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Hi,
Has any of you successfully replaced the PF30 bottom bracket with a Shimano HTII compatible one? What has worked best?
I have a 2014 (i.e. previous generation) Stumpy FSR Carbon 29, with OEM Sram PF30 BB and custom OEM Sram 1250 (36/22 double) crankset. I would like to swap these out for a Shimano double crankset (36/22 SLX) and a Shimano HTII compatible BB. I'm considering the Hope PF46 BB (which is a press-fit unit with an internal threaded sleeve that holds the two cups together), which comes in 24mm (i.e. Shimano) version. Another alternative is the Praxis Works BB conversion, but I've read reports complaining about creaking (it seems to work better with BB30 than with PF30). BBInfinite also looks great but is a bit too expensive for me now (and does not seem to have a European distributor either)
But I'm also a bit worried that the standard Shimano double crankset might have a different chainline or axle length from the supposedly "custom" Sram S1250 cranks. Shimanos have a 48.8mm chainline, while the Sram S1250 is presumably 49mm. Sram is the so-called "long spindle" version (with the 15.4mm DS spacer). I'm not interested in switching to a 1x system and 36/22 hits the sweet spot for me, so it is definitely going to be a Shimano double. IF it works.
I would appreciate any helpful input or advice.
I have a camber with a praxis conversion to fit the shimano 11 speed 1x. Absolutely no creaking. Done by the LBS.
Praxis here, it's very simple to install (unlike the Hope BB which needs specialist tools). All you need are is ordinary BB tools, the Shimano axle plugs straight in and away you go.
The Praxis bearings aren't as long lasting as I'd hoped - mine started to sound a little rough on the drive side after six months of Spring/Summer riding, but the bearings themselves are a doddle to drift out and a quick regrease cured mine. The best bit is that you can replace with off the shelf bearings and leave your BB in situ.
I have a Hope one in my spares box. It came out of a bike a couple of months back in perfect working order. I liked the fact that the cups press in, then the screw in sleeve holds them tight rather than the praxis which I believe is fitted by turning one of the cups in the frame.
If you're interested in a (s)lightly used one, my email is in my profile.
Wheels Manufacturing here, with Enduro bearings. Recommended to me by a mate who also has the Praxis one, which creaked for him.
Hope.
Wheels one was fairly rubbish, bearing life was dire. Praxxis was better and less prone to creaking, yet still creaked after time.
The Hope one was the best of the lot.
Running a Hope one in a 2013 Stumpjumper, fitted from new, and not had to touch it yet
Thanks for all the comments.
Gavinpearce and PJM1974: Did you have any problems with chainline/crank chainrings misalignment? (I'm not sure whether the stock OEM Sram S1250 on my Stumpy is "custom" in that sense). Is the Camber a carbon or an alloy frame?
Onzadog: yep, that's precisely why I'm considering Hope. Praxis does have a structural asymmetry (i.e. the DS is solid due to the collet, but the NDS is just like a regular pressfit cup, plus the rubber ring).
Hob Nob: So have you tried all three and Hope was the best? It is more expensive, but I don't mind paying extra if it's really better in the long run. Do you have a carbon or an alloy PF30?
Running a Hope one in a 2013 Stumpjumper, fitted from new, and not had to touch it yet
Tracey: Is that a carbon Stumpjumper? And did you go for the 24mm conversion (i.e. replaced stock crankset too) or is it a Hope BB for BB30 cranks?
Carbon Stumpjumper, came as frame only and fitted with XO GXP cranks. I also have the Hope PF46 fitted to BB30 SRAM cranks fitted to a Enduro
Wheels Manufacturing. Every time!
How about a Sram PF30 to BSA adapter pressed into the frame and then screw the standard hollow tech bb straight in.
How about a Sram PF30 to BSA adapter pressed into the frame and then screw the standard hollow tech bb straight in.
Way too many negative reviews of the Sram adapter.
I was about to ask about the SRAM adaptor, it's only £20. What's so bad about it then? A riding mate has done thousands of miles on them.
No issues at all with chainline or anything.
Not read the rest but I've recently gone for the Hope PF30 => 24mm axle bb. It is in a 2015 camber.
About £85 at CRC. Plus the fitting tool.
Piece of wossname to fit with the tool.
Works nicely with some XT cranks I had kicking about (ex 9speed running a n/w ring with 10spd drivetrain).
You may be already set on switching to 24mm cranks, but in case not, i thought i'd put forward a defence of PF30: I have had a couple of carbon Epics with PF30 and initially found the BB short lived an a PITA and expensive to change, but with my latest carbon epic I switched only the bearings (sticking with the OEM shells) straight out for ceramic versions and now have a long life BB and no need buy different cranks.
The sram adapters squeak like hell.
I have a Stumpy carbon. Had the Praxxis convertor and it creaked. Went over to an FSA frame insert and standard hollowtech BB works perfectly, no problems in over 10 months. I also use a 2x10 set up with no issues.
I switched only the bearings (sticking with the OEM shells) straight out for ceramic versions and now have a long life BB and no need buy different cranks.
Do you mean the Delrin cups? Is is easy to remove just the bearings? I thought that might easily damage the shells/cups (as they are are Delrin/plastic).
Of course, I might keep the Sram crank and replace the Sram BB with a Hope one (PF46 for 30mm crank axle). To be honest, I've had the bike for 2 years and the original Sram pressfit BB has not started creaking yet (but I'm sure it will at some point and I'm trying to plan ahead for that)
Carbon Stumpjumper, came as frame only and fitted with XO GXP cranks. I also have the Hope PF46 fitted to BB30 SRAM cranks fitted to a Enduro
Tracey, did you use grease to fit the Hope PF46 units into those carbon frames? Or did you use some retainer (e.g. Loctite 609 with primer)? Hope recommends grease, but I'm really not convinced that's a good idea for carbon BB shells
I've always used grease. Why wouldn't you? There's two surfaces that you want to slide together. Carbon isn't actually that delicate but if you're concerned, check with the manufacturer.
Rang Hope because I wasnt convinced but they said grease, even when I told them carbon frame. took their advise and use grease and its still OK.
Grease (unlike low-shear strength Loctite 609) is never recommended to be used with carbon interfaces. For one thing, many greases are acidic, which is not good for the resin in carbon frames. More importantly, the pressfit units are supposed to be fixed and held tight in the BB shell, while grease lubricates and can (in theory) help movement (i.e. creaks) down the road. In fact, Specialized requires the use of epoxy for the factory installation of the crappy Sram PF30 BB (due to tolerance imperfections in the shell). Epoxy or Loctite 609 can fill the potential gaps between the outer diameter of the BB unit and the inner diameter of the 46mm carbon BB shell. Grease can only fill these gaps initially, but is pumped out (it's hydraulics, really) and thus can lead to interface movement (and creaks).
I'm really puzzled, because Praxis also recommends grease for installation, but there have been people who contacted them with specific advice for carbon frames and were told to use Loctite instead.
Had same problems myself, PF would last a couple of months Praxis about 4 months had Hope conversion 18 months ago no problem now.
Had same problems myself, PF would last a couple of months Praxis about 4 months had Hope conversion 18 months ago no problem now.
Did you use grease with the Hope? And is it a carbon frame with carbon BB shell (i.e. no alloy sleeve)?
I wanted to retain my cranks so used a Praxis converter in Stumpjumper Carbon. Running XTR crank that started life as a double but running 1 x 10 and no obvious chainline issue - albeit not measured. But certainly no increased wear.
The Praxis unit was initially expensive but replaced the bearings easily after two winters and about 16 months for a tenner. No creaking and it was that snug a fit I was getting nervous using a mallet anywhere near my BB to get the unit out...
Wheels Man recommend the following to be applied to both mating surfaces for various shell materials:
Steel & Alu, grease
Titanium, anti-seize
Carbon, PTFE Teflon
And grease on the threads of the unit itself.
Dufusdip: Did you use grease or Loctite (or epoxy) between the Delrin sleeve that comes with the Praxis and the carbon frame's BB shell?
And how do you replace the bearings of the Praxis? Is it easy to drive them out? I know that leads to the loss of Praxis factory warranty, but that's no problem for me
Had same problems myself, PF would last a couple of months Praxis about 4 months had Hope conversion 18 months ago no problem now.Did you use grease with the Hope? And is it a carbon frame with carbon BB shell (i.e. no alloy sleeve)?
Posted 20 hours ago #
I switched only the bearings (sticking with the OEM shells) straight out for ceramic versions and now have a long life BB and no need buy different cranks.
Do you mean the Delrin cups? Is is easy to remove just the bearings? I thought that might easily damage the shells/cups (as they are are Delrin/plastic).
Of course, I might keep the Sram crank and replace the Sram BB with a Hope one (PF46 for 30mm crank axle). To be honest, I've had the bike for 2 years and the original Sram pressfit BB has not started creaking yet (but I'm sure it will at some point and I'm trying to plan ahead for that).
Yes, I kept the original plastic cups. I knocked the original bearings out with a large flat screwdriver from the opposite sides, which invariably means both cup and bearing come out. Once out of the frame, the bearing separates from the cup easily. Then I refit the shells, no grease, then refit the bearings, with a smidge of grease to ensure no corrosion of the outside of the races, with a homemade bearing driver (large bolt with giant washers the same size as the bearings which you slowly tighten up to squeeze new bearings back into the plastic cups in the frame symmetrically).
I've not run this particular one in much water yet, but its time will come and past experience has proved this to be reliable set up