So an oversized BB90 bearing would not fix your problem? Or it's not an acceptable solution for you?

All,

Sorry if this was previously covered. I ran several searches and I couldn't seem to find a similar thread. I was wondering if anyone else on a Speed Concept has experienced the bearings wearing away the carbon in the BB90 shell and what Trek has done to remedy the situation.

Here is a quick summary of the issue. The bike is approximately 9 months old:

- Trek 9 Series P1 Speed Concept delivered in May 2015
- Raced 1 HIM, 1st IM, training camp, 2nd IM
- Most weekly riding was done indoors on a second bike. Training from October 15 - January 16 was predominately indoors on a second bike.
- Last week half way through a longer ride the crank sounded a little funny. When I finished the ride there was lateral play in the crank.
- I figured the BB was shot, so I ordered a set of new BB90 bearings.
- The mechanic removed the non drive side bearing, which was filthy.
- The new bearing loosely slid into the frame and there was still lateral play in the cranks.
- The mechanic had seen this before and assumed the BB shell was no longer symmetrical.
- He performed micrometer checks on the shell and the non drive side had become elongated.

I contacted the LBS who has always been great and very helpful. They said they have seen this many times on Madones and Speed Concepts because the bearings are pressed directly into the carbon frame. They informed me that Trek's solution was to produce a BB90 Version 2 (oversized) bearing to compensate for the worn away carbon. I posed the question of "On your high end super bikes, you are forcing riders to ride an $8 bearing because of a defective frame?"

After a couple of quick google searches ("Trek oversized bearing" "BB90 V2" "BB90 worn away"), I found plenty of people having the same issue.

http://www.johnstonefitness.com/...bottom-bracket-saga/
http://www.braveheartfund.co.uk/...c.asp?TOPIC_ID=12204
http://ballbearingadventures.kogel.cc/...et-standards-part-2/

Trek's solution is to lay more carbon into the shell instead of replacing the frame. I was wondering if anyone has had this done, or if anyone has had the frame replaced for this issue?

I tried to have trek replace the frame, but was given the following response:

"They cannot build a brand new P1 an replace it outright, it just isn't within their capacity." Their "capacity" machine must only run on non-company dollars.
"This is not just a Trek problem but any frame with a direct fit bearing into carbon can be affected during oversize/undersize during the curing process."

Trek was right when the said "The fastest bike just got faster." This bike in particular now travels at about 600mph back to Wisconsin to fix engineering flaws. Unfortunately, the rider slows down when his rack in T2 is empty.

I was told the best thing to do is remove the bearings and clean every 6months.

On a $12k bike, running an $8 bearing is not an acceptable solution.

This is exhibit A for why press-fit bottom bracket bearings are an incredibly dumb idea. What exactly was wrong with the threaded outboard-bearing systems that prompted this design change? Easy to install and replace, reliable, did not require a perfectly molded BB shell or risk damage to the frame - yeah let's just do away with all that. So irritating.

All,

Sorry if this was previously covered. I ran several searches and I couldn't seem to find a similar thread. I was wondering if anyone else on a Speed Concept has experienced the bearings wearing away the carbon in the BB90 shell and what Trek has done to remedy the situation.

Here is a quick summary of the issue. The bike is approximately 9 months old:

- Trek 9 Series P1 Speed Concept delivered in May 2015
- Raced 1 HIM, 1st IM, training camp, 2nd IM
- Most weekly riding was done indoors on a second bike. Training from October 15 - January 16 was predominately indoors on a second bike.
- Last week half way through a longer ride the crank sounded a little funny. When I finished the ride there was lateral play in the crank.
- I figured the BB was shot, so I ordered a set of new BB90 bearings.
- The mechanic removed the non drive side bearing, which was filthy.
- The new bearing loosely slid into the frame and there was still lateral play in the cranks.
- The mechanic had seen this before and assumed the BB shell was no longer symmetrical.
- He performed micrometer checks on the shell and the non drive side had become elongated.

I contacted the LBS who has always been great and very helpful. They said they have seen this many times on Madones and Speed Concepts because the bearings are pressed directly into the carbon frame. They informed me that Trek's solution was to produce a BB90 Version 2 (oversized) bearing to compensate for the worn away carbon. I posed the question of "On your high end super bikes, you are forcing riders to ride an $8 bearing because of a defective frame?"

After a couple of quick google searches ("Trek oversized bearing" "BB90 V2" "BB90 worn away"), I found plenty of people having the same issue.

http://www.johnstonefitness.com/...bottom-bracket-saga/
http://www.braveheartfund.co.uk/...c.asp?TOPIC_ID=12204
http://ballbearingadventures.kogel.cc/...et-standards-part-2/

Trek's solution is to lay more carbon into the shell instead of replacing the frame. I was wondering if anyone has had this done, or if anyone has had the frame replaced for this issue?

I tried to have trek replace the frame, but was given the following response:

"They cannot build a brand new P1 an replace it outright, it just isn't within their capacity." Their "capacity" machine must only run on non-company dollars.
"This is not just a Trek problem but any frame with a direct fit bearing into carbon can be affected during oversize/undersize during the curing process."

Trek was right when the said "The fastest bike just got faster." This bike in particular now travels at about 600mph back to Wisconsin to fix engineering flaws. Unfortunately, the rider slows down when his rack in T2 is empty.

This is exhibit A for why press-fit bottom bracket bearings are an incredibly dumb idea.

I was told the best thing to do is remove the bearings and clean every 6months.

This is the best thing to do for ANY bearing.

that fix is news to me. thanks for checking back in.