UltraRear SLX 139g Tension limits...drifting to 12 8 Lacing

Everything about building wheels, glueing tubs, etc.
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sugarkane
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by sugarkane

I agree on SP hubs, while the Tesnion ratios are not amazing if you build them very Even in tension then they are more than ok. I find a bit of rim depth helps bring a bit of stiffness to the wheels

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WinterRider
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by WinterRider

The tension balance issue.. to me specifying 160 kgf max DS tension is over the top .. especially in light of the 70 kgf limit NDS. Hub material is same both sides .. total DS flange tension is 160 x 12 giving 1920 kgf total. So the limit of 70 x 12 at 840 kgf NDS does not make sense to me.. understanding of course I'm not a mech engineer etc :noidea: Understand also I'm not vs Extralite a tall .. I am impressed with their website. Well written from my view per data..laid out logically. Seems to me another niche market in the marketing world.. my opine they do well.. very. Definitely am trying an Extralite hub in the future. :thumbup:

But where I headed with this .. the triplet concept is just common sense solution to weak rear wheels .. per left spoke 'shake loose' and 'lazy left'. What IMO is overblown is the lateral stiffness angle. If lateral is of primary concern.. go conventional lacing. Your average bike power unit does not get the concept anyway .. 'isn't that dangerous with all those spokes missing' .. with explanation of the trip concept one sees that blank look of a bambi lost ---in the fog of headlamps in the dark. IMO a heavy rear trip designed to accommodate lateral stiff is a non starter.. defeating the original premise.

I'm a practical builder .. a recreational interest for my own, the scant custom I choose -- also supplying the few I flip. One solution I have used is to customize the rear to the bike/rider. Rider is weight reduction plan using bike .. rear goes crapper per shake loose aka poor factory assembly at that price point. Hub gave just under 50% tension left vs rt .. so I replaced the rim with OSD flavor, replaced axle to give 138mm-ish spacing (rear triangle easily allowed) and final balance was in the range of 85+% left side. 105 kgf right limit.. that '3 stones +' rider looks now healthy .. happy to ride with his grandkids ... and no wheel complaints. I plan the lengths to give just a smallish mm 'hat' above the nip double wall rims .. smallish dab of weak glue .. they stay put no matter the load.

Interesting the 'majors' haven't just went 135 or wider rear. But the bike game .. aka marketing to relieve capital from pockets given to such... must know that angle's limits with said check writer/plastic swiper. Yet staying 130 does present so many options to peddle .. which is the nature of the sell.

by Weenie


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ergott
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by ergott

One issue with 135mm is it compromises chainline particularly with bikes that have short chainstays. If you move chainrings outboard you increase q of crank. These are things that would need to be addressed if industry went 135 for road bikes. As it is, bikes like Tarmac disc are coming up with their own solution to the problem.

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bm0p700f
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by bm0p700f

Campagnolo have a good solution to the chainline issue with the new HO chainsets. Simply dish the chainrings as this does not affect the Q factor. 135mm rear spacing for all road bikes is the obvious solution however as that would be yet another standard it may never happen.

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ergott
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by ergott

We need the powers of Shimano to have the market heft to make that the new standard.

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Calnago
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by Calnago

Current, meaning non-disc road bikes, chainlines are optimized for 130mm rear spacing. Increasing it to 135mm, pretty much a necessity if you want to go with discs, compromises existing chainlines and thus shifting, and hence we're seeing some alternative solutions in the form of 1) longer chainstays... ugh, compromises the nice tight road bike handling we've come to enjoy and expect; 2) different hub designs like what Specialized was initially trying out, but I think have since abandoned... good; 3) Cervelo's proprietary crank design... another ugh; and 4) redesign of the cranksets which both Shimano and Campy have now done to accommodate the wider rear dropout spacing (for discs) and chainline issues without having to rely solely on longer chainstays... good, but still... why? So we can turn our roadbikes into mountain bikes? No thanks.

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ergott
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by ergott

Yes, but even a road bike with rim brakes could stand to benefit from 135mm spacing. As mentioned, moving the chainrings out 2.5mm would allow for the same 40.5cm chainstays of a pure race bike with great shifting. Looks like Campagnolo could move the rings without effecting the Q. One possible issue is heal clearance against the chainstay, but shaping carbon could easily solve that.

Last issue would be standardization.

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Calnago
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by Calnago

Agreed. But at least in the absence of discs the 130 spacing works just fine and wheels can be made to support all kinds of loads. Wider than 135 would be better yet for bracing angles but I'd like to see them as narrow as possible to do the job well. In the absence of discs it would seem that 130mm is just fine. There's how many "standards" for Bottom Brackets now? I could live with two standards for rear road bike spacing, depending on whether one wants discs or not. Choice would be good here.

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ergott
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by ergott

My cross bike is 135mm rim brake. I did that over a decade ago.

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Calnago
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by Calnago

Ha. I have a touring bike that I built up over 15 years ago. Custom frame, 135mm rear spacing. Used some XTR hubs to build some sweet strong wheels that would support 90lbs of bike/gear plus my fat arse. Triple 9sp up front 26/36/48. Bar end shifters and Magura HS77 hydraulic road levers with some hydraulics rim calipers. So, hydraulic rim brakes. 700c rims mated to 135mm hubs and 36 spokes. Awesome wheels for their purpose. Choices are nice.

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WinterRider
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by WinterRider

I'm trying to figure the loss of lateral stiffness between a conventional 24H rear and 16-8 .. with a practical bent rather than a theoretical view.

Using all same components.. albeit chg to drilling pattern .. from what I read .. lacing method is not in play (?).

What is the actual loss in brake pad clearance rear for a given power applied to rear? IE: how much wider must the brake pads be set to allow no rub?

For most of us riding .. me .. that isn't significant I am thinking.

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