Which crankset?

veronese68
veronese68 Posts: 27,743
edited June 2015 in Road buying advice
My 16year old son has a nice old steel road bike of unknown origin. It's running DA down tube shifters and 9 speed. The crankset is creaking like crazy. I've changed the BB, taken the rings off and cleaned the mating surfaces and threads, greased and reassembled and I've tried different pedals. Still creaked. So I put in the crankset off my bike and it was silent. I think he is particularly hard on the thing as he leaves it in top gear and mashes away from a start standing on the pedals using brute force and ignorance. It currently has a hollowtech Tiagra 9 speed fitted.
So looking at various options to replace it I found a cheap square taper at Planet X, but will the 53 tooth exacerbate the masing problem? Square taper BBs are cheap enough and seem to last. Or do I go for a Sora 9 speed for £40?
The main question I suppose is would a square taper be any stronger with respect to mashing away from a standstill?
Alternatively I could upgrade my 105 and give him my old one, or should I just convert the thing to single speed?

Comments

  • Anonymous
    Anonymous Posts: 79,667
    edited June 2015
    I have an ultegra one (silver 6500 series, 175mm though) but needs an octalink BB (I will double check if I have one, but I think I sold it) you can have for a tenner.
  • arlowood
    arlowood Posts: 2,561
    Just my opinion but I would guess the square taper BB's will be intrinsically stronger than any Hollowtech type BB since the bearings are inboard within the BB shell.

    With this set up they should be much more resistant to the "bending" forces applied when someone is mashing a high gear.

    I had a square taper Campag Mirage BB on my Mercian that was still going strong after 14 years and close to 10000 miles. I didn't mash high gears tho' so maybe not a comparable example
  • veronese68
    veronese68 Posts: 27,743
    I was wondering if square taper were more prone to bending type forces as the bearings are further inboard so there is more leverage. Not sure.
    For £10 that would be great Coriorioriordan, I'll PM you. In keeping with the rest of the bike being made up of used parts and hand me downs. I actually really like riding the thing, which is a large part of why I want to stop the creaking.
  • Anonymous
    Anonymous Posts: 79,667
    have emailed you. Let me know if you receive it.
  • veronese68
    veronese68 Posts: 27,743
    coriordan wrote:
    have emailed you. Let me know if you receive it.
    Yes, and replied to. Ta.