Retrobike Forum Index

It is currently Thu Nov 15, 2018 2:37 pm

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 15 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Wed Aug 15, 2018 5:30 pm 
Retro Guru
User avatar

Joined: Sun Jun 22, 2008 5:10 pm
Posts: 306
Location: Vancouver, BC Canada
Here's something we don't see every day! I'm a garage sale junkie and one never knows what pirate treasure they come home with...including a beryllium RekTek frame! I haven't felt this way about building up a bike in awhile, actually, and have dropped everything for it! I'm pretty stoked and wanted to share.

Image

Image

Image

What I do know is that this was built during the original RekTek days (pre Reckless Rider) and in 1991 they spent $18,000 in Russia having this made. I'm going to try to build it up with 91 / 92 Canadian parts and xtr m900 as best as I can.

Image

I remember a few companies back in the day had a try at making beryllium mountain bike frames and knew they were a rare bird, but it wasn't until I came home with this Canadian frame and started Googling them, that I found out that there's not much info to be found. Some great info was contributed on Facebook and if you have any info on this material and it's brief stint in mountain biking frame building, would be appreciated in the info and conversation. Cheers, Eric


Top
 Profile  
 
PostPosted: Wed Aug 15, 2018 6:41 pm 
retrobike rider
retrobike rider
User avatar

Joined: Tue Aug 11, 2015 4:58 pm
Posts: 1459
Location: Bridgend, S.Wales
Nice.
Don't remember this one though. The only beryllium bike was aware of before this is the American that was built just for Interbike in about 92/93? Super shiny if i remember right, and apparently that was $30K.
I believe that beryllium emits toxic fumes when machining or welding, hence it's not an easy material to process.
What does that thing weigh? 8)


Top
 Profile  
 
 Post subject: Re:
PostPosted: Wed Aug 15, 2018 7:08 pm 
BoTY & PoTM Winner
BoTY & PoTM Winner
User avatar

Joined: Tue Jul 13, 2010 10:19 pm
Posts: 7354
Location: KEEPING THEM SAFE FROM HARM, ANYWAY I CAN....!
Is it made with Beryllium or is it made with Boralyn ...?

The finish looks a lot like Boralyn,i dont know enough but i have owned a Univega bitd, which ever it is, very cool.


Attachments:
Uni2800.jpg
Uni2800.jpg [ 176.14 KiB | Viewed 504 times ]
Top
 Profile  
 
 Post subject: Re:
PostPosted: Wed Aug 15, 2018 7:52 pm 
Gold Trader / MacRetro rider
Gold Trader / MacRetro rider
User avatar

Joined: Mon Aug 27, 2012 9:56 pm
Posts: 2328
Location: Eilean Siar
Here's an interesting fact.... if you were to cast a bell made from Beryllium, it would not ring.... every day's a school day! :D


Top
 Profile  
 
PostPosted: Wed Aug 15, 2018 8:43 pm 
Retro Guru
User avatar

Joined: Sat Aug 13, 2016 8:08 am
Posts: 691
Location: Suffolk
Interesting frame and keen to see how it comes out. Lots of mystery about beryllium, used in loudspeakers, particularly the HF drivers (Yamaha NS1000 were the first in the late 1970s IIRC).
This is shat Ibis have to say on it:

Quote:
You may find this hard to believe, but there is a metal out there that is significantly more expensive than titanium. It's called beryllium. Beryllium has about two-thirds the density of aluminum, so it certainly fits into the category of non- density-challenged metals. Furthermore, beryllium has some amazing mechanical properties - and density is only one of them.The specific strength (strength divided by density) of beryllium is very high. The specific stiffness (modulus divided by density) is the highest of any metal on the face of the earth ... or within the earth for that matter. But beryllium is rare: Its concentration in the earth's crust is approximately 6 ppm. No rich deposits exist, and one of the results of this low concentration is the aforementioned high cost - compared to aluminum, it's about 200 times as expensive!

Here are some of the specific numbers for a tube of extruded beryllium: 40 KSI ultimate and 44 MSI modulus - which when combined with the low density, gives you the phenomenal specific stiffness numbers ... many times higher than any other metal. By comparison, the modulus of steel is only about 30 MSI, and the density of steel is nearly five times that of beryllium.

Had enough good news? The bad news is the horrendous elongation number of about 2 percent in the longitudinal direction, and 0.2 percent in the transverse direction. On planets where the surface temperature might be about 390 degrees F, the elongation number for beryllium goes way up, to 23 percent. Unfortunately, that doesn't do us much good here on earth. (An interesting note that appeared next to the elongation number in one mechanical engineering handbook was "Ductility values in practice will be found in general to be much lower, and essentially zero in the transverse direction." Ouch!)

Fortunately, there is an alternative to extruded beryllium: It's called cross-rolled sheet. The beryllium bike that Brush-Wellman (a vertically integrated beryllium company) made for American Bicycle Manufacturing a couple of years ago was fabricated from sheet, to take advantage of higher elongation (more than 10 percent) and higher ultimate and tensile strength. To make the bike, the sheet was rolled into tubes and welded together.

In further bad news, beryllium wins out over all metals on the toxicity issue - beryllium dust can kill you. Inhalation of dust particles or vapors containing beryllium may cause berylliosis, an inflammation of the lungs.

Due to cost, ductility and toxicity constraints, pure beryllium isn't commercially feasible for bicycle frames. Sure, you can make one, like that $25,000 showpiece that ABM did, but you can't call that project commercially feasible.

Brush-Wellman also has created an aluminum-based alloy with beryllium added to the mix. The patented metal is trademarked as AlBeMet, and it shows some promise for bicycle parts. The material is already being sold commercially in other markets - for computer disk drives, for instance - and Beyond Fabrications of San José, California, has seatposts and handlebars made out of it. Frames are on the way, according to a spokesman for Brush-Wellman. Altogether, the company has four alloys of AlBeMet, and they vary from 30 to 62 percent beryllium in the mix, with the following claimed mechanical properties:

AlBeMet Alloy: 130 140 150 162
% Beryllium 30 40 50 62
Density .086 .082 .080 .076
Yield (KSI) 23 30 33 40
Ultimate (KS) 34 40 50 55
Elongation (%) 17 15 13 7
Modulus (MSI) 19 20 25 28

Brush claims that these alloys are weldable. It's interesting to note that strength is quite low for the materials with less than 50 percent beryllium.A final practical use for beryllium is as a neutron source to charge the initiator in atomic bombs. When bombarded with alpha radiation, beryllium emits neutrons. Thanks to beryllium, that's how the neutron was discovered back in 1932.


Top
 Profile  
 
 Post subject: Re: Re:
PostPosted: Thu Aug 16, 2018 7:50 am 
Retro Guru
User avatar

Joined: Tue Jun 19, 2007 3:34 pm
Posts: 2211
Location: Launceston, Australia
sinnerman wrote:
Is it made with Beryllium or is it made with Boralyn ...?

The finish looks a lot like Boralyn,i dont know enough but i have owned a Univega bitd, which ever it is, very cool.


Yeah the American thing was more of a greeny bronzy colour for the tubes, this looks more boralyn, but who knows, crazy stuff happened back in those days.


Top
 Profile  
 
PostPosted: Thu Aug 16, 2018 8:45 am 
King of the DuckBoard
King of the DuckBoard
User avatar

Joined: Sun Jan 28, 2007 12:30 pm
Posts: 24466
Location: weight weenie 26er
nice find. keep the thread updated with the build progress. Looks a good build in progress


Top
 Profile  
 
PostPosted: Thu Aug 16, 2018 11:01 am 
retrobike rider
retrobike rider
User avatar

Joined: Tue Jan 29, 2008 11:04 pm
Posts: 2293
Location: A wretched hive of scum and villainy...
There are some vague mentions around of a RekTek beryllium prototype for the '92 or '93 Interbike, so maybe this is it?

The TT cable stops look to have been machined to fit a larger diameter of tube, so looks very 'prototype', yet the cast lugs would have been a considerable expense. Did RekTek make a bonded frame already, or are the lugs lifted from Trek or such?
Also, it looks like entirely bare metal, but since beryllium doesn't oxidise below around 600ºC, there's no need...

Hard to ID other than by the density and modulus, and those are hard to gauge with the tubes build into a frame.

If it isn't 100% beryllium tubing, then it's most likely to be one of the the AlBeMet alloys from Bush-Wellman mentioned in the Ibis quote which Gerard posted, which is allegedy fully weldable. Bonding would still be a good option, given the H&S/COSHH risks of the vapour.

It could possibly be Boralyn (Aluminium/Boron Carbide) alloy. The earliest MMCs (French Aerospace) were based on 2014 aluminium, which isn't weldable, so the bonding may have been essential.

If it were a weldable alloy based MMC then it would surely have been a welded frame? RekTek had plenty of experience welding aluminium frames, so a boron carbide metal matrix (still 95+% aluminium and fully weldable) Boralyn tube shouldn't have been any trouble, just like Specialized, Univega, Dean, Clark Kent etc. No need to cast lugs and bond it together. Unless Rek Tek already knew about the problems of the metal fibres migrating away from the weld pool causing weaknesses?...

Material properties: https://materion.com/products/metal-mat ... s/albemet#

All the best,


Last edited by danson67 on Thu Aug 16, 2018 4:39 pm, edited 2 times in total.

Top
 Profile  
 
PostPosted: Thu Aug 16, 2018 4:03 pm 
Retro Guru
User avatar

Joined: Sun Jun 22, 2008 5:10 pm
Posts: 306
Location: Vancouver, BC Canada
regan_ev wrote:
Nice.
Don't remember this one though. The only beryllium bike was aware of before this is the American that was built just for Interbike in about 92/93? Super shiny if i remember right, and apparently that was $30K.
I believe that beryllium emits toxic fumes when machining or welding, hence it's not an easy material to process.
What does that thing weigh? 8)


Thanks, regan_ev. The frame has been weighed once by myself on what I believe is an accurate scale and this 18" frame comes in at 2.1 pounds. I will use a different scale and do it again as I'm keen to know myself and strive for accuracy. I've read a bit about the American ones on the forums that Google brought up. Seems there were four made and then *poof* gone when the company folded. However, that might be true as I was talking to Rod K recently, the owner of Mountain and Beach Bicycles here in Vancouver, "Rodfather" of Toad Cycles, and he sold a couple of the American beryllium frames back in the day.


Top
 Profile  
 
 Post subject: Re: Re:
PostPosted: Thu Aug 16, 2018 4:06 pm 
Retro Guru
User avatar

Joined: Sun Jun 22, 2008 5:10 pm
Posts: 306
Location: Vancouver, BC Canada
sinnerman wrote:
Is it made with Beryllium or is it made with Boralyn ...?

The finish looks a lot like Boralyn,i dont know enough but i have owned a Univega bitd, which ever it is, very cool.


I'm not sure, sinnerman? An employee at RekTek came forward on Fb and said it was beryllium and gave me the additional info about the price they paid and where it was made.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 15 posts ]  Go to page 1, 2  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: Graham_hkr, kiwideturin, sthodgson, Trebz, WWC and 17 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group