Im looking to replace both my crankset on both by mountain bike and road bike. Is it necessary to also replace the bottom bracket if I am upgrading cranks or are the majority of cranks compatible with any bottom bracket. For example, can I replace a truvativ crank with a sram or shimano without replacing the bb? -Tom Most of today's modern cranks sets include the bottom brackets. They are more expensive now than back the "old" days when the cranks were sold seperately. If You do opt for a less expensive crank that does not include the bottom bracket. Make sure that they "match" Shimano will not fit Truvative. I would buy a new Shimano XT if I were shopping right now. Thanks for visiting Web Mountain Bike, Mike Hello Bike Doctor Please help, i am having a problem with my crank as it seems to creek a lot and produce a lot of noise when i pedal, is this a sign of old age and needs replacing? or does it need taking a part and serviced over? Contact me @ andarse_mc_flurry@hotmail.com Thanks Andrew Andrew, Hello! First you have to make sure that the noise is coming form the crank - either the bearings in the bottom bracket or the crank arms. Try to make sure that the noise is not from your pedals, seatpost, handlebars, rear shock, etc... Make sure that your pedals are tight, and the pedal cage is not loose (most can be tightened, but some are riveted). Also, check that the crank arms are tight. You need a long wrench here to insure tightness, torque em down... See if you can wiggle the crank by holding one crank arm with each hand and try to check for looseness. You can also put the crank arm next to the downtube and squeeze them together to see if there is any play in it. If you bounce on the bike with the crank arms parallel to the ground, do you here the noise? If so, it might be the cranks or bottom bracket. Most of the time the noise is not the crank or bottom bracket. If you are convinced that is where it is coming from, then it might need any overhaul, or just replace the bottom bracket (best done at the shop!) One time I had a noise like this, and it was solved by simply putting a little libe on the pedal where it joins the spindle... Hope this helps - let me know what happens! Ride On ~~Stan~~ I just bought a new crank arm but it keeps coming loose. It's not stripped and still holds its square shape. Could you tell me exactly how a bike mechanic(like yourself) puts it on? Awesome site. Thanks. -Brendan Brendan, Hello! I will speak to our mechanic (Myke) about your problem... but first I have a suggestion as the same thing happened to me! Assuming that the arm is the correct one and not worn, that the fitting on the crank is not rounded out, and that it is a press fit with no splines, the secret may lie in the allen or hex wrench that you are using to tighten it. Mine kept coming loose (on the left side) & in fact was showing some wear (rounding out of the square ). Anyhow, I tightened it with a hex tool & thought it was tight (it was as tight as the tool could get it). Then our mechanic took out an allen wrench about 18 inches long and put quite a bit more torque on it and got it considerably tighter. It has not come loose since! Most people don't have a wrench long enough to generate enough torque to make it tight enough. The wrench should be longer than the crank arm if possible. If you try this (really torque it down) & it doesn't help, please let us know... Ride On ~~Stan~~ |
