Transmission database - for all your crank / bb / bottom bracket questions

The original BB being asymmetric does complicate things.

The DS was 30mm, so in theory a symmetrical BB would be 114mm for a 43.5mm chainline (between the chainrings).

So 111mm should be close if you were to put the ring on the inside: is that possible with these cranks?

If you do need 109mm then I think Victory or Triomphe also used that, although they aren't much easier to find than Pista.

I'd be tempted to use a 107mm UN55.

The inner ring on these cranks mounts onto the outer ring using separate bolts and spacer rings, and therefore there's no 'inner' position on the crankset. You've also got the problem that the chainring mounting bolts sit about 1mm inwards of the spider, as they're not recessed.

Whilst I don't really want to use a JIS BB, it does sound like your suggestion of using a 107mm UN55 might be a good one. I'll still have a go with the Campag 111mm one first (when my Campag cartridge BB installation tool comes in the post).

Thanks again for your help and suggestions.

OK, so I did a little bit more measuring last night.

Whilst I couldn't fit the 111mm Campag cartridge bottom bracket fully into the shell without a proper tool, I could spin it in by hand, leaving a 3mm gap. With the crank installed on the axle, this gave me a chainline of 46mm, suggesting that with everything torqued down properly, I'd end up with a chainline of 43mm with this BB

So.... to get it down to 41mm, this would suggest I'd need a BB that was 4mm shorter: i.e. a 107mm ISO. St. Sheldon suggests that using a JIS one would leave the cranks 4.5mm outwards of where they'd be with ISO, so I'm not sure a 107mm UN55 would indeed work.

Miche used to do a 107mm ISO BB, which as a bonus was adjustable, but the more recent incarnation is JIS, with a flange on the RHS cup, so not adjustable. These days, this seems to be the only suitable BB I can find: http://www.totalcycling.com/en/gb/Kinex-ISO-Taper-Bottom-Bracket---107mm-Eng-Thread/m-18081.aspx

St. Sheldon suggests that using a JIS one would leave the cranks 4.5mm outwards of where they'd be with ISO...

Don't make me summon Tester!

In short, the difference between ISO and JIS, is the way they're measured: ISO from end-to-end and JIS from before the start of the 1mm taper.

In other words, 111mm ISO is the same as 109mm JIS.

Are you questioning the word of Saint Sheldon? You heretic!

OK, so if you're correct, then a 109mm ISO would give the same chainline as a 107mm JIS. By my measurements above then, I'd end up with a 42mm chainline with a 107mm JIS, which would still be a tad too much. Ideally, I'd want a 107 ISO, which would translate to a 105mm JIS, which as far as I know is unobtainable, or a 103 JIS with a spacer.

What a minefield!

Well Sheldon's dead, so I fancy my chances of winning an argument with him, rather than Tester...

Different cranks?

#justsaying

Different Cranks?

No - I've got my heart set on these now, especially since I've just got hold of a TA 1/8" track chainring to fit. The frame is early 70's, so they'd look the part, especially with the 27 x 1/1/4 Weinmann Alesa wheelset. I've had the crankset in my parts box ever since I wore them out riding my old Legnano in the early 90's, which is long gone.

I'm just about to hit the 'buy' button on an old stye Miche Primato 107mm bottom bracket which has the adjustable cups, and pray to St Sheldon that it'll work:
http://www.ebay.co.uk/itm/Miche-Primato-Track-Bottom-Bracket-/171992398650

Miche Primato 107mm bottom bracket

I'm pretty sure that Miche switched between JIS and ISO (or the other way around): it's something that crops up quite regularly (probably in this thread): that could be a JIS 107mm...

Ah, but if it's got the adjustable cups (as shown in the picture, and in the text), then the chainline can be adjusted by 1-2mm either way.... apparently. They used to be ISO with adjustable cups, but are now JIS with a flanged RHS cup. I'm hoping that these guys on eBay have stock of the old ones. Here's a close up of the same stock photo, where you can see 'ISO' written on the shell:
http://www.sjscycles.co.uk/images/products/medium/18665.jpg

OK, so it doesn't look like anyone actually has any of the old style Miche Primato BB's in stock. I've measured the cranks on a 107mm JIS, and the chainline is 44.5mm. What I'm therefore going to do is to get a 103mm JIS, giving a theoretical chainline of 42.5, but nipping it up super tight on the RHS. If I get a cheapo one with plastic cups, I'm guessing that there will be 1.5mm of 'give' in the flange to pull the chainline in by 1.5mm, or I could even file down or cut off the flange if need be. A cheapo one won't break the bank either, if it doesn't work.

Thanks again for all your help and suggestions. Picture of the crankset here (fitted on an old Mavic threadless BB that's far too long). Hopefully, the work to get them to fit will be worth it:

Omnium only have one length BB - 24mm stepdown GXP BB for 68mm

Some time ago I posted a question about a new Campag Veloce bottom bracket not feeling consistent through the pedal stroke. Fairly subtly but noticeably, part of the stroke feels what I can only describe as sticky or gloopy.
So I finally removed the chain and gave it a spin and it seems to spin smoothly enough except it is very quick to settle in one position, as though there is relatively significant weight to a part of the chainset. I tried this on another bike and although it does settle at one position, it's not as noticeable.
I don't really know how unbalanced chainsets are an how much they differ, but definitely does not feel right. It's all 10spd new Veloce.
Could this be my issue, any other ideas? Thanks!

I ended up taking this to the LBS. They said that it's the most stuck BB they've ever come across. It's been sent to Winston Vas to be melted out. It's being shot blasted while we're at it. The paint around the BB will be screwed anyway. I hope the GF appreciates this!

Just to update the thread, my wanted advert on another forum came up trumps. I can confirm that an SR Royal 106mm ISO BB gives me a 41mm chainline with this crankset: within 0.5mm of where I want to be, which is good enough for me!

What are my choices for an italian bb for use with sugino 75s?
Campag centaur?

Driving myself crazy here..

I recently bought a frame with a 65mm Italian threaded shell and I can't seem to find a bottom bracket anywhere (apart from possibly an old campag record pista?). I initially fitted a standard 70mm bb but there's obviously overhang on the NDS, which I'm sure could be remedied with a locknut and spacers; problem there is that for some reason I can't seem to find Italian BB spacers (36mm dia?) anywhere.

I'm hoping that my lack of BB knowledge isn't helping but this is making me even more grey at the temples so any help would be much appreciated!

a 65mm Italian threaded shell

Sorry I can't help, but I'm curious as to how it ended up losing 5mm.

Have you checked the crank clears the chainstay? You might need to spacer both sides.

Is the shell still centred, ie has the shell been trimmed equally on both sides?

I could be wrong but as it's an older, Italian made frame - this Waja frame to be exact - it's just how it was made as it is equal on both sides; again, that's just an assumption through a few sites I've been on so feel free to correct me if I'm wrong.

I think you're right, I'll probably have to space both sides but I've searched everywhere and can't find any spacers that will fit an Italian BB, apart from some custom made ones from the US but I was hoping to get some a little closer to home

107 JIS miche BB + Sugino Grand Mighty track + Miche Primato hubs with Miche cog/ring = Chainline fine (on Balk track frame)

107 JIS miche BB + Sugino Grand Mighty track + Novatec track hubs with fixiesupermarket (ebay) cog/ring = Chainline fine (on Balk track frame)

DO NOT buy Token 111 ISO bb it sits a mile out... Centaur 111 does work
(tx to @umop3pisdn)

Database left me at a loss. I've inherited a Shimano exage 500 ex crank set as my suginos messangers are dead. The shimanos are 170mm long and doubles I believe. They don't mount on my current bb which is 103mm.
I cant find anything anywhere to tell me the correct bb to swap into the mix to get a 42mm chainline and avoid hitting the chainstay.

Can anyone help me? Thanks

You need to find out what BB your cranks originally took and work back from there: try searching for the model number (on the back of the cranks "FC-*****").

With the correct BB, the inner ring will have a chainline of 41mm and the outer, 46mm.

Assuming you want to use the outer ring position the new BB needs to be 8mm shorter: 46mm - 42mm x 2 = 8mm).

Velobase can be handy for checking old BB requirements, but your cranks aren't listed. There are a couple of Exage variants though, which took 115mm and 113mm BB.

In which case you are looking for a BB around 107mm.

If your cranks still don't clear the chainstay, then you'll need to use the inner position and recalculate.

Probably already answered, but yes.

Do NOT buy Token ones, they don't sit right :/

I have also used a Miche Primato in 107 but it's JIS, works, but some ppl say don't mix JIS/ISO.

Cool thanks. It looks like the person who previously used the cranks was running it on the inner ring. I might install the arms on the current bb and measure how far they need to come out to not hit the frame as well to be sure that a 4mm increase from what I have now. I might just end up giving up on them and say they aren't compatible with the hub spacing.

Yes that would work too: just make sure they are all the way on and not being fouled by the BB cup.

I have a 107mm Shimano UN-55 going spare: just a few TT miles. Send me a PM if you want it.

I found the model number of the crank set its FC-A500. I only have the inner ring on it 42t.

I found on the Sheldon Brown site

Model BB Chainline BCD
Exage 500X A500 Double 113 Square 43.5 130 7-speed 1990-92

Im guessing the chainline given is for between the 2 chainrings? Or would that be for the big ring?

If so with a 113 would I get 42mm chainline to meet my hub. Would I be working this out correctly??