# QR to Thru-Axle (Rear!?)



## Farfrumhom (Nov 8, 2015)

I'm really wanting to convert the Rear QR on my '13 GT La Bomba 2.0 to a 15mm or 20mm Thru-Axle. The dropouts on this particular frame are Bolt-On... I know that it requires a wheel built with the proper hub and axle. I'll spend a few hundred- maybe more. I do not drive. I ONLY cycle. The GT is being used for my fastest possible deliveries for Jimmy John's here, in Tallahassee, Florida. I "BOMB" through FSU campus!... I'm 29 y.o. (About to be 30) and have destroyed more bikes than my age.... I FINALLY have a bike that can handle the pressure, but I still weigh 168 lbs. Calves the size of... well... Calfs. I need a rear end that can take a smash. Basically: Does anyone know of a metal worker/Forger within the U.S. skilled enough to replicate the Bolt-On dropouts to accept 15mm OR 20mm Thru-Axle?


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## Flamingtaco (Mar 12, 2012)

Have you tried contacting GT to see if they have what you need? A quick google brings up review articles that had mfg jargon indicating one could purchase upgraded dropouts for bigger axles.

If not, you might get by with using a DT Swiss RWS 10mm thru axle. This is the route I went, it's a bit stiffer than the old standard 5mm QR setup. You push a 12mm, 1mm thick carbon tube into the hub, they are about $15-20, available at RC aircraft stores online.

I was considering removing 2mm from the forward side of my dropout to permit a 12mm thru axle to fit. If 12mm dropouts are not available, but you can get 10mm ones, you can mod your dropouts, and if they fail, no problem.

There are also 12mm adapters on eBay and Amazon that are aluminum rods with bolts in each end. I did this for a bit, it was better than the 5mm QR setup, but the aluminum on these are a lower strength than what DT Swiss uses.

If you want to enlist an engineer, but not at the expense of making complicated dropouts like those on your bike, a simple upgrade would be to drill out a 12mm rod to take 10mm bolts in both ends. Using high strength carbon steel you can have the strongest setup available without modifying the dropouts.

Good luck!


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## Walt (Jan 23, 2004)

You can't, for any reasonable amount of money, convert your frame to 142x12. Sorry.

If you know someone who can weld or braze (and the frame is steel; I'm too lazy to look it up), you might be able to kinda/sorta do a 135x12 old school DH hub setup. But it's probably not worth it. If you have a decent rear hub, QR will work fine for bombing sandwich deliveries.

-Walt


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## noapathy (Jun 24, 2008)

Sure...


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## Eric Malcolm (Dec 18, 2011)

Walt said:


> You can't, for any reasonable amount of money, convert your frame to 142x12. Sorry.
> 
> If you know someone who can weld or braze (and the frame is steel; I'm too lazy to look it up), you might be able to kinda/sorta do a 135x12 old school DH hub setup. But it's probably not worth it. If you have a decent rear hub, QR will work fine for bombing sandwich deliveries.
> 
> -Walt


I read that the OP said that his frame had bolt on drop outs....

Just make some. Done.

Eric


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## Walt (Jan 23, 2004)

I read that to mean "takes a threaded/nutted axle hub".

-Walt


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## the-one1 (Aug 2, 2008)

OP has nothing on Stepalopalopalopodopples. Stepalopalopalopodopples is fast, freaky fast. Fast enough to beat a Camaro with slicks and headers.


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## DSaul (Dec 13, 2012)

After looking at some pics of the 2013 La Bomba, it does have replaceable dropouts that bolt on. You should contact GT or a GT dealer to see if they have a thru axle version of the dropouts available.


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## One Pivot (Nov 20, 2009)

There's no such thing as 15 or 20mm rear axles. It's 10 or 12. 10 is plenty strong for full blown dh racing. 12 is stiffer, but its not really a strength thing.


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