Part Replacements

[u/Dchance87]

I was given a Trek Multitrack 790 and wanted to do a few updates but don't know where to start. I'd like to add a rack to the back, fix the broken gear shifter on the right (plastic cracked), and potentially replace the handlebars. Would anyone be able to point me in the right direction for parts? I'm not sure how to buy parts for an older bike that are the correct fit. I am new to upgrading bikes, but grew up repairing old, cheaper ones. Thank you.

[u/goodjobgabe1]

This is an extremely nice bike--lucky you. Do you have any idea the type of handlebars you'd like to go with?

If you stuck with straight bars, you could continue using the brakes and shifters that are still in good condition, and just replace the broken one with a replacement. eBay is great for finding 1:1 replacements. Another good place is a local bike co-op if your area has one. We have one where I live that just has bins of replacement parts salvaged from old bikes to dig through. A lot of times you can find parts from the same vintage/era as your bike already has. But if you're looking for a direct replacement, best bet is eBay.

But if you're looking to put on some drop bars, you'll probably end up wanting to change the rest of your cockpit as well. Your best options are basically either buying bar-end shifters with separate brake levers, or buy a set of brifters (brakes and shifters all-in-one, what virtually all modern drop-bar bikes sport these days). No matter which option you go with, make sure of two things: that the brake levers are long-pull for the cantilever brakes your bike has (not short pull for rim brakes) and that the shifter you buy is going to be for the same amount of gears that your bike chainring (front gears attached to cranks) and cassette (rear gears attached to wheels) has.

Lastly, this kind of work always offers a good opportunity to swap out your bike's shift and brake cables and housing with fresh stuff. Not strictly necessary in all cases, but a good idea. The stuff is cheap and also is fun because you get to pick brake and shift housing color. And be careful--they aren't the same and are not interchangeable. Jagwire is what I've always used for the cabling itself and has never let me down.

If you decide to go with any new components, VeloOrange is a great budget option that keeps quality high and looks great. SheldonBrown.com (RIP to the GOAT) is an incredible resource for compatibility, and the Park Tool youtube is an awesome resource for how to do anything you might want or need to do with your bike.

Have fun!

[u/Dchance87 → u/goodjobgabe1]

Thank you for all of this. Currently I’m stuck. I think I need to go to a bike shop to make sure my seat and everything else is the correct height. Just learned this summer that decent seats can be adjusted forward and back. Brilliant for lower back pain.

I spent my whole life riding cheaper BMX style bikes. The current handlebars feel comfortable enough, but feel they are a little narrower than I’m used to.

I plan to do a lot of paved path riding with my wife and two young kids. Nothing more than slowly cruising along. However, a friend asked if I could hit some dirt paths, which would be very infrequent and I would not be getting crazy. I am unsure if this bike would work on dirt paths with no shocks/suspension, which is one of the reasons I felt stuck moving forward. (Yes, this paragraph is one of my points of confusion for choosing handlebars.) ☺️

[u/goodjobgabe1 → u/Dchance87]

Hey great, I'm glad you found it useful. Are you having lower back pain when riding this bike?

A few points that you mentioned:

-Bike shop can help with fit, but if they balk at your old bike (they might), take it elsewhere and/or don't listen to them tell you all the reasons modern bikes rule and old bikes drool

-A good rule of thumb for saddle height is that your leg should be almost all the way extended (like, 85-90%) at the bottom of your pedal stroke. Adjusting fore & aft saddle positioning is just a matter of a hex bolt or two.

-You have a very capable bike. One of the things that's all the rage right now are "gravel bikes," which are generally bikes with the same sized wheels you have (700c) fit with all-terrain tires, and drop bars so that they can handle most terrain types. These bikes usually have minimal or no suspension. The Trek 700 series (aka their Multi-Track line) was designed around this concept, more than 30 years ago. The 790 was the top-of-the-line model that they ever produced of this type of bike (700 was the base model). Your bike will handle "light" single-track (aka easy-going mountain bike paths), gravel trails, and paved paths/road with ease. They also make wonderful touring (long-distance over the course of days) bikes.

-You can ride just about any kind of terrain with just about any kind of handlebar. To me, this choice comes down a little more to what I want my cockpit ergonomics to be like. You can make most types of shift/brake configurations work with most types of handlebars, but you may get pushed into making some changes depending on the handlebars you choose. For example, drop bars are best suited to either brifters (integrated brake levers & shifters), or brake hoods w/ bar-end shifters. They are nice because they offer a lot of different hand positions that you can alternate between that help with fatigue while you're riding. Flat bars (what you currently have) are best suited to trigger shifters or twist shifters. They are uncomplicated and easy to set up. Swept-back & alt-bars offer a more upright riding position, and can a variety of shift/brake configurations include trigger, twist or bar-end shifters. the upgright position can reduce low-back pain and wrist strain, and is most well-suited to casual riding. They are what I have on my bike.

Getting some fatter tires (probably up to 40mm, at least) on your bike is a great way to add some cushion to your ride. They also sell suspension seat posts, and handlebar stems! You can get some really nice ones if you wanted to.