GaryinLA

Hi. I have posted on subject of asking how to modify a couple of old bikes i have to give me easier gears for going up steep hills for some intermediate level group rides I do.
I started out biking in my 40's about 10 months ago to drop some weight and soon I found some group rides which are for beginners and intermediates, and about half the group likes to go up some steep hills (0 feet to 800 feet elevation over about 5 miles, with some relatively steep hills up and down during that time) and some don't. I started out with my 1982 Trek 311 that is a 10 speed that has a 52/38-ish crank and gears in back something like 26-34-ish, I think. On that bike I can barely make it up the hills, not comfortably. Then I went to 2 1990's hybrids, a Univega via carisma and a Trek Multitrak 720. These 2 bikes both have the common triple crank setup of 1990's hybrids, they are 21 speeds and the gearing is fine for my needs. But those bikes are pretty heavy.

So as i dropped some weight, I wanted a road bike with easier gearing. I asked on here about modifying my Trek 311 and got some suggestions, and my local mechanic said he could do some modification either with the back wheel/cassette or the crankshaft (he didnt tell me details.) But i opted to leave that bike as is for riding around town where i dont go up steep hills (I like that bike as it is stock, has sentimental value to me stock.)

what people here said i could do FYI is put on a shimano 7 speed megarange cassette on back, and use a mountain bike rear derailler (still using friction shifting.)

So then what i did is get a 1983 Trek 760 in great shape, low mileage. I figured this was a top of the line bike, it will have to meet my needs. But it is worse than my Trek 311 for my needed gearing. It has a 52/42 crank and has a 12-21 cassette in back. It is a 12 speed i believe. I love this bike on a flat surface but i do not take it on the group rides up the hills because i cant do it.

I posted on here a few months ago and got suggestions same as with my Trek 311, about how to modify the Trek 760. But some people said dont modify that bike, the frame is a racing frame, bike is designed for racing on flats, not such a good idea to modify the gearing/crankshaft, etc. I have found with this 760 bike that the distance between the bottom of my pedal and the ground is lower than with any of my other bikes and this has caused me to ALMOST injury my foot a couple of times riding on uneven surfaces, where my shoe is jammed between the ground and the pedal. I dont like that at all. But i like the twitchiness/responsive of this bike, it is like a sportscar.

THen i got a 1983 Specialized Sequoia road bike, and after i got it cheap, learned that it is the very first model they made, and has a 3 renshaw (sp?) frame which is real good. THis bike has the stock triple crank setup and is an 18 speed bike i believe, and the frame is light and responsive (not quite like the Trek 760 but better than my Trek 311, which is an Ishiwata frame.) Also the Specialized bike has brazeons for racks which is nice but i havent used them yet.

THen by accident (looking for a bike just to use on a vacation to ship one way but i decided to keep it instead) I got a 1998 Jamis Aurora road bike that has a triple crankshaft and also has the gears i need, and also has brazeons for racks (that i hvaent used yet) and has RSX brifters that my mechanic was able to rebuild inexpensively. This is a good bike but as someone else commented on a review of this model, it is a little porky (meaning heavy) but it is really a touring bike so theres a good reason for that maybe. I test drove a Surly Cross Check and it was almost as heavy and sluggish as my Jamis Aurora I felt (so an LHT has to be even worse.)

So on my group rides now where i know i have to go up big hills (otherwise they drop me and i cant go to lunch with the group) I take either the 1983 Specialized Sequoia or the 1998 Jamis Aurora. I still have the 2 hybrid bikes but they are too heavy for the group rides i feel. I use them for riding on bad roads and sidewalks at night in downtown LA (where it is legal to ride on sidewalks.) I have wide tires on them.

Anyway, so as i said i want to leave my Trek 311 as is because I am sentimental. Also i dont need every one of my road bikes to enable me to go up steep hills. I can ride it around town just not up the very steep hills group bikers like to make me do.

But the Trek 760 is sitting in the garage. It is the least useful bike that i have and the most sporty. Again the rear cassette is a 6 gear 12-21 and the front crankshaft iis a 52-42. I am wondering what to do with this bike. I am thinking as i continue to drop weight and get more fit maybe over time i will be able to ride it up steep hills the way it is. But one or two people from here told me that wont happen, the bike wasnt made for steep hills and even pro racers if they were riding this bike up steep hills they would have their mechanics change the gearing before the race.

Also even if i were to improve the gearing i would still be left with the low ground clearance which I dont like due to risk of injury if i am riding over uneven surfaces.

I am not asking for offers to buy the bike. It is not for sale. I am just asking for input as to what if anything would make sense to do with this bike, either leave it as is and ride it around on the flat surfaces for fun, dont try to take it up steep hills, or do some particular modificaiton (maybe just changing the crankshaft to a modern compact 50-36 might help? and just leave the back as 12-21?

Or I could buy an old Trek 400 with a triple crankshaft and move all the parts of the drivetrain to this 760? Or maybe i could just have this bike rebuilt with a full modern drivetrain setup (which would be expensive, but the frame could probably handle the increased width in back.)

Right now the 760 is in the garage and doesnt get ridden much, Its a very nice blue color.

ThermionicScott 

That's quite the story.

If stock, the rear derailleur should let you swap the freewheel (not cassette) for one that has larger cogs that will make it easier to climb hills. Swapping the 42T chainring for a 39T would help a little, too, but switching to a compact crankset (not crankshaft) would do more overall good. (I bought a Bianchi off eBay recently that came to me with a 52/42T crankset and a 13-21T freewheel, much like your bike. After swapping the inner chainring to 39T and switching to a 14-28T freewheel, I'm much happier with it!)

Can't help with getting your feet caught under the pedals -- that's a new one to me.

- Scott

Sources:
https://www.vintage-trek.com/TrekBrochure1983Part2.htm
https://www.velobase.com/ViewComponen...=108&AbsPos=43

poke em

Put a compact crank in a shorter length on it, and replace the freewheel with a 14/28. Save all of the old parts. Done.

GaryinLA

"Can't help with getting your feet caught under the pedals -- that's a new one to me. "

Sidewalks with tree roots

wrk101

Sidewalks are for walking. Roads and paths are for bikes.

I would go with a compact crank up front, and then a 14/28 freewheel. Shimano 14/28 freewheels can be found new for around $10. Compact crank will cost you more, and plan on a new bb to go with it.

I have put compact cranks on all of my road bikes. For some, I have used modern external bb design cranks. One would think a modern crank like that would look pretty weird on a vintage bike, but I think they look fine. Picked up a couple of new Truvativ Elita compact cranks with bb cheap on ebay a while back. A seller was blowing them out.

The other choice depending on your crank ring sizing is to replace the rings with smaller rings. I've done that on a couple of 110 BCD cranks: replaced them with rings from donor MTBs. I ended up somewhere around 48/35, which is pretty close to a compact crank. Of course, this is a cheap option, allows me to reuse bb, keeps the look of the stock crankset, etc.

Captain Blight

Smaller ring in front, larger cog in back. Do it to the Sequoia. Can't get much simpler than that.

irwin7638

There is also a "Mega Range" freewheel with a 34 tooth bailout gear.. It works really well with a long cage derailer and a 50/36 crankset.
I also recently (yesterday) tried a 12-36 cassette with a VO Polyvalent 46/30crank on my '87 TREK 560. It worked well, of course you need a special Deore derailer and new wheel with 130mm spacing to make it work; but you can damn near climb trees with that!

Marc

Chrome Molly

I would get a shimano 13-28 freewheel, as that's easy enough of a change, and should work with very few other changes (if any). That alone will probably solve the problem. Then go with a 39 chainring. 39/28 is much lower than 42/21 and you'd feel the difference instantly.

Climbing ability vastly improves with experience and increases in fitness level. I have at least two bikes that I put low gearing on when I was really out of shape a few years ago, they all have since been changed to something that has finer gearing adjustments for the flats (with a single bail out gear for the climbs).

Not sure what you mean by uneven surfaces with the 760. It would have to be pretty uneven to drag a crank (or pedaling around a sharp corner). I do get your point in terms of it being a more sensitive steering bike (almost flicky if that's the term), more likely to have the front wheel wash out in a corner on an uneven surface. The 760 is a pretty racy bike, so if it were me, I'd modify it as little as possible to allow you to use it more often, but appreciate its differences vs the rest of your fleet.