LBCwanabe 

It appears to have faded anodized bars? What year y’all suppose? The Seller was nice enough to hold for a week before I could make the 70 miles. He said he was the original owner and it was original throughout. Thanks for looking

Bianchi84

It's an interesting mix of components with Shimano cranks and rings but Suntour Derailleur. The under-stay U-brakes make for a stiff mounting area but might be mud-magnet. I wondering what those pedals are. The bike looks cool! Best of luck and lots of fun with it!

eeuuugh

It's a 1986. Awesome bike!

stardognine

I can’t quite read the RD, is that XC Sport? 🤔 Metal U-brakes are better than plastic, lol. 😁👍

LBCwanabe 

Frame appears to be tig welded w/o lugs. when I google 1986 model they are all lugged?

I've found a pic of a green 1987 that is outfitted with same components.

cyccommute 

I’d say 1988. Here’s one. 1986 to about 1990 is the “mistake” years for most mountain bikes. The “mistake” being the under the chainstays U-brake.

LBCwanabe 

clubman 

Perhaps they weren't optimal but mistake is too harsh. I rode knee deep in TO's 4 season crud with the DX low mount U-brake for over 4 years . If you spray 'stuff' on them every so often, prise out the crud, change brake pads, clean your rims, they worked very well, better than most rear road calipers. Wide profile canti's at the front made sure you were stopping even better. Got my money out of them: the bike lives on today with a friend, still stopping fine..

That Stumpys great value at that price to me.

cyccommute 

Companies certainly thought they were a mistake. They dropped them like hot potatoes and even went back to cantilevers. Most brake systems can still be found on various quality bikes even now. Center pull calipers (Mafac style) are very rare but Paul still makes a version of them. Cantilevers are still available on a wide range of bikes. Disc brakes have replaced linear brakes but you can still find new bikes with v-brakes. The only place you’ll find u-brakes are on some freestyle BMX bikes. Nobody else wants to touch them.

From what I can see, the Stumpjumper only had them for that model year.

clubman 

Just saying, they worked, even though they were pilloried. That fact that they didn't meet market expectations and got dumped doesn't diminish their intrinsic value.
I get the history lesson, I lived it and rode through it.

TenGrainBread 

U-brakes work great. They are, after all, simply beefed up centerpull brakes, a design specced on millions of bikes over the last century. While centerpulls have lost popularity since the early 80s, it's not due to their braking performance but rather due to the ease of setup and marketability of sidepull brakes. In my opinion they are often more rigid than sidepulls and therefore offer slightly better braking performance. As to u-brakes, yes, the under-the-chainstay placement of mountain bike u-brakes in 1986-1988 was not the best idea, but the brakes themselves are great. Cantilever brakes offer more mud clearance and are a bit lighter, but generally do not offer better braking performance than u-brakes. In the vintage mountain bike world, some of the most sought-after bikes from the late 80s and early 90s are those with variations on u-brakes, by that time mostly mounted on the seatstays: Cunningham's lever-link brakes, WTB Speedmaster roller cams, and many other "boutique" brakes that boasted amazing performance compared to cantis, if you were willing to spend some time learning how to set them up. As far as BMX goes, u-brakes are the standard and there is quite a booming industry with hundreds of companies offering their own models.

By the way, centerpulls are still being made by a few more manufacturers than Paul. Rene Herse and Dia Compe both still manufacture them, for example. Dia Compe has at least 4 models under its own branding, plus they manufacture two separate models for a Japanese company called Grand Bois. Not to mention their full line of BMX u-brakes, starting with the cheaper cast Diatech "Magic" brakes up through their famous forged 990 model line from the late 80s, followed by their top-of-the-line "Box" U-brake which is fully CNC-machined.

mechanicmatt

I'm with you here, I rode plenty of bikes with them back in the day. They 'worked', they were not great and still are not great. Bad location and bad leverage.

cyccommute 

I choose not to ride through it. I broke a mountain bike frame in 1988 and refused to go the under the chainstay U-brake fashion of the day. I found a Bianchi Grizzly with cantilever brakes and rode it until the U-brake fad passed.

I wouldn’t consider the Cunningham nor the Speedmaster nor any other roller cam brake to be a “U-brake”. They are more like a modified linear brake than a U-brake. And, while they are mounted on the same bosses as U-brakes (whoever thought that was a good idea?), I don’t recall ever seeing them mounted under the chainstay in a place that collects mud.

The different boss mount location and different boss dimensions contributed to killing U-brakes as well. The brilliance of linear brakes is that they could be fitted on most any of the millions of bikes that existed before. And, as they are easier to set up than cantilever, many people embraced them. The brakes you referred to may be great brakes but they aren’t brakes that can be used on nearly all bikes. You have to have the right bike to use them.

I used Paul’s as an example, not an exhaustive list.

obrentharris 

Nice Stumpjumper. I hope you have a lot of fun riding it!

I rode with a roller cam brake under the chainstays for 12 years. On our steep terrain I was willing to trade the better braking control and stopping power for the increased mud accumulation.
I rode in the mud all one winter, then had to ride in my own erosion gullies all the rest of the year. After that I stay off the trails when they are at their muddiest.



Brent

bikemig 

The u brakes are definitely not great for riding off road but they're fine for gravel and trail riding. I have a late 80s Stumpjumper Comp with a u brake that I commute on regularly.

fleslider 

Like alot of things in the industry there are things that didnt work out well or they found something that worked better in this case U-brakes , Yes they didnt work well well when things were muddy etc. but they were still effective. I always liked them as i was a young teenager when they came out. i remember drooling over the 1987 Diamond back Arrival in the LBS and wanting that Deore XT U-brake. but anyways yes they weren't the greatest and today I wouldnt volunteer to go on a muddy ride with them or any seroius kind of offroad riding with a U-Brake bike. now maybe my Karakoram with a seat stay mounted U-Brake. I dont think of them as a mistake just a revision of many made to the MTB's over the years! like the URT suspension ,the wide rims.

just for the record here are two bikes i own that have under chainstay Roller Cam brakes


1986 Fisher

Kind of hard to see but theres a roller cam behind that Shimano 600 triple cranks

1986 Trek 850

cs1

I was thinking 86 or 87.

madpogue 

Markings are a close match to my '87 RockHopper. Serial number should narrow it down.

LBCwanabe 

Update:
the rear gx26 wheel had busted spoke holes at the hub. Lucky for me I had a spare While waiting for the front brake cable hanger to ship I disabled the front brakes and took it for a spin. I also added some bosco bullmoose bars, Shimano levers and thumbies. In this configuration the closest thing I can compare it to is a wheelbarrow. I mean this in the most sincere flattering way.