Surly fork dropout question

[bluesoleli]

Hi Everyone,

Just got a CHROMO STEEL surly 1x1 fork installed on my Giant bike so I could use my 200W front hub motor without snapping a dropout. Got a torque installed arm and all just in case as well.

However, I seem to have encountered a little problem with the dropout. It's a 9mm dropout so I had to file it a bit to get rid of the paint and the motor fit in nice and snug but I noticed it wouldn't go in all the way... there's a 2mm gap in the curvy end of the dropout... it's like the curve on the motor dropout isn't matching up to the curve bit of the fork dropout. Not exactly sure what to do but I do know it fits in there extremely tight as it is. The washers do not intefere with the QR lawyers lips on the fork either, I just feel a bit un easy about how it wont go all the way in as the curves don't match.

Do you guys think I'll be okay leaving it as is?

I swear with the SR Suntour alloy spring fork that came with the bike, it fit really well. New steel fork I bought specifically for my electric project and I have a gap at the end of the dropout...

Thanks.

 

[bluesoleli]

Doh, used the search function and found this...

http://endless-sphere.com/forums/viewtopic.php?f=2&t=43786

Think it might be the same problem as me?

 

[Drunkskunk]

its normal to have to take the paint off the inside of the dropout with a file. The motor is 10mm across the flat section, and 12mm across the threads. basically it's just a 12mm axle that has been thinned. A normal bike axle is based on a 3/8ths inch axle, that actually works out to 9.525mm. The gap left to hold it is usually between 9.7mm and 10mm. The paint often takes up .2 to .4mm width, so scraping or filing the paint allows a 10mm to fit just fine.


As for about 2mm sticking up, that is normal. As I said, your axle is 12mm, the slot is for a ~10mm axle, so 2mm sticking up is about right. at 200 watts that is fine with a good torque arm and a proper installation.

However, it is better if you make the dropout deeper by filing it 2 to 3mm deeper. You can trace out the new shape with a Sharpie by using one of the motor's washers layed on the dropout with 2mm of the bottom exposed inside the hole, then file until the Sharpie line is gone.

 

[dogman dan]

Yeah, file it a tad deeper. Unless it looks like it's plenty far in there now. I don't have experience with the surly fork, but I know some forks are shallower than others.

 

[bluesoleli]

I bought myself a round file and filed the round bit of the fork a bit more (the bit that stopped the axle going in further). Worked a treat and now my axle actually hits the end of the dropout!