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Old 11-13-04, 12:50 PM   #1
bikenutt
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how much to tighten?

how much should you tighten anchor bolts? i was tightening them way too much, ended up breaking a strand on my brakeline, i read that you tighten just until the cable begins to bend, what about other things such as handle bar stems and pedals?? brake levers??
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Old 11-13-04, 01:00 PM   #2
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Quote:
Originally Posted by bikenutt
how much should you tighten anchor bolts? i was tightening them way too much, ended up breaking a strand on my brakeline, i read that you tighten just until the cable begins to bend, what about other things such as handle bar stems and pedals?? brake levers??
Lacking a torque wrench and knowing the proper value for every fastener: tight enough to hold,not so tight as to strip,bugger,gink,spindle and mutilate.
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Old 11-13-04, 01:33 PM   #3
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indeed, it isnt worth thinking about too much. If it hoolds what needs to be helet well let it be.
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Old 11-13-04, 02:26 PM   #4
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The rule of thumb is that the bigger the bolt, the harder you tighten it. Cranks and pedals are pretty big bolts so you tighten them a lot. Stems have smaller bolts so don't snug them quite so much. Cable anchor bolts are real easy to overcook so be careful with them.
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Old 11-17-04, 04:14 PM   #5
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Everybody seems to have missed bikenut's point and question. He's over tightening his cables and wants to know how to avoid this. Tight enough to hold isn't really a simple guideline, how do you know if it's going to hold. Do you tighten it, then race down your steepest hill at top speed and slam on the brakes and see if the cable slips out?

I'm facing a lot of broken cables and am wondering why myself. Overtightening may be a reason, but I'll explore that in another thread. There may be other issues. Here, I'm just wonder, like bikenut, what is tight enough - to make sure that when I have to brake hard the cable will hold?
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Old 11-17-04, 04:21 PM   #6
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Maybe around 7nm or 60 in. lb. Somewhere around there would be my guess. What do you pros think?
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Old 11-17-04, 04:29 PM   #7
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Is it easy to find a small torque allen key? MY clamps use allen keys, and to measure 7Nm I'd need a small thing like that I guess. But it would indeed be nice if there were an accepted norm in this regard so we can rule out overtightening as a problem (for those of us afflicted with this problem )
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Old 11-17-04, 04:46 PM   #8
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Yes. The Park Tool is about a $35 wrench. You will need drive bits to fit the allen sizes you need. I would not worry about it if you are just concerned about over tightening cables. (IMO) You just need to get a feel for that ( I am not a real mechanic ). But if you are going to get into bigger bike maintenace I would get one. The high end stuff is all spec'd. For instance if you install a Campy Record crankset and you tighten it it Shimano specs you may ruin it. I tend to tighten things to tight. What taught me to torque stuff is when I about crashed cause I tightened my headset bearing too tight. It is not like working on my old Western Flyer anymore.
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Old 11-17-04, 04:56 PM   #9
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That sounds fair. Even so, it would be good to know what teh spec is for brake cablle clamps as a general practice (7 Nm?) and then maybe borrow a torque wrench once to establish a feel for what that torque is. Only really need to play withone a bit and establish the torque to hand feel relationship, and near enough will indeed be good enough for brake clamps I expect. But if I am overtightening the clamps I'd like some ay of knowing.

Indeed, I could even just do them up as I do, then go into a bike shop and measure the torque on it after the fact. If it's twice the norm, I have a problem ;-). Still have to work out what the norm is.
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Old 11-17-04, 04:59 PM   #10
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http://www.parktool.com/repair_help/torque.shtml
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Old 11-17-04, 05:04 PM   #11
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Quote:
Originally Posted by bikenutt
how much should you tighten anchor bolts? i was tightening them way too much, ended up breaking a strand on my brakeline, i read that you tighten just until the cable begins to bend, what about other things such as handle bar stems and pedals?? brake levers??
Here's the specs copied from Park's Bike fastener torque chart. Everything you asked about is on this. (http://www.parktool.com/repair_help/torque.shtml) :

Brake cable pinch bolt- linear pull/cantilever 53-69 Control Tech« 40-60
SRAM« 50-70
Brake cable pinch bolt-sidepull/dual pivot/centerpull 53-69 Campagnolo« 45
Cane Creek« 68-72
Mavic« 62-80
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Old 11-17-04, 06:18 PM   #12
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Thanks guys, that's great! Will explore my situation as soon as I can find a torque wrench to borrow (probably one our bike shops have them in their workshops and will let me try one out).

Forgot to mention units of inch punds when copy pasting,but that's cool. Just for the record .
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Old 11-18-04, 03:57 AM   #13
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Quote:
Originally Posted by bwechner
Is it easy to find a small torque allen key?
A few trips ago when I was in the U.S., I bought a set of metric allen sockets at Sears. You can also order online from them.

Cheers...Gary
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