I've been fixing up a couple of mid-1990's 26" steel mountain bikes, to use use as commuter/utility bikes. It's been a lot of fun to fix them up. I'm not brave enough to mess with wheel truing and bottom bracket issues yet, but I have recabled one bike and learned how to properly adjust derailers and brakes. I have to admit that I have no idea what gearing makes for a good road-use mountain bike. Does anybody have any good advice on which bike has the more appropriate gearing for a largely flat 15-mile one-way commute, with a couple of short but wicked hills?

The first bike is a Diamondback Topanga. $40.00 off Craigslist.
Chainrings: 22/32/42
Cassette: 7-speed, 11 - 28 teeth


The second bike is a Schwinn Frontier. $25.00 at a garage sale. This bike has come a long way since the picture was taken.
Chainrings: 28/38/48
Cassette: 6-speed, 14 - 28 teeth


Also, is it common to choose a larger framed mountain bike for road use? The Topanga is the size that I'd naturally choose for offroad use. I'd guestimate it to be about an 18" frame. The Schwinn seems to be a bit more comfortable to ride onroad, and is advertised as a 23" bike, but feels more like what I'd expect from a 19 1/2 or 20" frame.

I would ride what fits you better, regardless. The gearing looks pretty similar. But, if your hills are pretty steep, the Diamond Back offers lower gearing to compensate. It's much better to coast down a hill because you ran out of high gears than to walk up a hill because you ran out of low gears.

Ditto. I've been riding the same Specialized Rockhopper Comp since 1989. I did change some stuff around like a Scott AT4 Pro bar, 130mm stem, and some 26x1.75 Continentals. I also got rid of the Biopace chainrings. This bike fits me so well I ride it everywhere. On mine the frame was a little short (16.5" C-C) with a sloping top tube. That's the reason for the 130mm stem and Scott bar. I like to stretch out when I ride. These bikes are super durable.

I'll start chucking gear to lighten the load before I'll walk!! Lol. I have been known to coast leisurely down a hill whist checking out the local scenery (most likely looking for a pub)!

Jerry H

My old trusty rockhopper...




On a rainy day...



I say bigger frame for road use for sure....and to get a sense of the gearing you want, just go ride your route a few times. You'll know if you're close or if you need to make some adjustments.

I ride in a hilly little town and I'm really pleased to have mtb gearing when I'm climbing a big hill with a bunch of textbooks and a laptop in that crate...on that steel frame...holding my fat ass.

I prefer a slightly smaller frame for off road riding and the 2 mtb's that I use for road and touring use are the same frame size as my road bike and are similarly equipped with drop bars and trekking bars.

That d back looks really sharp and the set up looks correct... if the 42:11 has you spinning too much you can increase the outer chain ring to a larger one... you can't do this with the low end crank on the Schwinn.

My expedition bike runs a wider gearing with a 28/38/50 and an 11-34 8 speed but will soon be running a 7 speed with a half step gearing... those higher top gears are for fast descents or days when I have a 40km tailwind and are not for cruising.

I miss my '91 Rock Hopper - sure, it was battered (complete with a slight kink in the top tube), but I honestly enjoyed riding it as much as any of my other (more expensive) bikes.

As for gearing, I like close ratios, so that I can pick my cadence for whatever speed I want to run. The DB with the 11-28 cassette will have reasonably close spacing, probably more so than the 6-speed Schwinn. You could always swap cassettes to get closer ratios. 22 teeth on the inner ring is smaller than anything you'd be likely to need for commuting - I like 46-38-30 or thereabouts for chainring ratios. Again, these are easy to change.

I've got a steel Nishiki MTB I picked up out of the trash, it's great for commuting except it doesn't have eyelets for fenders. I need to replace the fork anyway, so it might work.

The Diamond back is the better bike by a long shot but the gearing on the Schwinn is better. You are going to be spinning out on the DB as you get stronger. You can find deals on cranks on CL so I would defiantly go with the DB. My personal favorite crank gearing for a Utility type of bike is 26/36/48 with a 11/28 cassette. It will let you keep a fast pace on the flat but still has plenty of low to get you up hills with a load.

Now a word of warning that 65er touched on. Older MTB bikes like the ones you are looking at are closer to a touring bike geometry but newer MTB have longer top tubes to make climbing steep hills off road easier. A classic road bike the top tube is close to the same length as the seat tube. A MTB it is longer even on the ones you have posted. The newer bikes you may run out of seat post when you get the reach right so you are wise to stick with the older models. Your top tube length is going to be the more critical measurement for a comfortable riding position something that is a bit of a Oxymoron on a straight bar bike. 15 mile commute I sure would be looking at a touring bike.

On my 1995 M-50 i run 28/39/50 and 11-28 cassette, works pretty good for me.

If the saddle on the DB is set for your riding position, I'd say the frame is a great fit for your use, but only you know if it fits comfortably. The DB is a much better quality bike, and is set up very nicely for commuting (great job!)
As 65er mentioned, you can get a larger "big" ring on the crank for better cruising gears.

Either bike should get you up your few "wicked" hills just fine.

Thank you everybody for the awesome replies. They really helped me to understand the strengths and weaknesses of each bike.

The Diamondback is out of commission for the next weak, while a new rear wheel arrives to my LBS. I am going to look into changing one or two of the chainrings, and maybe swap out the gripshifters for normal shifters. Some new brake pads are also needed for the cantilever brakes.

So I spent the weekend working on the Schwinn, just to make it road worthy, and transferred over a bunch of accessories from the Diamondback. The tires, rack, fenders, lights and pump moved over, and I installed some new Power grips onto the pedals. The gripshift for the front was toast, so I now have an old Shimano shifter for the front, and a gripshift for the rear. Kind of odd, but i don't want to put any real amount of money into it. I did buy some cheapo bottle cages for it this evening. I'll road test the Schwinn on Tuesday, with a 15-mile ride out to local park, hauling my daughter in her trailer. If the bike falls apart, the wife will be available for a quick pickup. If the ride goes well, it will get commuter duty for Wednesday and Friday.

+1. My early 90's Rock Hopper was probably my favorite commuter ever. Its the only old bike that I still think about riding.

Nice Schwinn! Is that a Filzer Mini-Zee Pump? If so, we have the same one. We also have the same Blaze/Super Flash combo (along with countless others here on BF, I'm sure), except in different colours. Here they are mounted on my Schwinn:

here's my old mid-90s Raleigh M-80 that i now use as a back-up commuter.


Uploaded with ImageShack.us

i switched out the suspension fork for a rigid one, and i upgraded the drive-train because the bike originally had a 42/32/22 with a 13-28 7speed cassette and i was spinning out on the flats. i put on a 48/38/28 sugino crankset along with an 11-28 7 speed cassette. because i live in chicago (the land that hills forgot), i'm almost always running on the largest 48T chainring, the other two chainrings are almost useless to me. i run 48/15 as my general cruising gear, and i'll bump it up to 48/13 if i have a nice tail wind or drop down to 48/18 or 48/21 if i've got a head wind to battle. my lowest gear ratio is now a 1-to-1 28/28, but there ain't a hill anywhere within a thousand miles of chicago that would require anything that low.

the Vuelta zerolite wheelsets and schwalbe marathon plus tires are also recent additions in the effort to "hybridize" the bike.

The Schwinn is a very tall mountain bike, most likely a 23". The Topanga looks like it's around a 20" frame. (Measure them and quit guessing) The problem with mountain bikes is that they are proportioned differently from road bikes. A 23" mountain bike is proportioned for someone who is 6'3" to 6'6". Which means a longer top tube...as evidenced by the extreme forward position of the saddle and short stem.

I'd go with the one that fits best. If you are around 6' tall that's the 20" bike.

The gears that these bikes have are okay for road riding. The Topanga is a bit low for a top end. I'd replace the outer ring with a 44 or 46. The 46 would be a better choice.