Allen Key Brand - to protect bolt head on Rare EBB

[Jupestar]

Anyone able to recommend a decent brand of Allen Key.

I'm specifically looking for a 5mm t-handle without the ball end.

I've a high torque bolt which Everytime I need to remove scares the **** out of me I'm going to strip the head.

I've been making do with a ball end one, but I snapped the ball end in the bolt today. Luckily the head is intact and the ball end fell out easily.

Need a decent replacement. £5 or £25 I'm not fussed. I can't afford to strip the head.

[Jdsk]

Treat yourself to a Wera, eg:
https://www.primetools.co.uk/product/we ... -long-5mm/

But why is the torque so high?

Jonathan

[Jupestar]

Cheers purchase made.

[pjclinch]

May be worth investing in a higher quality bolt as well, so you're less likely to strip it?

[Nearholmer]

It’s good to have decent bolts, because some have rubbish heads that can’t take their designed torque, but a 5mm key suggests a bolt that shouldn’t be taking a particularly high torque anyway. Almost certainly teaching grandmother to suck eggs, but do you know the designed torque, and do you have a torque wrench?

[Pebble]

other thing worth checking (even if a good make) is how close to the actual size they are, have seen plenty 5mm hex that are as far out as 4.8 (difficult to know if some are oversied 3/16), even good makes may be only 4.88, nice if you find one that is something like 4.95, bin anything below 4.9
And Hex bolts have their own tolerances, they could be 5.06 AF, A good quality bolt will not only be better quality steel but made to a better tolerance sizewise.

and don't use tools that come with flat pack furniture, they're made from cheese

in an ideal world, the bolt should be 5.0 AF and the hex key 4.94 That combination wont slip
but you could easy have 5.06 AF with a 4.86 Hex - that may not work too well
and even worse when some clown uses a 3/16 (that could be 4.7mm) then its rounded

[CliveyT]

I have a set of 1/2"" (maybe 3/8 can't remember if I use an adapter or not) drive hex head sockets that fit on my torque wrench I bought specifically for one high-torque bolt on our tandem. Not cheap (but then neither is the tandem) and not as maneuverable as a hex key but well made and certainly not going to round off any time soon.

[slowster]

It sounds like an application where it would be better to replace the allen bolt with a torx head bolt.

[Jupestar]

May be worth investing in a higher quality bolt as well, so you're less likely to strip it?

It sounds like an application where it would be better to replace the allen bolt with a torx head bolt.

Its not just a run of the mill bolt, so it not that simple to replace. Otherwise i would.

It’s good to have decent bolts, because some have rubbish heads that can’t take their designed torque, but a 5mm key suggests a bolt that shouldn’t be taking a particularly high torque anyway.

Agreed. but it is what it is. I don;t have a better solution, so i just proceed with caution

but do you know the designed torque

I don;t, but it almost certainly less than the required torque which requires it to be able to stand 100kg of human mass grinding the crankset up the hill.

and do you have a torque wrench?

Yes but i can't get it to fit the bolt, it needs at least longer drive. Hence the T-handle. anyway it requires gorilla level torque, hence why the ballend snapped off when i tried to adjust it.


The bolt in question, is the bolt which tightens up an wedge type EBB. Its an incredably rare EBB with a 51.2mm OD. After aquiring the frame for an absolute bargin price, i found out why. It took over 2 years to locate a suitable EBB. 3 years on i'm still searching for a spare!

I'd need to take it out again to double check but I believe the bolt has a flange about halfway down the shaft.

Basically this EBB and Bolt are the critical part to allow me to enjoy this frame as long as possible. Hence why i don't want to strip it.

I do recognise the design flaw in needing to tighten it so much, and i guess why so few bike adopted this style of EBB. As well as my bike i've only ever found one model (a chumba) which uses the same EBB.

51.2 OD is amercian BMX BB shell size so you can get converters, but they are not EBB which sort of defeats the purpose of the frame.

Love the bike, and this bolt is critical. hopefull the WERA t-handle will keep it on the road for a while longer.

[axel_knutt]

What you need is a good quality key that's at the maximum end of its tolerance, so I'd be inclined to take a digital calliper around all the shops and measure them. Don't forget to measure across the corners as well as the flats.

[cycle tramp]

Deleted

[Jupestar]

I have a set of 1/2"" (maybe 3/8 can't remember if I use an adapter or not) drive hex head sockets that fit on my torque wrench I bought specifically for one high-torque bolt on our tandem. Not cheap (but then neither is the tandem) and not as maneuverable as a hex key but well made and certainly not going to round off any time soon.

I have something similar, but the problem in the size of the shaft i need. They have to be fairly long. hence the t-handle. with the cranks on i can only get the long end in. Without the cranks the short end fits really well.

I only adjust it sparingly, i think about once a year. Unfortunately the last time i did was recently, as the shell slipped and the chain was too loose. . To do so i took the cranks and BB out to remove any additonal loads expanding the EBB. and also enable better access to the badly designed but crutial bolt.

Anyway the chain was a stretched but i didn't have a replacement handy, so i tried to judge it loose so a new chain would go on correctly. I didn't leave it loose enough and can't get the fresh chain on, so unfortunatley i need to run the gaunlet and adjust it again. It all freshly greased, so was hoping to do it without taking it all apart again hence. but thinking about it i will probably take it apart, take some dimensions of the bolt, and start hunting for a replacement bolt as well as the EBB.

[Jupestar]

But why is the torque so high?
Jonathan

i'm 100kg+ and spent about 20 years of my life training my legs for rugby and rowing.

the bolt is stopping the bottom bracket from rotating while i'm out of the saddle grinding 44/16 up hills.

and i know, i shouldn't do it, but i do. sympathy for the bike.

[Jdsk]

: - )

Jonathan

[cycle tramp]

Removed