Mechanics and Fixing Any Questions Answered

https://rec.bicycles.tech.narkive.com/1OIXhKT5/bottom-bracket-for-mavic-631-cranks

Halfway down the page there is a comparison of JIS, ISO & Mavic BB tapers.

Mavic looks closer to ISO.

I have a set of Mavic starfish cranks that I use with a 102mm ISO bb. But it is a singlespeed setup so that doesn't really help you. (41mm chainline)

My guess is a 114mm ISO bb or there about will work for you. (+6mm each side so the large chainring is at 47mm chainline)

Where should the chainrings be at campagnolo 10s? 40-47 (43,5mm)?

The answer to this is to install and check clearance.

Taper wear bugger things up.

Hi Ben, its Dan with the rowdy Columbus Max Somec I brought into BC recently.

Thanks for the offer dude, and sorry to hear you leaving wrench life, I'll miss you from BC for sure you've been great since you been there. Our loss is bankings gain, booo that sounds all wrong....

I've not got either crank or frame with me at the moment, so can't really commit to buying BB at this stage, and as you say in your later post I think the answer is to get both, rock along to BC and try a few and see what fits best, so I'll do that when I've got everything in a couple of weeks.

And thanks also to @svenhöek , oh man so its seems the Starfish its really neither ISO or JIS and there is a third way and its somewhere in between, how very French. I know the Chorus/Record 10 speed use a 102 axle width BB but I suspect that will defo be too short so the 113/115 options seems a good starting point.

At least now I think it can work one way or another, so thanks all for the input.

Given that any Mavic cranks have been in use for at least a couple of decades, don’t be surprised if the cranks ride further up the taper than when brand new.

And the Roberts and Tomasinni?

Thanks for the kind words, one could only try and I've always taken pride and put customer first in whatever I've done.

Last day on Friday, do swing by if you're free.

Tommasini yes, and some other Italians, and a handful of Merckx's, but I've never owned a Roberts :)

I'm working on Friday but should be able to swing by so catch you then, but all the best for the future, I'm sure there will always be bikes no matter what job pays the bills.

Last day on Friday

I'll sing a song for you as I wash the grease from my hands. Rest well, sweet Beags, may you buy and sell with the power of a thousand Hoy legs.

Polo bikes yeah? Still got 4 more to ship! ;)

Spot on mate.

Hence the sabbatical was pretty easy - you'll have to be a bit of a bike geek to work in a bike shop.

Lots of love for those who I worked with and served along the way, yourself included.

Might be hard to believe, the pressure working in a bike shop is simillar to banking.

Not gonna go into deets, just got to take my words for it.

I'm sure there will always be bikes no matter what job pays the bills

Can I use 3/32 single speed freewheel i found in my stash with a wide 1/2x1/8 chain/ring or best to get a new freewheel?

I would have no qualms using it

I have an 11spd 11-40? Shimano xt cassette

I put a new chain on and it skips under power on the 11t sprocket

Im guessing this is a worn sprocket and want to swap out the 11t rather than the whole cassette

Is any shimano 11sp 11t sprocket ok or do I have to get more specific?

Any would work ok but the CS-M9000 one has the shifty bits in the right place for the jump to a 13t on the MTB stuff.

Cheers!

I going to add some sweep back to my current Alu riser bars. I know its usually a no no, however I think itll be fine...right? just 5 to 10 degrees?

clamp the in a vice, bendy bendy etc

Should I add heat or not?

Please don't.

Experiment with a variety of cheap steel swept back bars first, and when you find an angle and rise that you like, take the aluminum bars and give them to a friend without putting them anywhere near a vise.

Everyone he needs to be more open minded.

(that's a joke and I kinda knew I shouldn't do this and wanted to confirm I was being stupid)

Thx

Cheers for the beers and glad we have the Mavic chamfer tool, never knew that!

Nah, no buy sell just middle office shit!

Hi all, I have a bottom bracket question:

I recently was passed on by a good friend a set of Suntour Superbe track cranks which I had fitted to my v1 Tokyo Fixed Dart by my LBS. I believe that they used the existing BB that was originally paired with a set of Strong Light cranks. After a hundred or so hilly miles the BB is now making a pronounced grinding sound leading me to believe that it is in need of replacement. I'm not mechanically minded but some reading has lead me to believe that I will need a square taper BB in 112mm x 68mm (this was quoted for Superbe Pro, but I believe its the same?) ala Campagnolo .

I was wondering if this is correct? ...and if it is could anyone recommend me a replacement? I was looking at Shimano BB-UN300 Tapered but I can only see 113 x 68 dimensions.

Thanks!!

If indeed you do need a Campagnolo (ISO) taper 112mm BB (which I haven't checked) then a 113mm spindle will only push each crank 0.5mm outboard compared to the 112mm spindle and I don't think your bike will mind at all.

You need to be careful with (potentially) mixing tapers though.

I have run a couple sets of stronglights on 107mm jis taper bbs with good chainline results so I believe they are jis and a quick google seems to support this. Thus we can assume that the bottom bracket currently fitted is a 107mm jis.

If you fit an iso bb,the jis cranks will sit further onto the taper than intended and the bolts may bottom out on the axle. The chainline would also be less than ideal. Going to a 112mm axle may rectify the chainline but there's still the bottoming out issue.

If you go to a 113mm jis bb then potentially the chainline will be out by 3mm which is fairly significant (that's assuming the 113mm spindle is symmetrical, I know Shimano 110mm spindles are not and actually produce the same chainline as a 107mm).

Long story short, you really want to be getting the cranks off and measuring the spindle and potentially getting the bb out to see what it is.

If you take the cranks off and the spindle is 107mm I'd say you're fairly safe to assume that its a jis taper.

I entirely agree