byrd48

Hi,
I have an older road bike, 80's era with square taper bb. It's geared 42/52 up front and 14-28 in the back, which is fine for most riding, but there are some hills around where I would need to stand up in this configuration. Furthermore, I would like to move from 170mm crank arms to 165, which from what I've read, is the right size for me. The rear end dropouts are not wide enough to bump up to a modern cassette with lower gear ratios, so I'm focused on the front end.
Thus far, the only crankset I've found that offers square taper, 165mm, and lower tooth count chainrings is the low wide model from Sugino. For $140, you can get it with 165mm crank arms, but the chain rings are 26 / 40. The 40 as an upper range would probably be ok, I would be coasting a bit, however the 26 might be a little low. So I looked at other chainrings (rivbike.com) and they offer a 74x32T for the low, but then I'm getting close to $200 for the crankset on a bike I will not ride all that often.
So my question is this: is there a company that will let you specify a crankset where you pick your crank arm length, and the tooth count on each chainring?

And for another question, I'm considering replacing the triple crankset on my mountain bike with a Sugino triple with 165 crank arms. At some point, I'm looking to build out a new bike with a touring or cross frame, like a Soma Soga, LHT, etc., but I'm looking to buy some of the drivetrain gear now and update my current ride to test it out so to speak, as opposed to ordering a frame and entire kit which will be close to 2 grand. I have noticed most current bikes have splined bottom brackets and cartridges. If I get the Sugino, which is square taper, will that limit me to any frame I may purchase in the future? Or will it just mean that for whatever frame I buy, I'll need a square taper bottom bracket? I mention this because I've seen Shimano compact doubles with 165 crank arms, but they are mostly 39 / 50, which is a bit high for me.
Thanks in advance.
Jon

TallRider

get used stuff. I have two 165mm cranks sitting around (both triples with 110mm outer bolt circle, if you want to run a 46/34 or 48/34 double chainring setup).
The vast majority of frames produced today work fine with square-taper cranks. No worries for you there.

byrd48

Thanks, I looked on Ebay and found a Sugino triple, but it was an odd combo, something like 26, 44, 48. Also, I'm hesitant to go with chainrings more than 10 teeth apart. Do you have experience with chainrings that far apart? Seems like the shifting would be even slower than a 10 tooth.

Jeff Wills

165mm arms, square taper, 26-36-46 chainrings, $150: https://harriscyclery.net/product/sug...r1029-qc49.htm
Talk to Harris about your requirements. They may be willing to swap larger middle and outer chainrings for a nominal charge.

Jeff Wills

The triple on my day-to-day bike is 24-42-52. The jump from the 24 to the 42 is large, but it's never failed to shift. I tend to stay in the middle chainring for most riding, dropping to the granny and spinning up really steep slopes. I don't use the granny often, but when I need it, I need it.

TallRider

message me if you'd want either of my 165mm triple cranks. I have steel chainrings sitting around but not aluminum, and not necessarily in the sizes you'd need. But it sounds as if your best bet is to go with a "compact double" drivetrain, like a 46/34 or 48/34.

Bill Kapaun

I stuck the triple off my 86 Rockhopper on to a 73ish Takara road bike.
Friction shifters made it easy to do.

HillRider

Many stock cranks have chainrings more than 10-teeth apart. A common double is 53/39 for a 14 tooth difference and Campy's older triples were 53/42/30 with an 11 tooth followed by a 12 tooth gap.

In fact, most current front derailleurs cannot be properly used with a smaller than 10 tooth gap since the inner cage plate is too deep to clear the middle ring if positioned correctly over the outer ring.

My current triples are either 52/42/26 or 53/42/26 and, as Jeff Wills also said, they shift fine even from the granny to the middle ring.

TallRider

Depending on the crank, you may or may not have to get a different spindle-length bottom bracket so that the chainrings sit at proper distance from the bike's centerline.
If you go for a triple crank, you'll probably need to replace both derailers. The rear will need a longer swing-arm to deal with greater possible range of chain-slack, and the front will need to have a longer cage as well.

fietsbob

many people like this triple crank ..

https://www.universalcycles.com/shopp...24&category=64

Oh, thinking alike, Jeff linked to the same part, through a different seller.

Jeff Wills

Oh, funny... both Harris and Universal are dealers for QBP, so it's possible the OP could get the same crank from his LBS. I was suggesting Harris since they might be more willing to swap chainrings. Maybe.

I usually go to Universal Cycles since they're local to me, and I can visit their cats:

gerv 

If on a budget and able to live with 170mm and a steel middle ring, Ben's has the XD-350 for $85.

Jeff Wills

The OP was looking for 165mm arms. But Ben's still has a good deal, with better "standard" chainrings to boot:
https://www.benscycle.net/index.php?m...roducts_id=695

FastJake

Depending what model Schwinn you have, I would go used and save money. Once you know what you need you can search ebay for deals. Unfortunately 165mm cranks are quite a bit harder to come by. A quick search pulls this one up as the cheapest, it is new actually, at $60: https://www.ebay.com/itm/FSA-Vero-Tri...item19d9b122ff

If there is a bike co-op around you go there and look. They should have tons of parts, but again good luck finding a decent triple in 165mm.

Also realize that you can swap chainrings if you decide you aren't happy with what comes with your crank.

jrhii

how many rear sprockets to you have? If it is 6 or 7, you should definitely be able to find a freewheel like this one, which has a nice 34t bailout gear that will help you out, and it is super cheap. Chance are that shifting will be much smoother with the hyperglide freewheel, too.

https://www.amazon.com/Shimano-MF-TZ3...9287470&sr=1-2

byrd48

Hi
I ended up finding (for my mountain bike) a Sugino XD600 for $96.00. My current triple is 170mm with 28/38/48 and the new one is 165mm with 26/36/46. Using Sheldon's formula for gear inches with crank arm length, it looks like I will achieve a slightly (maybe not noticeable) lower gearing, even with the shorter crank. So I'm going to try that first, then think about the Batavus. When looking at cranksets and crank arms, I don't normally see a spec for q factor or spindle length. From my limited understanding, on a triple, the big and middle ring bolt to each other through the crank arm and the granny ring bolts to the middle ring. So if I elected to go with a triple on the road bike and convert it to a double, I presume I could use the granny and middle ring and replace the outer ring with a chain guard or just use spacers in the bolt to leave it as is? But then the spindle may not be long enough?
My rear sprocket count is 6, and it's a stretch, I think it was originally a 5 speed, but the wheels were stolen from it back in the day and I replaced them last year with vintage Weinmann's off Ebay. I have to pull both the rear dropouts and the front forks apart slightly to fit the wheels in, I'm not sure why, they seem to be close enough of a fit for the frame size, I did not have to cold set the frame or forks, but they seem to be maybe 2mm too narrow for the wheelset. I did see the megarange type freewheels, but I'm thinking I will leave the rear end alone. And frankly, from an aesthetics point of view, I don't want marketing logos on my cogset
So as it stands, it looks like the Sugino low wide double from rivbike is the only option I'm finding.

byrd48

I suppose if I went with a triple as I described above, and the spindle was not long enough, I could just replace the bb?

byrd48

That's a happy cat you have there! One of the volunteers at our local co-op rides his bike there with a basket on front that he keeps his cat in. He parks the bike inside and opens the basket lid, but amazingly, the kitty stays in the basket all night, even though others bring their dogs. I have 4 cats myself, but have not yet considered travelling with them on my bike

Jeff Wills

No. On the Sugino XD cranks, the outer and middle bolt to the larger bolt circle (110mm diameter) and the inner ring bolts to a separate bolt circle (74mm diameter). If you want to make it a "low wide double", you would take the outer chainring, put it where the middle chainring is currently, and bolt it together with shorter "single chainring" bolts. This is how the Rivendell crankset is configured. This setup uses the same bottom bracket length as the triple.

FWIW: here's the crankset you're referring to: https://www.rivbike.com/product-p/cr7.htm. The chainring guard takes the place of the outer chainring.

Jeff Wills

That cat belongs to Universal Cycles. They have 8 or 9 that they foster at the shop, but only a couple wander the sales floor. Here's another:



You can see my two furry housemates in this thread: https://www.bikeforums.net/showthread...Pumpkin-update

byrd48

So my Sugino came in the mail today. I went straight to the co-op after work to install it. I knew my bottom bracket was square taper, so I thought since the Sugino was square taper, it would be plug and play. As it turns out, after I installed the Sugino, I had to move my front derailleur almost half an inch towards the outside of the bike. While I was doing the swap, I realized I needed to work on the bottom bracket as it was not turning smoothly. When I took it apart, the races were pitted. The co-op has a bike shop in the same building, so I asked them if they had a bottom bracket I could buy. What they had was an 118mm cartridge style bracket. So I took that to the coop and we compared the new bracket to the old spindle. Both were 118 mm from the end of the tapers, however the old spindle has male threads at the end of the tapers and the cartridge model had female threads inside. No problem, as the Sugino came with male bolts for mounting, however as we looked at it, we realized that although the spindle lengths were the same, the old spindle was longer on the drive side, while visually, the new cartridge appeared to be the same length on each side, so ultimately we decided not to go with the new bb for fear it may not work. So I found another used spindle from their parts bin with smooth races and put everything back together. Now, as I mentioned before, I had to trim the FD about a half inch to the outside of the bike and the granny ring seems to be inline with the 2nd or 3rd cog in the back, so it seems the new chainrings are too far out. There is at least a half inch between the crank set and frame, so I'm thinking I may be able to go with a shorter than 118 bb. I'm not sure how to measure the width of the cranks themselves, perhaps the Sugino is narrower overall than the old Altus C-20 it replaced. I'm not commuting again until next Tuesday, so I hope to have it fixed by then. My options appear to be:
1- go with the new bb from the shop by the co-op and replace it myself on Saturday and hope it works.
2- find a bb I know will work, and take that to the co-op, assuming I can find it locally, and I don't know exactly how to determine which bb I need.
3- take the bike to the lbs tomorrow and ask them to fix it.
What do I need to know when choosing a bb that will work with the smallest q factor?

Thanks much,
Jon

Bill Kapaun

Flip the spindle.

byrd48

Won't that put the other crank farther out? I looked around a little and found a post where someone used a 110 bb on a Long Haul Trucker. So I'm thinking either a 110 or 113 should work. I'll call around tomorrow and see what they have locally.

TiBikeGuy

Way back in 1993 when I was building up my Cannondale Hybrid, I was using an XT crank that has 26-36-46 teeth. I found that I often max out on the big rings so I searched and found a Sugino road chainrings of 50t and 40t. Back then, some mtn cranks can use road chainrings. So far, my 26-40-50 teeth set-up has worked fine.

fietsbob

80s Shimano M730 .. 110/74, have a touring 50,40,24, & a single 38t used w R'off hub.