Praxis BB30/PF30 to Shimano Hollowtech II Conversion
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- Опубликовано: 8 фев 2025
- This video shows the upgrade of the bottom bracket in my Specialized Sirrus Carbon Comp (2014) from a BB30 to a 24mm Shimano Hollowtech II so I can replace my old FSA Gossamer crankset, which I've wore out, for a new Shimano Tiagra (to match the rest of my drive train).
To do this I used a Praxis 68MM BB30/PF30 to Shimano Hollowtech II 24mm conversion kit. This kit uses an expanding rubber seal to provide a tight fit in the frame rather than their previous expanding steel collet arrangement.
The Praxis BB converter worked very well, I did get a bit of creaking initially so took it apart and refitted it, but it was a massive improvement on the BB30.
Helped me a lot, thank u for the Instructions!
Greetings from Germany
Glad it was useful.
@@davidb5255 Can u still recommend the Praxis? Do u already heard some noise/friction or play in the crank arm after a few months? I just saw Hambini does some too, quite expensive at 160€, but considering long-term mb worth... I was told those plastic-o-rings from praxis are going to make troubles...
Now i want to rebuild my 2010´ carbon frame with PF30 and again i dont know which way to go.
Maybe u can tell me ur opinion of the praxis after some while, so i can decide if i really have to go for the hambini version or not...
Thanks!
@@kevingrabosch4638 Yes the Praxis BB is still going strong. I put about 2000-3000 miles on my bike a year and most of the time it's quiet, no BB noise or obvious friction. Most noise is from dirt/grit on the drive train, good wash and it quietens down. No movement if I twist the crank in the BB.
Did initially get a bit of creaking but refitted the BB and it went away. Can't comment on longevity of plastic o-rings, not taken mine apart since fitting (2017). More likely to get movement on non-drive side which is press fit I would have thought.
Wow Hambini BBs are expensive. Look like push fit, would have thought you would be at the mercy of how worn the existing BB30 seat was as to how well that fitted. At least with the Praxis (on the drive side) the rubber o-ring should take up any slack.
Excellent video. Just about to change my praxis 105 for Shimano and add a power meter. Thanks
Glad you found it useful. Good luck.
David B parts arrive mid next week. Finger n toes are crossed.
Awesome thanks!!!
If we stick to the old traditional bottom bracket we wouldn't have this kind of problem. They should keep the BB30 to a professional racer because they require a stiffer. I have bb30 and I need to convert it to a regular bottom bracket. that's why I am here watching it .
You are lucky to have original BB30 with an aluminium BB, much stronger / better than carbon fibre.
So are the later ones a carbon seat for the bearing instead of the alloy insert? Did not realise that, had assumed the alloy seat was there because the tolerances were better and it was harder wearing.
Hi
Looks like i have the same problem with the wobbly cranks and wear on the inside. Praxis do 2 versions for specialized, which one did you use. My frame looks like it's the same as yours.
Thanks
I'm sure when I bought mine, which was a while back now, the only choices where which crank set you were going to use and what bottom bracket type you had, nothing specific to the bike manufacturer. So as I wanted to upgrade to Shimano Hollowtech and my frame was a BB30/PF30 I went for this one 68-3001R. The different sizes between the BB30 (mine) and PF30 are accounted for by a sleeve included in the kit. I guess the only other difference maybe road or MTB, mine is road hence the 68 in the part number which is the 68mm frame width.
Hope that helps.
Instructive, but you skipped a couple of procedures I would like to have seen. The first is actually tightening the drive side with the tool. Do you need to hold the nondirve side? I don't know bc you didn't show it. The second is putting the crank in. You don't show it. The next scene the crank is already installed.
Hi, sorry for the missing steps, this was one of my first YT videos and was done with the camera hand held so operations requiring two hands were impossible. I now have a phone mount for tripod so could now do it better.
To answer your question, yes you do need to hold the non-drive side still while tightening the drive side, do you need two hollotechb socket tools. Inserting the crank was not actually that exciting, you just carefully feed it in from one side keeping it as straight as you can. It's a tight fit but will slide reasonably freely if aligned. Can be a big tricky to get the crank end through the other side bearing and you need to be careful you don't push of the orange bearing cover, not that that is bad but if it falls on the floor it gets covered in dirt which you need to clean of.
Thanks anyway for the contents, will try and do better in future videos.
Cheers
Hi! Thank you for your video. Do you need to adjust your derailleurs after changing to Shimano system?
No I didn't need to when I did the upgrade, but I did check it just incase. I have subsequently readjusted the derailers after changing the cables.
@@davidb5255 Cheers!
Thanks for the video. Can you share the specific icetoolz tool part number or model? I’m planning to do this with my tarmac and not sure which tool to get
Hi. The BB tool I've got is the IceToolz M296828 for Shimano HollowTech II compatible crank adapters. Due to a slight over ordering cockup I've actually got two unused ones in the garage still. Regards
hi,
do you know of a way to get a existing bb30 bb to accomedate a hollowtech II crank? thx
Hi
Yes I believe there are inserts you can get that fit in both sides of the BB30 and provide a Hollotech drive. I think wheel manufacturers do one. Not sure how good they are in terms of fit and stiffness.
Regards
Did you need any spacers? Thanks.
No, no spacers needed for either the bottom bracket installation or for fitting the crank in the bottom bracket.
did you take the metal clip?
Do you mean the inner circlips inside the bottom bracket shell? If so then yes you need to take the circlips out of the BB shell on both sides in order to push the Praxis converter in. IIRC the circlip was on the inner side of the bearing to prevent it pushing further into the frame.
@@davidb5255 cool, big help. I am using a SRAM BB30 with 24mm adapter to fit my Shimano ultra 6800s crank.
The wear on the crank looks inside of where the bearing meets the crank. Could it have been something else rubbing on the crank? Or could the bearing have moved in board?
No the wear was exactly where the bearing was sat on the crank shaft as its very close to the non-drive side splines for the pedal shaft. Also the seat had an internal circlip which stopped the BB30 bearing pushing too far into the frame.
Aren't you supposed to remove the orange covers from the bearings?
No the orange covers are the dust covers. Additional protection to the seals on the cartridge bearings themselves.
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What a long video just to replace a bottom bracket. I guess he loves to hear himself talk. Just my opinion.
The beauty of RUclips is that you can skip past any part of a video if you are not interested in the specifics of maybe how the circlips fit in a Specialized Sirus frame or if you know how to preload a bearing, there is no obligation to watch it all start to finish, I rarely do for other videos.
Personally I'd rather have a more detailed and longer video than a fancy scene fade from parts on the garage floor to fitted in the bike in 5 minutes without knowing the crucial step half way through.
And 24 minutes was a lot quicker than it actually took in real life! Things are much quicker if you have done it before and know what you are doing, neither of which I had.
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Maybe I do but I'd rather make sure I describe everything as the watcher can always skip or run the video at 2x speed.