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Dremeling/cutting AL fenders?

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Dremeling/cutting AL fenders?

Old 10-08-20, 08:38 AM
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Dremeling/cutting AL fenders?

Hi. I have a Lynskey Sportive Disc which started life at 700x28, but on which I've been running 650b wheels with 42mm Paselas for the last year or so. I love it. I also happen to have a 650b dynamo wheel and some B&M lighting I'd like to install so I can get through the winter months without relying on my trainer for miles. If possible, I'd like to make 650 my year-round standard and rig it up with good-quality AL fenders like the PDWs or maybe VO.

The front fork is a ginormous Lynskey Pro GR, so I'll have no problem fitting 650b fenders in there. The back is a little tight, though. I haven't measured yet, but I guarantee there will be pinching at the stays. Any idea if I can get away with snipping / dremeling back some of the fender edges to get it to fit through and sit high enough, or will that compromise the fender? I called PDW, and they weren't sure.

I'll PROBABLY give it a shot, regardless, but that's a lotta fender to buy if it won't work. I might go VO and save $80 if I'm not sure.

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Old 10-08-20, 10:40 AM
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For aluminum fenders, if you can lightly hammer the fenders to shape, that will help the fenders last. Any cut will be a place for cracks to start. If you can figure out a way to hammer against a shaped "anvil", that would have the best result.

One other piece of advice that I would give is to "pre-bend" the stays and fenders. If you rely on the stays to bend the fender into position, they are much more likely to lose adjustment as well as fail prematurely. A fender that is installed without any residual stress will last longer and be less likely to rattle.

If the fenders are laminated construction, you should be able to dremel or cut without risking future damage. Same advice for pre-bending stays, but that is more to keep adjust than prevent damage.
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Old 10-08-20, 10:43 AM
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I find that a #561 bit in a Dremel tool works well on thin aluminum. https://www.dremel.com/en_US/product...se-cutting-bit
If you make smooth curves and use a rat tail file to remove any notches (or just use the file to make the cutouts) where a crack might start you should be OK.
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Old 10-08-20, 10:59 AM
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Cut SKS Fender to Fit Fork



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Old 10-08-20, 11:48 AM
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Here are some pics of the clearance. It's pretty tight. Even the Velo Orange 50s would need bending/cutting.

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Old 10-08-20, 09:52 PM
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Posting a pic of the underside of the fender would be helpful, along with where you intend to cut them....if the fender has a rolled lip cutting the lip will make the fender weaker.
If the fender is rolled, then squeezing the lip may be better than cutting it.
Best, Ben
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