jambon

Hi there ,

Interested to hear some thoughts on this riddle.

Installing a Funn Hooka 1x crank into a BB52 Hollowtech 2 Bottom Bracket in a 68cm Bottom Bracket shell.

The BB52 comes with 2 x 2.5mm spacers and a 1.8 and a .7 spacer.

I install the 2 x 2.5mm spacers on the drive side. The 1.8 +.7 go on the non drive side. This gives perfect chainline for a singlespeed.matching directly up with the cog in the rear.

There are no more spacers included with the BB52.

I install the cranks , tighten the lock nut up to set the non drive side crank on the splines and snug up the bolts on the crank arm.

But the cranks are not set against the Bearings , there is a bout a 4mm gap.

I am confused , guy I bought the crank off said he had it on a bike with a 68cm BB shell. The crank is marketed as compatible with hollowtech2.

That crank comes in a longer spindle size for 83mm Bottom brackets but the gap should be much larger in that case.

I'm tempted to find some more plastic spacers to put behind the bearing cups but then what about there being very little thread for the cups to grip on.

Any ideas?

DrIsotope

Well, if the crank were snug in the BB52 with all four spacers installed, I presume it would be the correct spindle length. But shell + cups + 7.5mm of spacers + 4mm of gap... sure sounds like the spindle for an 83mm shell to me.

Andrew R Stewart 

I suspect "the guy" who you bought the crank from had a different set up then you think or his was also not quite right. But it has to be right as he said so

When you installed the RH arm/spindle did it seat against the BB cup/spacers? If not then something was wrong from the start. If not why didn't it. Not all 1 piece spindles from all brands share the same tolerances and the fit can be problematic with mixed brand set ups. Does the brans offer it's own BB? Is that what you have? The MTBR reviews seem to suggest some QC problems on at least one production/shipping run. Andy

jambon

Yes the Right hand spindle seated fine against the cup.

if it were designed for an 83mm BB shell shouldnt I expect to see a lot more than 4mm of a gap?

DrIsotope

From my limited memory of wrenching on an MTB frame, I don’t recall any BB spacers at all. Perhaps the original FUNN bottom bracket just has 2mm wider cups.

wsteve464

According to the Funn instructions for their other crankset the 4 spacers you have should work. Loosen the crankarm pinch bolt and hit the arm with a mallet/piece of 2x4 to make sure it is seated. Or take the crank out and measure the unsplined spindle length to see if it matches the bb width across the outside of the bearings. Or return for refund.


https://www.funnmtb.com/upload_file/...Manual_514.pdf

jambon

got onto Funn

They make a 107 mm spindle for 68/73 BB shells and a 122mm spindle for the 183 BB

This one measures 107mm

Also tried tapping thee arm onto the spindle with a mallet but I can see its seated correctly anyway.

Total Head scratcher

wsteve464

I measured 2 Sram MTB cranksets (73mm BB width) the spindle with the left crank bolted up tight both measure 100mm. So even putting in 7mm of spacers, 68mm of BB plus the 4 spacers with the BB kit, on a BSA bottom bracket you are still 5 mm too narrow. Call Funn and find out what part you are missing. Alternately put some crank spacers on the spindle between the arm and bearing

https://www.coloradocyclist.com/shim...RoCOdsQAvD_BwE

https://www.nashbar.com/shimano-holl...BoC32kQAvD_BwE

Iride01 

Most of the new ones I saw advertised came with their own BB's to match the shell it's going in. Perhaps their external cups are wider than what yours are.

This is ISIS? Similar to hollowtech, but you better be certain what their procedure is for installing the arm on the non drive side.