chrisp993 Posted June 3 Posted June 3 So, I'm closing in on the end of my build and wanted to adjust the pedals ... the brake and clutch seem set too high, I almost have to push down on them toward the floor vs. pushing them more horizontally toward the firewall. Anway, today I opened up the pedal box and spent a very frustrating time trying to figure out adjustments: Brake: mounted with a pin and clevis to a threaded rod, I ( eventually!) worked out that since the nut was captured within the clevis, turning the threaded rod would move the brake pedal along the rod toward the firewall and in so doing move the "arc" of pedal movement in the direction I wanted. But there was very little adjustment, really less than 1/2" of rod before the end of the rod butted up against the pedal. But this might be enough if I can get the clutch and gas pedal to work with it. Clutch: plenty of locknuts etc. but no actual freedom to really move these without moving the clutch stop - which seems like a bad idea. I'm stumped on how to make any real adjustment to the clutch pedal Gas: assuming Brake and Clutch are lowered, the Gas pedal will also need to be swung down in order to match. The WOT throttle stop is easy to adjust but the resting position has a ridiculously small, couple of threads adjustment - do people switch this out for a longer nut in order to move the resting position lower, or am I just misunderstanding? I feel like I'm missing something with all of the above - attached some pics to try and show what I mean. Can anyone who's ventured down this path help me out? 1
KnifeySpoony Posted June 3 Posted June 3 Can you take a picture in your pedal box - your description of the position/orientation of the pedals doesn't seem right.
chrisp993 Posted June 3 Author Posted June 3 Thanks for the reply! Different to the two pictures I attached? Can you be more specific on what you want to see?
chrisp993 Posted June 3 Author Posted June 3 Two more pictures ... the brake pedal is adjusted as low as it will go, feels OK Gas pedal seems too high, much higher than brake pedal when brake is depressed Clutch is a little high, would like it save as brake but per my original post there doesn't seem any adjustment in the clutch withiut altering the clutch stop.
7Westfield Posted June 3 Posted June 3 For the clutch, take out one (or both) of those nuts behind the clevis To lower the brake, cut 1/4" off the pushrod, so it doesn't hit pedal Looks like you just need a different (longer) bolt to lower gas Re-adjust brake switch and throttle cable after heights are right 1
chrisp993 Posted June 3 Author Posted June 3 7Westfield, thanks! For the clutch, the lower nut is a locknut for the clutch stop so needs to stay. I could remove the middle nut but then would have to lock the clevis against the clutch stop locknut i.e it's a two position option, stock or remove one nut (or possibly source a half height?). Really seems like this adjustable setup should actually ... adjust. Still feel I'm missing something! Brake is probably OK at limit of adjustment. Don't want to cut pushrod until I know what I'm doing ... one way trip! Gas pedal, yes, that was my conclusion, and easy to get a longer bolt! Still just confused ... online searches show easy adjustment of the RHD pedal box 🤔
chrisp993 Posted June 5 Author Posted June 5 I posed my question to Caterham's build support team who were good enough to provide a very detailed response. TLDR version is that unfortunately the LHD pedal box has very limited adjustment. The full exchange with the build support team (lightly edited) is reproduced below: The LHD pedal box is very different in comparison to a RHD setup. The master cylinders are a different specification and are mounted much lower down on the pedal box, so although you are a bit more limited in terms of the amount of adjustment that you can make to these pedal, it is still possible. Brake: confirmed that adjusting the brake pedal position is limited in terms of how far you can wind the threaded rod into the pedal clevis before it begins to contact the rear of the pedal. To arc the pedal further away from you requires shortening the threaded rod accordingly, but you would need to be careful not to limit the overall pedal travel. Clutch: adjustment is incredibly limited in its standard form. It is possible to switch the half height nut contained within the pedal clevis with the full height lock nut and thereby gain a few mm of adjustment. More than this would require removing material from the face of the clutch stop, allowing you to wind the lock nuts further down the threaded rod and lower the clevis mounting position. Gas: the bolt fitted at the top of the throttle pedal arm is used to set the amount of free play in the pedal when it is a rest and should not be used to set the position of the pedal. Setting the position of the pedal at rest is done through adjustment of the cable, using the adjuster nuts at both the pedal box end and the throttle body end. Once the throttle is in the desired position, you should adjust the pedal stop accordingly so that the pedal meets this at full throttle, and you should adjust the upper arm bolt so that the pedal has approximately 2mm of free play when at rest. 1
jmaz Posted June 7 Posted June 7 On 6/5/2026 at 6:34 AM, chrisp993 said: I posed my question to Caterham's build support team who were good enough to provide a very detailed response. TLDR version is that unfortunately the LHD pedal box has very limited adjustment. The full exchange with the build support team (lightly edited) is reproduced below: The LHD pedal box is very different in comparison to a RHD setup. The master cylinders are a different specification and are mounted much lower down on the pedal box, so although you are a bit more limited in terms of the amount of adjustment that you can make to these pedal, it is still possible. Brake: confirmed that adjusting the brake pedal position is limited in terms of how far you can wind the threaded rod into the pedal clevis before it begins to contact the rear of the pedal. To arc the pedal further away from you requires shortening the threaded rod accordingly, but you would need to be careful not to limit the overall pedal travel. Clutch: adjustment is incredibly limited in its standard form. It is possible to switch the half height nut contained within the pedal clevis with the full height lock nut and thereby gain a few mm of adjustment. More than this would require removing material from the face of the clutch stop, allowing you to wind the lock nuts further down the threaded rod and lower the clevis mounting position. Gas: the bolt fitted at the top of the throttle pedal arm is used to set the amount of free play in the pedal when it is a rest and should not be used to set the position of the pedal. Setting the position of the pedal at rest is done through adjustment of the cable, using the adjuster nuts at both the pedal box end and the throttle body end. Once the throttle is in the desired position, you should adjust the pedal stop accordingly so that the pedal meets this at full throttle, and you should adjust the upper arm bolt so that the pedal has approximately 2mm of free play when at rest. Thanks, this is useful info, for sure. It's a bummer that a LHD pedal box has limited adjustment. I haven't gotten to the point yet in my build where I'm fine-tuning the pedal situation, but I'd gotten the impression from build blogs, etc. (mostly, if not all, UK blogs maybe, and thus RHD) that there was a fair amount of adjustment possible.
KnifeySpoony Posted June 7 Posted June 7 The free play bolt on the throttle pedal isn't really important (mine doesn't do anything the way it's set). The position of the throttle at the point where the cable slack is taken up is what is important. That is set by adjusting the throttle cable, and by bending the throttle pedal itself, which many people do. I bent mine towards the tunnel, but didn't need to bend it in the other axis to have it at a good height for heel toe.
chrisp993 Posted June 7 Author Posted June 7 (edited) Having thought about Caterham's response and looked again at the gas pedal arrangement on my LHD pedal box: The two nuts at the throttle body take up the slack in the cable, so need to be adjusted to do this without causing the throttle to be > zero. This doesn't alter pedal position in the pedal box. The adjustment where the cable enters the pedal box adjusts the starting position of the pedal - unless limited by the small bolt at the top of the gas pedal. The spring on the throttle body will push the cable "in" to the pedal box, so the threaded entry to the pedal box will change where this rest position sits. It will not adjust the cable slack in any way. The pedal stop on the firewall needs to be set so that there is WOT at the throttle body as the gas pedal hits the stop. Edited June 7 by chrisp993 Typos 1
chrisp993 Posted June 7 Author Posted June 7 11 hours ago, KnifeySpoony said: bending the throttle pedal itself, which many people do. I bent mine towards the tunnel, but didn't need to bend it in the other axis to have it at a good height for heel toe. Can you elaborate on what you did? I'm trying to understand if you bent it side<>side to be closer/further to the brake pedal or if you bent it to be closer/further away from the seat i.e. which axis did you bend?
KnifeySpoony Posted June 8 Posted June 8 I bent it towards the transmission tunnel so that I could brake without hitting the throttle at same time. Most people bend in the other axis, which it sounds like you might want to do if you can't adjust cable enough to get it where you like it. There's many mentions of this on UK build blogs/blatchat. 1
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