Tuesday 19 February 2013

Living with a Chinarello

Hi,

Thought I'd update a bit now the weather has improved and I've been out on the bike and ridden my first TT.

First few test runs were fine, then the front derailleur started catching on the chain ring  Had to ride on the big cog till I got home and found that the front bracket had rotated slightly, enough to be a problem. So I undid and tried to tighten it more to find the hex hole in the bolt starting to round.

I backed off and ordered some more higher grade Stainless bolts. The ones installed are longer than a bottle cage bolt so I had ordered 16mm long M5's in A4 grade stainless (marine grade)

first bolt went in fine, second one got stiff as I screwed it in. After trying a few more bolts with the same problem, I thought OK a bit of resin, so used a bit of force, not much, and the whole insert started spinning. WTF! Not happy! Why two separate inserts and not one? Why can an insert spin so easily. My look 481 has a spinning insert on one bottle cage, come on RnD peeps, inserts with a non circular outer please or double inserts connected at the back, with actual metal!

So, I had to cut a groove in the insert so I could hold it and withdraw the bolt. I've cut grooves in the side and re-applied resin to stop it spinning. I tried re-threading the insert but it's aluminium and I'm scared of it just messing up, So I have cut the new bolt to same length as the old one and it's fine with a good 5mm's worth of thread gripping. I can torque it up adequately and carbon assembly grease is very useful to stop things slipping.

So one drama sorted, re-installed and got a similar thing, slight rotation but this time between setting and tightening the hanger bolt. I checked the bolts, used some carbon assembly paste behind the bracket to stop any movement but it's still doing it.

I've discovered the problem. The Bracket is made from aluminium and after the slot is cut in it for mounting the hanger, there's just not enough material left, there may be a bit of over torque on my part but the bracket is just deforming as I tighten it. I've had it in the shed and hammered it back into shape, re-installed using assembly compound to prevent slippage at lower torque and it's fine but I've also ordered a new bracket.


This one looks like it's made from steel, granted I'll need to flatten the frame side but that's no problem. If this one doesn't fit due to me having to flatten it, then there's this one too which is aluminium. Both are less than £10 so it's no big deal and have a substantial amount more material on the outside of the slot.



Other than this small teething problem, the rest of the bike is performing very well. My first TT was a hilly 14 mile, I hoped for sub 50 and got sub 43. I've only been riding 6 months so averaging 20mph was my goal and managed it. Doing the same one again this weekend with some position adjustment after seeing pics and realising that I need to make a few adjustments. This is my first venture into tri-bars too. So far so good.





8 comments:

  1. Thanks for the updates, I'm just getting all my bits together to start my build this weekend. Any advice on what torque setting you used for clamping stuff on?

    When you mention the inserts i'm not 100% which part of the assembly your talking about, is it the bolt hole the hanger bracket screws into on the frame?

    Thanks
    Phil

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  2. Inserts are the bolt holes yes, your frame will come with the front bracket already attached but they don't tighten it much, my best advice is to get some carbon assembly grease, I'll post a pic of the stuff I have, you can use it behind the bracket and you will deffo need it for the seat post. Also good on stem. This means you will not need more than 5nm for most parts. I found a lot of torque values here

    http://bicycletutor.com/torque-specifications/

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  3. I've put a pic of the assembly grease I use Tacx, it's really useful.

    As for the other torque settings, my groupset was brand new and all instructions and settings were included.

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  4. Dang!, I just finished building up my bike and I had forgotten to tighten the front D screws....It works well for now... I will tighten it then the front shifting gives problem....

    From your description, you are talking about the bolt thread inserts on the seat tube behind the front D mounting position? Or the bolt threads on the front D itself?

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    1. Hi Lukman, it was the actual aluminium insert, moulded into the frame. Nothing wrong with the D itself being brand new.

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  5. This comment has been removed by the author.

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    1. I had the hanger page removed after a copyright infringement, I can only assume it was due to me naming either the make of hanger or the shop I bought it from as I have not as yet been given a reason so I've had to remove the references. I bought the hanger in the UK from an online shop, they currently do not show them as in stock but if you read this backwards it's the hanger you need to find

      d e c n a v d a y t i n i r t

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  6. Hi Michael im glad I came across your blog as I'm interested in building a bike like yours. Just wondering how its been holding up since your last update??

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