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Difficult to explain, hope you get the gist.... Changing the BB on my bike tonight, noticed that there are two types of bearing system on the stuff I have been using..
Hope BB, the metal bearing face actually contacts the crank spindle on a machined surface.
Shimano/Gub BB have a plastic insert that is both a bearing cover/shim. This plastic sits on the crank spindle where it passes through the bearing. Remove the plastic cover and shim insert and the bearing is obviously a rattling fit on the spindle.
The drive side of the bearing had play in it so I swapped it out. On checking it looks like the plastic spacer has worn or compressed, causing the play. The actual bearing looks ok. Its a shame to scrap the BB for the sake of the plastic part...
Any other peoples experiences? Can you find these plastic parts as new replacements anywhere?
Plastic part won't wear unless the bearing has seized (at least at some point)
superstar sells some top hat bushes - name angletech or something. SOmeone linked to them once from here
I bought some but haven't tried 'em yet
Edit: [url= https://www.google.co.uk/#hl=en&sclient=psy-ab&q=site:singletrackworld.com+%22top+hat%22&oq=site:singletrackworld.com+%22top+hat%22&aq=f&aqi=&aql=&gs_l=hp.12...92589.107874.2.111451.35.35.0.0.0.0.100.2189.34j1.35.0...0.0.POSRt1xwr3o&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=45f95ee2823d921f&biw=981&bih=1374 ]here you go (1st result)[/url]
rick - your expericence is the opposite of mine. It's usually the nds that fails first. Usually due to water and / or grit.
I've never had to replace a DS bearing before a NDS one.
They always go due to water / grit or at least a gritty feeling NDS.
BTW :
A: I Cant afford a those hope ones
B: Those SS top hats are significantly smaller than the HTII races / original top hats so I doubt they are any use. Like scaredypants - I bought them - but I've not had the reason to use them yet. So no real experience.
CSW, I bought a GUB Ceramic from ebay, I'm sure its the plastic top hat thats the problem but they are not the same as Shimano so I couldnt swap them over... Tempted to try a bodge with ptfe tape....
Scaredypants, thanks for the link... I even posted about kaesae, he is just round the corner from us too...
Apologies Rick - the GUB bit didnt register / click with me. Sorry - I've no experience with that.
No problem.... the GUB bb from China uses the same top hat system as GUB, just a bit of a different shape around the bearing cover/seal. This stops it being a simple swap.
I tried a GUB. Nice idea, but was made to the wrong dimensions! Ie when I fitted it to a 68mm shell, and therefore used all 3 spacers, I couldn't fit the crank. It did fit with only 1 spacer. Which means it wouldn't fit a 73mm shell bike frame. They gave me a full refund when I pointed this out. Which was nice.
I don't like the concept of plastic spacers, so its Hope FTW.
I had the same with the GUB dimensions, but happy once I worked the spacers out for the 68mm shell.... I want to try and resolve the plastic top hat issue really..
Good they gave a refund.... gives me more confidence working with them in the future.