disco_kevin30

Would a 1984 Schwinn World Sport or a Univega Nuovo Sport (not the nicer triple butted version) make a good candidate for a conversion? I have the frames and a lot of the parts around already so the only expensive aspect would be new wheels and tires, but I think I could find some for a reasonable price. My plan was to swap out the stem for one that brought the bars up a bit and move to a flat bar. Probably mountain group set on the rest and trigger shift. Not a Cross bike per se I guess, but i wasnt sure where else to take the question.


The intended use would be really light, just trails. Nothing competitive. I figure I can do the whole project for less than 200 which seems reasonable. Is there any special considerations to take into account involving the wheels or frame geometry? Anyway, thank you for reading. I hope this question is in the right place.

Clem von Jones

Were both of them 27-inch wheeled frames, if so the trick would be finding a center-bolt brake set to clear wide tires, so for example my Tektro long-reach calipers only clear about 34mm. Ideally you'd want to run something like the Panaracer Gravel King 40mm tubeless and get them thru a brakeset without deflating the tires. Unsure if there are any brakes out there that do this but those old Dia Compe center-pulls might work.

mrv 

Based on my past failures experience, put your effort into the frame that has: 1) the longest length from the drop-out center to the brake bridge 2) the widest chainstay where the rear tire will be in the frame.
Rim width will matter if you don't have wheels yet.
A skinny rim (19~20mm) will reduce the tire height. A wider rim will make the same tire taller. It's like only to be a few mm, but when you install your long reach TEKTROs (or whatever), you're like to only have a few mm of clearance. And when you open the brakes, the bottom of the brake may even hit the tire if you're really pushing things.

I have a NIKSHI frame (some mid-80s sport tour thing) that will happily run 32mm (700c) tires using DYAD rims, but I got to 37 or 38mm tires and in the rear triangle I hit the bottom of the long reach TEKTRO brake.
I have a mid-80s TREK 420. The brake bridge is further away from the hub-center, so I'm limited by the chain stays. I can run a 37mm CONTI on MAVIC pro rim (20mm wide? not sure) and everything clears with a few mm to spare. Those little sprues sticking off the side of the tire actually cleared the paint of my chain stays! Ugh! Fixed it with a bit of touch up paint.

Some photos:
TREK: https://goo.gl/photos/7CSoyncDZavYT1zw8 - several iterations of the bike, but leaning against the MANISTEE sign has the 37mm (700c wheels)
counterfeit Detroit Bikes (Nishiki): https://goo.gl/photos/GiNjLLpLL4nAWHqW6 - got like 3 bikes in the folder, but it's the blue one



SERFA 38mm tire on 700c MAVIC Rim (i think....)

chas58

I think it is a great idea, but the real question is what size tire will you target? Going from 27" to 700c buys you significant tire clearance. Some good tubless wheels/tires in the 32-35mm range would be best. I love 32mm tires on hardpack and rail trails (as long as the surface isn't too soft). If you need to go bigger, you'll have the problems mentioned above, but it sounds as if tires around 32mm in size will fit you fine.

mstateglfr 

Use whichever fits you best and can take the largest tire.
neither will excel compared to a purpose built gravel frame.

and if you like it but don't want to go new, look at quality 90s hybrid frames from trek, Univega, etc. They have good geometry, can handle wide tires, and can take drop bar conversions without lot of concessions.

mrv 

+1 - those hybrid frames had linear pull or canti brakes - allows lots of room for cushy tires.

disco_kevin30

Nice. I dig those old Treks a lot. Probably my favorite bicycles.

Apologies for not responding sooner, its been a busy week. Anyway, to answer some of the comments, the frames are designed for 27" and the intention was to move to 700c and the biggest tire I could fit. Unless I am able to find a set of centerpull with enough reach I was going to swap the brakes to Tektro r556; I have a pair on another bike and I am really happy with their performance.

One point I would like to dig further into is: should I go tubeless? I hadn't taken it into consideration but after some research it seems like this is the best route. I looked up the Park Tool tubeless conversion video and it seems easy enough to do so why not, right?

As for the hybrid frame being a better option, I will keep that in mind. When you say drop bar conversion without as many concessions, do you mean comfort and fit or drive train and parts? A little of both?

Thank you again.

fietsbob

It, just an unpaved road, , why overthink it?

mstateglfr 

This is a website where people come for ideas, suggestions, assistance, etc. Why be here if you arent interested in assisting?

mstateglfr 

Compared to any converted 80s road bike(competition, sport touring, or even touring), 90s hybrid frames will have wider tire clearance, cantilever brakes(again for more tire clearance and easier wheel removal), buily for wider range 3x gearing, usually have mounts for racks and fenders, will have 2 bottle mounts, and typically have geometry that is often more relaxed than road bikes(72deg HTA and STA, for general example).

rosefarts

I don't think you should go tubeless.

This is a budget build, where you're not quite ever going to get the ideal set up. Tubeless means buying new rims and lacing to old hubs for this bike.

I am tubeless and love it but you need to be realistic with this bike.

mrv 

The only tubeless wheels I have are on my car.
I run inner tubes on all my bikes. I suppose if I raced I would consider tubeless, but my main consideration is getting home (or getting to work or to the campground or the coffee shop).

There's some recent changes to cycling that I don't think of as progress for the recreational cycling. Tubeless wheels being one of those. All the other changes are off topic from this post, so I will digress.
But I will leave you with a funny picture related to the topic!!




https://janheine.wordpress.com/2019/...-supple-tires/

disco_kevin30

Cool, sticking to tubes makes the project even easier. I have decided to go with the drop bars as well so the only thing I have to spend on is some brakes and wheels/tires. There is a good local shop that has a nice selection of used parts so it shouldnt be difficult to put the rest together.

I will post photos when I am finished if anyone is interested.

disco_kevin30

Man, that sucks. It seems like a bad situation to be in if you were out somewhere and that happened.

Lemond1985

Shifters could be problematic on the World Sport, stems shifters are a real pain if you ever stand up while pedalling (they get banged by your knee constantly and "ghost shift"). Tire clearance can be tough to figure out, but generally if you're going from 27" to 700c, something like 32's should not be a problem. Good luck, and post some pics. Sooner rather than later.

irideiam

I am not sure about the frames your asking about, but I used a 700C 1991 Trek 520 Touring frame to build a gravel bike last year. The touring frames of the 80s & 90s tended to have wider stay clearance for wider tires & fenders. the purpose built touring frame were also build a little stouter to handle extra carrying capacity. It also has built in bolt ones for racks & panniers. I have 1000s of miles on it on mixed terrain, and it's performed flawlessly. In my mind the the only drawback is that it's not a disc brake frame, otherwise geometry & tire clearance are real close to today's frames they market as gravel/adventure bikes (I know because my son owns one). The other difference is my frame is lugged chromoly and made in USA!


I will post up pics & specs once I get to post #10 .

irideiam

1991 Trek 520 Touring frame (Made in Waterloo, USA lugged cro-mo frame), converted to a Gravel Grinder.
The bike is relatively quick for a touring frame and handles more like a CX bike with the 429mm chainstay, but can still handle a 42C tire without finders, 40C with fenders.
All new parts:
-Velocity Dyad / Shimano 105 hubs, custom wheelset
-700x40 Maxxis Rambler DC/EXO TR Gravel
-Rival 1 crankset 42T, 1X11
-Apex 1 rear derailleur, shifter/mechanical levers
-Paul Motolite Brakes (yes they work with the Apex levers)
-Thomson Elite Layback Seat post
-Brooks B17 Imperial
-Salsa Guide Stem & 46cm Woodchipper bars
-Speedplay Drillium flats pedals




Rides like a dream!

Lemond1985

I'm not a fan of the 90's hybrid frames. Great tire clearance, yes, but the bizarre geometry, and lack of comfort, and weight of these things made me write them off. If you like the handling of a good road frame, I would suggest a late 1970's or early 80's road bike like the Univega. Tire clearance ought to be at least 32 mm, which is fine if you can avoid significant mud or sand. Around 1985 or so, tire clearances started getting very restrictive, to the extent that most late 80's and early 90's road bikes will only take a 25 mm tire, max.

But if wide tires are a major consideration, it might be worth it to put up with a hybrid.

mstateglfr 

The early 90s Univega hybrid I used to make my first gravel bike used double butted cromoly tubes(on the thicker side of butting), had 72 head and seat tube angles, and was quite comfortable. It had mounts for racks and fenders and fit a 40mm tire without issue. It wasnt extremely light, but it was comparable to a modern Surly Crosscheck frameset.
My brother-in-law has a converted gravel bike based on a Trek 750 frame that uses TT Double Butted tubing and is the same geometry as Trek's 520 touring bike that year. Again, I would not say it has bizarre geometry or lacks comfort.

Perhaps the confusion is how 'hybrid' is used to describe a wide range of bikes. There were(and are) comfort bikes that are called hybrids, then there were bikes that I am referring to-
Schwinn Crosscut, Trek 750, Trek 7900, Trek 790, Bianchi Project line of bikes, Univega Via series, and others which were all double butted cromoly frames with geometry that isnt bizarre with clearance for wide tires.

I do agree that if a wide tire isnt needed, then something with light tubing from the early 80s that would have been considered 'sport touring' would make for a great platform. But 40+mm tires are the single best part of a gravel bike for where I ride. I own multiple road bikes with 25-31mm wide tires and have 0 interest in taking them on gravel rides. The narrow tire is simply too uncomfortable and uncertain to be fun. If I rode dry hardpack dirt roads, then sure a 32mm tire would be great. The gravel roads in my region are crushed stone and narrow tires are fine for short segments to connect pavement, but are no fun for anything longer than that.

katsup

Do you trust that threadless stem adapter on technical trails? I ran one on my 520 for a bit, but when it came loose while riding so I changed it out. Using a 110mm Origin 8 Pro Fit quill with 31.8 clamp at the moment and it has been secure. The other option I know of is the Velo Orange stem, but it is pricey.

It's mostly used for commuting or easy trails as I don't like the stand over to do more technical gravel.

irideiam

[QUOTE=katsup;21154005]Do you trust that threadless stem adapter on technical trails? I ran one on my 520 for a bit, but when it came loose while riding so I changed it out. Using a 110mm Origin 8 Pro Fit quill with 31.8 clamp at the moment and it has been secure. The other option I know of is the Velo Orange stem, but it is pricey.

It's mostly used for commuting or easy trails as I don't like the stand over to do more technical gravel.

/QUOTE]

Nice 520, the quill adapter has been great so far, but I torqued it down pretty tight, and check it every so often and it has not come loose yet. However, it pretty much only sees gravel and some light XC trails that I am sure are not as technical as what you have in Cali, but who knows, it's all a matter of definition. Regardless, thanks for the tips, but I sure like running threadless and those Salsa bars!

katsup

I had a longer one as I was working on the fit, but it came loose climbing some basic XC switchbacks. I was able to tighten it and finish the ride, but didn't trust it after that so it got replaced.

I would agree about Salsa bars, I like the Cowbell.

irideiam

Of coarse I meant torqued it down not "torched". I am using this one https://www.thebikesmiths.com/products/origin8-6703

It's inserted all the way down. The spacers are only for aesthetics. I used the riser stem to get the bars up to where I needed them.

rando_couche

Why hasn't anybody mentioned converting to 650b???

My "go pretty much anywhere" bike is an old Mondia Super converted to 650x42b. The one thing I had to look for was indented (vs ovalized) chainstays, and even at that there's barely clearance for 42's. The ovalized stays on mid-80's bikes will usually clear 38's. Also, finding brakes to fit can be a challenge. MAFAC Raids are tailor made for 650b, but they've gotten obscenely expensive of late. Like $250 for a pair of calipers. IIRC, Tektro makes dual-pivot calipers that will work, but I've never used those.

So anyway, that's another option for you.