THM-Clavicula SE

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audiophilitis
Posts: 479
Joined: Sun Jul 29, 2012 12:49 am

by audiophilitis

not an issue -- i have a Clavicula Classic that was modified by THM for use on a Cervelo R5ca. Although the Classic has the aluminum ring on both ends of the axle, when installed on a R5ca, the drive side bearing actually sits on the carbon section of the axle due to the 9.5mm spacer needed on the drive side so the arm clears the chain stay. After over 2k miles of use, the carbon section of the axle still looks new -- no scoring or signs of wear whatsoever.

i have the SE installed on an RCA with just a few hundred mile logged. I know it's too soon to tell but when i took them off last week to try some new bearings, the axle looked brand new. I guess this is due to the fact that the bearings (on both the Classic and SE cranks) sit snuggly on the axle and don't really move.

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liketoride
Posts: 408
Joined: Wed Nov 21, 2012 3:05 am

by liketoride

audio did you have the classic and then send it back to get updated to the direct bbright when you got the r5ca? As if that is the case it would be great so i could put my classics that i had on my RCA and put it on my R5ca. When i was reading your post it sounded like the metal rings did not get pushed in enough on the classic, why is it still on the carbon? Also i have xd-15 bearings on all the bikes and sometimes those pre loads come undone and then those bearings move around. I just wanted to know if those would scare the axle and then damage it in a way it would be unsafe in the future.

Wingnut
Posts: 2196
Joined: Sat Jun 23, 2007 12:41 am

by Wingnut

Of the Praxis chainrings I only ever liked the classic style which I think would suit these cranks better?

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mnmasotto
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Joined: Mon Jun 06, 2011 7:16 pm
Location: Irvine, CA

by mnmasotto

Does anyone know who has these in stock?

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F45
Posts: 1077
Joined: Wed Jun 08, 2011 6:08 am

by F45

Yes Wingnut I think you are correct. I like the style of the cx chainrings even better but they only come in 48t maximum.

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audiophilitis
Posts: 479
Joined: Sun Jul 29, 2012 12:49 am

by audiophilitis

liketoride wrote:audio did you have the classic and then send it back to get updated to the direct bbright when you got the r5ca? As if that is the case it would be great so i could put my classics that i had on my RCA and put it on my R5ca. When i was reading your post it sounded like the metal rings did not get pushed in enough on the classic, why is it still on the carbon? Also i have xd-15 bearings on all the bikes and sometimes those pre loads come undone and then those bearings move around. I just wanted to know if those would scare the axle and then damage it in a way it would be unsafe in the future.


I purchased a new Classic when I built the R5CA -- I was assured by THM that it would work without any modifications but that was not the case. They had to build up the carbon on the drive side to the same diameter as the aluminum ring (you will notice that the axle of the Classic tapers right before the aluminum ring on the drive side only -- it's flush on the non-drive side). Not really sure what the reason was for that design. The R5ca requires the use of a 9.5mm spacer on the drive side to push the arm to the right so it clears the chain stay. By doing this, the bearing no longer aligns with the aluminum ring. THM did a great job building up the carbon and it now fits snuggly. Once the bearings are pressed in -- either on the carbon BB housing of the R5ca, or the BBRight cups on the RCA, they should not move laterally.

I also had the Classic on the RCA but upgraded to the SE soon as it became available (preordered from Fairwheel).

Feel free to PM if you have further questions.

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mythical
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by mythical

Sounds like a weird problem to me, extreme crankset modification an all. Why not have someone turn a BB cup/adapter on the BBright driveside to place the bearing where it should sit on the axle? Also makes the cranks retain it's resale value.
“I always find it amazing that a material can actually sell a product when it’s really the engineering that creates and dictates how well that material will behave or perform.” — Chuck Teixeira

audiophilitis
Posts: 479
Joined: Sun Jul 29, 2012 12:49 am

by audiophilitis

The R5Ca does not use the standard BBRight -- it's the BBRight Direct Fit. Bearings are pressed directly into the frame. It's really a minor modification on the Classic and does not alter it's usability for other applications. It works flawlessly.

UpFromOne
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by UpFromOne

For those lucky enough to ride these, any mid-term use comments not before seen?

RedRacer
Posts: 412
Joined: Sat Jan 21, 2006 6:13 pm

by RedRacer

I have often considered buying a THM crankset but the limited chainring choices always puts me off.

I agree with Denavelo that shifting performance is very important but I really dislike the look of the current Praxis rings. Are there any other rings that shift well, are light weight and are black in color?

Denavelo wrote:
wheelsONfire wrote: Don't skimp on performance when it comes to shifting.
Extralite RC2 = 94g
Praxis 50/34 = 124g

30g difference and better shifting performance.

kode54
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Joined: Tue May 23, 2006 9:39 pm

by kode54

RedRacer wrote:I have often considered buying a THM crankset but the limited chainring choices always puts me off.

I agree with Denavelo that shifting performance is very important but I really dislike the look of the current Praxis rings. Are there any other rings that shift well, are light weight and are black in color?

Denavelo wrote:
wheelsONfire wrote: Don't skimp on performance when it comes to shifting.
Extralite RC2 = 94g
Praxis 50/34 = 124g

30g difference and better shifting performance.


you can use Stronglight chainrings...similar to the Praxis Classic rings that they only sell for regular cranks.
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mythical
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by mythical

I had Praxis rings since 2007, back when they were still prototypes. Their durability is amazing! Before that I swore by Spécialités TA Hegoa chainrings, also very good chainrings, but what a difference in shifting. Praxis rings are is miles ahead. No wonder, given that Dave spent over a decade on developing them.
audiophilitis wrote:The R5Ca does not use the standard BBRight -- it's the BBRight Direct Fit. Bearings are pressed directly into the frame. It's really a minor modification on the Classic and does not alter it's usability for other applications. It works flawlessly.
That great, man. Even so, there are more ways to skin a cat.

A little clarification. The idea behind my suggestion is maximum width bearing spacing and no crankset modifications (resale value?). The adapter cup is simply pressed into the drive side bearing seat increasing the spacing of the bearing in the cup by 9.25mm, to make up the difference to the aluminum bearing seat on the carbon axle.

That gives 2.25mm space between the outside of the frame and inside of the outer race. I'm quite sure wider bearing spacing also increases durability of the bearings, though I think it's more important to have an equal bearing spacing from the centerline of the frame, given that all the power transfer to the rear wheel takes place on the drive side.
“I always find it amazing that a material can actually sell a product when it’s really the engineering that creates and dictates how well that material will behave or perform.” — Chuck Teixeira

2old4this
Posts: 366
Joined: Mon Jan 13, 2014 7:26 am

by 2old4this

Fairwheel do have SEs in stock now, in case you are interested ...

spdntrxi
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Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

I'll get one likely in April .. As I am dealing with a m3 I was sending back to Germany that is lost in the mail ..


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UpFromOne
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by UpFromOne

Ordered mine from good'ole Starbike, the site said 6-8 weeks but it shipped a week later, due any day now 8)

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