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What crank do i have?

by kellyllek
Wed, Apr 05, 2017 16:18
5

I have a bike with missing parts and I need to replace the crank. It's a 2x6 drivetrain.  The bottom bracket appears to be around 68mm.  with outboard bearings it appears to be 89mm, and the spindle is about 18mm, though looking around I think I totally messed up as the smallest seems to be 24mm? . I'm really not dead sure as  Idon't have a caliper.  It also appears to be 175mm crank arm length.    It also appears to be ISIS? 

I'm hoping someone will instantly know what I have and possibly suggest a cheap replacement!   1 

All Im missing is the crank arm and whatever secures it on, but the crank markings are so worn I don't know what it is. I think it best I just pick up another crank if I can find one, and i really want 170mm which is better for me; i plan to use this bike on the trainer. 

Here are a couple photos. I'm hoping someone can tell me the standard I'm after to replace it? I guess I can replace the outboard bearings too if needed. 

Photos: 
https://goo.gl/photos/Z4W3STkv4H9yCH5aA

Tks! 

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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5 comments

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kellyllek | 7 years ago
1 like

Thanks all. Alas I ordered an ISIS arm and didn't work! Then I end up finding  the original arm after all. So I installed it only to find the pedal threads were stripped! (no wonder someone took it off).  I then ordered a new square taper bb and the cheapest cranset I could get on amazon. Put it all together and of course it was not great, but good enough for the trainer... only to find when I put the bike the trainer that the rear wheel was so jacked with a  massive hump in it that means it misses the trainer completley for a 1/4 a revolution...          It is a Ribble frame I got from a buddy probaby 6 years go.  I then found a cheap bike with 6speed shimano 105 on gumtree that  I  canabalized and put on the Ribble. It was OK for a long while but then got used by my nephew and others just to get around, and eventually it's gotten messed up and canalbalized itself.  

All this came about because my beater bike that I use to get to the shops got stolen. I also used that bike successfully on the trainer with Zwift. Meanwhile my main training bike, a Specialized Epic MTB, went into the shop.  Unfortunatley there's an issue in the linkage the mechanic thought best I don't ride it until we switch out all the linkage bolts and bearings. I've done it before (the bike has 18,000 miles on it) but I just didn't expect to be without it for a couple weeks. Suddenly I find myself bikeless!  

Anyway,  I ride with Kingston Wheelers though I don't live close. but I put the word out to the team and a chap came through with a road bike for me to borrow and perhaps buy. For now it's working great on the trainer and even though it's 10speed and a few years old, it's carbon and nicer than anything I've ever been on (road-wise).  It needs  TLC too as it's been sitting a few years, but I'd rather put resources into something like this beause it's better quality and fits me, where as the Ribble does not really fit me to begin with. 

Thanks again for the comments. With the Ribble I think it's just best I sell it as a project for anyone who can use it. I could patch it up and sell it but really I've wasted so much time on it I think it's just time to say goodbye. 

 

Avatar
TypeVertigo | 7 years ago
0 likes

Bottom bracket does look like an ISIS unit judging from the splines. Octalink splines look more squat.

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dottigirl | 7 years ago
1 like

Truvative ISIS external bb (Holzfeller/Howitzer?):

http://blog.artscyclery.com/mountain/ask-a-mechanic-indexed-headsets-isi...

(halfway down that page)

Looks like you're missing the crank and the retaining screw. You'd have to be careful you get the correct crank to match up with the splines.

As BTB says, you may be better off getting a crankset/bb off eBay.

 

Out of curiosity, what's the bike?

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Leeroy_Silk | 7 years ago
0 likes

Spindle resembles Shimano Octalink figment. 

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BehindTheBikesheds | 7 years ago
0 likes

Is there a drive side arm? A photo of that would give us a better clue as to what you're after.

if your spindle is contained within the bottom bracket itself and not attached to the drive side arm then that could be a Truvativ GXP bottom bracket which is quite unusual to have an outboard cup BB with its own splined axle.

If you can't find a matching arm and the fact you've only 6 sprockets at the rear will mean you can use pretty much anything. so just remove the bottom bracket and simply buy another chainset with the correct crank length you require with matching bottom bracket, this need not be expensive. Good second hand ones with a BB might set you back as little as £25-£30

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