Carrera Zelos Hex bolt on frame, snagging rear tyre

acarden
acarden Posts: 6
edited September 2013 in Road general
Hi all, I have always been interested in bikes from a young age, with commuting, some mountain biking, and this year road biking. I purchased a Carrera Zelos large frame from Halfords in December, and on the whole I am happy with it for the price, I changed the stock wheels to some second hand R500's and the change was instantly noticable, a 75 mile sportive in Colchester was fine. Then I have changed the wheels to Shimano RS30's from Ribble as a treat, and have Giant PR3, 700/28 tyres to help absorb the poor roads. Now to the question, I have a duathlon on Sunday, and note that my tyres were pretty low pressure, so pumping them up as high as they could go (5 bar), I went out for a ride. I noticed a fair bit of friction on the back wheel, so put the bike on the stand, and spun the wheel. In the stand, it was obvious what the cause was, the rear wheel's tyre was snagging a random hex bolt at its highest point, and the tyres highest point, think of it as the top of an arc, when spinning along the whole circumference (m4?) that had been placed in the frame around the crank area, it doesn't appear to have any benefit at all. Can you please confirm what this hex bolt is for, and what effect removal will have?
Thanks
Ash

Comments

  • slowbike
    slowbike Posts: 8,498
    I'm assuming that bolt is the one that holds the front of a mudguard.
    28mm tyres may be a little big for your frame - perhaps 25mm would be more suited?
  • g00se
    g00se Posts: 2,221
    A photo would help.

    If it is for an optional mudguard, you should be able to remove it. Though I agree, a 25 tyre may be a better bet.
  • cougie
    cougie Posts: 22,512
    5 bar ? 72 PSI ? I think that's a little low ?

    No idea on the bolt - is it between the chainstays ? If so I'd think it was for mudguards too.
  • acarden
    acarden Posts: 6
    Guys, thanks for your swift replies, yes that makes sense, it probably is for the mudguard, it is directly between the rear parts of the frame that ultimately lead to the rear drop-outs. Apologies on not having a photo, as you state 72 psi seems a little light, my dual cylinder pump from Aldi seems to max-out at 5 to 5.5 psi.. Any good pumps you would recommend? Thanks all
  • acarden
    acarden Posts: 6
    And yes, 28 is a little too big perhaps, but I found that compared to the 23's I was using, they rode nicely over the pot holes and broker up road surfaces, so I will put some miles on them before replacing.
  • g00se
    g00se Posts: 2,221
    If the m4 hex bolt head is cylindrical, you might be able to replace it with a shallower dome- headed one?
  • acarden
    acarden Posts: 6
    That could work, but I have removed with peace of mind for now :-). I am used to running and cycling in the rain, and I get changed at work when commuting so I don't use mudguards. Cheers Ash.
  • rolf_f
    rolf_f Posts: 16,015
    acarden wrote:
    That could work, but I have removed with peace of mind for now :-). I am used to running and cycling in the rain, and I get changed at work when commuting so I don't use mudguards. Cheers Ash.

    The mudguards aren't to protect you - they are to protiect the bike (mainly) :wink:
    Faster than a tent.......
  • MichaelW
    MichaelW Posts: 2,164
    I use nylon M5 machine screws (slotted cheese head) to protect empty threads. They are cheap, light and low profile.
  • acarden
    acarden Posts: 6
    I have never thought of mud guards to protect bike :-) Perhaps I have missed something.... My computer bike is left outside in all conditions, the frame is intentionally chipped and rusty to deter thieves, the R500 wheels have the decals removed for the same reason. My road bike is kept in the shed, so hopefully shouldn't succumb to rust, time will tell. Good tip about the nylon machine screw, I think I have some steel ones in a drawer, but if not I will order some. Cheers

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