Manu431

Hi,

I am working on a scott arapahoe, and I am currently looking at what may be conserved or need to be replaced.

I have seen that on all cantilever , the plastic is broken like on the picture
One is even with no plastic at all, and all was working properly on the bike.

Do they need to be replaced due to security reasons ?
is this plastic only here in order to make the setup of the brake easier ?
Is it possible to find plactic replacement somewhere ?

Thanks in advance for any advice

I personally don't dislike the look without them. I mean with the spring visible.

JohnDThompson 

That's one of the poorer brake designs I've encountered. Sometimes the brake will continue to work ok without the shroud, but sometimes not. Replacements would need to be salvaged from other calipers.

Possibly a better idea would be to replace them with linear-pull brakes, which are compatible with the cantilever mounts.

Wilfred Laurier

Breakage of those plastic bits was endemic when those brakes were common, and that usually resulted in brakes that would always rub or not properly return to their home position after braking. Shimano used to sell replacement plastic spring covers, but more recently I have seen whole new sets of brakes for only a couple bucks more than the plastic parts.

leob1

Endemic? They had close to a 100% failure rate. Shimano sold the replacements by the sack.

TiHabanero

At one point Shimano sent our shop bags of the springs at our request. They were considered a warranty item.

restlessswind

https://www.jensonusa.com/Shimano-Altus-CT91-Brakes
Comes with new pads, plastic bits and equalizer cable. Problem solved.

thumpism 

When repping I carried a sack of them with me to dispense as necessary.

grizzly59

Do this. That brake has to be one of the worst Shimano ever made. Kill it with fire. Avid v-brakes would be a good start:

https://www.ebay.com/itm/New-Avid-Si...wAAOSwuwBbVatE

Manu431

Thanks for all advice.

I will order new one, no problem.

Dealing with renovation of old original parts is a part of the fun, when it doesn't compromise the security.
In this case it may in some circumstances compromise the security, and it is not acceptable.

I am pretty sure that in some part of the world these cantilever will be repaired and used .
The broken part is just some kind of plastic tube after all.
There is something to be made with a piece of inox/alu tube of the same dimensions and some drilling for the screw. (only if I can find this for free at home or for free)
I will give it a try for sure, even if I must admit that it is not my first priority.

I think I will probably stay with cantilever, just for a question of look at the rear part of the bike. (look at the small brake support bridge for the cable)
Plus it will be easier with the brake lever (drop bar conversion)

hokiefyd 

I've been happy with Tektro's CR510 brake. You can get them in anodized silver, so they still look somewhat "classic" and period correct. But they use linear pull-style threaded brake pads, which I find much easier to setup than the smooth post brake pads common to cantilever brakes. I have these on a Trek 750 painted in a blue very similar to your Scott, and they look pretty sharp.

Wilfred Laurier

I will add another vote for direct pull 'V' style brakes, even though OP said he doesn't want to. The function and ease of setup is far superior to centre-pull cantis, where the geometry change in the straddle cable as the brake is actuated actually reduces power the harder you pull the lever, while linear pull brakes are... well, linear.

You can also get 'mini Vs' if you are staying with narrower road tires and not planning on fitting fenders. These have all the benefits of full-size Vs but they work with the same levers as canti brakes (almost all drop bar levers are perfect).

On the other hand, one of the main advantages of canti brakes is the large amount of clearance for fatter tires and fenders. If that is a commuter or town bike and you are planning on mounting fenders (you should) then cantis are probably a better choice.

Wilfred Laurier

Also! In the mid nineties there was a major recall on certain Shimano cranks due to a problem with the forging of the crank arms. There is still information on the web about these cranks and you should look this up to make sure yours are not affected. The cranks were prone to snapping near the BB spindle with no warning.

Manu431

The goal is very clear.

I want to make use of this old scott from my son to make it has a second bike for my wife.
We have a camper van and we need a second bike which is easy to transport in the camper or on bike carrier , and not to heavy in comparison with our Ebikes. They also have to be easier to carry sometime on the train, which is very complicated with the ebike due to weight and dimensions. They also to be cheap bike, just in case , because we are visiting cities .

Two years ago I already made a bike for my wife, but she never really have liked it. She just doesn't feel secure on it . Maybe the bike is to small.
She has tried the scott and she likes the position on it . I could have make it has mountain bike, but she prefers some kind of road "utility" Bike version ("RUB" ; it sounds cool isn't it ?)

The old bike


The new goal (found on the drop bar conversion thread) ; She is decided for this kind of color.
The bike should have fenders (I have black ones like on this bike) , have a back rack , and be robust.
It should use as much as possible parts I have at disposal, but not necessary.
It must looks good, because it will be my wife's birthday present (she prefers by far something made from hand with heart as a fancy expensive present)

Wilfred Laurier

Why are you changing to a drop bar if the intended rider is comfortable with the position with flat bars?

Manu431

I have a shorter stem as disposal (the orginal on the scott is 100 mm long).
At the end, the position of the hands on the brake should be approximately the same (distance) has currently on the scott with the flat bar (I hope i write well so).
And she has approved the current position with the flat bar.

The drop bar allows more various hand positions for a mainly road / city / gravel paths.

But drop bar is not 100% sure yet.
I also have the possibility to use the current peugeot bar/stem., or even stay with the scott config has it is
We will try all of this and she will decide. I have parts for the three configurations, plus a fourth one.

In case she doesn't want to use the drop bar at the end, I could use the bar from my son's bike and use the drop bar for him .