kommisar

I've got a old schwinn mountain bike with chrome-moly main tubes. I assume the stays and fork are hiten. Would getting a better frame with chrome-moly fork and stays make it ride significantly different? Would the cantilever brakes work better on chrome-moly stays?

RCMoeur 

(gets out popcorn)

In my assessment, it might be difficult to notice any performance difference in terms of stiffness, ride quality, or brake performance (but you're getting a reply from someone who rode an all-hi-ten frame as his primary bike for decades). A frame with chromoly or mang-moly stays would likely be lighter - one recent example from my experience was a Barracuda frame with all thin-wall Tange chromoly tubing was 35% lighter than an identical-sized frame using thicker chromoly main tubes and hi-ten stays.

If you happen into a light all-chromoly frame with similar geometry in good condition and have the skills, time, and patience to swap over all the components, you might be happier, perhaps because of weight savings or just because many human brains associate "new" with "better". Or you might be less happy. No guarantees.

Soody

lets see it

Schweinhund

Lets put it this way, I have a 6KU 42cm fixed gear, deep v's, 23mm tires, cool little rider. I also have a schwinn premis, all original.
The premis is columbus tubing, the 6KU is hi-ten. The fully equipt schwinn weighs in a half pound lighter than the single speed 6KU

52telecaster

The stays being chromolly will not improve your braking performance. Better brakes or adjustment might improve what you have now. So many variables trump your stay material.

T-Mar

Due to the slenderness of the stays, manufacturers cannot take full advantage of the weight savings of CrMo. They would not be stiff enough. This is why manufacturers used lower grade material in the stays. It saves the most money with the least impact on weight.

Using lesser grade material in the stays does have advantages. It's thicker, which means the stays are stiffer. There's less bowing and twisting in reaction to the braking forces, meaning more of the braking force goes to stopping the wheel rotation. This was one of the prime reasons for the late 1980s move from seat stay mounted cantilever brakes to chain stay mounted U-brakes. Then manufacturers realized that they could get similar results by using larger diameter seat stays to increase the stiffness and everybody went back to cantilevers, except on small frames where heel strike could release the yoke cable. U-brakes disappeared from even that application with the arrival of V-brakes.

Given equivalent diameter, the same cantilever brakes will theoretically work better on hi-tensile stays as they will be stiffer. However, you may not be able to the difference. If you're looking for better braking performance, my recommended approach is to look at the brake pads, rims, and the the brakes/set-up themselves, in that order. The combination of pads and rims determine the coefficient of friction, while the brakeset (including cables and housing) determines the stiffness, mechanical advantage and amount of modulation. The latter is very important, especially if you ride a lot in wet, slippery conditions.. I've always considered good modulation to be more important than outright stopping power, though ideally you want both. You don't want brakes that flick on and off like a light switch. You want brakes that act like a dimmer switch, where you have good control over the stopping force.

kommisar

Here are some recent photos of it:

bboy314

Based on your seatpost and stem height, the frame does seem too small for you. But as long as it’s comfortable and those components aren’t past their minimum insertion point I’d see no reason not to keep it.

oldbobcat

It's a 35 year-old price-point step-through "mountain bike" being ridden as a commuter. Maintain it, ride it, enjoy it, or buy a new bike. There is nothing worth upgrading here.It already has a nice saddle.

But I'd be concerned about the stem being raised past its safe insertion mark. If it is, lower it. If it isn't invest in longer cables for the shifters and rear brake.

phtomita

Not a mtb, but road bike here.
I owned once a Sekai GT2700 hi ten frame I commuted for one season and the feel was heavy.
Then I got a Centurion ProTour15 in cromo tange 2, that I like much more.
I also have the tange 1 Nishiki Tri-A modified to fit wider tires and all bosses added for fender and racks. It has better ride than the Centurion, for me.
Last year, I tried a Ti Litespeed with carbon fork that would weight around 3 pounds less than Tri-A, but it is jus not there for riding, you know something missing.
Currently happy with the tange 1 frame that fits 700x32c

kommisar

No this is ridden as a mountain bike. It is just wearing its gravel / road tires because the routes I ride this time of year are single track uphill only and then I come down on paved roads. The stem and seat post have at least 2cm more until they reach min. insertion points.

davester

As others have noted, the high tensile stays are going to have no negative effect on the cantilever brakes. However, it sounds like you are having problems with your brakes. Can you tell us exactly what the problem is? Obviously the brakes won't work well if the pads are old and hardened, or the rims are dirty. In addition, how good are your cables and housings. Old, unlined high friction housings and cables can have a substantial negative effect on braking power. Furthermore, cantilevers are very sensitive to setup (i.e. straddle cable lengths and angles, spring preload), etc. It looks to me that someone has changed the setup of those brakes so that may be part of the problem. Check out this article for some tips: https://bike.bikegremlin.com/1739/ca.../#comment-3402. One more thing...it looks like you have changed the stem and handlebars. Have you also changed the brake levers? The photos don't show the levers so I'm wondering if you have perhaps changed levers and are using a type with a different mechanical advantage than is required for the cantilevers.

oldbobcat

Well, I doubt shaving a couple hundred grams of frame weight is going to buy you much.

kommisar

I would like the brakes to be stronger. Sometimes on a steep hill I'm squeezing them hard and I can't seem to come to a complete stop. The pads are old and replacing them with some salmon kool stops will probably make it better. I'm just waiting for the old pads to wear out before putting new ones on. I think the levers are high gain specifically for cantilevers. Housings are lined. Not sure about the setup of the straddle cable to be honest as I don't have a lot of experience with cantis. Photos of the relevant parts below:

jethin

This is a silly question. Everyone knows that all bikes ride the same.

davester

Not so sure about those levers since they seem to be very short (i.e. less leverage) compared to what was probably originally on there. However, your first step should definitely be to change out those pads ASAP. Do not wait for the old ones to wear out...that may never happen if they are hardened with age, and hardened brake pads won't bring you to a stop.

Schweinhund

Your brakes appear to be Lee Chi cantis, they were weak in the day, with old pads they would really suck.
Some low end V brakes would be an improvement for you
These are not wonderful, be they are better than what you have. Actually decent is what they are, but nothing to shout home about
https://www.amazon.com/RUJOI-V-Brake.../dp/B081F29D6C

prairiepedaler

HiTen stays. Should I upgrade my mtb?

Definetely not. If it is a good rider and suits your needs then use it until dust. If you are a heavier rider, even more so. I don't know if the ones I've owned had hi-ten stays and didn't care too much; a GT timberline (snapped drop out), a Raleigh Elkhorn (snapped seatstay top tube joint) and a BRC explorer (multiple headtube failures).

ClydeClydeson

As above, those brakes are the cheapest and most craptacular, although may still be acceptable. CHange the pads and you might see a significant difference. THe straddle cables are already nice and low so there is likely not much improvement to be made in setup.

As for changing to a lighter frame looking for braking improvements - no. A lighter frame will almost definitely have more flexible stays - all steels have approximately the same stiffness and density per unit of material and the only way to decrease weight is to use less material, which is possible with higher strength (ie hi ten vs cromoly) but will result in more flex. Perhaps an aluminum frame would have stiffer stays, but I don't think it's worth the trouble.

I would also be concerned that the bike is too small for you, but if you like riding it, to hell with what I think.

SurferRosa

My '75 Moto has hi-ten stays, and it just rides ... beefier. Like a Porsche 928. That's why I made it my grocery getter. I love it.

I once saw a picture of a 928 hauling a boat trailer. That's style.

cyccommute 

Honestly, there is nothing that you can do to improve the action of your rear cantilever brake. The problem isn’t with the brakes but with the design of the bike. You can improve the action slightly by going with longer cable housing on the front but that will only be a slight improvement. The problem is the tortuous route of the cabling on the rear brake. The red line in the picture below is the route of the cable. It has two rather sharp bends in the housing to get the cable to align with the brake straddle cable. The cable simply can’t move freely enough.

If the cable could run along the green line, the brakes would work much better but you can’t have the cable just hanging in air and make it work either.



If you are going to replace the bike to replace the rear triangle, you should get a bike with a larger front diamond frame but a change in material won’t make this frame work better.

cyccommute 

Your comment is both correct and incorrect at the same time. The front of the bike is obviously too small. But the rear of the bike is the right size for a much larger bicycle frame but far too large for that front end. Having that much seatpost showing is actually about right for a properly sized mountain bike.

Overall, this is an example of an extremely poorly designed bicycle. It would be far too large at the seat for someone who it is designed to fit at the handlebars.

tricky 

I think you are saying "action" to mean the feel of the brake. I mostly agree with you that there is going to be a ceiling to how well the rear brake will feel. That cable routing is tortuous, but I do think the OP can improve brake performance with new pads. A new brake could also improve things too since those cantilevers with plastic arms can flex and reduce brake feel as well.

Soody

I'd like to know if your stupidly long stem makes the front end of the bike super flexy and it handles wierd, or is scary down hills, aside from the braking. If not it's perfectly fine and i'd keep the bike because the colourscheme is really nice.

Schweinhund

What's your metro area? Craigslist or offerup may have a screaming deal available. You might be surprised.