Check out Figure 1 to see the most extreme case we’ve ever had in our shop. This causes creaking for obvious, common sense reasons, but it also causes corrosion problems that are exacerbated by water intrusion. I'm sure the thought was, "Why not just slide the spindle right into the bearing, what could be easier". We’re baffled by Trek’s insistence on using bearings with a 24mm inner diameter (ID). The second reason for a creaking Trek BB90/BB95 bike is the typical steel on steel interface between spindle and bearings. Loctite is not glue and its use does not violate your warranty. The bearings can still be removed and serviced in the same manner over and over again using proper bonding practices. To ease your mind, here's a picture of the labels from a bottle of 609 and 638 note the depiction of a bearing being bonded into a rotating assembly and the description of what it does, "Augments Press Fits" and "Slip Fits": There’s nothing to fear from bonding the bearings in the frame as long as you use the right retaining compounds such as the specific VibraTite and Loctite products I just mentioned. No movement, no creaking, no frame damage. If the frame is worn to the point that the bearing can be pushed in easily by hand or they basically fall out, you’ll need VibraTite538 or Loctite 638, which we package with our Shimano bearing repair kits.Ī bonded-in bearing can’t move anymore. We prefer VibraTite530 or Loctite 609 for STANDARD frames where the bearings still require the use of press tool. We advocate bonding the bike bearings into the frame with a Loctite-style product. As long as you get on it right away there won’t be any lasting damage to your Trek MTB. Yes, every time you pedal a stroke and hear a creak from a loose bearing you are causing damage to your carbon frame.
![crank arm length on 2018 stache 7 crank arm length on 2018 stache 7](https://bmxmuseum.com/forsale/img_039457e0a34c9b_lg.jpg)
This causes creaking, which is annoying, but the real danger here is that this loose condition leads to ovalization of the bearing bores in the carbon frame, and that ain’t good. The first and most common reason for mountain bike creaking occurs when the bottom bracket bearings start moving around in the frame with each pedal stroke. Let’s talk about the two major reasons why Trek BB90 and BB95 bikes creak, and then I’m going to tell you how simple it is to make sure creaks don’t happen to you anymore. Get it wrong and you’re hating life because of mountain bike creaking. Get it right and you’re riding on a dream. With Trek BB90 bearings the setup is everything.
![crank arm length on 2018 stache 7 crank arm length on 2018 stache 7](https://bmxmuseum.com/forsale/img_20181230_1934245c299449a9_lg.jpg)
Our answer to them is simple: You’re not doing it right. We get a lot of grief for saying things like this because there are legions of BB90 haters out there who are convinced it is the worst thing since unsliced bread. Trek BB90, and its mountain bike sibling BB95, are excellent bottom bracket systems.