‘92 Rockhopper Comp retro mtb with a kick

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  • New project time! I’ve never really jumped on the mainstream retro mtb bandwagon, I think my couriers are just on the fringe of that, so I wanted to build something based on an early 90s frameset. There will be a twist to this project that many will balk at, it will probably push the build into anti territory, but we’ll see.

    So the thread is playing catch up somewhat as I already have 90% of the parts needed. I’ve not yet assembled anything however so I’ll try and set the scene from when I started out. The bike is going to be a utility bike, with simplicity, robustness and reliability being the main criteria for all component choices. Aesthetic perfection is also not the goal here so it won’t be a NOS project. It will be based on functionally good condition parts saying that.

    The starting place was the frame set, I needed a quality steel frame and fork, pref early 90s geo, with clearance for 2.2ish slickish tires, with good wide set chain stays and seat stays (more on this later), and a rear drop out design that allows something to be bolted flat to it on the axle from above, with nothing to interfere with (like cowled dropouts, seat stays welded on top on the drop out etc (more on this oddity later too).

    For the wheels I wanted something absolutely bombproof, with enough width to provide some good support for a 2.2” tire. There was never really any doubt for rim in my mind, I wanted some Mavic D521s in 36h. These are mid 90s but close enough to the age I wanted. The hubs were more open to what I could find. In my mind I wanted to run 3x8 shimano, so needed to be a standard shimano free hub. I want bolt on solid axles on both wheels though so some thought is needed.

    The group set needed to fit the criteria already mentioned, but as I wanted to incorporate a ‘retro mtb’ element to this I was thinking along the lines of early Shimano XT or DX. No STIs, no discs, no hydro, no plastic etc. Indexing is desirable though, even though I quite like the friction shifters on both my couriers I want SIS on this. You get the picture. When I set out on this build the only component I already had earmarked was a pair of XT PD-M730 platform pedals. These were on the first courier, but after being rebuilt ended up back in the parts box, waiting for a more suitable project.

    Finally finishing parts, no real wish list here other than compatible parts that are the right fit and size, are roughly age correct, and are not cheep shite. The only thing I already had is a slightly tatty original Turbo saddle, which will do just the job.

  • So continuing rapidly on, the hunt for the parts first came up with a set of wheels, a pair of Mavic D521s laced to XT M737 hubs. These were 36h and in pretty good shape. They would get a full overhaul and rebuild before being fitted to the main bike.

    Frame hunting had me looking at all sorts, Alpinestars, Saracen, Trek, Diamond Back, Orange, etc etc. Really difficult to judge the clearances I wanted from eBay however so I turned to Pinterest and Pedalroom to look for examples of likely candidates to see what each offered. I decided upon originally a 90-92 Stumpjumper Comp as a) it was quality and cool, b) it had good clearances for an old f&f, and c) the semi horizontal dropout arrangement looked perfect for my needs. I almost pulled the trigger on a couple but I realised I had missed one small detail, Stumpjumpers lack some brazeons that the same age Rockhoppers have, so at the last minute I changed my focus to a 90-92 Rockhopper Comp. I still want a Stumpy but that can wait for now.

    I eventually found a red ‘92 Comp with full Shimano M550 LX for good money quite close to home. It had lots of paint chips but is otherwise straight and solid. The Groupset and wheels were reasonable, but quite well used, and not really special enough I wanted DX really.

    Pics of the frame to follow. It is currently stripped down having some tlc before being built up.

  • Component wise, I have now amassed pretty much all of it, I've been quietly collecting parts for around 6 months now. The M550 cranks on the Rockhopper were 175mm, the LH one also had its extraction thread totally stripped. I needed a pair of 170mm replacements, which ended up being another pair of M550 LX ones.

    The brakes were acquired next, some M650 DX cantilevers and matching MT63 2 finger DX levers. I’m really happy with these so far and they seem to tick all the boxes - if I can set them up well enough. The bike will be heavy when loaded up so I need something that can stop me.

    Other groupset bits picked up over the recent weeks have been, an M735 XT long cage rear mech, an M737 11-28 8s XT cassette and a bread and butter UN54 122x73mm bb (sadly the BB-M550 loose ball bb on the bike was beyond repair. I would have preferred to keep it looseball but 122mm x 73mm axles seem to be impossible to find).

    The obvious choice for shifters would be XT thumbies but I remembered running these on 8s was a bit of a bodge. Less of a bodge would be some good 8s SIS bar end levers on appropriate mounts, so I located a pair of Ultegra SL64-8 shifters. I’m now looking for some Paul Components Thumbies if anyone has a spare set to shift?

    Seat post and stem would be original, but I got a dirt cheap Salsa MotoAce bar to fit. This is wider at 680mm and has a 17 deg sweep so more like the position I want. The stem is typical for the age at 135mm long. I’d prefer slightly shorter, but want to keep an integrated cable stop. If I find something better I’ll change this.

  • Outstanding parts are:
    Paul shifter mounts, 22mm black Shimano ones please if anyone has some to sell? I’d specifically like the old style ones without the hinged bracket.
    Some tires. I was hoping my 2.35 Supermotos would fit, but it just hasn’t the frame clearance. Thinking of getting 2.15 Maxxis dth instead.
    A solid rear axle. I need a wide axle for this, so am trying to source a Wheels Manufacturing #20 tandem axle. I have however found an old Deore MT60 front hub with a solid axle and track nuts. I’ve swapped the axle to the M737 front hub so now have the front hub ready to be rebuilt.
    Some spokes. I have spare DT Champ spokes the right length to relace the front wheel, I just need a few matching ones to rebuild the rear also.
    A front rack. Thinking of trying a Blackburn Outpost rack on this. I’ve seen them work on Direct Drive forks to good effect, however mixed reviews leave me a bit hesitant. We’ll see.
    Lastly I need carry a few more bottles, so more cages needed. Need to get some more King USB mounts to stick an Anything cage under the downtube.

    Once I have these the build should be quick, unlike my other recent projects as I won't be polishing everything to a mirror.

  • TLDR, where are the pictures!

  • Yes pics please! Loving your builds , total inspiration for my own 90’s mtbs

  • Third some pictures, looking forward to this.

  • A quick few pics. The frame:

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  • Some of the groupset parts held so far:

    New chainset has the crap looking chain guard, but the rings are almost unworn, and they aren't Biopace! I would take the guard off but as it is a utility bike I might just keep it on in the long run.

    The mechs are the ones removed from the Rockhopper and cleaned up well. I've since bought the XT rear but that hasn't arrived yet to photograph. Part of my wants the matching XT front so these will more than likely be sold on.

    The pedals were fully stripped and rebuilt for The first courier build. They are a bit scratched but spin super smooth.

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  • Few additional bits I've amassed. Got the obligatory shark fin!

    The headset is obviously out of place being 105. It is an HP-5501 which uses the identical cartridge bearings as some '95/'96 Shimano MTB headsets so should work ok. The colours also match the slightly earlier DX/XT stuff quite well too. I bought it for a long abandoned road project, but for this I can live with it.

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  • This is the donor front hub, before it lost its axle. Slight shame to waste a NOS part but it was cheaper to do this than source just an axle and decent rotating washer track nuts. I might make the hub shell into some drawer handles :-)

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  • Dibs those swore lx mechs if and when....

  • Very cool, I used a 105 h/set on my similar vintage rockhopper as it was low stack and JIS. I'm sure you already know this but some are ISO and some are JIS, might be worth a check

  • I do but thanks for the tip. This 105 is ISO, but if it is a JIS frame I've also a spare JIS HP-1055 105 headset that was also on the courier.

  • Just checked, it is ISO.

  • Gonna be good!

  • Just chucked a few bits together to gauge position. The wheels are other spares with a very narrow rim. The Super Motos fit in on these but have no clearance at all.

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  • Lush frame! Yeah, these retro MTBs rarely fit such wide tyres. I'd go with Maxxis DTHs or Schwalbe Big Apples, 2.3 should clear.

  • Not quite happy with that position leant on a wall. So dug in the parts box and found the original stem from the '87 Courier. This and a Sim Works Getaround bar seem to get it more how I wanted.

    Can anyone tell me how wide the bar clamp is on Paul Thumbies? Might not be able to get the levers as far in as I'd like.

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  • Looks loads better with the sim-works bars.
    Makes me want a 90's rigid mtb again.

  • So got some Paul thumb shifter mounts so they are now on. They are very positive and solid but they are very exposed on the bar top. I'll stick with them for now but may ultimately try old XT ones instead which do sit down a lot further.

    Got some tires too, went or some Schwalbe Marathon Almotions in 2.15". They don't look quite as good as the Supermotos but they clear well and still fit the bill. I went for these over Dths as on paper seemed more robust and more appropriate. They are well reviewed online also for a relatively new tire. Not ridden them yet to see.

  • So part 1 of the build is done, bike is now rideable. The MF stem wasn't great so I swapped in a Tioga T-bone which is halfway between the MF and the 135mm stretch-stem that was the original. The solid axle for the rear is proving tricky to source, have one coming across the pond at the moment. I have an XT mech to match the rear waiting to go on. Pretty happy with the rest of it, its playful, reminds me of the Orange P7 I had in 1995.

    Next stage is to make it functional and a bit more pokey . . . . .

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  • Found some original Onza Ules grips too that Ive had stashed away for over 20 years! Yay for hoarding

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  • Looks super nice man. Shame the Supermotos didn't work out

  • Drive

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‘92 Rockhopper Comp retro mtb with a kick

Posted by Avatar for joel_austen @joel_austen