Bmx cranksies on mountain biksies

[klunkrider]

Dmr cranks I had were 19mm but the spindle is a weird tapered thing, 19mm at the ends, 20/22mm or something in the middle. Bloody strange system.

 

[klunkrider]

Oh, I think they were like 36(?) spline as well. Definitely not the usual 48.

 

[Imlach]

Dmr cranks I had were 19mm but the spindle is a weird tapered thing, 19mm at the ends, 20/22mm or something in the middle. Bloody strange system.

Appreciate the info mate. Reckon it's time I go back to contemplating Profile setups instead.

Not a fan of some proprietary junk that isn't interchangeable with other bits...

 

[klunkrider]

Appreciate the info mate. Reckon it's time I go back to contemplating Profile setups instead.

Not a fan of some proprietary junk that isn't interchangeable with other bits...

Profile are going to be the best, at least if you are buying new as I think you can specify which spindle you get possibly for a small price supplement but it’ll be a lot better than buying any other cranks and then having to buy the long profile spindle separately.

Fwiw though, I’ve had bmx cranks on a few mtbs and really wouldn’t recommend it, especially on anything that’ll be ridden hard.

The bottom brackets work well enough in a USA, mid or Spanish shell but in euro/bsa the bearings end up being really small which decreases service life significantly. When I was riding bmx I remember people getting mere weeks out of 22mm euro bbs, 19mm we’re a bit better but still terrible.

Profile do an external bb but I don’t know if there’s a spindle long enough to make that work on a mtb.

I still have some WTP 19mm/48 Spline cranks on my klunker which has a USA shell but they require regular stripping and rebuilding to keep the death creaks at bay and are not noticeable stiffer than a set of Deore hollowtechs.

Worth noting is that being proudly made in ‘murka, Profiles require non standard tools to work on. The sprocket bolt is an imperial size that a 5.5mm hex wrench will about work in but will eventually round out and the latest set I worked on just the other day needed a 7mm hex wrench for the crank bolts.

 

[Imlach]

Profile are going to be the best, at least if you are buying new as I think you can specify which spindle you get possibly for a small price supplement but it’ll be a lot better than buying any other cranks and then having to buy the long profile spindle separately.

Fwiw though, I’ve had bmx cranks on a few mtbs and really wouldn’t recommend it, especially on anything that’ll be ridden hard.

The bottom brackets work well enough in a USA, mid or Spanish shell but in euro/bsa the bearings end up being really small which decreases service life significantly. When I was riding bmx I remember people getting mere weeks out of 22mm euro bbs, 19mm we’re a bit better but still terrible.

Profile do an external bb but I don’t know if there’s a spindle long enough to make that work on a mtb.

I still have some WTP 19mm/48 Spline cranks on my klunker which has a USA shell but they require regular stripping and rebuilding to keep the death creaks at bay and are not noticeable stiffer than a set of Deore hollowtechs.

Worth noting is that being proudly made in ‘murka, Profiles require non standard tools to work on. The sprocket bolt is an imperial size that a 5.5mm hex wrench will about work in but will eventually round out and the latest set I worked on just the other day needed a 7mm hex wrench for the crank bolts.

Sobering information, may need to hydrate more. Wasn't aware of the poor BB service life, certainly makes you think. Perhaps I should just go back to trusty old middleburn which I've got on my 1x1 and would suit the new build. I just always liked the feel and look of BMX cranks, compared to classic alu cranks. But I'm starting to feel like it's not worth the hassle if I'm going to end up having to get proprietary tools.

I was going to try out my poor man's chinese takeaway faux cooks but when I got in touch with the supplier and asked about weight limits and durability, they said it should all be fine as long as "I don't ride hard"

But anyhow mate, really appreciate the concise summary of the cons of my obsessive BMX adventures.

 

[KermitGKona88]

Why not go for some DH specific cranks instead, always built to be stronger...

 

[Mickeyspinn]

Now I know diddly squat about BMX cranks on an MTB....but I do in my compendium of useful stuff have a profile bottom bracket for a 19mm axle for a 68 mm shell...it came off a GT frame that I bought that the previous owner had if I remember rightly fitted profile cranks!
If it's any use to you imlach just shout old bean!
It's in cracking order!

 

[Imlach]

Now I know diddly squat about BMX cranks on an MTB....but I do in my compendium of useful stuff have a profile bottom bracket for a 19mm axle for a 68 mm shell...it came off a GT frame that I bought that the previous owner had if I remember rightly fitted profile cranks!
If it's any use to you imlach just shout old bean!
It's in cracking order!

Problem isn't so much the BB but the spindle length. If he included a 6 inch spindle I'd have taken it. But yeah at this point it's either getting the profile mtb crankset from the good ol' Amerikay or Middleburn or finding a cheaper pair of Turbines and calling it a day.

 

[Mickeyspinn]

Problem isn't so much the BB but the spindle length. If he included a 6 inch spindle I'd have taken it. But yeah at this point it's either getting the profile mtb crankset from the good ol' Amerikay or Middleburn or finding a cheaper pair of Turbines and calling it a day.

I feel your pain
I too have been having a mare with BB,ring,chainline, crank clearance on the flunker klunker...thought I'd stuffed it for a bit turns out I'd stuffed the bit of paperwork i needed in the seat tube
Well if you get your spindle length sorted and my bit helps I'll smuggle it over

 

[madjh]

I haven´t seen a spindle like this. The length is variable? From this web site, lot of cranks, cheap and expensive. I like the eclat ones in rainbow color. https://www.skatepro.es/c379.htm Shop in continental UE.