Wednesday, December 21, 2022

Roller Cams On The Brain: Dorado Sherpa

'Nuthin' fancy! But it has roller cams!
 So, you may recall that I hinted around recently regarding the possibility of restoring/resto-modding an old mountain bike that I came across which was equipped with roller cam brakes. (You can read that post here if you want a reminder or missed it) Roller cams are odd-ball brakes but I find them fascinating and well......I just couldn't resist! 

So, I brought the thing home in pieces after inspecting it thoroughly and researching the frame and fork as much as I could. I didn't want to waste my time if it was going to be a bad foundation to work from. The bike had to have good bones first and foremost. I didn't need anything that would need major repairs or that was compromised by age and its accompanying rot and rust. 

I also did not want to be blinded to the facts that the bike had to (a) fit me and (b) have an end purpose to be worthy of working it up into a bicycle again. Roller cams are cool and all, but I don't need another bike, and roller cams are not enough to make me want to add a bike to the fleet. 

This thing seemed to pass all the test criteria I had. The frame seems to be a main triangle of 4130 CrMo steel, (or maybe its just a seat tube?) ,with high tensile stays. The fork is most likely a CrMo steel steer tube and high tensile fork uni-crown, but I could not find any specs to say one way or the other. So, it's no Ritchey, but I think it is good and high ten steel doesn't scare me. I toured on a high tensile steel fork and a frame that very likely had similar stays to this one I brought home. 

It's a true basket case!

Some of the spec on the bike will not be used in the finished product. I am leaning toward a resto-mod type build. My inclination is to convert it to a drop bar bike. But at any rate, I am not using the Sakae forged "bull-moose" stem because the OG handle bar, a steel one specially made for that stem, is pretty pitted out. 

The story here was that this bike sat in a barn for a long, long time. I had to be sure that this wasn't a bike that was rusted out or dinged up so badly from being kicked around that it had been compromised in some way. So, everything came apart and the first clue was that it came apart without a fuss. The visual inspection showed no signs of terminal damage. Just years of gronk on corners and a patina on the paint which can only be gained by sitting around for years. 

The welds and brazing all looked okay. there is paint there and it doesn't look all bubbled up or odd. It doesn't have the prettiest welds, but they are not terrible looking from what I can see. Speaking of paint, it is not in good shape. There has been a lot of scuffing, outright patches of paint scratched off, and it will need attention. 

It does have some pretty impressive investment cast rear drop outs which I found to be an oddity for a "budget" department store brand bike. (Costco, by the way). These rear drop outs have eyelets for rack and fenders, which plays into my purposes for the final build on this, by the way. 

Yes- That is a long steer tube!

The fork has low rider rack mounts, again something that plays into my designs for this project. I have my suspicions that this uses a BMX standard head set. I will have to do some finer measuring. That said, I see that good BMX threaded head sets are still a thing, so I could replace the one in this bike if need be. It's steel and pretty non-descript, so I am leaning on getting a replacement.

The triple crank set is in remarkable shape, and it looks little used, so that will probably go back on here. The free wheel is an old SunTour one, (of course it is), and so I think I will see if it can be revived, but I won't be broken hearted if I have to source a Shimano free wheel. Those old two-prong SunTour free wheels are not my favorites! 

Of course, the roller cams will be revived, it is kind of the point of the whole exercise, but not the deciding factor. Had the bike shown issues which I was not willing to, or could not address, I would have just bagged the brakes and sent the rest to the recycling bin. 

I haven't mentioned the wheels, but there were wheels with this bike. Old Suzue sealed bearing, nutted axle hubs. The bearings were pretty crappy, so those would have to be replaced. The rims are single wall, aluminum, silver anodized hoops that are not anything special. Additionally, I have a brand new Velo Orange free wheel rear hub which I can use to build a new wheel with, plus I have a set of wide 26" rims in silver waiting to be used up. I'll have to see if everything matches up hole-wise. I may end up with new rims, spokes, and a new front hub. 

 Okay, so what is my goal here? The "bones" of the bike are okay, but what would I build this up in to and how would I use it? 

Remember me mentioning the braze-ons on the fork and rear drop outs? Well, my vision for this bike is to build out the thing into a 26"er touring bike with friction shifters, a drop bar, and a leather saddle with platform pedals. I want to add racks and fenders and a nice, plump set of 26"er tires. Then I want to do a self-supported tour, over-nighter, week-long, or whatever I can. If I do this, here are a couple of other thoughts I have had.

First, I was looking at all these blinged out rides people have built up and I was thinking that's what I was going to do. Then I came to realize that this would be a huge mistake. I don't need a fancy-pants looking bike for a couple of reasons. One- If I am really going to do some self-supported, self-contained touring, my bike needs to be a tool. Not eye-candy which may cause trouble. Think about it...

Secondly, if it is more utilitarian in looks and in nature, I will use it more. I won't be afraid to drag it through the mud, ride it in the rain, or have gravel bouncing off the paint on the frame. A tough, durable finish then, with no real flash or anything to recommend it to the eye. That's going to be better than a shiny garage queen, I think. 

In fact, I thought about just sanding off the corrosion and touching it up with yellow paint from a spray can. Ha! That would be pretty "low-key" and low cost! But we'll see. This isn't going to happen quickly, I don't think. The wheels are the first big issue to tackle. 

Stay tuned....


Phillip Cowan said...

Rescuing old bikes is fun. Much like saving old cars,motorcycles or houses, it's the thrill of making something out of nothing. You should start a Youtube channel. You could give "Old Shovel" a little friendly competition.

Guitar Ted said...

@Phillip Cowan - You are so right. Rescuing old bikes is a great way to put what I do at the Cedar Valley Bicycle Collective. And we ask for people to come and "adopt" them, don't we? Yes, I think we do that.

I guess I knew that intrinsically but you put that into words that make sense for me. Thank You!

Tman said...

That sticker says "main tube" cr-mo so the frame is hi ten with one tube of better steel. Prob only the seat or down tube.

Derek said...

Interesting. I've never seen a chromoly main "tube" sticker, only "main tubes". To me the chromo main triangle vs full chromo frames sorta have a similar feel, until you get into the full air-hardened 853 or OS Platinum frames, which are a good jump up in spectacular springy steel feel.

Guitar Ted said...

@Tman, @Derek - I've seen spec on entry level steel frames back in the 1990's where only the seat tube was CrMoly. It wasn't uncommon. But I've also seen my fair share of frames with stickers that would lead you to erroneous conclusions. That's why I stated in the post that I could not find any official specs to corroborate the message on that frame sticker.

And in the end, I really don't care too much. If I go ahead with the project it will be because I'm interested in the form factor of the bike and what it could do for me as a tool to do a certain job.

Mike said...

I'm Mike. I bought my Dorado Sherpa Mountain Bike brand new from The Mountain Bike Factory Outlet, in Oregon City OR. Mine is yellow, just like the bike pictured. It has no original parts and has gone through many iterations. The bike fits me. It is old, like me. Good luck with your project.