Reducing Press Fit seal drag
Moderator: robbosmans
I'm curious about this as well, my PF86 frames, I can barely get the crank to rotate a half revolution on its own.
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LouisN wrote:Any ideas/solutions to help?
Not sure if this is still the case, but when SRAM first introduced the PF30 assembly, there were two sets of seals, for which removing the outer seals helped reduce rotational drag. My solution was to replace the SRAM assembly with a 3rd party BB, which at the time, I went with Cannondales PF30 solution, but Wheels Manufacturing or similar would be cheaper.
- Michael
"People should stop expecting normal from me... seriously, we all know it's never going to happen"
"People should stop expecting normal from me... seriously, we all know it's never going to happen"
RyanH wrote:my PF86 frames, I can barely get the crank to rotate a half revolution on its own.
What cranks and bottom bracket? In my experiences with BB86, binding like that typically indicates that either the bearing cups are misaligned or the bearing races are experiencing too much preload.
- Michael
"People should stop expecting normal from me... seriously, we all know it's never going to happen"
"People should stop expecting normal from me... seriously, we all know it's never going to happen"
I had a Wheels Manufacturing PF30 BB installed but it was misaligned ( by the BS ) and I experienced what RyanH is talking about.
Removing the cups was hell, as the BS mechanic had put Loctite on the BB cups. I had to use a saw to cup the alloy cups in 4 pieces, and then remove them...
Yeah, the Sram external seals have a thick outside lip and maybe that's what causes the most drag.
Thinking about maybe using another type of external seal or spacer. Not the best in wet weather though...
Louis
Removing the cups was hell, as the BS mechanic had put Loctite on the BB cups. I had to use a saw to cup the alloy cups in 4 pieces, and then remove them...
Yeah, the Sram external seals have a thick outside lip and maybe that's what causes the most drag.
Thinking about maybe using another type of external seal or spacer. Not the best in wet weather though...
Louis
I'm not exactly sure what those bearings look like but I have read about people removing the inward facing seal since it is less likely to be exposed to dirt and moisture. It will probably still have a negative effect on the lifespan of the bearing though.
My stock sram PF30 bearings spun well when i had the seals removed for a clean/ regrease. I installed the cranks without the seals in place just to see how they would spin. Really well. But you snap the seals back in and your lucky to get a a few revolutions. I have the Hawk bb now and they are effortless with seals in place. They did have to break in first. Its not like the seals in the hawk bearings are loose. Looks like a bearing to me. They have been though many rain storms and still spin effortlessly and smooth. Maybe the material of the seal isn't as slick or to soft causing more friction in the sram bearings?Maybe trim inner material from the seal edges?
nickf: thanks to your suggestions.. i got hawk and really enjoy using it. i emailed them asking how to service it and was surprise to hear not to open them up and just wipe the outside clean and add a couple drops of white lightning as needed.
- Gearjunkie
- Posts: 877
- Joined: Tue Feb 19, 2008 5:17 am
- Location: NZ
Ok, I'm over my PF30 Cannondale Evo having way too much drag so I think you've convinced me on the Hawk.
So do I need the PF30 Hawk (and so will have to go through the whole Locktite prep and seal thing) or can I just buy the Hawk BB30 bearings and use them in my existing PF30 cups?
Or is that just a bad idea? (not worried about cost, just ease of successful drag free, no creak install).
Cheers
GJ
So do I need the PF30 Hawk (and so will have to go through the whole Locktite prep and seal thing) or can I just buy the Hawk BB30 bearings and use them in my existing PF30 cups?
Or is that just a bad idea? (not worried about cost, just ease of successful drag free, no creak install).
Cheers
GJ
Gearjunkie wrote:Ok, I'm over my PF30 Cannondale Evo having way too much drag so I think you've convinced me on the Hawk.
So do I need the PF30 Hawk (and so will have to go through the whole Locktite prep and seal thing) or can I just buy the Hawk BB30 bearings and use them in my existing PF30 cups?
Or is that just a bad idea? (not worried about cost, just ease of successful drag free, no creak install).
Cheers
GJ
GJ, depending on where you are located.. if you are in US.. i can give you the link and the promo code to save on buying the PF30 Hawk. i bought two set of BB86 for my Addict R1 & TMR02. i'd say just replace the whole thing and install the hawk. since installing it.. i don't have any creaking issue. since installing hawk.. i've been bettering my own PR every time i ride the same climb.. maybe that's all mental. haha
- Gearjunkie
- Posts: 877
- Joined: Tue Feb 19, 2008 5:17 am
- Location: NZ
Hey, thanks for the offer, very kind. But I'm in New Zealand (little Country in the South Pacific near Australia.
When you installed your Hawk PF30, did you use any loctite or just press it in?
When you installed your Hawk PF30, did you use any loctite or just press it in?
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