Hi,

I'm pondering with the possibility of converting my old 1988-ish Specialized Rockhopper into a fixie.

Here's what I think I need to do, please correct me if I'm wrong:

- Remove cassette and freewheel and replace with something like a Surly fixxer, a cog and some spacers
- Remove extra front chainrings get one more suitable, depending on the gearing I want to use (will ask the locals for the best combo for our not totally flat city, and adjust to compensate 26 inch wheels)
- Replace chainring bolts with BMX chainring bolts
- Get a new chain
- Rip off a bunch of stuff, but not the front brake.
- Replace headset (has nothing to do with fixxing the bike, but the current one is dead)

Am I missing something???

Thanks!

Are the frame's dropouts vertical or horizontal?

Old Rockhoppers have horizontal drops

Very good idea.

i was told you can just use a formula hub with spacers and relace the wheel to that.

Instead of getting the surly fixxer I would just buy a disc rear wheel and use a bolt on cog(tomicog or londonfixiebike) they should give you a 52mm chainline or so which should line up with your outer position of the current crank.

Also with large tires (2" or so) the gear ratios end up being pretty similar to what you would use on a 700x23. on my converted MTB I ran a 44x17 and that worked pretty well for me(I live in a really flat town)

I ran mine SS for a while. Its a bit newer than yours (91ish). Mine had semi horizontal dropouts and 48x16 fit well. This winter I'll run it fixed + studs. What's your intended use for this bike? Trails, snow, street?


Edit: Isn't there a SS MTB dedicated website?

yes

Intended use is street, and possibly some snow, but I work from home so I don't commute.

I think I'll actually shell out a few bucks and buy proper hubs/wheels since my existing ones are really old, and will need to be replaced pretty soon anyways.

My wheels aren't worth relacing

^^^^then space hub for chainline and redish rim, more work but cheaper than a fixxer. Whatever you decide, it's a good idea, my late 80's Bianchi Forte mountain bike gets more use than anything else in my garage.

well the hub is only 30-40 dollars

having it ss would be pretty sick IMO

Can't you figure this out yourself before you convert? Find one of your gear combinations that you can cruise in comfortably, climb hills well enough, and spin downhill without having to coast.

I guess I didn't think that out. I'll probably get as may answers as I ask people. I'll go out tonight and figure out the ratio myself.

I ended up ordering 2 new wheels. The front one was in a shameful state, so with new wheels, the bike will be fully functional. Front wheel is a standard issue Shimano hub with a quick release and rear one is a steelwool with a 16T cog. Rims are nothing fancy - double walled, and spokes are DT Swiss. I am on a tight budget, having already bought a new bike this year

Now, I need to figure out the front chainring size!

Thanks for your help!

I'll post a pic when it's done. In the meantime, you can look at the before pictures:

lolcat says: clean your chain !

Use the big one on there now, what is it a 44t or 46t?

GOnna be a fun project, nice with the Brooks, I'm jealous. You have inspired me to finish my own projects.

Will do

Actually, that chain will be going to recycling.

The new one will be (and stay) clean, I promise. I sort of neglected that bike for a while. I use it about twice a month for 30km rides and maybe 2 or 3 times a week to go to the corner store, etc.

I keep my other bike's drivetrain is super clean though, and I'll do the same to this one too.

It's a 48 biopace, which isn't a problem according to the Sheldon Brown, may he rest in peace. I'm going for a test ride to figure out if the 48 will do.

I just converted a 91 Rockhopper Comp a few weeks back. Here's what did:

I bought a Performance Forte Singlespeed Converstion kit for the new cogs and spacers, a new KMC chain (purple), a new 46t Rocket Ring from Dan's Comp and some BMX chainring bolts off ebay. Two tools you'd need are a chain whip and a freewheel removal tool. Before I did this, I had already put on a quill to threadless stem converter and a short threadless stem and a set of riser bars and Ritchey Moby Bites so it was street ready.

Total cost for the converstion specific stuff was less than 50 bucks, probabaly about 100 for everything. 46/18 was a "magic" gear on mine so I didn't use the tensioner that came with the kit, at least till the chain stretches at which point I might suck it up and buy a ENO eccentric hub and have my local bikeshop build it up with the old specialized rims which are still in good shape.

In short, I love it. Bike is lighter, super responsive and the most fun I've had since I did my original fixie conversion like 10 years ago.

I'm currently setting up my 93 Rockhopper (my first MTB which I can't bring myself to ever sell) as a BMX style cruiser. SS with 24" cruiser bars and stem.

So, I did my test-ride while I still have my derailleur, and 48x16 seemed pretty close to perfect. I rode up to my parents place to fetch a BB and an old set of Shimano 600 cranks. I realized that the new cranks are 130 as opposed to 110 so I'll need to get a new chainring - can't use my 48. Considering the skid patches issue, I'll go with a 47.

Yeah, 47x16 seems right. that's 71.9 gear inches with my 26x1.25 tires. And for the winter, should I decide to get some studded tires, I'll use the 39t chainring I have lying around for 59.6 gear inches.

71.9 make sense?

So here's the result:

I went for 47x17. Sprayed the frame yellow over the old brushed on paint. Maybe I'll strip it down and paint it properly this winter if I have the time.

DSC_6997.jpg

That looks really nice

on some older steel mtb frames, you might have clearance for 700c wheels. and you might be able to get a front road caliper on that chromo fork as well. just sayin'