Trek Bottom Bracket Install help or "Did I put this in backwards??"
 

Well I have gotten this far on another "non-factory/factory looking" Trek project. This was/is a 1983 model 613 frameset that I received in trade from Chalres Wahl. It was originally red and actaully shedding its paint for some odd reason. Anyway, dreams of a "pass hunter" style bike and a small budget led me to Bilenky Cycle works for paint and some braze-ons. JR Restore (from C&V) supplied the decals.

[IMG]http://i91.photobucket.com/albums/k2...ar13/015-1.jpg[/IMG]

I am moving in less than a month and will soon have a C&V house to take up my time and excess project energy.:twitchy: In light of that, I am scrambling to finish my bike related projects prior to 3/10. In that frame of mind, I ordered some parts from Velo Orange including a Gran Cru (house brand ) cartridge style BB. The orignal Nervar spindle was shot and measured 117mm. The VO bb is 116mm.

Please see the pictures and let me know if it looks to be installed backwards. The gap on the non-drive side looks large to me. Is it possible to install this type of BB backwards? I can't remember the last time I used one of these. Thanks!

[IMG]http://i91.photobucket.com/albums/k2...ar13/016-2.jpg[/IMG]

[IMG]http://i91.photobucket.com/albums/k2...ar13/017-1.jpg[/IMG]

Looks like you have plenty of chainring clearance. Did you check to see if one side of the spindle was longer than the other? If one is, that usually goes on the drive side. You might check the size of the ends of the spindle squares, vs the original Nervar spindle. It does look like the left-side crank is too far out on the tapered square.

I read up a bit in Sutherland's, and on the VeloOrange site. The Grand Cru is a JIS-taper spindle. JIS is the "chunkiest" of the standards, meaning that the ends of the spindle are larger than any other type: Campy, ISO or some even smaller (like Stronglight and TA, I think). Sutherland's says that the most compatible spindle replacement for a Nervar is Campy. Campy is smaller than JIS (though it's the closest one to JIS). On a JIS spindle, cranks intended for one with a smaller end will sit further away from centerline than they did on the original spindle. That may not be a problem, so long as there's enough overlap of crank arm to spindle. Generally, it's good to have some clearance between end of spindle and washer seat for the crank bolt, but not 4 or 5 mm. If you've torqued the crankarms, then loosen the bolts again, and see how recessed the spindle end is from the washer seat -- if it looks okay to you, then you may just need a shorter spindle. Otherwise, you might need a Nervar or Campy spindle. I believe that the Suntour Superbe and Sugino Mighty spindles are the same size as Campy, too.

The Trek never looked better. And not that it matters, but it's a 1982, not '83.

That's a nice Bilenky paint job. Did you install the decals yourself? Lovely vintage Trek goodness. I think you may have an asymmetric spindle and just have it in backwards. Happy riding and good luck with your C & V house; I'm on the third round of resto/remodel on mine.

That looks like the removal tooth pattern of a Shimano cartridge BB to me (EDIT: It's a cartridge, just re-read the OP's post). English threading would make reverse-installation impossible.

On a related note, what spindle taper were these TA's designed for?

-Kurt

Charles pegged it: it's a JIS taper on a ISO crank and there's not enough contact due to the mismatch...the crank arm is too far outboard. All you need is to find a BB or spindle with the ISO taper and using your original length of 117 or 116 should get you in pretty close.

Thanks for the replies. Ok, so who has an ISO tapered catridge bb they might want to trade???? 117mm?? Anyone?

Maybe a quick trip to your local bike shop with the original spindle is in order. How were the cups? You can probably find a replacement spindle as long as the cups were fine. Nothing wrong with the older style bottom brackets.

The cups were fine as were the bearings. The spindle was badly pitted. Unfortunately the 4 shops I visited did not have anything/ had no interest in looking for the part. I searched ebay for a couple of days with no luck and posted a request in the WTB/ For trade thread. I actually prefer the older style BB to the cartridge type. I like being able to service it if need be. If anyone can direct me to either a 117mm spindle or cartridge style BB 117mm, ISO taper, I would be grateful.

Those 118mm Stronglight spindles do seem to come up on eBay fairly regularly. Here's a complete BB.

Neal

I'll look through my spindle collection(s) that's right, plural cause they are in 3 different places, and PM you if I have something good.

^
+1 - the Stronglight BB's are the best bargain in ISO spindles presently.

-Kurt

but he says this one^ is French threads, and the OPs Trek is British...could just buy it (or one like it) for the spindle only...and trade the cups to one of us ;)

I was thinking the OP could just use the spindle and trade or sell the cups. That's one of the reasons I have lots of cups without spindles in my parts drawer!

Neal

Here's a cartridge that might work. Comes in 119, and they tell me the taper is ISO.

They're full of it - if the picture is any indication, it is JIS.

-Kurt

you should give me that TA crank for my motobecane. that would solve your problems.

How can one tell if a BB is jis or ISO? If someone can let me know I can check through my spare parts to see if I have one.

Find a known JIS spindle, and butt it up with others until you find one with a smaller flat at the edges. It's trial-and-error, but soon enough, you can train your eyes to spot the difference.

-Kurt

Have you removed a crank bolt to see how much distance there is between the washer flat of the crank and the end of the spindle? Theoretically (ISO standard) there's supposed to be min. 1.5 mm when the crankarm is torqued down. Sheldon Brown's spindle compatibility page says that he mixed JIS and ISO without too much difficulty.
http://www.sheldonbrown.com/bbtaper.html
So what I'm suggesting is that if the distance between spindle end and washer flat doesn't look dangerous to you, like 3 mm rather than 6 mm, and you'd like to stick with a cartridge bearing BB, just buy an inexpensive IRD BB that's shorter than the one you have: measure your current chainline and chainring-frame clearance, figure out how much you'd like to move the crankarm inward, and just get a unit that's twice the difference shorter than the one you have.

If the spindle end/washer flat clearance looks scary, then go to plan B: ISO spindle and loose-bearinged BB.

Charles, Thanks for the tip. I did remove the bolts and the distance is a bit scary. Also when I pulled the cranks off the spindle, they came off with very little effort. I am going to use your plan B scenario. Can anyony tell me if Campy NR is ISO taper?

I have a Nervar spindle in good condition, but it's 121mm...maybe too long...I have a 118 Stronglight spindle but it's in BAD shape..oh well, I tried.
Have you looked at the Miche sealed BB units? I think they are all ISO.

Here are some taper comparisons from Phil Wood (found on this page):

"Phil (JIS) taper"
http://philwood.com/technicalinformation/crank%202.jpg

"Campagnolo taper"
http://philwood.com/technicalinformation/crank%203.jpg

"JIS low profile taper"
http://philwood.com/technicalinformation/crank%201.jpg

Neal

Thanks and I did look at a Miche unit on ebay. I was unable to tell what the taper was and when I have asked a few sellers they are not sure.

Neal,

Thanks for the visual aid. I am assuming that the Campy is ISO, correct? I have a Phil BB but the axel is for a triple and the longest he sells in ISO (I think) is 115mm.

The nature of BB sizing and compatibility is definitely a black art. For one thing, there are "standards," the manufacturing tolerances for which actually may produce articles whose sizes might overlap, in terms of "bigger" or "smaller." For example, Sutherland's notes that the JIS standard spindle end is 12.65 mm, but where that's measured is not specified (you can't measure right on the end of the spindle, which is generally chamfered). ISO standard, in Sutherland's Appendix, is 12.6 mm measured 1.5 mm from the end of the spindle plus 0.02 mm, minus 0.05 mm. Sutherland's betrays a bit of frustration itself:

http://farm4.static.flickr.com/3432/...3396f6b9_o.jpg

So, Campagnolo fits somewhere between ISO (smaller) and JIS (larger). And that's not all Campagnolo, apparently. Phil Wood said (more on this later) that if you had a crank pre-1994, it took Phil's JIS taper, while 1994 and later take the "Campagnolo = ISO" taper.

http://www.philwood.com/index/2008%20Catalog.pdf see page 14 -- it't not in their FAQ for some reason. That page also has the three tapers shown side-by-side. I defy cudak888 to tell them apart visually if we cut off the top part of the photo.

Phil Wood is also a bit strange in that they recommend using a small amount of lubricant on the spindles, saying something like "our tapers are designed for that."

From all this, I infer that Campagnolo changed from their own proprietary taper to the somewhat smaller ISO taper in 1994, meaning that if you get a newer Campagnolo BB, it should provide the right taper for an ISO-sized crank. The problem is finding a longer one that doesn't cost $200.

Given manufacturing tolerances, it's a wonder that anyone can get a decent chainline. Sheldon Brown said that the difference between chainline produced by an ISO and JIS taper is about 4.5 mm. On a 20-degree taper, that translates to 0.16 mm difference in the size of the spindle end. And that is approximately (but a little more than) the difference I measure between a TA spindle, a couple JIS, with a Campagnolo falling between them.

SUCCESS!!!! I picked up a 120mm Campy spindle from a shop far away from my house! Even better the shop owner actually knew what I was talking about regarding ISO/JIS tapers etc.!:thumb: He charged me $25 for the spindle and some genric steel cups & bearings. It has been installed and looks good.

Thank you all for you help.