How to keep Lightning crank from untightening?

Discuss light weight issues concerning mountain bikes & parts.

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Martin.F
Posts: 759
Joined: Sat May 28, 2005 9:21 pm
Location: Norway, Drammen

by Martin.F

This crank has been nothing but trouble for me. The bearings are horribly sealed, it squeaks and creaks and to top it all of, it disassembles during use. I've tried using loctite on the center bolt, I've tried tightening to recommended torque using a wrench and I've tried going tighter than recommended torque. The center bolt just wont f'ing stay in place.

Follow-up question: What is the best BB30 crankset of the following? I just want to throw the lightning crankset in the river and be done with it for good.

Sram XX
FSA K-force light
Rotor 3d

by Weenie


Ottoturbo
Posts: 54
Joined: Sat Dec 10, 2011 11:58 am

by Ottoturbo

Best BB30 crankset: viewtopic.php?f=1&t=102440

Don't know why Hollowgram SL is not on your list, but it's something to consider.

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Martin.F
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Joined: Sat May 28, 2005 9:21 pm
Location: Norway, Drammen

by Martin.F

But they all just talk about hollowgrams. The reason I don't concider them is the price. I can get the XX for less than 1/3rd of hollowgrams...

musk3t
Posts: 38
Joined: Thu May 10, 2012 11:43 am

by musk3t

The 3D+ is a great crank, and definitely worth looking at. Light, very well priced and they work great.

Ottoturbo
Posts: 54
Joined: Sat Dec 10, 2011 11:58 am

by Ottoturbo

Which Loctite do you use? There are different strengths and some handles vibrations better.

For bearings, you could use the E.13 bottom bracket or press in some other bearings in the Lightning cups. Do these use 6806 bearings? There are alot of options. You might have the road bearings with "no touch" seals. Other BB30 cranks uses the same bearings so why should they work worse or better for you.

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Martin.F
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Joined: Sat May 28, 2005 9:21 pm
Location: Norway, Drammen

by Martin.F

Disassembled the whole thing today and cleaned it up. It's NOT the cranksetbolt itself that comes loose. It's the bearing cups themselves that has enough room to move inside the frame. For those of you that don't know, the Lightning cranks have a 30mm spindle, but for it to work on a bb30 frame it needs cups to place bb30 bearings outside of the frame.

Any tips on how to get the cups to stay in place? I tried loctite on those as well, no luck. I don't think a beercanshim will work well... But right now, it's not press fit, it's slide fit. I can easily take them in and out using my fingers only.

Gosh, BSA was so much easier.

02GF74
Posts: 562
Joined: Thu Jan 13, 2011 4:04 pm
Location: Sunny UK

by 02GF74

if I understand you correctly, the cups containing the bearings fit loosely into the frame bottom bracket and spin. (you do not want that to happen for any length of time as they will wear the frame).

you could try another set of cups as the cups themsleves my be a tiny amount on the small size.

also what loctite are you using? there are many different formulas and I know there is at least one for holding bearings into place, googling comes up with this, it would not surpise me if there were others.


hmm, looking on loctite website there is quite a choice for retaining:

Loctite 121078 Retainer - High strength, good temperature resistance, high viscosity retainer, maximum diametrical clearance 0.25mm

Loctite 601 Retaining- High strength, low viscosity, small gaps retainer, maximum diametrical clearance 0.1mm

Loctite 603 Retaining - High strength, oil tolerant retainer, maximum diametrical clearance 0.1mm

Loctite 620 Retaining - High strength, high temperature resistance retainer, maximum diametrical clearance 0.2mm

Loctite 6300 Retaining Compound - High Strength Retaining Compound with "white" Material Safety Data Sheet

Loctite 638 Retaining - High strength, general purpose retainer, maximum diametrical clearance 0.25mm

Loctite 640 Retaining - High strength, good temperature resistance, slow curing retainer, maximum diametrical clearance 0.1mm

Loctite 641 Retaining - Medium strength, if disassembly is required retainer, maximum diametrical clearance 0.1mm

Loctite 648 Retaining - High strength, good temperature resistance retainer, maximum diametrical clearance 0.15mm

Loctite 649 Retaining - High strength, no acrylic acid retainer, maximum diametrical clearance 0.1mm

Loctite 660 Retaining - High strength, gap fill for repair retainer, maximum diametrical clearance 0.5mm

Loctite 661 Retaining - High strength, low viscosity, also UV-curing retainer, maximum diametrical clearance 0.15mm

Loctite 675 Retaining - High strength, slow curing retainer, maximum diametrical clearance 0.1mm

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Martin.F
Posts: 759
Joined: Sat May 28, 2005 9:21 pm
Location: Norway, Drammen

by Martin.F

You understand me perfectly. The cups fit loosely and spin. And thank you very much for that list, very helpful! I've been using Loctite 5926 on both the threads and the cups.

The 5926 seemed to work fine on the threads. Maybe 660 or 638 for the cups?

thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

loctite 5926 comes up as a gasket sealing material, not a cylinder fitment adhesive.
i use 603 on press fit assemblies. on slip fits, i go for 638, as it has the maximum fill for bike applications (no heat tolerance needed, etc.)

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Martin.F
Posts: 759
Joined: Sat May 28, 2005 9:21 pm
Location: Norway, Drammen

by Martin.F

I will search some stores for 638 tomorrow. If it helps I keep the crankset, if not, it's up for grabs.

Ottoturbo
Posts: 54
Joined: Sat Dec 10, 2011 11:58 am

by Ottoturbo

Loctite for axle fastening should work. Use it also on the axle.

by Weenie


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