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I have a Nukeproof Scout that the bottom bracket became very stiff after only 300 miles and was almost seized. Thought I’d treat it to a Hope BB so ordered the 68/73mm one and installed it using one 2.5mm spacer as the Hope compatibility page shows but the cranks now have quite a bit of lateral movement. Tried 2x2.5mm spacers but then when tightened the cranks won’t spin!
Did I wasted £90 (its installed and covered in grease) by ordering the wrong part? Do I need the 30mm Hope 73mm bottom bracket? a lot of googling and I’m none the wiser!
30mm bbs / cranks are a crap shoot for fitment.(And lifespan in 99% of BBs). No suprise it's totally different one bb to the next. What cranks are they?
300miles on a nukeproof 30mm bb sounds average.
Raceface cinch cranks I think!
Do I need the 30mm Hope 73mm bottom bracket? a lot of googling and I’m none the wiser!
Might be stating the obvious, but just in case...
68/73mm is the shell width, measure the bit of your frame it goes into. They are usually the same BB and you adjust with spacers, or no spacers.
30mm is the axle diameter on the cranks. It will most likely be either that or 24mm. GXP has some sort of weird tapered thing, you've not GXP cranks and that's causing the wobble have you?
Raceface cinch cranks I think!
Have you adjusted the preload collar on the crank?
Shimano is traditionally 2 on the drive side and one on the non drive side, for 68mm and 1drive side for 73mm IIRC, but no idea about Hope. If there is play it sounds like you need more spacers. What did you take off?
Definitely 73mm shell width, cranks i am unsure but pretty certain it’s a 30mm spindle.
the thing confusing me when ordering from tredz was it gives two options:
68/73mm MTB or
68/73/83mm -30mm
I ordered the first one and the crank slides in no problem just the lateral movement once fitted, no wobble so I am assuming it’s the correct diameter BB just not width or needs more spacers maybe!
How much lateral play? A tiny amount is no issue. Contrary to common belief bb bearings do not need preload. Angular contact ones need zero endflat. Normal bearings a bit of endfloat is no issue.
Ive been running my bikes like this for years and very rarely have to change a bb
As posted above, if you haven't adjusted the preload collar they will be too loose with the correct number of spacers in the BB. Remove one spacer then follow the instructions in the video earlier in the thread to tighten the preload.
@willstaffs - I had exactly the same issue with a Hope 30mm BB and some Race Face Turbine Cinch cranks.
In a 73mm BB on a Ragley frame I ended up having to use a 2.5mm + a 1mm spacer to get it right. With one spacer the preload collar wound off the threads, and with 2 spacers the cranks would barely turn with no preload added
As you found 1 x 2.5mm spacer is too narrow and 2 x 2.5mm spacers are too wide.
I think Hope BB cups must be slightly narrower than standard.
All this talk of preload collars and I’ve just been out to garage and it doesn’t have one, there wasn’t one when I removed the old bb as I’ve saved all the parts,
@ajantom Great, I’ll try and find a 1mm spacer and give that a go!
Nukeproof Scout likely to be RaceFace Ride model which is 24mm axle with no pre-load collar. Recommend actually measuring the crank axle diameter.
If is 73mm shell, 24mm axle and loose with one DS 2.5mm BB spacer fitted; if its Ride or Aeffect then there is a fat 6-7mm washer that goes on before the DS crank with chainring attached, its sits inside the cinch chainring lockring and holds the DS crank off the BB. Check still have that (NB has a small lip that goes inwards). There are also meant to be some plastic spacers on the NDS crank spindle. One white & two black. Can add / remove to adjust side play.
Succinct & easy to use (lols) RF Guide here:
RES.CLOUDINARY.COM