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26” to 700c conversation. Change my mind?

Old 01-05-20, 08:59 AM
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LBCwanabe 
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26” to 700c conversation. Change my mind?

Please stop me. Plenty of clearance and it looks like the brakes might reach? Any input is appreciated!


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Old 01-05-20, 09:12 AM
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The brakes will have a much different mechanical advantage, and might not have satisfactory stopping power. Be extra careful on the first ride.
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Old 01-05-20, 09:54 AM
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What do you hope to gain with this project?

If you have any intention of installing mudguards in the future, larger diameter wheels may not have enough clearance.
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Old 01-05-20, 10:07 AM
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There are several different adapters made just for this. Just do a search. I can't post URLS because of my post count. Mavic makes one...for example...
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Old 01-05-20, 10:09 AM
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This model is typically used with a larger diameter tire and is more road/trail/gravel than strictly road. From the very skinny tires in the pictures it looks like you want to try to turn it into a road bike.

The 700c has a nominal rim diameter of 622mm. The 26" is 559mm. This 63mm difference means a 31.5mm difference in radius. About an inch and a quarter. As others have mentioned, this nearly doubles the distance between the canti brake pivots and the rim. So you'll have much less braking force if you use the current setup. Further, the braking system (specifically the welded-on pivots) may be subject to twice the torque they were designed for. There are (or at least were) adapters available(see pic, below, also here). Not sure if you can still find them. Anyone?

Might be useful to folks answering your question if we knew your goals in modding the bike. Most of us understand that its fun and interesting, but when making mods like this one should begin with the end in mind.



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Old 01-05-20, 11:48 PM
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IMO, the problem I see, is the rims are not for rim brakes, if those are the wheels you are using.
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Old 01-06-20, 05:30 AM
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It all boiled down to not having enough room in the stand and needing a spot to keep the 700c wheels safe while I did a tear down. Just so happens the spacing is the same
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Old 01-06-20, 06:07 AM
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You may find you are limited on tyre width. 650b might be a consideration for hub options and tyre clearance in a wider width. On the other hand there are a lot more options for road tyres with 700c.
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Old 01-06-20, 06:15 AM
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Assuming that you install rims meant for rim braking, you could possibly switch to V-brakes with an extension adapter. Like the post above, the Mavic caliper adapter would work. But it's out of production. You might find it for $20-30 on the internet. You could also use the adapters pictured below. They're $5-12 per pair on AliExpress, or you can look on eBay or Amazon. These ones say 22mm extension. The LitePro version might have a different length.



According to RJ the bike guy, the Mavic adapter is longer.
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Old 01-06-20, 06:58 AM
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Those look handy!
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Old 01-06-20, 08:30 AM
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Why? Why not get a 700c frame and be done with it if that's what you want? Or judging from the pictures you have a lot of bikes. Just leave it as is, it won't be worth the effort.
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Old 01-06-20, 09:03 AM
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Handy, yes, but keep in mind you are doubling the lever arm by using a longer brake arm. This doubles the forces and torques on the welded brake mounting point. In fact, its worse: the design of the smaller single-sided adapters (as opposed to the Mavic horseshoe) actually adds brake force torque to the mounting points. So in the original design, the holes in the mount points only handle the torque of the return spring. In the adapted single side design, those holes support actually braking force. I don't like it.
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Old 01-07-20, 10:44 AM
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As others have said, the brakes, even if they reach the rims, won't work right - likely 1/3 the braking power for the same force at the levers.

Furthermore, why?
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Old 01-07-20, 12:28 PM
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Originally Posted by MarcusT View Post
IMO, the problem I see, is the rims are not for rim brakes, if those are the wheels you are using.
They look like rim-brake rims to me. (Araya ADX or Aero model?)

Still not seeing the point of a 700C conversion though. Skinny tires are OUT!
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Old 01-07-20, 07:34 PM
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I vote for fat slicks.

1/ keep your brakes
2/ maintain your ride height


Last edited by DorkDisk; 01-07-20 at 07:46 PM.
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