GXP Pressfit BB

slc123

Hi All,

I've just replaced the BB on the Trek Slash with a new GXP pressfit. There is a wavy washer that came as part of the BB. A quick Google tells me that I may not need this when using a SRAM crankset.

Anyone shed any light?

Thanks

swod1

A search on this I’ve found it’s not needed on gxp bottom brackets unless your using bb86 or bb30 as it then acts as a preload for the bearings.

Someone correct me if I’ve misunderstood.

steve_sordy

According to the workshop guy at Rutland Cycles, bottom brackets are a nightmare. He doesn't mean fitting them, he means identifying them. Change your crankset and you may need a completely different BB. Unless you are replacing like for like, it is dead easy to get the wrong one.

When I converted my YT Capra from Shimano 2x10 (PF30) to SRAM 1x12, not even the SRAM PF30 BB fitted properly. The telescopic tube that goes inside the frame had to have 10mm shaved off the length.

The Raceface externally threaded BB on my Whyte T130 failed and I was advised not to replace it with another one ("RF BB's are made of cheese!"). It looked exactly like a Shimano Hollowtech II, only it wasn't in subtle but important ways.

Because I was working on both bikes at the same time, I ended up without a bike to ride! :shock:

t0ffeeman

I have a GXP pressfit BB with a SRAM S1000 crankset and the wavy washer is fitted to the inside of the drive side of the crankset.

https://imgur.com/a/n4jNeeJ

Vino'sGhost

steve_sordy wrote:

According to the workshop guy at Rutland Cycles, bottom brackets are a nightmare. He doesn't mean fitting them, he means identifying them. Change your crankset and you may need a completely different BB. Unless you are replacing like for like, it is dead easy to get the wrong one.

When I converted my YT Capra from Shimano 2x10 (PF30) to SRAM 1x12, not even the SRAM PF30 BB fitted properly. The telescopic tube that goes inside the frame had to have 10mm shaved off the length.

The Raceface externally threaded BB on my Whyte T130 failed and I was advised not to replace it with another one ("RF BB's are made of cheese!"). It looked exactly like a Shimano Hollowtech II, only it wasn't in subtle but important ways.

Because I was working on both bikes at the same time, I ended up without a bike to ride! :shock:

you should tell him to get a caliper and measure things then. also the chart here

https://wheelsmfg.com/bottom-bracket-wall-chart.html

steve_sordy

That looks like a great chart, in that it shows all the various standards. It is too small for me to see whether it shows which axles sizes the bearings need to fit. It appears to show only the products of Wheels Manufacturing.

Anyone have a free version of that chart or similar?

SJH76

I use a GXP SRAM red chainset on a Trek and you do need the washer. I know MTB and road BB90/95 are slightly different but only in width. The interface is the same.