Scott Spark RC 650B

Who are you (no off-topic talk please)

Moderator: Moderator Team

Post Reply
User avatar
Mads Kock
Posts: 2767
Joined: Thu May 26, 2005 7:52 am
Location: Malmö, Sweden
Contact:

by Mads Kock

Image

Trying Sram XX1 crankarms and Absolute Black DM chainring. First testride resulted with dropping the chain about 6 times on a 27 km bumpy singletrack so that wasn't perfect. I will try with a type 2 rear derailleur now :-)

Edit: I have shortened the chain by 2 links after the first ride. Maybe this will help a little bit.

DanW
Posts: 1037
Joined: Fri May 02, 2008 5:39 pm
Location: Here, there and everywhere

by DanW

Hey Mads, what are the new bar and stem? Very impressive weight!

You chain looks very, very short and I would imagine the shifting will not be so great when you add in some extra resistance of the new clutch mech.

I have just put an Absolute Black chainring and XTR clutch rear mech on my Scalpel and it isn't an entirely faultless solution. It has only taken me 200km to drop the chain repeatedly. In the dry these chain rings seems to be perfect. However during a very muddy, very wet 60km ride in torrential rain there was gritty mud building up around the wide teeth on the chainring which stops the chain from sitting low down on the teeth like it should. The shape of the wide teeth does not allow the mud to be pushed down and off the tooth as it does on the narrow/ normal teeth. Several times during the ride I noticed the chain sitting high on the teeth then eventually clunk down and locate properly (or fall off). My opinion is that the clutch mech does most of the work keeping the chain on and the chain rings are a bit of a gimmick. Sure you can feel the chain grip a little better on the ring and Absolute Black have the pictures to prove it but I feel the effect of the new mechs is more significant. I feel a better set up is probably a normal single speed chain ring with a clutch rear mech to help the mud clear, but no-one seems to ride this combination (hence difficult to find others' experience of this). FSA are soon to be releasing the Megatooth ring which relies on a longer, more hooked tooth and avoids the narrow/ wide approach which seems to be prone to issues in thick, gritty mud... at least in my limited experience.

I would be very interested to hear your thoughts when you get the new set up up and running, especially in mud :beerchug:

by Weenie


User avatar
Mads Kock
Posts: 2767
Joined: Thu May 26, 2005 7:52 am
Location: Malmö, Sweden
Contact:

by Mads Kock

Hi Dan

Haven't tried it in any mud yet because I'm so lucky that it's very dry here :-P

Picture from today:
Image

I think you are right about the rear mech does most of the work - thought the chainring would have a more "glue-like" feeling but still... 6 times is 6 times too much but after the first couple of chaindropping I sometimes looked down because I thought the chain would have went off but it was still there so it probably does a bit.

Yeah - I know the chain looks really short but I will try tomorrow :-)

User avatar
Mads Kock
Posts: 2767
Joined: Thu May 26, 2005 7:52 am
Location: Malmö, Sweden
Contact:

by Mads Kock

BTW:

New Ultimate stem (old design) and New Ultimate EVO Wide handlebars (700mm).

DanW
Posts: 1037
Joined: Fri May 02, 2008 5:39 pm
Location: Here, there and everywhere

by DanW

Are those the 110g 700mm bars Mads? They look very tempting but there is something about about New Ultimate products I do not trust in the same way as say KCNC. Have you have a lot of time riding New Ultimate stuff in the past?

User avatar
Mads Kock
Posts: 2767
Joined: Thu May 26, 2005 7:52 am
Location: Malmö, Sweden
Contact:

by Mads Kock

117 grams/700mm - from what I remember :-) Yes - tried alot of their stuff and very durable :-)

DanW
Posts: 1037
Joined: Fri May 02, 2008 5:39 pm
Location: Here, there and everywhere

by DanW

Excellent, New Ultimate will go on the shopping list then :D

User avatar
Mads Kock
Posts: 2767
Joined: Thu May 26, 2005 7:52 am
Location: Malmö, Sweden
Contact:

by Mads Kock

Yeah - it's a really nice flatbar.

Sorry to hear that you don't trust NU - had any bad luck with them in the past?

DanW
Posts: 1037
Joined: Fri May 02, 2008 5:39 pm
Location: Here, there and everywhere

by DanW

Only bad luck on small parts like seatclamps and I think when they first started they had quite a few seatposts failing but it is nothing rational really that stops me trusting them...

It is more that they actually manage to make good looking light products that are really well priced and when you see them alongside much more expensive parts for similar weights I am naturally cynical :D

I think the only reason to not feel the same about KCNC is that they tend to be more popular so you hear more good reviews of their products. It is all psychological I'm sure! :D

User avatar
Mads Kock
Posts: 2767
Joined: Thu May 26, 2005 7:52 am
Location: Malmö, Sweden
Contact:

by Mads Kock

I have tried their seatposts from the begining (and have had alot since :-P) I have only had 1 problem where I broke a part of the seatpost when I tried to jump a tree log and didn't get the rear wheel over :-D

But seriously - the flatbar feels very firm and like you say the weight is great.

deek
Posts: 406
Joined: Fri Aug 31, 2012 6:32 pm

by deek

Mads Kock wrote:Trying Sram XX1 crankarms and Absolute Black DM chainring. First testride resulted with dropping the chain about 6 times on a 27 km bumpy singletrack so that wasn't perfect. I will try with a type 2 rear derailleur now :-)

Edit: I have shortened the chain by 2 links after the first ride. Maybe this will help a little bit.


I've had good luck (along with a lot of people) with the XX1 ring and a non-damper derailleur. Any reason why you're using Absolute Black instead?

Also, I'm not sure how much the chainstay grows on the Spark but it might be worth checking your chain when your suspension is fully compressed.

DanW
Posts: 1037
Joined: Fri May 02, 2008 5:39 pm
Location: Here, there and everywhere

by DanW

Some weight (50g?) to be saved with the spiderless chainring vs XX1 spider and XX1 ring I imagine

User avatar
Mads Kock
Posts: 2767
Joined: Thu May 26, 2005 7:52 am
Location: Malmö, Sweden
Contact:

by Mads Kock

Still sucks so have ordered a x.0 type 2 rear derailleur (short cage). Hope this works out for me.

Chose the Absolute Black because it was lighter (like Dan said hehe).

It's "funny" though - there is no consistency in where I drop the chain. Sometimes I'm just riding some fairly technical in pretty slow speed and off goes the chain. Other times it stays on. The same goes for speed downhill with some small drops - sometimes it stays on and sometimes it doesn't.

jooo
Posts: 1504
Joined: Wed Feb 02, 2011 3:48 am

by jooo

Just remember, the direct mount chain ring has a different tooth shape altogether which may not be as secure as true XX1 or copies.

by Weenie


User avatar
Mads Kock
Posts: 2767
Joined: Thu May 26, 2005 7:52 am
Location: Malmö, Sweden
Contact:

by Mads Kock

Are you saying that the Absolute Black DM chain ring is not as good as XX1 and Wolftooth? Thought that it was as good.

Anyway - tried it tomorrow with my front derailleur mounted and adjusted as a chain guide and it worked fine. Was thinking - a Sram X.0 Type 2 derailleur is about 40 grams heavier than my XX rear derailleur. A sub 40 grams chain guide would also be good - is it possible to buy something light or is it just DIY?

Post Reply
  • Similar Topics
    Replies
    Views
    Last post