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Is this even possible?

Old 09-15-18, 12:04 PM
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getspinchflats
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Is this even possible?

A Shimano Claris 8 speed brifter (Right side) throwing an 8 speed chain over a sun race 8 speed mtb cassette (11-40) employing a long cage derailleur with a single chainring up front (undecided, but shooting for 48 or 50 tooth) any derailleur advice (thinking deore)...
8 speed cassettes are same width road to mtb, and have the same click spacing so it should work in theory.... Bike is currently all Claris (triple)

Last edited by getspinchflats; 09-15-18 at 12:23 PM.
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Old 09-15-18, 12:24 PM
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? why not try it, ?

first people use these https://www.wolftoothcomponents.com/...r-optimization

moves whole RD down, so May Be a better option than just putting in a longer B screw
to rotate the RD further away .. which will be cheaper..
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Old 09-15-18, 12:38 PM
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Single plate in front is so fashionable.
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Old 09-15-18, 07:47 PM
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Originally Posted by getspinchflats View Post
A Shimano Claris 8 speed brifter (Right side) throwing an 8 speed chain over a sun race 8 speed mtb cassette (11-40) employing a long cage derailleur with a single chainring up front (undecided, but shooting for 48 or 50 tooth) any derailleur advice (thinking deore)...
8 speed cassettes are same width road to mtb, and have the same click spacing so it should work in theory.... Bike is currently all Claris (triple)
1. Make sure the rear derailleur has capacity for a 40 tooth large cog.
2. Forget about 48+ chainrings. With only 8 speeds it's a waste to have a downhill only 48-11. Even if you limit your top crank revs to 100rpm on a 26" tire you're at 32mph (35mph on a 29r). Even the 48-13 is questionable on a mountain bike.
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Old 09-15-18, 08:16 PM
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I am planning on a long cage derailleur to cover the 40 tooth cog.
This is on a 700c road bike. My mtb has a 32-11 top gear and that's just fine for that bike.
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Old 09-15-18, 08:24 PM
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Originally Posted by getspinchflats View Post
My mtb has a 32-11 top gear and that's just fine for that bike.
A long cage is for taking up chain slack on a wide range gear system. Although a long cage derailleur typically can handle larger cogs it does not necessarily mean the top pulley is low enough to handle a 40 tooth cog. Example - Deore XT long cage cog capacity is 34t. Deore XT specs. You may be able to use a hanger extender to increase large cog capacity by 4 teeth or so: Wolf tooth hanger extender review

What does a 32-11 on the MTB have to do with a 48-11 on the road bike?
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There's no such thing as a routine repair.

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If you think I'm being blunt take it as a compliment - if I thought you were too weak to handle the truth or a strong opinion I would not bother.

Please respect others by taking the time to post clearly so we can answer quickly. All lowercase and multiple typos makes for a hard read. Thanks!

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Old 09-15-18, 10:59 PM
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The issue is that no Shimano compatible 8 (or 9 speed) speed derailleurs have an official rated capacity for a 40t. Also they actually have longer than necessary cages than needed for 1x. The best bet is something like an M3000 derailleur (rated for 36t) and possibly a longer B tension screw if necessary or a Wolftooth Goatlink.

You can also use a Jtek Shiftmate 6 to pair your 8 speed Shimano road shifters with a 10sp Shimano MTB rear derailleur, which will let you use a clutch derailleur; I'd probably recommend RD-M6000-GS in this case; Microshift also makes some offerings for this.
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Old 09-15-18, 11:26 PM
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He thought I was talking about a 26" mtb is what I thought?


QUOTE=cny-bikeman;20568295]A long cage is for taking up chain slack on a wide range gear system. Although a long cage derailleur typically can handle larger cogs it does not necessarily mean the top pulley is low enough to handle a 40 tooth cog. Example - Deore XT long cage cog capacity is 34t. Deore XT specs. You may be able to use a hanger extender to increase large cog capacity by 4 teeth or so: Wolf tooth hanger extender review

What does a 32-11 on the MTB have to do with a 48-11 on the road bike?[/QUOTE]
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Old 09-15-18, 11:28 PM
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This is what I was after, thanks!!!



Originally Posted by cpach View Post
The issue is that no Shimano compatible 8 (or 9 speed) speed derailleurs have an official rated capacity for a 40t. Also they actually have longer than necessary cages than needed for 1x. The best bet is something like an M3000 derailleur (rated for 36t) and possibly a longer B tension screw if necessary or a Wolftooth Goatlink.

You can also use a Jtek Shiftmate 6 to pair your 8 speed Shimano road shifters with a 10sp Shimano MTB rear derailleur, which will let you use a clutch derailleur; I'd probably recommend RD-M6000-GS in this case; Microshift also makes some offerings for this.
Thanks!
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