Big Dummy, Big Appleas and Cranks

[santiago]

I have an 18" Big Dummy sitting at my LBS waiting for me. Originally I was going to transfer a fair amount of parts off of my hardtail mountain bike but decided that instead of stripping that bike to a frame I could leave as much on it and give it to my brother.

What that means is that I will be purchasing new cranks and would like some clarification on cranks and running wide Schwalbe Big Apple tires.

Specifically my plan was to go with the 2.35" Big Apples but the Surly Blog posting on the Big Dummy (http://www.surlybikes.com/spew19.html) states in the Cons section, "There is more potential for the chain to hit your rear tire when in the low gears. Select a square taper crank and bottom bracket so you can get a longer bottom bracket spindle to accommodate for this".

I was hoping to go with an outboard bearing offering from Shimano, something like an LX model but wondering if I should heed the warning on the Surly Blog.

So, what are your thoughts, opinions and experiences regarding the above? Should I got for a slightly narrower Big Apple? Should I look for a square taper crankset or stick to my plan to use an outboard bearing Shimano crank?

[jimisnowhere]

I think a mountain crank on a square spindle will give you ample clearance. You may wanna post this ? on the Mechanic's forum though. They'll know more about spacing issues.

[santiago]

I think a mountain crank on a square spindle will give you ample clearance. You may wanna post this ? on the Mechanic's forum though. They'll know more about spacing issues.

My LBS got back to me and told me that the only square-taper cranks he's aware of are low-end stuff, single speed or pricey Middleburn cranks.

I told him to go with the LX cranks as none of those options fit what I was looking to do with the build. I'll come back to share what this actually means.

[CaptainCool]

I wouldn't worry about it, personally. Nominally, 2.35" tires are only 1/8" closer to the chain than the 2.1" tires the Big Dummy was designed for. The Big Apples are smooth, so they shouldn't grab the chain, and in bottom gear you should be moving under 5mph anyway.

[dwainedibbly]

I think the Shimano UN53 (or is it the UN54?) BB is still available.

[dwnptrl_777]

Santiago...are you running a traditional external drivetrain on your BD?

[santiago]

Santiago...are you running a traditional external drivetrain on your BD?

Yes - Shimano LX front derailleur and a SRAM X-7 rear derailleur paired with SRAM X-9 triggers.

[ong]

I'm just using the Shimano UN54 square taper BB and some beat-up old square taper cranks I got off eBay for like $10... Specialized something-somethings (insert tough-sounding but meaningless product name here). They work fine, and there is a ton of clearance for tires -- could easily run a 2.4".

[Lamplight]

My LBS got back to me and told me that the only square-taper cranks he's aware of are low-end stuff, single speed or pricey Middleburn cranks.

I told him to go with the LX cranks as none of those options fit what I was looking to do with the build. I'll come back to share what this actually means.


Sugino makes some great square-taper cranks, fwiw. I have a forged set on my bike that I got for less than $60.

[ong]

Yeah, the Riv people love Sugino cranks -- even the pretty nice ones are only about $90.

[AsanaCycles]

im using a shimano square taper with a 118.5mm spindle, and Truvativ cranks.
i had a set of Maxis Holy Roller 2.4's and the chain did hint to rub. if your pedal stroke was smooth and the chain tension was even, it didnt rub. its when the pedaling was "stomping" like... when the chain would slack a bit, then it would wonder a bit and rub the tyre.

a lot better than the Cdale convert job i was using with the FreeRadical. it had plenty of chain rub issues.

peace...d

[IXXI]

The Big Apple 2.35's have been without issue on my Big. Am running the stock build from Xtracycle.

[vik]

My LBS got back to me and told me that the only square-taper cranks he's aware of are low-end stuff, single speed or pricey Middleburn cranks.

I told him to go with the LX cranks as none of those options fit what I was looking to do with the build. I'll come back to share what this actually means.

I use a Shimano Deore MTB crankset [$45] and square taper BB [$25] on my Thorn touring bike. Deore may be pretty low on the Shimano food chain, but it works great, is inexpensive and easily replaceable should it need repairs.

[Doug5150]

Specifically my plan was to go with the 2.35" Big Apples but the Surly Blog posting on the Big Dummy (http://www.surlybikes.com/spew19.html) states in the Cons section, "There is more potential for the chain to hit your rear tire when in the low gears. ...
It is true that on many bikes while in the granny/big cog combo, the chain will rub on 2.35 Big Apples, some will not shift onto the big cog at all. Most bikes can use the 2" Big Apples without incident.

Also I have seen that it is difficult to find lightweight/plastic fenders that really fit over the Big Apples well. The width of the fenders is not the problem--it's the radius that the fenders are formed to.
~

[invisiblehand]

It is true that on many bikes while in the granny/big cog combo, the chain will rub on 2.35 Big Apples, some will not shift onto the big cog at all. Most bikes can use the 2" Big Apples without incident.

Also I have seen that it is difficult to find lightweight/plastic fenders that really fit over the Big Apples well. The width of the fenders is not the problem--it's the radius that the fenders are formed to.
~

Interesting observations. My first guess would be that the standard MTB chainline of 50 mm should be more than wide enough to avoid the wide Big Apple.

Let's see ... working this out as I am typing ...

the 2.35" Big Apple has an ERTO size of 60-559 which should mean the the outside of the tire will be about ~30 mm from center.

granny ring should be at 45 mm

I read that the right flange is 22.05 mm from center on a Deore LX rear hub with disc brakes. Anybody have a rear wheel handy that can measure the distance from the right flange to the center of the big cog? The center to center distance from one cassette cog to another is 4.34 mm according to Sheldon (http://sheldonbrown.com/speeds.html).** Of course the chain has width too.

Given the long stays of the Big Dummy (~830 mm) the chain should be at approximately 5/12 - 1/3 the lateral difference from the centerline from the big cog to small chainring. I guess that max width of the tire occurs at 559/2 + 30 mm from the center of the rear hub.

Now it looks pretty reasonable that chain could rub against the tire and that the extra 5 mm of the "narrow" Big Apple would make a difference. Particularly if one allows the Apples to vary in width from the ERTO specs.

[invisiblehand]

Also I have seen that it is difficult to find lightweight/plastic fenders that really fit over the Big Apples well. The width of the fenders is not the problem--it's the radius that the fenders are formed to.
~

Does that mean the tires need fat fenders for a 700c wheel?

[Lamplight]

I used 2.35 Big Apples on my commuter breifly with Freddy Fenders and had no trouble. 60mm Berthoud fenders also seem to be adequate, though with either it's going to be close, of course.

[Doug5150]

Interesting observations. My first guess would be that the standard MTB chainline of 50 mm should be more than wide enough to avoid the wide Big Apple. ...
I have a couple bikes (Cycle Genius Falcon and RANS Fusion, neither of the MTB's) and the chain rubs the 2.35" on both of them.

The rims on these bikes are wider than the usual 1-inchers--the first bike has Sun BFR rims that are about 30mm outside width, and the second bike has Mavic EX 325's that are about 32mm wide. I measuered the tire width with some dial calipers (on the 30mm rims) and the tire measured 55mm wide. *

Both these bikes also use road triples, but then, they have very long chainlines so the extra width of a wider crank set wouldn't help as much as on a normal upright bike frame.

Considering what the Big Apples cost, it is wise to either test-fit them or to measure very carefully if you use your shortest gear combo much--or if you just want a bike that functions perfectly.

------

*If you want to run fat tires, it's highly beneficial to get some wheels built with wider rims as well. The 2.35's should only need 30-35 PSI of pressure at most.
~

[Val]

As for the fenders, I recently discovered that the Planet Bike Cascadia 29" fenders fit the Big Apple perfectly - just the right amoungt of added radius, 65mm wide, and nice long mud flaps. Inexpensive, too!

[invisiblehand]

Interesting. So there are road cranks on both then? OK ... that would pull the chainline in ~5 mm.

But yes, once I started putzing with a few figures, it isn't too hard to imagine the chain rubbing.

Personally, I am fairly unfamiliar with wide interior width rims; although I have seen Sheldon's page (http://www.sheldonbrown.com/tire-sizing.html). What are good options in ERTO 559 and 622 sizes (26" and 700c)? The only one that I have only heard of with a lot of feedback is the Sun Rhynolite. I believe it is available in both sizes.

By the way, does anyone think that there is much of a difference between the 50, 55, and 60mm wide Big Apples?

I have a couple bikes (Cycle Genius Falcon and RANS Fusion, neither of the MTB's) and the chain rubs the 2.35" on both of them.

The rims on these bikes are wider than the usual 1-inchers--the first bike has Sun BFR rims that are about 30mm outside width, and the second bike has Mavic EX 325's that are about 32mm wide. I measuered the tire width with some dial calipers (on the 30mm rims) and the tire measured 55mm wide. *

Both these bikes also use road triples, but then, they have very long chainlines so the extra width of a wider crank set wouldn't help as much as on a normal upright bike frame.

Considering what the Big Apples cost, it is wise to either test-fit them or to measure very carefully if you use your shortest gear combo much--or if you just want a bike that functions perfectly.

------

*If you want to run fat tires, it's highly beneficial to get some wheels built with wider rims as well. The 2.35's should only need 30-35 PSI of pressure at most.
~

[tim24k]

Specifically my plan was to go with the 2.35" Big Apples but the Surly Blog posting on the Big Dummy (http://www.surlybikes.com/spew19.html) states in the Cons section, "There is more potential for the chain to hit your rear tire when in the low gears. Select a square taper crank and bottom bracket so you can get a longer bottom bracket spindle to accommodate for this".

I was hoping to go with an outboard bearing offering from Shimano, something like an LX model but wondering if I should heed the warning on the Surly Blog.

So, what are your thoughts, opinions and experiences regarding the above? Should I got for a slightly narrower Big Apple? Should I look for a square taper crankset or stick to my plan to use an outboard bearing Shimano crank?

I had the LBS set my Big Dummy up with 2.35" Big Apples and with Deore LX crank. It works great! No chain tire rub at all. I still have about 3 mm clearance left.

[Lamplight]

By the way, does anyone think that there is much of a difference between the 50, 55, and 60mm wide Big Apples?

I have a bike with the 50mm and another with the 60mm, I didn't know there was a 55mm as well. Between the 50 and 60 there is plenty difference. The 50mm look downright puny if one has been riding the larger tire for a while. Overall I think I've come to prefer the 50mm size, as it seems like it's just easier to keep the bike moving for some reason. I don't pretend to understand all the aspects of rolling resisistance, but when I'm riding the 2.35" tires it seems to be harder to keep the bike moving even with 50 or so pounds in the tires. The larger tires are fun, though, as it feels like you can run over just about anything in your way. :D

[dwnptrl_777]

I have a bike with the 50mm and another with the 60mm, I didn't know there was a 55mm as well. Between the 50 and 60 there is plenty difference. The 50mm look downright puny if one has been riding the larger tire for a while. Overall I think I've come to prefer the 50mm size, as it seems like it's just easier to keep the bike moving for some reason. I don't pretend to understand all the aspects of rolling resisistance, but when I'm riding the 2.35" tires it seems to be harder to keep the bike moving even with 50 or so pounds in the tires. The larger tires are fun, though, as it feels like you can run over just about anything in your way. :D

Is the width of the Big Apple tire shown on the actual tire?

[Maxwell]

My big dummy's chain was rubbing on my PB fenders, the notch wasn't high enough, but no tire rub.

[tim24k]

I have a bike with the 50mm and another with the 60mm, I didn't know there was a 55mm as well. Between the 50 and 60 there is plenty difference. The 50mm look downright puny if one has been riding the larger tire for a while. Overall I think I've come to prefer the 50mm size, as it seems like it's just easier to keep the bike moving for some reason. I don't pretend to understand all the aspects of rolling resisistance, but when I'm riding the 2.35" tires it seems to be harder to keep the bike moving even with 50 or so pounds in the tires. The larger tires are fun, though, as it feels like you can run over just about anything in your way. :D

My Big Dummy with 2.35 BAs rolling resistance is is vary low with 60psi in them. And they seem to handle best with that psi in them.

I have SKS fenders and no chain rub. But they are a little short in the back, DRATS!

[invisiblehand]

Is the width of the Big Apple tire shown on the actual tire?

I'll check when I get home. Although, my Big Apples are on a 16" wheel folding bike.

[Lamplight]

Mine do have the size on the sidewall: 26 x 2.0

[flatboarder]

Using a narrow 103mm square end BB (Token) with TA Specialites Vega Crankset and some Shimano Alfine internal gear hub (narrow chain line: 42mm), in combination with Schwalbe Fat Frank 2,35" tires there is plenty enough chain clearance. It is hard to see here (http://home.pages.at/flatboarder/big/bd2.jpg), probably a bit better here (http://bla.obda.net/wordpress/wp-content/top.jpg). In my opinion there is no problem at all.

[invisiblehand]

I'll check when I get home. Although, my Big Apples are on a 16" wheel folding bike.

The size is on the side of my tires too.

[AllenG]

Is the width of the Big Apple tire shown on the actual tire?

Yes.

I originally bought 2.35 inch Big A's for my bamboo bomber, but ended up running 1.95 inchers for better clearance. They are so marked on the sidewalls.

[Giro]

There is also an intermediate size Big Apple, at least in the 26"/559 size. It is not the easiest to find but both the Schwalbe North America web site and Every Bike Tires lists them. The Schwalbe site also has a fairly extensive section on tire dimensions, some specific to the Big Apple LINK (http://www.schwalbetires.com/tech_info/tire_dimensions).

I can verify that the 55mm 26"/559 Big Apple mounted on a 24 mm inside width rim (Alex DM-24) and inflated to its mid-range pressure measures almost exactly 55 mm wide on my vernier calipers.

[noriel]

I'm running an 8speed XT drive train with my Xtracycle and I do get some rub when I get on the granny gear with my 2.35 Big Apples on Sun ditchwitch rims.