Fender clearance
#1
Senior Member
Thread Starter
Fender clearance
I asked these questions elsewhere but didn’t get much traffic and the context is in long distance cycling. So I’ll ask here.
Do you run fenders on your bike? How much clearance between fender and tire do you have?
What would you consider a minimum acceptable clearance?
Do you run fenders on your bike? How much clearance between fender and tire do you have?
What would you consider a minimum acceptable clearance?
#2
Senior Member
Join Date: Dec 2010
Location: northern Deep South
Posts: 8,900
Bikes: Fuji Touring, Novara Randonee
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 2604 Post(s)
Liked 1,926 Times
in
1,209 Posts
Yes, I've got fenders. Fun story: 30 miles from the end of a rainy century, a guy at a rest stop offered me $100 for my fenders. I should have taken him up on it -- they only cost $35 and it didn't rain the rest of the way.
I just eyeball the clearance, maybe 1/4-1/2"?
Two things to consider. What's the largest tire you'll run on a given bike? -- make sure you've got room for that under the fender. And where are you going to ride? I've very careful about getting off clean, paved roads. You don't want to get a large piece of gravel or a stick jammed at the fender, even if it's got a quick release it's jarring. I'm not sure what I'd do on a brevet with long gravel stretches.
I just eyeball the clearance, maybe 1/4-1/2"?
Two things to consider. What's the largest tire you'll run on a given bike? -- make sure you've got room for that under the fender. And where are you going to ride? I've very careful about getting off clean, paved roads. You don't want to get a large piece of gravel or a stick jammed at the fender, even if it's got a quick release it's jarring. I'm not sure what I'd do on a brevet with long gravel stretches.
Likes For pdlamb:
#3
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,394
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,694 Times
in
2,516 Posts
It's really nice to have 10mm or more. With bigger tires, more works better. If you only have 6mm or less, it's likely you will find yourself fussing with the fender pretty often.
When I build frames, it always seems to disappear somehow. Especially with forks. One thing I found was that dual pivot side-pulls actually reduce the clearance available as they are actuated. On my one bike, I just got tired of messing with it and got rid of the front fender. Prior to that, I had switched to a Mafac Racer, which helped a little.
When I build frames, it always seems to disappear somehow. Especially with forks. One thing I found was that dual pivot side-pulls actually reduce the clearance available as they are actuated. On my one bike, I just got tired of messing with it and got rid of the front fender. Prior to that, I had switched to a Mafac Racer, which helped a little.
Likes For unterhausen:
#4
Senior Member
Join Date: Aug 2010
Location: Madison, WI
Posts: 11,201
Bikes: 1961 Ideor, 1966 Perfekt 3 Speed AB Hub, 1994 Bridgestone MB-6, 2006 Airnimal Joey, 2009 Thorn Sherpa, 2013 Thorn Nomad MkII, 2015 VO Pass Hunter, 2017 Lynskey Backroad, 2017 Raleigh Gran Prix, 1980s Bianchi Mixte on a trainer. Others are now gone.
Mentioned: 48 Post(s)
Tagged: 0 Thread(s)
Quoted: 3459 Post(s)
Liked 1,465 Times
in
1,143 Posts
Like Unterhausen, I aim for 10 plus mm of clearance. That said, right now I have a bike with 45mm fender over 37mm tires and another bike with 65mm fenders over 57mm tires.
I have some older Zefal fenders that have fairly tight stays on the side, that 45mm fender works well with 32mm tires, but not 37mm.
I have some older Zefal fenders that have fairly tight stays on the side, that 45mm fender works well with 32mm tires, but not 37mm.
#5
Member
I have one bike with fenders, I'll second or third the ~10mm of clearance. The only time I run into issues with that is with wet/sticky snow gumming up between the tire/fender, but that is only a couple days of the year. Haven't had issues with rocks/debris getting caught in there.
#6
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,394
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,694 Times
in
2,516 Posts
I'm a bit curious what brought this question on. A bike has the clearance that it was made with. If you are getting a frame built, tell them 20mm of clearance, unless it's going to be used a lot on gravel, in which case tell them 30mm
I don't think I'm the only builder that has aimed for 10mm and gotten less. It's okay, but I hate the sound of gravel scraping the inside of the fender.
I don't think I'm the only builder that has aimed for 10mm and gotten less. It's okay, but I hate the sound of gravel scraping the inside of the fender.
#7
Senior Member
Thread Starter
Fork clearance is about 12mm with 32’s minus the fender. That’s at the front of the crown, at the rear it’s significantly more. ( Can’t measure it at this moment)
#8
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,394
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,694 Times
in
2,516 Posts
okay, that sounds like plenty. Berthouds have a dimple for the crown, not sure if other metal fenders do. That increases the average clearance a little. Which is also important.
#9
Senior Member
Join Date: Dec 2010
Location: northern Deep South
Posts: 8,900
Bikes: Fuji Touring, Novara Randonee
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 2604 Post(s)
Liked 1,926 Times
in
1,209 Posts
If you don't like gravel, you should try mud. A while back I hit a muddy road with fenders, probably an average of 15-20 mm clearance. It sounded like the bike was hawking and spitting all the way down that stretch: mud accumulating on the tires and scraping the fender (haw-w-w-w-k) and the flying off (spit). I was happy to get off that stretch!
#10
Senior Member
Join Date: Jan 2015
Location: Los Angeles
Posts: 4,703
Bikes: 82 Medici, 2011 Richard Sachs, 2011 Milwaukee Road
Mentioned: 55 Post(s)
Tagged: 0 Thread(s)
Quoted: 1947 Post(s)
Liked 2,010 Times
in
1,109 Posts
I'll put in my $0.02
If you are running 32s you should hope there is room for 50mm fenders. I had 40mm Bertouds on my bike with 28s and it was doable with the caliper (BR 650s) squeezing the fender a bit. I have since removed the fenders and put on centerpull brakes and 32s. I don't think 50mm fenders will fit without some crimping and cutting. Also consider the fender inside width as the metal fenders get narrow because of the folding of the edges while plastic fenders have more room inside for a given "width".
If you are running 32s you should hope there is room for 50mm fenders. I had 40mm Bertouds on my bike with 28s and it was doable with the caliper (BR 650s) squeezing the fender a bit. I have since removed the fenders and put on centerpull brakes and 32s. I don't think 50mm fenders will fit without some crimping and cutting. Also consider the fender inside width as the metal fenders get narrow because of the folding of the edges while plastic fenders have more room inside for a given "width".
__________________
I don't do: disks, tubeless, e-shifting, or bead head nymphs.
I don't do: disks, tubeless, e-shifting, or bead head nymphs.
#11
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,394
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,694 Times
in
2,516 Posts
I have Berthoud 40mm on my bike with 32mm and it works, but it would be a lot better if there was a 45. I need to order some 50mm rims.
#12
Senior Member
Join Date: Oct 2008
Location: Portland, OR
Posts: 3,842
Bikes: Trek Domane SL6 Gen 3, Soma Fog Cutter, Focus Mares AL, Detroit Bikes Sparrow FG, Volae Team, Nimbus MUni
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 896 Post(s)
Liked 2,062 Times
in
1,080 Posts
About 1/4" where the tire enters, increasing from there. That's the goal anyway.
#13
Senior Member
Thread Starter
The fenders I’m planning to use are SKS Longboards at 45mm. Recommended for use with 28-38mm tires.
#14
Jedi Master
I run 38mm RH tires on my bike with 45mm longboards, and I've never had a problem. They measure out at 35, so I'll go along with the 10mm minimum recommendations. I tried to run 40mm duranos and there was too much fiddling.
#15
Overdoing projects
Join Date: Oct 2011
Location: Rotterdam, former republic of the Netherlands
Posts: 2,397
Bikes: Batavus Randonneur GL, Gazelle Orange Excellent, Gazelle Super Licht, Gazelle Grand Tourist, Gazelle Lausanne, Gazelle Tandem, Koga-Miyata SilverAce, Koga-Miyata WorldTraveller
Mentioned: 58 Post(s)
Tagged: 0 Thread(s)
Quoted: 784 Post(s)
Liked 1,238 Times
in
686 Posts
I have Gilles Berthoud fenders on two of my bikes and a pair of vintage stainless steel Weinmanns on another.
- 42mm tyre + 50mm fender + vertical dropout = perfectly fine > Gazelle Lausanne. Designed for 37mm tyre.
- 35mm tyre + 45mm fender + Shimano dropout = deflate tyre to take the wheel out > Batavus Randonneur GL. Designed for 32mm tyre
- 37mm tyre + 50mm fender + reversed horizontal dropout = deflate tyre to take the wheel out > Koga-Miyata SilverAce Designed for 32mm tyre
#16
Senior Member
Thread Starter
I suppose I should have been more specific. I’m really after what clearance you guys feel comfortable with at the top of the tire. In my mind, side clearance is less crucial. I’m prepared to be corrected on that however.
#17
Senior Member
Join Date: Oct 2008
Location: Portland, OR
Posts: 3,842
Bikes: Trek Domane SL6 Gen 3, Soma Fog Cutter, Focus Mares AL, Detroit Bikes Sparrow FG, Volae Team, Nimbus MUni
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 896 Post(s)
Liked 2,062 Times
in
1,080 Posts
I think you get more play side to side, so you need more space to accommodate that.
Aesthetically, closer is better. But closer means more time fiddling with rubbing noises. Closer also is more problematic in muddy or snowy conditions. Most important in those conditions is that space increases from where crap enters to where it hopefully exits. You also want to discourage sticks from entering by having it closer at the entry point.
Aesthetically, closer is better. But closer means more time fiddling with rubbing noises. Closer also is more problematic in muddy or snowy conditions. Most important in those conditions is that space increases from where crap enters to where it hopefully exits. You also want to discourage sticks from entering by having it closer at the entry point.
#18
Senior Member
Join Date: Jan 2015
Location: Los Angeles
Posts: 4,703
Bikes: 82 Medici, 2011 Richard Sachs, 2011 Milwaukee Road
Mentioned: 55 Post(s)
Tagged: 0 Thread(s)
Quoted: 1947 Post(s)
Liked 2,010 Times
in
1,109 Posts
Also at the top of the tire you likely have fasteners that eat a few mms.
__________________
I don't do: disks, tubeless, e-shifting, or bead head nymphs.
I don't do: disks, tubeless, e-shifting, or bead head nymphs.
#19
Senior Member
One thing to keep in mind that with plastic fenders is a stick of just the right size that jams between the tire and fender will accordion the fender up into the fork crown, the front wheel will stop rotating with respect to the bike, and you will find yourself flying over the handlebars in the amount of time it takes for the front wheel to rotate 1/4 turn. You can do the math but take it from me, it happens very very quickly.
So be sure to install the quick release features on the front fender stays. Or mount metal fenders.
So be sure to install the quick release features on the front fender stays. Or mount metal fenders.
#20
just another gosling
Join Date: Feb 2007
Location: Everett, WA
Posts: 19,528
Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 3886 Post(s)
Liked 1,938 Times
in
1,383 Posts
The fenders are going to mount where they're going to mount. That's determined by the frame and fork. So the question really is, "How big a tire can I run under my fenders?" Simple- experiment. I've seen road bike fender clearances of as little as 1/8". I like more, as above, maybe 6mm minimum, for the reasons given above. Thing is, you don't really know how big a tire is until you inflate it on your rim. It'll still grow a bit for a few days. OTOH, maybe the OP has the tires and wonders if they can run fenders over them. Try.
__________________
Results matter
Results matter
#21
Senior Guest
Join Date: Jan 2008
Location: Upstate NY, USA
Posts: 375
Bikes: Jamis Endura, Cannondale CAAD, Raleigh Cross, Fausto Coppi.
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 80 Post(s)
Liked 47 Times
in
31 Posts
I run 45 SKS longboard fenders on the road bike with 28- 32 mm tires. They did not fit under the calipers, so I cut them and made aluminum brackets that mount into the Sheldon nuts for brake calipers. I used to run SKS 35 fenders, but 45mm work better. need to make better pictures of the brackets, but that is the only picture I have available now.