J.Higgins 

Do the drop bar conversion for sure! I've never liked bar-ends anyway.

wrk101

Rigid frame for SURE. Save the parts you take off the lower one, and go drop bar. Realize if you don't like it, you can always go back.

As far as drop bar hand positions, I just use from the stem to the brake lever. I am not using the drop portion. But even just the part I use, I have dozens of hand positions which really helps!


I would be looking for a shorter stem. Those two are super long. I have pretty much copied the geometry of my road bike with my drop bar conversion. So distance from the nose of the saddle to the handlebars is the same, distance from the saddle to the pedals are the same, etc. I've managed this by watching out on TT length. MTBs are all over the place TT length wise. Some are super long. I had a 1989 High Sierra that had a 1 1/2 inch LONGER top tube than the same size 1988 Schwinn Cimarron. So I went North Roads on the High Sierra.

Measurements above are from my memory, I could be off a little.

On your top bike, that came in two versions, one had a rigid fork. So you could put a chrome MTB fork on it (think co op).

And on stem, hey, maybe that long one will work just fine for YOU. Its all about how it fits YOU.

And on the Rock Combo, one of the early drop bar conversions, just came that way from the factory... While Specialized was busy with Rock Hoppers and Stump Jumpers, they decided to take a shot at it.

Needs pink bar tape and cable housing. I have some. Wheels and saddle are not original. Wheels when acquired did not match, and cones were bad anyway.

Specialized Rock Combo by bill, on Flickr

Specialized Rock Combo by bill, on Flickr

katsup

Personally, I'd leave the 970 as is, you may have trouble getting the bars high enough with a drop bar conversion. However, I may be bias as your 970 (in that color) is the bike I've been lusting over (22in frame though). If it doesn't fit, I'd move it onto someone that will fit it. Sadly, I've had to move on some nice bikes due to them being too small.

rossiny

Thanks for input. Yeah the 970 is about a 19 , 20 depending how measured I am 6ft..
I already know some one might fit it and I got it for a great price , so might just let him have fir same price. Now the 930 with the upslope toptube seems to fit . Was surprised, does not seem heavy just by lifting it.. I am not that experienced so how do I measure for the fork. ? The head tube or steerer, not sure how called looks a bit larger diameter than the 970. Thanks again.

squarenoise 

Awesome Rock Combo wrk101!

Slowly making some progress on mine. Decided to use the Specialized Flag crankset on another build and going with Shimano Deore XT paired with Deore DX derailleurs on this one. Hubs are also Deore DX with Specialized Rims. The original stem is way too long for me with the top tube being 59cm, so I still gotta figure that out. Other details for now...

- Specialized Touring Pedals
- Speedic Leather Saddle
- Dia Compe 987 Brakes paired with Deore LX Pad Holders
- Maxxis DTH Tires


1989 Specialized Rock Combo


Shimano Deore XT Crankset


Specialized Touring Pedal


Dia Compe 987 Cantilever Brakes

jreeves 

Nice! What's the difference between biopace HP and Biopace?

zjrog

I've got a 89 950 20" that I just snagged a taller quill stem with rise to it. Thinking it will get the bars high enough to be comfortable. I'm 6'1". I toyed with the idea of doing drop bars on my 90 Trek 7000 22". But I like it being all original.

squarenoise 

Biopace HP is not as oval as regular Biopace, kind of in-between regular round chainrings and Biopace. Marketing wise, I think the HP was "High Performance".

katsup

At 6ft, you are be in the ballpark for a 19-20in frame. This depends on other factors, but you may be able to get away with a higher stem or handlebars with some rise.

wrk101

On size everyone is different. But I find on a true MTB I go for an 18 inch frame size. On a road bike I tend to go with a 22 inch frame size. With a drop bar conversion, I end up in the 19 to 20 inch size. 18 is too small, 20 is pushing it. Note, I have to be careful with TT length as some get silly long. As I recall, my 1988 Cimarron is 19 inch CTT.

IsleRide

Found this interesting Scott full chromo frame with quality dropouts and "suspension geometry" 20.5" CTC.

Budget build using new and used parts. Stable geometry. Climbs like a Billy Goat. (11-34 8 speed cassette, 42 32 22 LX crankset.
Just finished today.

May fender it with SKS for the winter.
Friday update. Bars wrapped.

due ruote 

That looks great. How do you like those tires? I have a set laying around but haven’t mounted them yet.

IsleRide

Thanks. Just mounted them yesterday but used them years ago on my hardtail mountain bike when I got into less aggressive trail riding.
I remember them surprisingly able to hook up in the dirt but the inverted tread makes them pavement friendly.

They're now made in India and very affordable. Found them a little hard to mount but not overly so.

tricky 

Awesome! I didn't know they did a drop bar MTB. Just curious, what's the seat tube CTC and top tube CTC? I am wondering if they shortened the TT on this compared to their flat bar MTBs. Or maybe squarenoise could measure theirs? Edit: found some interesting info about Rock Combos here: https://forums.mtbr.com/vintage-retr...l#post12122919

squarenoise 

From what I found online, they came in 3 sizes - 17, 19 1/2 and 22, that's seat tubes measured CTC. Mine is the 22 and has a 59cm top tube. The 19 1/2 frame has a 58cm top tube. Not sure of the top tube on the 17" frame.

I have a Stumpjumper Comp, also from 1989 with a 59cm CTC top tube and seat tube is about 21 1/2" CTC.

squarenoise 

Nice! thanks for sharing that. Interesting comment about the "heavier tubeset". I read elsewhere that the Rock Combo was on the heavier side, but wondered if it was because of the frame or the components, sooooo I weighed just the frame/fork with headset installed and my 22" came in at 8lbs 11oz. I then weighed my (same size) Stumpjumper Comp and it came in at 8lbs 9oz so pretty dang close, especially considering the Rock Combo has a longer seat tube. Anyhow, I'm a big guy and not concerned about the weight factor, but thought it was interesting.

tricky 

Thanks for the measurements!

Interesting that the Rock Combo is so close to the Stumpjumper Comp. I held a Street Stomper frame before and thought it must have been a heavier frame than Stumpy's of the era, but, wow, 8.7 lbs? I didn't realize MTB frames were as much as twice as heavy as road frames. I was being willfully ignorant about the weight of my '87 Fisher, but if it's anything like the weight of the Stumpy, or the R Combo, it is quite the porker as well.

spedrunr

Well thought out cable and tape colors. Cool bike

spedrunr

What kind of handlebars are those? I never really cared much for the speckled tape but you've really made it work well with the frame and cable colors.

spedrunr

Is that logo Bike Saviors in Tempe?

spedrunr

!st time seeing a Rock Combo, was that a hybrid mountain bike in it's day?

spedrunr

Man, I'd like to see more pictures of the Salsa bike to the left (or a link to already posted pics)

Korina

Me too. It seems to have been a proto-gravel bike. The link is well worth following.

PJ943 

I was seriously contemplating one of these as a project....any tall people have experience with doing this and have advice since 21" seems to be the max size on the older MTB frames?

Classtime 

PJ943 I'm not tall but to get you started, you shouldn't have any trouble getting the proper reach because most of these bikes have longish to tubes and most of us use a shorter than original stem. MTB seat posts have plenty of length so your saddle height should be easily achieved with a 21" bike. Of the ridged bikes, high end early 90s bikes seem to be the lightest. Have fun.