Carbon forks - Specialised Crux E5 - Front hub 250w

rotoq

Just Joined
Dec 3, 2018
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I need some advice. My cyclotricity 250w front hub conversion kit is on its way to me, and I've been searching for steel forks to swap out on my Crux E5. It's proving very difficult (for a n00b like me) as Specialised don't seem to make swapping out the fork particularly easy. So I have a few questions on how to proceed:

  • does anyone here run a 250w hub motor on carbon forks?
  • can anyone advise me if its even possible to fit steel forks to my specialised tapered headset without completely custom parts?
If the conversion isn't going to work, it would cost me more to post the kit back and change it that it would to get a used steel frame hybrid bike, so if all else fails, that's what I'll do. But I'd like to stick with the Crux if possible.

Thanks in advance,

rotoq

EDIT: Apologies, I was browsing the Electric Bicycles and Electric Bike Conversion Kits forums in two different tabs and accidentally posted this in the former rather than the latter. If it needs deleted or moved, let me know what I need to do. Thanks.
 
Last edited:

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
561
77
I need some advice. My cyclotricity 250w front hub conversion kit is on its way to me, and I've been searching for steel forks to swap out on my Crux E5. It's proving very difficult (for a n00b like me) as Specialised don't seem to make swapping out the fork particularly easy. So I have a few questions on how to proceed:

  • does anyone here run a 250w hub motor on carbon forks?
  • can anyone advise me if its even possible to fit steel forks to my specialised tapered headset without completely custom parts?
If the conversion isn't going to work, it would cost me more to post the kit back and change it that it would to get a used steel frame hybrid bike, so if all else fails, that's what I'll do. But I'd like to stick with the Crux if possible.

Thanks in advance,

rotoq

EDIT: Apologies, I was browsing the Electric Bicycles and Electric Bike Conversion Kits forums in two different tabs and accidentally posted this in the former rather than the latter. If it needs deleted or moved, let me know what I need to do. Thanks.
Sadly, I cannot help except to say that as far as I am aware, tapered forks are available in steel as well.
Also, you could measure the top and bottom headset bearing outer sizes and maybe there is a "parallel" fork that can be fitted with different bearings? Sadly, you will probably need to remove the bearings to actually measure. I use a cheap Chinese Vernier gauge with an electronic display as they can easily measure inside and outside dimensions to around a 1/100th of a millimeter, good enough for Government Work!
I got one off ebay, the other one was a present!! Two is not too much!!
I still have two mechanical ones, without electronics, that I can read, but you do need to know exactly "how" to make correct usage.....
See here:-
https://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_nkw=vernier+scale&_sop=15

If you buy a plastic one, treat it gently as it might distort and give you the wrong reading. See if you can read the measurement on this picture! If you have trouble, buy the electronic version it does the reading for you!!!
PracticeVernier Scale Gauge.jpg and practice!!
Best regards
Andy
PS. Maybe someone will know if the carbon fiber forks may be strong enough for you!!!
 

rotoq

Just Joined
Dec 3, 2018
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Thank you for your advice! I actually bought a cheap set of those the other day, however now I'm noticing that they are being dispatched from china and wont be here for quite some time :-(
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,994
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West Sx RH
You can't use carbon fork as you will be unable to alter the drop outs.
Sometimes up to 1mm of material needs removing for the 10mm axles to slide in and then often they don't sit in deep enough as the axle is 12mm compared to 9mm of QR's, 3mm is needed to be removed to allow correct hub axle depth and to allow the AR washers to fit.

It is bad enough using Ali but modifying carbon is a NO.

A purpose made carbon fork with steel drop outs may work but the material join would likely be a weak point due load/stress.
 
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Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
561
77
Thank you for your advice! I actually bought a cheap set of those the other day, however now I'm noticing that they are being dispatched from china and wont be here for quite some time :-(
It was my thoughts only, most kind of you to call it "advice"!! :)
regards
Andy