Pedal Adjustment Struggles

[chrisp993]

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?

[KnifeySpoony]

Can you take a picture in your pedal box - your description of the position/orientation of the pedals doesn't seem right.

[chrisp993]

Thanks for the reply!

 

Different to the two pictures I attached? Can you be more specific on what you want to see?

[chrisp993]

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]

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

[chrisp993]

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]

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.

 

[jmaz]

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]

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]

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

[chrisp993]

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]

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.

[awatkins]

Getting back to adjusting brake pedal height:    Today I made some progress toward being able to do the adjustment from above rather than within the footwell.  I discovered it is not difficult to remove the brake pedal from above, which would be needed to have reasonable access to the adjustment nuts.  However, I am currently stuck at how to loosen the forward nut on the push rod (the one that is not trapped in the clevis).  The reason is I cannot figure out how to get a 13 mm wrench onto the forward nut while holding the clevis and rear nut pair.  I suspect I will have to crawl into the footwell for this.

 

The pedal leverage ratio is about 3.5:1, so that (I believe) 1/3” of adjustment should about result in about  1” of movement at the pedal, which from what I can see is about what’s needed for reasonable heel & toe action.  I believe there is enough room in the clevis to allow that without shortening the push rod.  But of course, I will not know until actually do that.

 

Hope this helps.

 

Alan Watkins

[chrisp993]

Alan

 

To loosen the forward nut: like you I could not reach it from above, so had to reach into the pedal box and break it loose with a wrench, once this was done I could reach my fingers in from above and spin it freely. Tightened it by the same method. Hope that helps?

 

Chris

[KnifeySpoony]

Have you driven the car (ideally in anger) yet? I wouldn't move heaven and earth adjusting things if you haven't driven it yet to see where the brake pedal will actually be during a braking event.

[KnifeySpoony]

To actually answer your question, when I adjusted my brake pedal (interestingly, in the opposite direction than you), I think i used a crows foot wrench on a long series of extensions.

[chrisp993]

Good advice. First drive was 2 days ago (blog needs to catch up) so I have some basis for evaluating. Still think the brake and gas pedal would benefit from being swung down, but also think I need to adapt my pedal usage to the caterham box.

 

Mostly ... I'm enjoying the drive 😁

[pethier]

I have the opposite problem.  Short legs. 

 

My 1700 Super Sprint is OK, probably due to the "Lotus Position" of the seat.

 

CSR has a Tillet seat with a more-upright back.  With the seat all the way forward the brake is OK but the clutch and full power are a bit of a stretch.  Taking out the removal device saved me 2.5 inches on the steering wheel.  Momo brand steering wheels are immune to my "negative spacer" trick with the Moto-Lita in the Super Sprint.  It's OK, the CSR has a longer cockpit, so when I move the seat back all the way, i can get around the steering wheel OK.  Driving shoes help.

 

I'm thinking of adding pedal blocks to clutch and gas and leaving the brake alone.

[awatkins]

Yes I have over 100 mile on it and heel and toe would be impossible without high heels made by Laboutin.

 

However, not anymore, because since my last post I figured out how to loosen the brake rod locknut from above and therefore now have the approximate position I want.  Any further adjustment will be to the throttle pedal position.

 

In the end KS’s technique probably would have been faster, but by the time I had it all apart there was pride invested.