Inside Renthal - Moto & Mountain Bike Component Manufacturing

Mar 26, 2018
by Ross Bell  




Through the somewhat muffled blur of earplugs and protective eyewear, the Renthal factory floor appears bewildering, but also enthralling to an engineering and manufacturing mortal like myself. The place is a hive of activity. A constant hum from the CNC machines is the factory’s chorus whilst the purple glow of a plasma cutter makes light work of a chunky aluminum sheet. Fatbars are bent effortlessly into shape, motorbike sprockets are counter-bored and their teeth cut. The ‘heavy industry’ feel to the buildings and their contents are satisfying, following the journey from raw aluminum billets right through their birth and into adulthood as they head to the warehouse and distributors, before beginning the next chapter of their life on the world’s trails.

What would later become the Renthal brand we know was started by Henry Rosenthal for his own personal moto-trials demands on the UK national circuit. After bending the steel handlebars on his bike and realizing the market’s offerings were of the wrong material, he took matters into his own hands. People began to sit up and take notice of his custom bars and, before too long, other riders were asking for their own set. In 1969, alongside fellow motorbike and engineering enthusiast Andrew Renshaw, they embarked on the manufacturing of trials handlebars, giving the foundations to their company. The ‘Renthal’ name of course coming from the chopping and conjoining of the duo’s surnames.

Motocross was the next entry into Renthal’s portfolio along with a move into the US market in the 80s, the disciplines of motocross and supercross then took off with Renthal surfing the wave. The green light for their bicycle story illuminated in 2007, three years before they hit the market in 2010. Seeing the crossover between moto and mountain bikes, they first embarked on gravity disciplines with an aluminum handlebar which garnered immediate accolades with Specialized’s Sam Hill and Troy Brosnan taking gold at Mont Saine Anne World Champs. Their ‘Fatbar’ evolved new iterations including a carbon version, as well as bringing chainrings, stems, and grips to their offerings. The moto market is still the heft (75%) of Renthal’s income, although the bicycle products are continuing to see a steady growth as they expand into new markets and consolidate their ‘core’ products. Bear in mind their bike side is still rather youthful...

We took the trip to Renthal’s factory on the outskirts of Manchester, UK, to get a behind the scenes snoop:

Inside Renthal
Inside Renthal
Renthal are proud of their racing and competition history. Taking pride of place at reception, there are plenty of big names with championship success: Hill, Graves, Ragot, Rude, Gwin, Hart, and Ravanel to name but a select few...

Inside Renthal
The custom Fatcreations Fatbars sprayed for all of Renthal's racers selected for the Val di Sole World Champs in 2016.
Inside Renthal
One of Broc Tickle's Kawasaki race bikes greets you as you open the front door.

Inside Renthal
A rapid 3D prototype of an Apex stem which gives the engineers visual clues to work from.
Inside Renthal
An early data acquisition system Renthal has used, the products are tested extensively both in the lab and on the trails.

Inside Renthal
Inside Renthal


Inside Renthal
bigquotesFrom a bicycle perspective, it was seen that we had the capability and capacity to make bicycle products, there was a lot of crossover between motocross and mountain bike, so the decision was made to move into that market. We made that decision in 2007. There were two years of development to get to the first products which went to market in 2010. Initially, it was to use the crossover from motocross to try and be recognized in the marketplace, the most obvious move was to downhill so we went with pure gravity products to start with.Ian Collins


Inside Renthal
Testing a Fatbar tube to breaking point in the lab. The materials are punished and put through far more pain than they'd ever see on the trail... the noise made from the 'snap' caused for a change of underwear!

Inside Renthal
Checking a stem to make sure its geometry and detail matches the computer data it was designed around.

Inside Renthal
The engineers can program various amplitudes and frequencies of loading into the test rigs to replicate any eventuality they might be met with on the trails.

Inside Renthal
Checking the deflection of the bars under extreme loads...
Inside Renthal
... after holding the bars in this position it was amazing to see them spring back into their original shape.

Inside Renthal


Inside Renthal
bigquotesThe manufacturing methods between the motorcycle and bicycle products are similar. For example, swaging, bending and heat treatment processes are all transferable between products of a similar type. If you build up your manufacturing knowledge in those particular areas then that suits you well for manufacturing products in the other disciplines, but you’ve still got to understand the load cases, fitments and other requirements to drive the design of a particular product.Simon Brocklehurst


Inside Renthal
Raw materials and billets waiting their turn to be put through the mill.

Inside Renthal
Eddy's electrical current test checks for defects in the aluminum bars.

Inside Renthal
The bars then begin their first process, the 'swaging' sees them get their chunky center clamping area and narrower ends before going for heat treatment.

Inside Renthal

Inside Renthal
A plasma cutter busy at work producing the circular shapes for chainrings and sprockets.

bigquotesWe found that the typical mountain bike rider was far more concerned in having lighter products than we had previously experienced in motorcycle products, so every gram in the design was critical. Since then, we’ve adopted a similar mentality with our new motorcycle products; focusing on removing unnecessary weight where possible. Obviously, the distinct difference with mountain bikes is the largest mass is the rider, not the bike. But we can still apply the same methodology to make all products as light as possible.Ian Collins

Inside Renthal
Inside Renthal

Inside Renthal
Inside Renthal
There is, of course, a large amount of waste, this is all recycled. For the first part it's environmentally friendly, but for the second part, it helps put money back into the business with the waste sold off.

Inside Renthal
Motorcycle sprockets get their teeth cut on a gear cutter. The mountain bike chainrings are fully CNC machined, which allows the intricate thick-thin tooth profile to be produced.

bigquotesAt Renthal, we design around the technical aspects of the product, far more than fashion. Until very recently we’ve only produced one color of handlebar which is in our own signature AluGold. Although we’ve just introduced black, we are not a brand that’s out there to produce every colour under the sun with graphics to match your wheel or forks… We think it’s more important to develop and produce technically derived products.Ian Collins

Inside Renthal
Inside Renthal

Inside Renthal
Inside Renthal
A Renthal chain ready for breaking into correct lengths.

Inside Renthal

Inside Renthal
Getting that classic textured finish on the Renthal Fatbars with a two-stage shot peening process.

bigquotesAll our product development goes through a multiple stage-gated process. It starts off at Gate 1 – essentially a feasibility assessment. We review subjects such as the available production resources, manufacturing technology and current supplier base to determine if this product is viable. We then proceed to Gates 2 and 3, where the product is developed from initial sketches to a fully signed off design which has passed all required laboratory and field testing, has material requirements fully specified and all the engineering drawings are completed. Not only does this involve the engineering departments but also requires input from the commercial department to design the packaging, compile fitting instructions and review any relevant intellectual property subjects. The later gates then control the project from the manufacturing side. We hand over a design to the Production Engineering Development department, who implement the manufacturing systems to make the product. Prior to launching the product we run a pilot production run which verifies all aspects of the manufacturing process.Simon Brocklehurst

Inside Renthal
Inside Renthal
The bars get subject to two different grades of blasting which gives them their hard wearing finish.

Inside Renthal
All the CNC machine tooling racked up and awaiting their turn.
Inside Renthal
The mounts to hold all the various components in place.

Inside Renthal
Inside Renthal
These are almost like templates, allowing engineers to check the finish of their batch of components - they aren't used to check tolerances.

Inside Renthal
The CNC machines at work on an Apex stem, which takes roughly 15 minutes per cycle.

bigquotesFrom a technical point of view, when we’ve brought stuff in-house it’s always interesting to understand about materials and how they process. As far as the user is concerned they are the features of the products, like the hard anodizing, or whatever else is beneficial to them. From a design point of view, when something new comes along it’s not just making new geometry of something, it’s an understanding of how the materials need to be processed. The heat treatment operations, the forming operations, the bending, there are lots of subtleties in the way you can manufacture these things that affect the final product, getting to the bottom of those and understanding what makes the best product is probably the most rewarding thing.Simon Brocklehurst

Inside Renthal
With only three stems to a cycle, the machines need to work flat out to keep up with demand.

Inside Renthal
Inside Renthal
With the main bulk of machining done, the clamps need to be remounted for the rest of the excess material to be removed.

Inside Renthal
Stems getting their logos laser engraved, the final step before assembly.

bigquotes[On bringing more in-house] If it means a product will be better, we would definitely consider it. It’d be really nice to make everything ourselves, but you’ve got to look at it from a viability and from a product performance point of view. What can you make better by producing in-house? If you bring a process in-house, then you’ve got to bring in or develop the resources and the knowledge base which accompanies it. The people with their experience and understanding makes something successful, not just having a particular machine. We have suppliers who may have 20-30 years of experience in providing a product or service. There must be a benefit to the final product for us to decide to bring something in-house.Simon Brocklehurst

Inside Renthal

Inside Renthal
Moto Fatbars getting their decals applied.

Inside Renthal
The water transfer logos used on BMX handle bars are cured in the oven.

Inside Renthal

Inside Renthal
Inside Renthal
The final few steps are assembly and packaging before they are shipped out.

Inside Renthal
Inside Renthal
Next stop the trails...

For more photos, view the full album here.


MENTIONS: @renthalcycling @rossbellphoto



Posted In:
Stories Renthal



80 Comments

  • 107 1
 Cool article. Really enjoy these kinds of features. Thanks @rossbellphoto
  • 63 0
 Thanks for the props. The team at Renthal gave me great access which was appreciated and made my job straightforward!
  • 2 0
 @rossbellphoto: One of my projects at Engineering Uni was the development of a direct mount stem which was itself inspired on a 2012 Pinkbike report of a visit to their plant! Eventually had a job interview there last year and even if I wasn't the chosen one I think they were quite proud that their work was inspiring people like that.
  • 38 1
 I have used Renthal products for years. When I was road racing, their sprockets were the ones I went to for the quaility. Then on my Moto bike, their bars and sprockets found their way there too. I never had one failure with them, I still use them to this day..It was nice seeing how they went about creating their products.
  • 4 0
 I have used their stuff forever on everything I ride. The best!
  • 25 3
 page 3, *cough, cough*:
www.freeride-magazine.com/mein_dk/freeride_download/action/purchase/getFile/pdfId/17117.html

This test from 2014 was done in a neutral lab, but of course you never know, if there is 100% integrity. It passes the minimum requirement, but falls massively short in the multiload test, which they say was developed with real data from the field.
I mean the whole test rig world is insanely complex, when you wanna do it "right" and I have never seen a test in the bike industry with a sufficiant amount of samples to do even half valid statics (e.g. Weibull B10 or similar on the basis of min. 6 samples), but this test still makes a statement. And their recommendation for results under 150000 cycles is to change bars in freeride application yearly! I hope they have improved their benchmark testing and general inhouse testing big time over the last 4 years. I mean, they got everthing they need to do so...
  • 2 1
 May explain why I’ve broken more than one Apex stem...
  • 2 1
 thats why i changed to Titan bars
  • 2 0
 thanks for posting the freeride-article, just wanted to look it up and post it. Staying with Syntace, those products always lived up to their hype even in independent product tests.
  • 5 0
 Perhaps Eddy needs to be more careful:-) "Eddy's electrical current test checks for defects in the aluminum bars.".|
It's an Eddy current tester and that's what you use to find cracks in the aluminum.
  • 2 0
 @surfhard987:

Oh, but I was assured by Renthal that my broken apex was a rare instance. At least they warrantied it at their cost. I sold it and got a Deity though. Wasn’t going to risk another failure.
  • 1 0
 @Maverick18T: hairline stress crack on the top surface of the central bore thru the stem?
  • 1 0
 @surfhard987:

Nope, upper steerer clamp split in two where they machine it out to make it lighter. Happened on a ride and never noticed, happy the lower clamp was enough to keep the bars on that day. I discovered it a week later while prepping the bike for a ride.
  • 4 1
 Am I the only person who opened the link and was surprised it was all in German?
  • 11 1
 They don't produce any carbon bars in that factory, do they?
  • 4 2
 My thoughts.... "So where is the carbon?"
  • 6 0
 I think that’s where they allude to the value of outsourcing technology to firms that may already have decades experience.
  • 8 0
 Ahhh glorious Stockport
  • 12 1
 The armpit of Manchester
  • 3 0
 LOVE these behind-the-scenes manufacturing articles! It's great to see behind the face of a company to the inner workings, and it also helps me appreciate how much work goes into making the stuff I like to buy Smile
  • 2 0
 Only realised the other day I bike past the estate the factory is on every day on my way into Stockport for work. It did explain why I always see a guy on a cheap supermarket bike with a Renthall Fatbar on it biking the other way. He must work there lol.
  • 2 0
 I love seeing how things like this are made!

@renthalcycling Can you confirm that you black Fatbar Lites are made in the UK? I understand that your carbon bars are made in the Far East, but can't find anything about your aluminium bars.
  • 2 0
 too lazy to look it up, but if I remember correctly Paul quoted in his "geometron Euro-manufacturing project" they only produce Moto-parts in the UK. Everything MTB related comes form the far east.
  • 1 0
 @crisotop: I read that too, but thought I had read another article about the aluminium bars in the UK, and carbon in the far east.
  • 1 0
 About ready to pull the trigger on a new set of their carbon bars. 740mm width seems perfect for the type of ST we have here in PA quite a bit of it is very tight and twisty. Aside from the guy who broke his does anyone else here have experience with their Carbon bars?
  • 2 1
 Personally, I found my Carbon 740 Fatbar lite too stiff for my liking (me 65kg), so I went back to Aluminium bars. Never had a prob with the Renthal one, though (perhaps again a result of the 65 kg ;-)
  • 2 0
 My Renthal Fatbar has significantly reduced the tendency of my hands to fall asleep on long descents verses my Raceface Turbine aluminum bar.
  • 1 0
 @ashlemon: probably because Race Face bars are hatefully stiff. My SixC bars destroyed my hands. The repalcement Chromag bars are much nicer as are / were my ali Answer bars.
  • 2 6
flag ashlemon (Mar 26, 2018 at 12:46) (Below Threshold)
 @mindmap3: I disagree. The more flex in your bar = more vibration in the hands/arms. The Renthal carbon bar is way stiffer than the RF aluminum.
  • 1 0
 I ride Renthal Carbons. Came from Race Face Atlas bars and other brands of alloy. I’ll probably never buy another bar. Arm fatigue was reduced and they’re lite! Love them.
  • 2 0
 The massive / sad retro-dork in me is smirking at the fact that Collins Boy says that Renthal went to market for MTB bars in 2010, yet he probably had a set on his Pace RC100 circa 1990 Smile
  • 4 0
 Now if they can just get their new 31.8 800mm black bars out to market so I can pay them already......
  • 1 0
 Yes, where are those confounded black aluminum bars. I'll take one in 35mm.
  • 1 0
 @DBone95: Cool thanks. Quite a bit more $ than CRC but at least in stock
  • 1 0
 renthal why oh why cant you just make a black bar? i dont want to read fatbar you fatbar logo, i really dont like any logos on bars it looks tacky imo. please, just make it a black on black logo so i wont have to resort to shoddy methods of covering it up.

but renthal angles over dietys every day
  • 2 0
 Renthal chainrings move some of the crap out of the way, last longer and look cool. Renthal stem with a fatbar lite and kevlar grips is my favorite.
  • 3 0
 Nice. This video is worth a watch too: youtu.be/Q-89to2q4gg
  • 1 0
 There's a video of the crash that broke that - it's on a direct mount stem, so with no way of the stem moving, it was the only place it could fail. The crash was huge, in to tree, which broke the bar.
  • 2 0
 Just ordered a set of 40mm black alu. Should look sweet. Always loved Renthal. They should start making cranks.
  • 1 0
 From where if you don't mind me asking?
  • 1 0
 @AntN: You must've got the only one. I only see MX bars in blk on ebay
  • 1 0
 @AntN: Cool, I guess they are Banned in the USA for now. Not on US eBay site as far as I can tell.
  • 1 0
 Well if this article was meant to scare me into buying renthal fat bars, just in case my current handlebars couldn't handle that kind of deflection, it worked.
  • 2 0
 ...and then your non-biker friends will ask why you pay so much for “a piece of metal”
  • 2 0
 Yep! Just so much that goes into these products that the average consumer doesn't think about. You're not just paying for the material, or even the labor or machine used to make it. You're paying for the R&D, for the engineering, the testing, etc.
  • 2 0
 Renthal for decades, one place to go for Moto, easy transition to MTB

Keep it up

Good to see Fatcreations paintjobs tup
  • 2 0
 fatbars&kevlar grips all day for throttles and pedals
  • 1 0
 Great Article but your history regarding entry into the bicycle market is a little off . I rode renthal bars on my BMX back in the 80's ..
  • 1 0
 I have had Fatbar lites for the past 4 years and have driven them into the ground on more than one occasion and other than scratches to the decals they are perfect.
  • 3 0
 Please make a cinch ring
  • 1 0
 Renthal fatbar carbon is the best bar I've ever owned. Very comfortable and perfect flex.
  • 2 1
 Best bars in the business!
  • 1 0
 Hope tech videos have ruined me for any factory insider articles..
  • 1 0
 Seriously cool and has given me the urge to go online shopping
  • 1 0
 in pinkbike anything can happen.
  • 1 0
 Have fatbars on my old bike, Very nice parts!
  • 1 0
 awesome photos! I love learning about how our expensive toys are made
  • 4 4
 That coolant is doing bugger all!
  • 14 0
 The flow was turned down and the cycle stopped so I could get some clear photos... At full speed there's no chance of getting good shots through the windows!
  • 2 0
 @rossbellphoto: good to hear! My machinist brain was having a meltdown!
  • 1 0
 metal slivers ouch!
  • 1 2
 Very HARD PORNO !!! Thanks a lot Pinkbike !!! More on this subjects !!!
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