The price of learning to do it yourself..

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Postby janus77 » Wed Jul 09, 2008 11:10 am

Bah?
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by BNA » Wed Jul 09, 2008 12:09 pm

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Postby mikesbytes » Wed Jul 09, 2008 12:09 pm

If those crank sets were any cheaper they'd be giving them away.

I'm assuming it includes the arm on the other side?
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Postby janus77 » Wed Jul 09, 2008 12:27 pm

haha, would be dissapointing if it didn't!
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Postby familyguy » Wed Jul 09, 2008 4:29 pm

Even if you replace the road cranks with a MTB crankset, the axle widht should be what controls your chainring spacing, no?

Is this a road bike or MTB that this is on? A road chainring of 53T may just be too damn large for an MTB setup.

Jim
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Postby janus77 » Wed Jul 09, 2008 4:37 pm

it's a MTB frame wiht 700c wheels.

Yeah, it's because the chainring is just too large. Guess I'll ebay the new one and order another from Chain reaction.. bah!
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Postby Kid_Carbine » Fri Jul 11, 2008 7:22 am

LuckyPierre wrote:You can buy 're-threading' kits - try some-one like Moruya Bicycles or your lbs - although it might be simpler to buy new cranks. :?
The best basis of learning is experience, so as long as you're learning ...
I'm quite familiar with the HeliCoil & ReCoil kits, however & don't know about the availability of a left hand 9/16" kit. Certainly not likely to be a stocked item at Repco but some of the larger LBS's might be able to help to save the cranks.

A thread that has been properly repaired with one of these kits is actually stronger than the original one that was cut into the parent alloy.
It must have taken quite a bit of effort to do that much damage with parts that are supposed to screw together by hand.

Hopefully, what has been learned here is that when dealing with something that we know absolutely nothing about is to LOOK TWICE, then act once & also, if it doesn't simply fit together by hand, find out why before inflicting grievous bodily harm on innocent alloy parts.
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Postby janus77 » Tue Jul 15, 2008 10:17 am

Ok, so I'm ordering a new crank from chainreactioncycles..

Figure this time I might get some advice before buying.

http://www.chainreactioncycles.com/Models.aspx?ModelID=13554 - this is what I'm thinking of getting. Now after buying the previous crank (which was listed as a road crank), I've learnt that the larger chainrings don't fit, or the road rings sit too close to MTB frame.

This is what i've got: http://www.konaworld.com/08_dew_w.htm

Thing is all the MTB cranks are 44/32/22, but the crank I've stuffed is 48/38/28, and I don't want to go any smaller than I already have.

hmm, any advice/opinions? BB is square taper, so any square taper MTB cranks will fit right?

Thanks! :)
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Postby thomas_cho » Tue Jul 15, 2008 11:50 am

I bought a XT Crank 48/36/26 from chainreaction before. Have a browse through their list. The one I bought required external bearings tho. The price of the crankset included the external bearings as well.

In reagrds to square taper cranks, Campagnolo also have square tapered BBs ... so use Shimano with Shimano.
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Postby janus77 » Tue Jul 15, 2008 12:01 pm

ah ok, thanks.

I'd assume most of the cheaper cranksets would be shimano and not campag compatible if square taper though right?

And what does this mean:

"104/64 BCD and chainline 48mm"?

Thks.
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Postby thomas_cho » Tue Jul 15, 2008 12:08 pm

This is the one I bought. There is an LX version as well.

I guess you are probably right in respect to the square tapered cranks. Campag does not have MTB parts!

So you should be safe.

48T will give you more top end speed, if you are into that sort of speed thing :)

Just read your edit. The BCD = bolt circle diameter. That is the diameter of the bolt pattern of the crankset. So if you are buying replacement chainrings, you have to buy those that fit that BCD. Chainline is the distance between the seatpost to the centre of the crankset.
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Postby janus77 » Tue Jul 15, 2008 12:14 pm

thanks Thomas
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Postby Hawkeye » Tue Jul 15, 2008 12:47 pm

One morning last year I came across a guy on the Sydney harbour bridge who was in a bit of a mess. Badly cut up leg and had gone over the bars. The cause was his pedal parting from the crank due to a stripped thread.

It was just at the start of the bridge heading northbound after the bike on-ramp. He wasn't going that fast or applying a lot of force, fortunately - could have been a lot more severe.

The bridge security guys were quite good and locked up his bike in their storage area so that he didn't have to worry while he was off to hospital in the ambulance to get treated.

I think replacing your crank is a better idea than trying to bodge it with a helicoil.
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Postby MJF » Tue Jul 15, 2008 2:51 pm

janus77 wrote:"104/64 BCD and chainline 48mm"?

Thks.


BCD is Bolt Circle Diameter for the chainrings, chainline is the distance from the centre of the seatpost to the middle chainring (triple) or between the inner/outer on a double. 48mm would be a MTB crankset.
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