Press Fit BB Stop You Buying A Bike ... Can It Be Converted

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Witterings
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Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by Witterings »

Would a press fit BB stop you buying a bike nowadays or are they as good as threaded BB's and if it did fail in the future how easy / costly would it be to convert it ... it's a BB 86
Brucey
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by Brucey »

yes, no, and you can buy conversions (between many standards not all of course) for not too much.

cheers
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Tiberius
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by Tiberius »

Witterings wrote:Would a press fit BB stop you buying a bike


Yup, in fact it already has.
amediasatex
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by amediasatex »

Would a press fit BB stop you buying a bike


It would depend on the bike and it's other qualities, it would certainly be listed on the 'con' side of any comparison I was doing but it wouldn't outright stop me buying one if it was otherwise ticking all the (other) boxes and there was no equal threaded alternative option.

I do have a bike with a PF BB and it's not be too bad, adn if it ever does get to the point where I'm fed up of it then adaptors are available.
Witterings
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by Witterings »

So frustrating .... I even rang the distributor last week and asked if it was a threaded BB before asking the shop to order it and paying a deposit.

Someone made me question if it had a press fit over the weekend so I rang and spoke to the same person at the distributor this morning, he's gone away and done some extra research and come back and said he'd made a mistake and they are press fit .... grrrrr.

They shipped the bike Friday to the shop who's closed today and I really don't know what to do as it ticks a number of other boxes.

The bikes a Merida Silex 400, the alternatives I was looking at aren't due in stock until next year the Pinnacle Arkose 3 ... meant to be end of Jan but they've moved the date 3 times due to the recent problems they've had already and the Cannondale Topstone which aren't due until May.

I've done more research since posting about Hope, Praxis and Wheels Manufacturing BB's ...... my understanding is they don't actually convert it to a threaded BB with the associated ease of servicing but just provide what I guess what is meant to be a superior quality press fit that supposedly eliminates the creaking associated with some press fits ... is that a correct assumption??
Brucey
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by Brucey »

in some cases you can get a conversion in other cases all you can get is just a 'better' BB like you say.

cheers
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hondated
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by hondated »

Definitely NO. In fact as far as I am aware press fit BBs are fitted to the more expensive bikes. As for fitting a new one really easy with the correct tool and I have fitted one to my Trek Madone. Got the tool which is an home made tool but well engineered from a seller on Ebay for I think it was £15.
fastpedaller
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by fastpedaller »

hondated wrote:Definitely NO. In fact as far as I am aware press fit BBs are fitted to the more expensive bikes.

Why would that influence your decision? No trying to argue, just curious.
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Cugel
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by Cugel »

Witterings wrote:So frustrating .... I even rang the distributor last week and asked if it was a threaded BB before asking the shop to order it and paying a deposit.

Someone made me question if it had a press fit over the weekend so I rang and spoke to the same person at the distributor this morning, he's gone away and done some extra research and come back and said he'd made a mistake and they are press fit .... grrrrr.

They shipped the bike Friday to the shop who's closed today and I really don't know what to do as it ticks a number of other boxes.

The bikes a Merida Silex 400, the alternatives I was looking at aren't due in stock until next year the Pinnacle Arkose 3 ... meant to be end of Jan but they've moved the date 3 times due to the recent problems they've had already and the Cannondale Topstone which aren't due until May.

I've done more research since posting about Hope, Praxis and Wheels Manufacturing BB's ...... my understanding is they don't actually convert it to a threaded BB with the associated ease of servicing but just provide what I guess what is meant to be a superior quality press fit that supposedly eliminates the creaking associated with some press fits ... is that a correct assumption??


I have two bikes with press fit BBs, both Trek BB90. I recently changed the bearing races (which is all that needs changing when a BB90 bottom bracket needs renewing) with no issues at all. The bearings had been in for 7 years and done thousands and thousands of miles. Only one was a bit notchy, probably because I took the protective washer off that side to fit a non-standard chainset.

The new bearings (identical to those already installed in the bike) were £14 for the pair. I used a £15 tool to knock the old ones out and a £20 tool to press the new ones in. In truth, I think I could have pressed the new ones in without the special tool. Still, best to do a job properly. The new bearings have already done about 400 miles and seem just as free running, smooth and unproblematic as the old ones.

Those old bearings have never creaked, graunched or given any other issue until I noticed on the last chain change that there was a very slight notichiness when I spun the chainset. Only one bearing felt slightly rough when removed. The other was indistinguishable from a new bearing - still very smooth and nice when rotated inner against outer race.

So, not all press fit bearings are problematic. In fact, they're rather easier to deal with than other types. There are some cheap & nasty ones, their problem being that they are housed in plastic shrouds or other stuff that squishes, so they can move in the BB shell and hence creak. In addition, some frames aren't well made and their BB shells are not fully round or otherwise made to specification.

I don't know about Merida Silex as I haven't got one. Why not check out the details of the BB design? If it's just good quality bearing races pressed into a well-made BB and covered with some sort of blanking plate to keep out dust and water, I imagine they'd be fine.

Should there be a problem, you can buy a replacement arrangement that's basically a sleeve, with the bearing races in it, that comes in two parts that screw together inside the BB shell, pulling the flanges of the whole thing against the outer faces of the BB shell. The sleeve is usually made of aluminium or something else that won't squish; and is well-formed to exactly fit into the BB shell ends where the BB races are located.

Cugel
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Spinners
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by Spinners »

I'd say I'm hesitant about buying a bike or frame with a press fit BB so this thread is great in seeing the range of views.

I do have my eye on the Giant Contend SL1 and the spec's just says 'Shimano Press Fit'.
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fastpedaller
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by fastpedaller »

Maybe I'm wrong, but a friend who has worked as a mechanic in a bike shop for many years has said he'd have an external bb, but not a press fit. They are poor engineering, as taking out/in will compromise the bb shell over time.
thelawnet
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by thelawnet »

Spinners wrote:I'd say I'm hesitant about buying a bike or frame with a press fit BB so this thread is great in seeing the range of views.

I do have my eye on the Giant Contend SL1 and the spec's just says 'Shimano Press Fit'.


Shimano Press Fit is BB86.

There are some analyses of various press fit bb standards on this channel. E.g., BB86 here:

[youtube]1XXrVoF2TwY[/youtube]

and frame tolerances:

[youtube]zryhuHkbb-o[/youtube]
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hondated
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by hondated »

fastpedaller wrote:
hondated wrote:Definitely NO. In fact as far as I am aware press fit BBs are fitted to the more expensive bikes.

Why would that influence your decision? No trying to argue, just curious.

FP pretty sure you not looking for an argument so no problem. I read it as asking whether if it was fitted with a press fit BB would it put you off of buying it so my response was No. I went on to say most expensive bikes have PF BB rather than screw in one's. Prior to buying the tool I mentioned I did try using a bit of wood & hammer but soon realised that was not a good idea :lol:
Don't mind being questioned on anything I write but it muffs me when I offer advise and it's then not even acknowledged + another thread )
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willcee
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by willcee »

A Definite NO.. These AND BB30 are the source of more complaints on top end machinery than ANY other problem .. i have renewed them, yes with or without tools, not a great problem if you have sufficent tool nouse.. I wouldn't have a so equipped machine about me.. period..like others have said wait a few years until the carbon recess into which they press fit is not longer press fit but sloppy fit, or the metal inserts some manufacturers regard as an upgrade lose their ineffective grip on the carbon..its bad engineering design, ok for factory teams where they are handed another new bike but not for the private owner who has coughed up several grand to have such a machine.. modern throw away thinking which hasn't ever trickled down to my house..nor never will.. will
alexnharvey
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Re: Press Fit BB Stop You Buying A Bike ... Can It Be Converted

Post by alexnharvey »

hondated wrote:
fastpedaller wrote:
hondated wrote:Definitely NO. In fact as far as I am aware press fit BBs are fitted to the more expensive bikes.

Why would that influence your decision? No trying to argue, just curious.

FP pretty sure you not looking for an argument so no problem. I read it as asking whether if it was fitted with a press fit BB would it put you off of buying it so my response was No. I went on to say most expensive bikes have PF BB rather than screw in one's. Prior to buying the tool I mentioned I did try using a bit of wood & hammer but soon realised that was not a good idea :lol:
Don't mind being questioned on anything I write but it muffs me when I offer advise and it's then not even acknowledged + another thread )


I think fastpedaller is trying to politely query your specious reasoning that because Press fit BB is a feature of expensive frames it is better.
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