Monday Mystery Pic

bikerumor monday mystery pic submitted by University Bicycles in Boulder, Colorado,

Photo submitted by Andy Wiedrich, Warranty Manager at University Bicycles in Boulder, CO,


matthew Sutcliffe - 04/21/14 - 7:07am

Chain / derailleur tensioner

Gerard - 04/21/14 - 7:09am

Old School type2??

Magnus - 04/21/14 - 7:10am

Whats so mysterious about about this?!? Weren’t you guys around when this “early version of Shadow+” was out?
They bent terribly easy!! :)

Andrew - 04/21/14 - 7:14am

Too easy! Bullet Bros chain tensioner.

okiefo - 04/21/14 - 7:15am

Ha! Bullet Bros. tensioner.

Auto_Xer - 04/21/14 - 7:15am

Jury rigged chain/deraileur tensioner?

David Pratt - 04/21/14 - 7:16am

The bullet brothers chain tensioner i had one

f. - 04/21/14 - 7:24am

that was ment to increase the chain-tension back in the late nineties.

mop - 04/21/14 - 7:26am

bullet bros chain tensioner. still got one in the spare box somewhere.

tom rinker - 04/21/14 - 7:26am

The original ‘clutch’ derailleur in a sense. Thanks for the picture, I have been looking for an image of one of these bad boys.

jen - 04/21/14 - 7:29am

bullet bros mtb chain tensioner

Wes - 04/21/14 - 7:31am

Goes perfectly with a Hite-Rite and some purple anodized brakes

The Conductor - 04/21/14 - 7:34am

Originally sold for downhill racers, even those with Blackburn racks. Those were the days…

Evant19d - 04/21/14 - 7:37am

1st generation rear derailleur clutch mechanism to reduce chain slap.

[SCI-FI] - 04/21/14 - 7:43am

Shimano Shadow Minus

Evolvo13 - 04/21/14 - 8:01am

Bullet Bros. Chain tensioner. I used one successfully on my Fat Chance dual slalom bike back in the mid 90’s. It was the only thing on the bike not anodized turquoise! Goes great with grip shift and grunge music over the PA system.

Tim - 04/21/14 - 8:21am

Bullet bros chain tensioner. I still see the odd guy riding with one! Shadow+ is better

nurse_pete - 04/21/14 - 8:30am

Bullet Brothers chain tensioner….94 or 95…I had one…and didn’t they buy a helicopter with the money that made off this stuff?

@Evolvo13….only goes good with the Gripshift if you also have a bassworm or replaced the spring in the Shimano rear derailleur so it worked with the SRT-800 Gripshift…stupid Shimano.

Ryan - 04/21/14 - 8:44am

Wow. That was something I came up with in 94. I even had a two piece one that was shorter. It would have been nice if they gave me some cash for taking my idea.

david - 04/21/14 - 8:58am

I don’t see anything weird other than a badly-kinked piece of cable housing. (And my tandem still has a bassworm – makes avid disc brakes work a LOT better with the long cable)

nurse_pete - 04/21/14 - 9:19am

@david…in all my time spinning wrenches, I’ve never heard of that one…that is brilliant!

Topmounter - 04/21/14 - 9:56am

That’s what we used before derailleurs had “clutches”.

david - 04/21/14 - 10:29am

@nurse_pete – I’ve been keeping a couple of bassworms in my spare parts box for a LONG time to take care of bad cable routing or poor return-spring tension. They’re great. I’ve got some spare tubing to use when they eventually die, too.

Greg - 04/21/14 - 10:49am

Apparently it is a Bullet Brothers chain tensioner.

DeeEight - 04/21/14 - 11:34am

Bullet Brothers chain tensioner, I happen to have one on ebay right now.

mechanic - 04/21/14 - 11:35am

Yeah, that one is easy. I have one on a bike right now; the pre-clutch clutch.

Scott Feldman-Peabody - 04/21/14 - 1:47pm

It was part of the Tyson system with a couple of rollers around a single chainring. Of course, when the license ran out it was simply called the Mr Dream system.

Eric - 04/21/14 - 6:24pm

I made them by my self

Troy - 04/21/14 - 11:36pm

I had one of those on my proflex.

spokejunky - 04/23/14 - 7:47am

A spring for the screen door. I win.

TJ Platt - 04/25/14 - 4:27am

Andy, I think Hossaflook still has one of these hanging in his garage. It was a great idea, think about it, all new rear derailleurs have have a “locking” mechanism in them now to prevent chain-slap.

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