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Twinloc Fox CTD Fork compatibility

9K views 11 replies 6 participants last post by  MasterOMayhem 
#1 ·
Ok guys, let me explain my situation to see if someone more expertised can answer my doubts.

I have a 2012 Scott Spark 50 with DT M210 rear shock and RS Recon Fork, working together with a 2 positions Twinlock lever. I just wanted to upgrade the whole suspension system to Fox (I really like it as I have always had Fox in my other bikes). I was looking for a brand new Fox CTD shock, but suddenly an uncommon option came to my door: a second hand (almost new) 2014 Fox Nude CTCD shock, removed from the latest high end Spark model. Given that my Twinloc lever is old, I have ordered a new replacement from Scott (part no 230097) with 3 positions and compatible with this shock as well as the previous DT Nude 2.

I want to purchase a Fox CTD fork, buy here is my concern. Any CTD fork should be compatible with the Twinloc lever? I am not sure since Fox 2013 forks have a different remote system than 2014/2015. Actually they sell its own Fox lever for 2013 forks and 2014/2015 and they do not assure backwards compatibility. I guess they have a different pull ratio. So, with Fox model should I buy? 2013? 2014?.... It is a bit messy...
 
#6 ·
Well, I answer to myself just in case may help someone else:

1) New Fox Nude CTCD rear shock can be mounted in old Spark frames (at least 2012 models) although Scott claim to be not compatible. The only issue is that Nude shock has very little distance between its stroke end and sleeve, therefore, the bike should be setup in High bottom bracket mode. Otherwise (Low BB), stroke may contact frame where the bushings are installed.

2) I went for a new Scott Twinloc lever from 2014 to match the new rear shock taken from a 2014 high end Spark model (I pressume 700RC or 710). I wanted a Factory series Fox fork in front, so I decided to go for a 2013 model as they are much cheaper than 2014/15 models. The systems work like a charm. Lever is compatible with older CTD forks models. Fox has published a reclocking process for 2013 remote CTD forks to fit Twinloc lever, but after talking with a Fox representative, this is not always needed. Actually, my setup works with no reclocking needed. But in case your lever doesn't reach the proper pull ratio, you can relay on this process to modify tension in remote spring.
 
#8 ·
I guess you Spark is a 2014 model with a 2014 Twinloc lever. In that case you can go for any Fox CTD fork (2013, 2014 or even newest 2015 models) and it should work with your lever with no problem. You can choose a Fox CTD Remote (with the remote spring already installed and also comes with a Fox lever) or just CTD and buy the remote kit apart.
My advice is that you think carefully if that travel increase is really needed as you will be changing bike geometry. Although you may get a plusher feel, a slacker headtube angle will make you feel harder to control the bike. Also, make sure warranty is not avoided with this change.
 
#9 ·
Thank you for sharing info and your thoughts. When you say difficult to control, i wonder dropping HTA from 68 to 67-sh would really cause serious issue. Apart from HTA what other changes in geometry to expect? I read a lot about Giant Trance Advanced SX which has 140mm rear travel and 160mm in the front. I thought it would also be reasonable if I would have 120 in the back and 140mm in the front.
Buying a new bike would be much more expensive for me than changing a fork, honestly speaking. Any thoughts would be appreciated.
 
#10 ·
Well, I am far from being an expert, these are just thoughts. But I think when a frame is designed many factors are taken into account and geometry plays a key role. I guess engineers and designers do a very fine tuning in terms of geometry, angles, lengths, etc to achieve what they have in their minds ( at least I expect they do in reputated brands). Spark model, for example, can be set to low or high bottom bracket, but just a few milimeters. That gives you an idea of the tight tolerances required for a specific frame design.

I dont think the change you propose is that serious. It is a matter of getting used to the new geometry. But it is also true that those few milimeters in BB height I mentioned before modify HTA in almost 1 degree, and many people report a significative difference in handling. Actually, I read somewhere that an experienced rider is able to notice a 0.25 HTA difference. In theory, the slacker the angle the higher stability you will get in high speed descends, but the price you pay for that is a reduction of 'easy' handling specially in close turns and climbs.

Regarding the Giant you put as reference, I think it is a more agressive design oriented for enduro mainly, while Spark sits closer to XC-racing with some all mountain capabilities. Take a look at the pivot design in the Giant, its pretty different, as well as the long travel fork with wider bars. I am not sure if you can get same behaviour from a Spark frame.
 
#12 ·
Hi I have a 2013 spark 900 sl... I called scott and they said you cant change out the DT nude to the nude CTDC because of clearance.... BUT from reading above its the high position it will run in... not the low... I run in the High all the time. So has anyone run the Fox Rear shock, with rockshock fork with the scott damper?

Also has anyone run a differnt fox shock with the twinloc?
 
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