jamesdak 

So, I have a really good shape early 80s Fuji S12-S that I bought purely to convert to 650b for pleasure riding, dirt road use and some light weekend touring.

Right now I'm thinking of a set of Velocity touring wheels built up with Atlas rims and 36H road hubs. This bike should be able to run a 42 tire with fenders setup as 650b.

The gearing is my real question. I plan to convert to triple while trying to keep the same RD so I'll probably be able to run a 7 speed cassette on the new wheels. Current freewheel setup has a 30 tooth large cog. So a cassette with a 30t is the plan.

So in a triple what are the recommendations for the small chainring? It looks like 30, 28 and even 24 are easy enough to source. I double I'll do any Cat 1 climbs with this but you never know. I guess the thing is I don't know what to actually figure when it comes to getting a loaded bike up a mountain. I climb regularly on road bikes and can do a local 25 mile Cat 1 climb with all my bikes. From a standard 39 -23 to a compact 34 - 32. Even made it up a shorter 8 mile Cat 2 with a 42 - 23 with no real problem.

Anyway, thoughts on a triple setup from those who actual carry some loads would be appreciated.

And please, the touring part is something additional to the 650b conversion. Not trying to debate 27" vs 700 vs 650b. Thanks! I already know this won't be the "perfect" touring setup.

Oh and the bike as it sits right now.

bradtx

jamesdak, I'll give you a couple of recommendations based on my two touring bikes. One happens to also serve in the beater/gravel/grandkids rolling roadblock role and it has an 11-28T 7S cassette and 24-34-42T chain rings. Not a bad set-up for light to medium touring loads. My primary touring bike uses a 11-30T 8S cassette and 22-32-44T chain rings. Better range for medium-heavy loading as well as unloaded riding. Of the two crank sets, I prefer the latter. I may try a 12-32T 8S cassette for a wee bit lower granny...

Brad

mstateglfr 

A few ideas/suggestions to ponder.

Since you are getting a new wheelset, you can run more than 7 in the back. You could have it set up as 8 or 9. This would allow for smaller steps when you shift. The new hub will be 130mm in the back and already set up to accept 8 or 9(could do more, but with friction shifting, it can sometimes be a little tough to find the right cog at more than 9).
Your rear derailleur will pull the chain to wherever you want, it doesnt care if there are 6 cogs in back or 8. Just something to consider since you are making the change.


I dont know how an 8 mile cat 2 translates to incline, but ill give you this general statement- if you are riding up a hill thats 6% or more for .5mile or more with loaded gear, you want gearing that is 21 or so gear inches. Thats a general statement and significant variables like gear weight and rider conditioning arent taken into account.
With that said, a 650b wheelset and a 30t rear cog would need a 24 or 26t front ring to get around that 21" mark.


An old Sugino, Shimano Deore, or Sakae triple might be best for you.
1- the BCD is 110/74 so rings are readily available and relatively cheap. 26t and 24t Sugino brand rings are all over the internet for $15 or less.
2- they look period correct for your bike.
3- they are all over ebay for relatively low prices. examples are Vintage SR Sakae SX Bicycle 175 mm 46 36 28 Tooth Alloy JIS Crankset | eBay and SR Sakae SX Bicycle 175 mm 48 38 28 T | eBay

If you want a more modern crank, consider the Deore M590. It comes in black or gray and has 2 gearing choices that may work. The BCD is a little less replacement friendly, but you would need thousands of miles of use before the rings will wear out.
Shimano Deore M590 9 Speed Triple Chainset | Chain Reaction Cycles
Options are a 48-36-26 or 44-32-22. And with a $13 bottom bracket, you would have a modern crankset thats problem free and geared for what you need.

HTupolev

Be careful with chain wrap. If that's a SunTour Vx-S derailleur, its wrap is just 30 teeth. A 13-30 cassette is going to leave only 13 teeth for the chainring difference. Couple that with a wide-range triple, and you'll have a choice to make when you select your chain length: err long, and your drivetrain will sort of drop out whenever the small chainring is used with little cogs; err short, and you'll rip the rear derailleur off the bike whenever the big chainring is used with big cogs.

jamesdak 

Good to note and something else I have to do my research on. I'm sorta thinking already that as much as I want to use current components reality is going to be different. I really got this for the frame and the ability to fit the fat tires with fenders so if I wind up modernizing the drivetrain it's no big deal.

Keep them useful thoughts coming.

bradtx

jamesdak, If you haven't seen this already, take a look at the bike in post 12. https://www.bikeforums.net/touring/10...ng-change.html

Brad

mstateglfr 

Oh yeah, I didnt realize the derailleurs on there were made for a standard 12speed drivetrain. Not sure why that wasnt thought of since the model is an S12s.
The front and rear derailleurs would need to be changed to a long cage rear and a triple front derailleur. The shape of the FD is different than what is currently on the bike and is needed for 3 rings. The long cage rear derailleur is needed to take up the extra chain that will come from riding in the granny ring and the smaller cogs.



A couple years ago I changed a 1980 Schwinn Voyageur 11.8 with a standard double into a 3x7 for lighter touring using all 80s SunTour components. It was fun and I love the bike, but just be aware that some derailleur groups from that period will cost more than others on ebay. I went with later 80s SunTour derailleurs since they were good quality and about $40 cheaper than more period correct ones.

jamesdak 

Yeah, mine seems a bit odd. It's got a 1981 paint scheme, 1980 dated serial number and a 1980 date on the wheelsets. Yet the catalog shows the 1981 as having a triple and being 441 straight guage steel. Mine has the double setup and has a lable saying it's the 331 double butted. So either the factory messed up the label or someone put the wrong one on later. And maybe the bike was built as they were swapping the double 1980 models for the triples 1981s?

Anyway, I knew I'd need to swap the FD, just wasn't sure about the RD. Quality function and price will win over period correct when it comes to swappng parts.

jamesdak 

Thanks, lots of good info and looks like I need to figure in lower gearing than I thought. No problem with that.

It's just a shame that Shimano is so ugly now days. While I'm not normally about looks modern Shimano's appearance always makes me look elsewhere even though I'm sure it's fine gear.

fietsbob

People have done 27" to 650 B conversions , you do need longer reach brakes to get to the Rim.

Few small towns will have tires , though because the new thing in MTB is "27.5" which is for inner tubes close enough.

HTupolev

27.5 and 650b are the same thing.

fietsbob

My LBS will only have Knobby Off road tires, & may Be typical.. No road 650B, so I'm saying, Bring a spare tire with you ..




./.

ironwood

You will probably need long reach brakes. Weinmann or Dia-Comp 750s (centerpulls) should do it, But long Tektro side pulls could be short by 2mm. Measure very carefully to be sure.


A 46 30 teeth double crank might be enough. IRD makes one, the Defiant. You can get a lot of combinations with a TA copy such as the one sold by VO or the Sun Race imported by Merry Sales.


If you are worried about finding a replacement tire or tube, you can carry a spare folding tire and tube.


Some old front derailleurs might be able to handle a triple with a 46 or 44 teeth large ring.

bradtx

jamesdak, The gearing on that bike reflects it's loaded touring role. Something with a 23-103 GI range, like my 7S touring bike, should be pretty close to what you'd use in the role you described for your Fuji.

Shimano mountain bike derailleurs aren't exactly graceful looking...

Brad

Sharpshin

Hope these are helpful...








9 speed cassette w/original friction shifters and Suntour derailleurs.

In the photo that's a 20 tooth granny, worked fine in Texas. On 20+% grades in the UK it began to skip, turns out once the chain settled in under load I hadn't ground enough clearance for the chain on the chainring mounting points and mounting bolts, so I switched back to a 22 tooth.

There was no problem going from 27" wheels to 700c, the brakes had enough adjustment.

With a nine speed cassette the chain does rub slightly against the chainstay on the smallest cog (12 tooth) in back, no problem when riding as I simply don't use it. With an eight speed cassette this doesn't happen. I went to a nine speed to get that 36 tooth sprocket on an inexpensive cassette. I have not found nine speeds to be any problem at all with friction shifters, if anything its easier because there is less dead space between gears. I will say I really like the downtube shifters, feels like the short cables give a really positive feedback making slight adjustments easy.

The crankset is actually an inexpensive Bike Nashbar Mt Bike triple (44-32-22). When putting everything together I never really thought about looks. I ended up with a sorta grey and dark bike.




Mike

jamesdak 

Ok, just an update on this post to share where I'm at and where I'm going with it.

So decided on some 36 spoke 650b Velocity Atlas rims laced to some Shimano hubs. For now I've got a Shimano 11-30 cassette coming that will let me use this with the existing drivetrain until I upgrade to a more touring friendly setup if I decide that is still how I want to go. I've got Panaracer Col de la Vie tires coming for now to use for the fall dirt road riding. I'm hoping to go to a more supple and wider compass tire once I sort the whole thing out.

I'll be switching over to Dia-Compe Centerpull brakes and have ordered in all the mounting hardware and such for them. Still deciding on what to do about the levers, keep what I got or upgrade. The current setup has no hoods which is an issue.

Once I get everything in and mounted up I'll decide on fenders and such. Then over the winter I'll sort out the new drivetrain if I go that route still.

I did get this out last week as it's currently setup for a 25 mile ride. It was quite nice and easily went up a short but steep climb with the current gearing. I just wouldn't want to do that loaded though.

What are everyone's thoughts on these for a front setup? Not classic looking at all but I have a Wickwerks 53/34 setup from them I'm running on one of my road bikes and the shifting is totally amazing with a standard FD. Just wondering if the "improvement" in shifting would be worth it from those more versed in touring.

https://wickwerks.com/products/mountain-triple-443322/

Chris Pringle

For touring purposes, the gearing is perfect. Aesthetically speaking which seems to be a major concern on your part, I don't think it is an improvement from the Shimano M590 that was suggested before, IMO. These actually look even more out there in design. The M590 crankset is really popular among bike tourists because it is quite inexpensive and it shifts really nicely right out of the box.

Did you decide to go with a 9-speed drivetrain? Both the Shimano and Wickwerks chainrings are rated for that.

jamesdak 

Well if I do decide that looks aren't that important and decide to go ugly then I'll probably do the Wickwerks. I know the owner and he's helped me on a lot of projects. So I could run his triple and give him feedback I guess. Like the road setup I'm running for him.

I'm not certain on the 8 or 9 yet. I want to research more on all of this.

For road riding I have everything from friction shifting 5 speed to indexed 6 and 7 up to a couple of modern Campagnolo 11 speed setups. In all honesty except for long climbing rides my averages stay around the same no matter what I take out. So I just wonder how much difference on a light tourer with a triple will it make whether it's 8 or 9 speed?

Chris Pringle

Speak with your friend at Wickwerks about his opinion on using his chainrings on 8 vs 9 speed drivetrains. This might sway your decision on what to choose for your build.

bradtx

jamesdak, I experimented with my distance roadie carrying a max. 20 lb. load last year. It has a ~32-100 GI range that worked well. It uses a 30-42-52T road triple with a 14-25T 9S cassette. A good combo for trimming headwinds. I mention this because initially the small MTB crank set looked odd to me on what is basically a roadie (Oddly it looked fine to me once I had the adaption of my rear rack figured out and installed, go figure.). Just a third option to what I've already posted that I've found to work, at least for light loads.

Brad

jamesdak 

Well to be honest it will come down to whether I stick with friction shifting or go indexed....