# Mongoose Amplifier



## LQQK (Jan 6, 2004)

I just picked up a Mongoose Amp + Judy's off ebay (AU$50!), and am trying to find the seat post size. I've looked at all the usual sites, and have read everything from 27.2 mm(way too small) to 31.6mm (more like it).Anyone know for sure?


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## cegrover (Oct 17, 2004)

Don't assume 27.2 is too small - I have two 1990s FS bikes with that seatpost diameter. Your frame's tubing certainly doesn't look large in diameter. I assume that's just the Ebay pick and you don't have the bike yet...

Given the mixed internet results, you'll probably just have to wait and measure it.


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## erkan (Jan 18, 2004)

It is 31.6


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## DeeEight (Jan 13, 2004)

31.6, i scored an NOS frame/fork packaged from Dalerider1 before his untimely demise. Ended up selling it to my friend rob who built it up and is now forced to get another XC bike on account his gf keeps using his amplifier.


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## older guy (Mar 9, 2004)

Wow, Was that the predecessor of the Horst Link design?

On a related note, I saw a NOS Mongoose brand Ti mountain bike but the mono seatstays and chainstays are steel. Any info on these?


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## robinmiller (May 31, 2005)

older guy said:


> Wow, Was that the predecessor of the Horst Link design?
> 
> On a related note, I saw a NOS Mongoose brand Ti mountain bike but the mono seatstays and chainstays are steel. Any info on these?


I think that WAS the Horst Link. looks like a rebranded Amp Research frame to me..


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## DeeEight (Jan 13, 2004)

Mongoose was one of the leading high-end brands back in the day and had a number of bonded frames with mixed construction... carbon/aluminium, steel/carbon, steel/al, ti/steel, etc. Them and Miyata really liked doing mixed-bonded setups. As to the amplifier... Mongoose commissioned Horst Leitner to design them a full suspension bike, after they saw some of his early work at a trade show (Amp B-1), and the Mongoose Amplifier was the result. They were all made by horst in his factory, and were essentially identical to the Amp B-2 frames. After problems with racers using them for DH and yanking the headtubes off from the dual-downtubes when casing jumps or crashing, they went to a single downtube in 1995 and thus the B-2 design was replaced by the B-3 (the mongoose version was labeled Amplifier 2). Mongoose also had the Amp F-1 forks on the amplifiers, and the only way you got them was buying the framesets (frame/fork) and building them up yourself. They didn't sell complete amplifiers till the 95 model year.

Univega also had Amp making them versions of the Amp F-1 forks, called the Univega Concept fork, and was using them on their higher end models. And Amp history doesn't end there... a couple dozen other brands either had complete Amp frames made for them, or purchased just the rear ends to mate to their own front ends (Rocky Mountain, Dagger, etc) or otherwise copied (often without licensing, coughGTcough) the horst-link rear end which is what made them a viable design. I think its in a 1994 MBA article they tested FIVE mac-strut bikes... Supergo's Access FS version (taiwan made licensed copy of an Amp), Amp's B-2, Rocky Mountain's Edge, Battle's Tomahawk, and I think the fifth was a Proflex design which was the only mac-strut that wasn't an Amp clone.

Mac-struts refers to the intergrating of the shock to the seatstay without a pivot between them. You'd find them on bikes both with horst-links and without (seatstay links). They were popular because they were simple to understand for the consumer, and by borrowing a car suspension term, made it seem like the idea of full suspension was more refined than it really was at the time, so easier to seperate consumer from contents of wallet.


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## stan4bikes (May 24, 2006)

*concept and goose stuff*

thanx DeeEight, that was a great history. I always wondered about the "goose" models and the "concept" forks. I was just too lazy to research it. are the Concept forks less desireable than the Amp's? they look just the same to me...


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## DeeEight (Jan 13, 2004)

Nope, they're identical, which means most likely they'll need the link pins and bushings replaced if you find one used. Amp's were coil-sprung forks with oil-thrushaft dampers, which are maintenance dreams for service. Couple wrenches, some o-rings and some oil. The linkage was the nightmare. Takes a good hour or so to pop all the pins out and replace them and the bushings if you're trying to improvise up some tools (ie, too cheap to buy the $20 tool from Amp Research).


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## azjeff (Jun 3, 2006)

Something to watch on these MacStrut bikes, the shock is a stressed member of the suspension since it isn't isolated behind a link and if you ride very hard you'll go through seals like crazy. These were built pretty lightweight. I had an early mac strut FSR that ate shocks like candy. A friend with an AMP like this went to an air shock and solved his problems. Rides nice though. Get the fork.


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## Elevation12000 (Jun 16, 2004)

Here are two bikes from the 1994 MBA test DeeEight refered to:

Fat Chance Shock a Billy, MBA June94








2
3
4
5

Rocky Mountain The Edge, MBA June94








2
3
4
5
6

The simple setup and the clean, fast lines make the AMP -imo- one of the most aestethicly pleasing FS bikes till today.


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## Sideknob (Jul 14, 2005)

Beat me to it. It was the Shock a Billy with the cool lavender paint job. Got the same article too.


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## LQQK (Jan 6, 2004)

Thanks for all the info. In my searches I found there were a Mongoose Amplifier II and the Mongoose Amplifier 2. The 2 seems to have the 27.2mm seat post while the II has the 31.6mm post.


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## DeeEight (Jan 13, 2004)

Right, fatchance... forgot about that one in the test. A friend had one of them, destroyed one of the chainstays when he bent a hub axle DH'ing at Saint-Anne and the wheel twisted enough for the tire side knob to buzz the inside edge of the driveside chainstay.


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## Elevation12000 (Jun 16, 2004)

SaB raced:


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