Possible play in bottom bracket...Sram GXP.

[Salty seadog]

Hi all, did a 40 miler the other day and I think i may have some play in the BB, a Sram Gxp on a Whyte Montpellier hybrid.
I noticed after a while that the left crank was able to slip ever so slightly if I was not putting full pressure through the peddle (I.e if i just eased of the power for a split second and then reapplied full power) It felt like the crank was catching up on itself and i felt no resistance against the peddle stroke for that split second, so the play seemed rotational. It was at about the horizontal in the peddle stroke with the peddle to the fore. It felt like a slight knock as I reapplied the power.
I later noticed it on the right side crank under the same circumstances.
Gave the cranks a quick wiggle but could not detect any lateral play.

I hope my description is clear enough and welcome any advice/opinions and things to try to diagnose.

Many thanks,

Ssd.

 

[Levo-Lon]

Id check the crank torque..sram cranks ?
are these the 8mm bolt on the end compress type? They need about 50nm ..if there not tight they move a little under load and then fall off after the bolt losens

 

[Salty seadog]

Id check the crank torque..sram cranks ?
are these the 8mm bolt on the end compress type? They need about 50nm ..if there not tight they move a little under load and then fall off after the bolt losens

Hi, meta Ion, yes they are sram cranks, Im not sure what you mean by 8mm bolt on ends. my experience with bottom brackets is zero. does that mean they are 8mm hex bolts to torque it up? If so then i think they are.

 

[Levo-Lon]

If you look at the pedal arms Cranks..
See my next post ...i think you have similar?
on the left side there should ..will be what looks like a big bolt hole...inside that is the 8mm bolt that secures the pedal..pop an allan key in and see if it will tighten..
they are tight at 40 newton metres of torque..i use a torque wrench and a strong allen fitting in a socket..
if your unsure ask at the bike shop as they will nip it up with a torque wrench..if your not able then it would be similar to an old bike wheel nut sort of tight..its 8mm for a reason ..

hth

 

[Levo-Lon]

View: https://m.youtube.com/watch?v=zku_zqTCdPQ

 

[Salty seadog]

If you look at the pedal arms Cranks..
See my next post ...i think you have similar?
on the left side there should ..will be what looks like a big bolt hole...inside that is the 8mm bolt that secures the pedal..pop an allan key in and see if it will tighten..
they are tight at 40 newton metres of torque..i use a torque wrench and a strong allen fitting in a socket..
if your unsure ask at the bike shop as they will nip it up with a torque wrench..if your not able then it would be similar to an old bike wheel nut sort of tight..its 8mm for a reason ..

hth

Thanks again, im away from the bike until wednesday but Im certain it has bolt on ends. Thats great to hear it should only need nipping up, will get my lbs to nip it up as my torque wrence is only a 2-24Nm.

 

[Salty seadog]

Thanks for the Video aswell, very informative.

 

[gibgrth]

Have a Planet x rt58 alloy with sram rival fitted, through cycle to work scheme. It has this bottom bracket fitted and they are rubbish!!!!!!! Am currently in discussion with planetx on a resolution. Had to replace it after 4 months! You can buy a hope BB with a conversion kit! So BEWARE any potential buyers of Sram think Twice before purchasing!!!!

 

[jack smith]

Have a Planet x rt58 alloy with sram rival fitted, through cycle to work scheme. It has this bottom bracket fitted and they are rubbish!!!!!!! Am currently in discussion with planetx on a resolution. Had to replace it after 4 months! You can buy a hope BB with a conversion kit! So BEWARE any potential buyers of Sram think Twice before purchasing!!!!

Sram stuff is fine you just have to install and maintain it properly.
if you don't tighten it enough and get play that's when stuff starts to wear pre-maturely.