Thinking about the brake bosses from an engineering basis, it's probably an eccentricity for pace to put the bosses working under compression rather than tension.

If you think about the horse and cart analogy, it stands to reason that any sideways twisting loading on something being "pushed" will cause sideways deflection. Pushing on things tends to crumple / bend, whereas pulling on things even if the material is flexible, it'll straighten. The magician's rope-climbing trick is a fine illustration: much easier to swing from a cord than it is to run about on stilts.

Pushing on something doesn't self-align. Pulling on it does self align. I suspect this is the reason why some high quality frames put the brake bosses on the underside of the seat stays.

However, because of the off-center loading on the bosses, it does mean that the bosses are only going to twist one way, which is into the rim, rather than away from it. So waffles for pace's eccentricity, it'll tighten the braking force if any twisting does occur. Nothing wrong with that piece of design.

Rather than mess about, think I may as well leave them "wrong for pace", not break anything, and leave the XT linear pull brake on display.

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[ishaw]

Always happy to trade if there's anything I can use.

From your list, the following might be of interest:

Stratos XC pro shock (minty & never used)
White Bros UD150 forks
XTR 9spd right hand shifter
L&M square taper cranks

 

[FluffyChicken]

You would be better of just buying the right bottom bracket unless you have your heart set on M95x chainset*. The current cranks suit the frame well.

Canit's studs can be used either side, jut check cable routing if moving to the rear.
It looks like you need to use the shorter spacer on the brake pad holders, switch the front and rear spacer around, the arms are being forced to lean too far out at the moment


*especially as you'll need to find a 4 arm spider for the crank, which you have currently on that crank arm.

 

[bishopdante]

Re:

Indeed, fairly wise words FluffyChicken.

Brake blocks are now set up properly, the right way round, and with the spacers set up correctly. I have no idea who owned those before me, but the ebay listing looked like it'd been typed by a goldfish. Listed merely as "bike brake". Price was accordingly reasonable, been in storage in my hands for a couple of years now & found its home on the C16.

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Think you might also be right about the pulling the BB. As-is the chain line is perfect (although doubtless the fit with a different bottom bracket might be different, the spider allows a bit of budge bolting the single ring to either side of the spider.)

Thought I was being smart hiding the XTR bits out of sight away from thieves, but then got unforeseen incompatibility. It's all a learning curve. The legit M952 crankset (which I have coveted since it first came out) does have an inflexibility with the integrated 40t sprocket, and would prefer 38t for singlespeed, the current gear ratio is perfect (16t SRAM PG990 sprocket on the back with a converter, so 38:16@26").

Hence the existing BB could go back in its box awaiting another build w/the ideal cranks, on a more befitting frame, or could be thrown back into the pond.

Curiously the drive side seems to mesh up perfectly with no play, it's only the left that's a tiny bit sloppy, but was solid enough for a careful quick test ride. Goes like a rocket.

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Still got to get the new (hard) elastomers into the forks, which should turn up next couple of days. Old ones in the forks were ozone-rotted & knackered (hence very cheap, also).

 

[bishopdante]

Re:

FluffyChicken's advice was eminently wise, managed to find a BB for less than the postage cost!

Fresh elastomers and RC7 grease now in forks, old elastomer-grime-jelly mixture removed.

I'm riding dat ting, and experiencing the reassuring "clank" of (british) steel, been on aluminium/carbon frames too long. It's wonderfully agile, and doesn't punish one for hard landings nearly so fiercely.